File:  <diptera.htm> Indexes:  < (Entomology),      (Invertebrates),      (General Index)>      <Invertebrate Bibliography>       <Glossary>      <Site Description>        < Home>

 

 

            Introduction                                                                                                                                                    Contents

 

Entomology:  DIPTERA 1

Kingdom:  Animalia, Phylum: Arthropoda

Subphylum: Hexapoda: Class: Insecta: Order: Diptera

(Contact)

 

       Please CLICK on underlined categories to view and on included illustrations to enlarge:

            Depress Ctrl/F to search for subject matter:

 

 

General Summary of Diptera

 

          The Diptera -- <General Characteristics> <Juveniles> -- have only one pair of functional wings, hence their name meaning "Two-wing".  The hind pair of wings is reduced in size to highly sensory stumps or halteres.  The mouthparts are usually suctorial but sometimes piercing or biting, and elongated to form a proboscis.  The prothorax and metathorax are small and fused with the large mesothorax.  They have a complete metamorphosis.  The larvae are often worm-like and always without legs.  Their head is usually small and retracted.  The pupa is either free or enclosed in a puparium that is made of the hardened last larval skin.  [For terminology please refer to: Glossary]

 

 

           This is a very large and specialized order of insects. The adults are mostly diurnal, feeding on the nectar of flowers, but a number are predaceous living on other insects (e.g. the robber-flies), while some, e.g. tachinids, are parasites. Several families have acquired blood-sucking habits, the representatives of which are of great importance because they harbor and transmit pathogenic organisms, causing such diseases as malaria, sleeping sickness, elephantiasis, yellow fever and some cattle fevers.


          The several kinds of mouthparts that have been developed in the Diptera are completely different from the primitive biting type. They have a proboscis formed principally by the elongated labium, which ends in a pair of lobes, the labella. This labium may serve as a support and guide to the remaining mouthparts that are enclosed within it.


          Very advanced mouthparts are found in the gadflies, e.g. Tabanus and Chrysops. Within the groove of the labium a pair of mandibles and a pair of maxillae. Lateral movements of the sword-like mandibles make a wound in the skin of a mammal, to be deepened by the backward and forward thrusts of the maxillae. Into the wound so formed is inserted a tube composed of the epipharynx, an elongated chitinization of the roof of the mouth to which the labrum is fused, and the hypopharynx, a corresponding elongation of the mouth floor. The blood passes into this tube, being drawn up by the pharyngeal pump within the head. The hypopharynx carries a duct down which the salivary fluid is passed. Besides this, the proboscis of a gadfly can be used for taking up fluids exposed at surfaces. Such exposed fluid is drawn on the labellar surfaces into small channel~, the pseudo-trachea, which converge to a central point on the undersides of the labellar lobes. There it meets the distal end of the epi-hypopharyngeal tube, up which it passes by the pumping action of the pharynx (
Borradaile & Potts, 1958).


          The female mosquito has mouthparts that differ in degree more than in kind from those just noted. The labium is elongated, and deeply grooved on its upper surface.  It bears distally a median point and two labellar lobes. The paired maxillary and mandibular stylets occur in the groove, as do also the median labrum-epipharynx and the hypopharynx. The labrum-epipharynx is grooved ventrally and its lateral borders curve inwards so that by their overlapping they form the food tube. The hypopharynx carries the salivary duct.  In male mosquitoes mandibular and maxillary stylets are absent and they feed on fluid that is found on  exposed surfaces.


          The blowfly Calliphora has also lost its piercing mechanism.  Mandibles are absent and the maxillae are represented only by palps. The labium is broad and deeply grooved interiorly to carry the labrum-epipharynx and hypopharynx within it and is so constituted that the whole of the proboscis can be folded up under the head when not in use. The labellar lobes are large and complex, making possible a variety of feeding behaviors depending on whether the food is fluid or semi-solid.


          The surface of each labellar lobe in its inner median part forms a pseudotracheal membrane. This is a flexible membrane that is interrupted by some thirty fine canals running transversely across it. These converge, either directly or by union with a common canal, to the central region of the labellum towards which the epi-hypopharyngeal food tube is directed.  These fine canals are the pseudotracheae. Each forms a fine incomplete tube imbedded in, and running parallel to, the labellar surface. The interior of each tube is in communication with the oral surface of the labellum through a very narrow irregular crack, the lumen of the tube being kept open by means of incomplete cuticular rings running transversely found the tube-thus giving a superficial resemblance to a trachea. At the junction between the labellae and the body of the labium, to which place the pseudotracheal tubes converge, there is a complement of prestomal teeth lying between the inner ends of the psuedotrachchae (
Borradaile & Potts, 1958).

 

          The food tube is formed mostly by the conjoined labrum-epipharynx and the hypopharynx, and at the lower end of the labrum where the latter structures do not reach the full distance.  The overlapping sides of the labial groove form a food tube.  In this way food collected at the median part of the pseudotracheal membrane to which the pseudotracheae converge is brought into contact with the food tube and so with the pharynx.

 

          Calliphora feed largely on fluids, but in the presence of soluble solid food the groove solution is affected by regurgitating alimentary fluid onto it. In other cases the prestomal teeth can abrade temporarily dried surfaces and so bring the regurgitated fluids more effectively into contact with the food material. When the labellae are completely retracted food enters the wide-open food tube irrespective of the pseudotracheae and the passage is then large enough for semisolid food or even the eggs of helminths to enter (Borradaile & Potts, 1958).

 

          It has been suggested that in the evolution of the Diptera there has been a trend towards surface fluid feeding involving the loss of piercing stylets. However, there are forms, closely related to the blowfly type in which mandibular and maxillary stylets are lacking, but which can pierce the skins of mammals, using the labium., e.g., the tsetse fly Glossina and the stable fly Stomoxys.  In these cases the labium has become so rigid that it cannot be folded under the head. Therefore, with its contained labrum-epipharynx and hypopharynx, it extends stiffly forwards. The labellar apparatus is reduced and consists of three small, stout lobes that bear rasping teeth, some of which represent the prestomal teeth of Calliphora

 

          Diptera larvae are among the most specialized of all insects. Legs have been entirely lost, and the head and spiracular system have undergone varying degrees of reduction. Thus the most generalized larvae are at the same time eucephalous, i.e. with a complete head capsule, and peripneustic, i.e. with the lateral spiracles on the abdomen, e.g. Bibio. In the most specialized forms, the acephalous larva's head capsule is absent, e.g. Musca. Such acephalous larvae may either be amphipneustic, with only prothoracic and posterior abdominal spiracles, or metapneustic, where only two spiracles exist at the posterior end of the body. The first instar larva of Musca is metapneustic, subsequent instars being amphipneustic.


          The eucephalous larva develo0s into an exarate pupa from which the adult emerges by a longitudinal slit on the thorax.. The pupa resulting from the acephalous larva is coarctate, the last larval skin being retained as a protective puparium, and tracheal connections maintain contact between the pupa within and the larval skin outside.   Final emergence of the fly in this case clearly involves two processes, (1) the liberation of the fly from its pupal skin, and (2) the further release from the puparium. The latter splits transversely the top being thrust away by an eversible head-sac, the ptilinum.  These features of metamorphosis are typical of many flies and, by defining one of the suborders, make up an important basis of modern classifications.

 

           The Suborder Orthorrhapha includes those flies which are liberated by means of a longitudinal split in the mid-dorsal line of the pupal case  Such flies do not have a ptilinum. Many of these, the Nematocera, have slender antennae and usually pendulous maxillary palpi.  Their larvae are eucephalous with transversely biting mandibles and their pupae are free. To this series belong the crane flies the larvae of which often damage cereal crops by devouring their roots. The Culicidae are the gnats and mosquitoes, the piercing proboscis of which has already been described. Their wings that are fringed with scales further distinguish them. Both larvae and pupae are aquatic, the former being metapneustic, the latter propneustic (with anterior spiracles only). With the blood-sucking habit of these flies has evolved an association with certain organisms that when, transmitted to humans, cause disease. Anopheles is concerned with the transmission of malaria. Stegomyia transmits the pathogen of yellow fever, while Culex fatigans, a widely distributed tropical form, is a carrier of the threadworm Wuchereria bancrofti, the cause of elephantiasis.


          Nearly related to these are the Chironomidae (midges), the mouthparts of many of which are not adapted for piercing and sucking. A few of these, however, do suck blood, e.g. the midges of the genus Forcipomyia, whose larvae breed, some in water, others behind the bark of trees.


         
The Cecidomyiidae are the gall midges notable by their beaded antennae decorated with whorls of setae. The larvae of a few of these are parasitic, others are predacious, but the large majority are phytophagous, forming galls in plant tissues, e.g. of grasses. Contarinia pyrivora is the pear- midge, the larvae of which develop in the flowers of the pear so as to abort fruit production. Miastor lives behind tree bark in the larval state and, as mentioned above, is noteworthy for the phenomenon of paedogenetic parthenogenesis.


          Another family of blood-sucking flies, known as the Simuliidae, consists of small flies with a hump-backed appearance and with broad wings. The spindle-shaped larvae live in running water and are characterized by the possession of thoracic prolegs and an anal pad provided with setae by means of which they adhere to rocks, etc., in the rapidly flowing water of their environment. Still included in the suborder Orthorrhapha are the flies with short antennae, the Brachycera. Though included in this system with the Orthorrhapha, their wing venational characters indicate a close relation with the Cyclorrhapha. In general, the basal joints of the antennae are larger than the terminal ones, these being reduced in number as compared with the nematocerous condition. The maxillary palpi are porrect (not pendulous).  Their larvae are bemicephalous (head capsule incomplete posteriorly), with vertically biting mandibles, and the pupae are free and spiny (
Borradaile & Potts, 1958).

 

          From this great assemblage of flies the Tabanidae or gadflies, the mouthparts of which reference has already been made, are of stout build and possess large eyes occupying a great part of the head surface. Though a few transmit disease organisms (Chrysops dimidiata, as the vector of the nematode worm Loa loa, is responsible for calabar swelling in the natives of West Africa), the majority are harmful chiefly through the annoyance that their bites cause. Tabanid eggs are usually laid on the leaves of plants overhanging water and their carnivorous larvae are either aquatic or ground-dwellers.
  

          The robberflies (Asilidae) are large hairy flies with a proboscis that is pointed to the rear. They feed on all kinds of insects that they paralyze with their salivary fluid, and their legs, which are strong and equipped with powerful claws, are well adapted for grasping the prey. The Empidae, flies of more slender build, exhibit similar habits. Their larvae are terrestrial as are also those of the preceding tabanids.

 

          The Suborder Cyclorrhapha are flies that emerge from a pupa which is enclosed in the last larval skin or puparium, and the commonly transverse or circular split in the latter, for release of the adult, gives the name to this suborder.  Therefore, it is really a characteristic of the larvae that establishes the position of these flies in the classification.


          The antennae have three joints, the last of which is greatly enlarged, carrying a dorsal spine or arista. The maxillary palpi are one-jointed and porrect. A crescent suture on the head lies above and encloses the bases of the antennae. This, known as the Jrontal suture, is a narrow slit along the margins of which the wall of the head is invaginated to form the ptilinal sac. The eversion of this enables the adult to emerge from the puparium. The extent to which the frontal suture is developed and the ptilinum persists varies. The Syrphidae, for example, usually have no persistent ptilinum and the frontal suture is not well developed. In the larva the true mouthparts have atrophied and the head capsule is lacking. There is a complex pharyngeal skeleton to which are attached mandibular sclerites which work in the vertical plane.


          The Syrphidae (hover-flies) form an important family of brightly colored flies, whose most obvious mark of distinction is the possession of a false longitudinal vein lying about the middle of the wing. Their larvae are amphipneustic leathery maggots, some of which (Syrphus) devour Aphidae, others live as saprophages in decaying material (Eristalis), others are phytophagous (Merodon, the bulbfly).


           The rest of the Cyclorrhapha may be considered as the muscoid flies. The frontal suture is prominent and the ptilinum persists.  Many families are included here, to some of which belong such serious agricultural pests as the frit fly of oats, Oscinus frit, and the gout-fly of barley, Chlorops taeniopus. In such cases the larvae bore into the growing shoot, or into the stem. Larger and better known are the saprophagous housefly, Musca, and the blowfly, Calliphora. The larva of Hypoderma lineatum is parasitic in the bodies of cattle, causing' warbles' on the backs of affected animals, while Gastrophilus equi, the bot-fly, is parasitic as a larva in the alimentary tract of horses (
Borradaile & Potts, 1958).


          The Tachinidae are important parasites that attack the larvae of Lepidoptera, Coleoptera, Orthoptera and Hemiptera and some myriapods and terrestrial isopods. The parasitic larvae become associated with their hosts in a variety of ways. This usually takes the form of an enclosing sheath produced by the host tissue that allows the parasite to breathe either from the outside air by a perforation in the body wall or from air in the host's tracheae.  Ptychomyia remota is produces good biological control of the Levuana moth, Levuana iridescens, in Fiji.


          Blood-sucking muscids are important, e.g. Glossina, as the vectors of trypanosomiasis that causes sleeping sickness of humans and cattle in Africa. The tsetse flies are pupiparous and their larvae are nourished by special glands opening into the genital tract. The larvae are deposited as soon as they are fully-grown and pupation follows quickly.


          Some Diptera also have a modified structure resulting from an ectoparasitic habit, some on mammals, others on birds. They are known as the Pupipara, being similar in their viviparity to Glossina.  Some examples are Hippobosca  a winged fly with body dorsoventrally compressed, and ectoparasite of cattle; Melophagus a wingless species, similarly associated with sheep, also known as the sheep tick and Nycteribia  a wingless form parasitic on bats (
Borradaile & Potts, 1958).

 

= = = = = = = = = = = = = = = = = = = = = =

 

Detailed Morphology & Habits

 

          All species of Diptera have two wings, the hind ones being reduced as remnants to halteres, which vibrate in flight to act as a kind of gyroscope.  This aids them in very rapid and agile flight.  There are many aquatic larvae and their size ranges from minute to 16 centimeters long.  The larvae are maggots with very few appendages.  There is much mimicking of wasps and bees found in the order.  The Diptera are important for their annoyance to or feeding on humans and animals, being disease carriers and some species are also injurious to plants.

 

          The order is especially homogenous and is divided into to principal groups:

 

          1.  Nematocera have antennae with distinct segments varying from 5-30.  Most larvae have a distinct head capsule, and the tentorium is developed so that the mandibles are opposable.

 

          2.  Brachycera have antennae with a reduced 3-4 segments.  The head capsule is very much lost, and the larvae are worm-like maggots.  The mouthparts are developed as hooks and function by moving up and down.

 

          Other divisions for Diptera are Orthorrhapha and Cyclorrhapha as follows:

 

          3.  Orthorrhapha is a circumscriptional name which historically was used for an infraorder of Brachycera, one of the two suborders into which the order Diptera, the flies, are divided. As the group was paraphyletic, it has not been used in classifications in the last decade, and is effectively obsolete. However, many catalogs, checklists, and older works still contain the name. The taxa that used to be in the Orthorrhapha now comprise all of the infraorders in Brachycera excluding the Muscomorpha (= "Cyclorrhapha"). A recent revision of the taxonomy of the order Diptera revived the name Orthorrhapha.

 

          4. Cyclorrhapha is an unranked taxon within the infraorder Muscomorpha. They are called "Cyclorrhapha" ('circular-seamed flies') with reference to the circular aperture through which the adult escapes the puparium. This is a circumscriptional name that has significant historical familiarity, but in the present classification, this name is synonymous with the more recent "Muscomorpha/"  Cyclorrhapha underwent major adaptive radiation that led to the creation of over 72 000 species. These species share multiple attributes such as the 360-degree rotation of the male terminalia.

 

----------------------------------------------

 

          Mouthparts. -- There are three types found in adults:  (1) nectar-feeding or sucking, (2) sucking-lapping or sponging and (3) true blood sucking that are rasping sucking.  Simplified diagrams of these types are shown in the following:

 

                               Sucking (mosquito)           Sponging (housefly                    Rasping-sponging (horsefly)

 

 

          Larval Spiracular Arrangement. -- The spiracles of dipterous larvae may be arranged in either of four ways:  (1) peripneustic,-- lateral spiracles on the abdomen. (2) amphipneustic-- only prothoracic and posterior abdominal spiracles present, (3) metapneustic-- only two spiracles are retained at the posterior end of the body. (4) propneustic -- lateral spiracles on the thorax.

 

          Pupal Spiracles. -- In many species the spiracles of pupae are moved to the head and thorax.  Here they appear as "pupal horns."

 

= = = = = = = = = = = = = = = = = =

 

Selected Families of Diptera

 

          The following discussion includes only the most common or important families of Diptera. For greater detail please refer to Borror et al. (1989), and for an expanded treatment of Diptera taxonomy with 125 families noted please see: <207 Families>.  Additional information on <Habits>, <Adults> and <Juveniles> is included when available.

 

Nematocera = "long antennae."

 

Bibionidae. -- Bibionidae have a body length of about 4-10 mm. The body is black, brown, or reddish, and heavy, with broad legs. Antennae are miliform and the front tibiae have large spurs or spines. The tarsi have 5 segments with tarsal claws, pulvilli, and a well formed empodium. Wings have two basal cells (posterior basal wing cell and basal wing cell), but there is no discoidal wing cell.  R4+5 is simple or branched; at most, only three branches of R developed. The front edge wing veins are thicker than the trailing veins.

 

 

          The larvae inhabit grassy areas where they feed on dead vegetation or living plant roots.  Larvae are sometimes also found in pockets with many others.  Adults of most Plecia and some species of Bibio do not eat, but rely on the food of the larval stage.   Adults are short-lived, and some species of Plecia (lovebugs) spend much of their adult lives copulating.  The male and female (attach themselves at the rear of the abdomen and remain that way at all times, even in flight. Adults often swarm in large numbers.

 

---------------------------------

 

     Blepharoceridae. -- <Adults> & <Juveniles>   Members of this family are largely or entirely aquatic in habit.  The larvae feed in part on minute organisms such as diatoms and on small Crustacea.  Adults feed extensively on midges and other small, soft-bodied insects.

 

 

 

---------------------------------

 

     Ceratopogonidae (Heleidae). -- <Habits>; <Adults>   The Biting midges, Punkies and No-see-ums are biting flies, with the Genera Culicoides and Leptoconops being especially problematic.  Most species are very small and stout, with rather broad wings that they hold flat over their abdomen when resting.   They are very pestiferous due to their habits of sucking blood from animals including other insects. The bites often result in painful swellings.  Some species may be recognized by their spotted wings. 

 

 

          The primary habitat is along the seacoast and the shores of lakes and rivers.  The larvae are aquatic or semiaquatic in the sand, decaying vegetation or mud and in tree holes containing water.  Breeding along the seacoast is possible in the intertidal zone. Their habit of remaining close to the larval developmental sites allows one to simply move a short distance away to avoid being attacked.

 

---------------------------------

 

     Cecidomyiidae. -- <Habits>; <Adults> & <Juveniles> -- The gall midges or gall gnats have larvae that occur in plant tissues.

 

 

          One important species, the Hessian Fly, Mayetiola destructor (Say), attacks wheat stems in the larval stage.  It was introduced into North America during the Revolutionary War with the Hessian insurgents.  It is an important pest of wheat, barley, rye and some wild grasses.  Injury is caused when the larvae burrow into stems, which results in stunted grain and sometimes in the death of the plant.  The puparia overwinter in the grain.  There are one or two generations per year.  Control has involved planting wheat so that it germinates after danger of infestation is past, deep plowing grain stubble and reducing volunteer grain.

 

          The genus Miastor is one of the few examples of paedogenesis.  The larvae give birth to progeny.  They produce eggs, which produce more larvae that also may produce eggs, etc.

 

---------------------------------

 

     Chironomidae. -- <Habits>; <Adults> & <Juveniles> -- The Midges also appear as very large mosquitoes, but they do not bite humans or animals.  The male antennae are usually conspicuously plumose.  They are one of the most abundant and important foods for fish in freshwater habitats worldwide.  Most species are small and resemble mosquitoes but lack scales on their wings and are without a long proboscis.

 

 

          The larvae of most members are aquatic, but several species also occur in decaying vegetable matter, under tree bark or in moist soil.  Most are scavengers.  Aquatic species usually form tubes or cases in which they are protected.  Some species are red in color from the hemoglobin in their blood, hence their name, "bloodworms."  The larvae may exist at varying depths in water, and they swim by whipping their bodies similar to that of mosquitoes.

 

          Chironomids pose an annoyance because of the male's swarming habits.  However, they are an important food source for freshwater fish and other aquatic inhabitants.

 

---------------------------------

 

     Culicidae. -- <Habits>; <Adults> & <Juveniles> -- The Mosquitoes are identifiable by having scales present as patches on their wings.  Only the female mosquito is capable of sucking blood.  The eggs are laid in water and the pupae are capable of locomotion. There are two groups:  The Anophelines and Culicines:

 

          Anophaline-- Anopheles spp.

 

               The wings are spotted with definite patches of scales.  Their feeding position is at a 45-degree angle with the surface.  The aquatic larvae feed horizontal with the water film due to short terminal spiracles.  Members of the genus are the sole vectors of malaria.  They have long palpi and the eggs are laid singly.

 

 

          Culicine -- Culex spp.

 

               The wings are not spotted and mostly entirely clear.  The feeding position angle is primarily horizontal with the surface.  The aquatic larvae have developed an elongated siphon and feed hanging down from the water surface at an angle.  Members of the genus include the common pest mosquitoes, which carry many viruses such as yellow fever, dengue, encephalomyelitis and the filarial worm.  They have short palpi and the eggs are laid in masses.

---------------------------------

 

     Limnobiidae. -- <Habits>; <Adults> & <Juveniles>  Members of this family are largely or entirely aquatic in habit.  The larvae feed in part on minute organisms such as diatoms and on small Crustacea.

 

 

---------------------------------

 

 

     Mycetophilidae. -- <Habits>; <Adults> & <Juveniles>  The Mycetophilidae or "fungus gnats" are a family of small flies.  There are about 3000 described species in 150 genera, but the actual number of species is probably higher.  They generally occur in the damp habitats of their host fungi and sometimes form dense swarms.

 

 

          Adults of this family are distinguished from other small flies by a pronounced humped thorax, well-developed coxae, and often spiny legs. However identification within the family between genera and species requires close study of microscopic features in wing venation and variation in chaetotaxy and genitalia.  Larvae are terrestrial and usually feed on fruiting bodies, hyphae and spores of fungi, but some species have been observed on mosses and liverworts.  The larvae of some species, are also partially predatory.  Some species when attracted to the fungus odor of Jack-in-the-Pulpit, fall into the inflorescences and accomplish pollination.

 

---------------------------------

 

     Psychodidae. -- The Moth flies and sand flies have abundant scales on their wings.  They are small to very tiny insects with a large number of hairs on their bodies.  When at rest adults may hold their wings roof like over the body.

 

 

          The habitat is in moist shady areas but can also be found in drainages or sewers.  Adults may occur in bathrooms that they enter via sink drains.  Larvae inhabit decaying vegetable matter, moss, mud or water.

 

          There are some medically important species that are vectors of various fevers, such as Leishmania, Pappataci fever, Kala-azar and Oroya fever, especially in tropical regions.

 

---------------------------------

 

     Simulidae. -- The Black flies or Buffalo gnats are biting flies that draw blood, especially around the head region of humans and animals.  Their color is generally dark and they have short legs, broad clear wings with 4-5 veins.  Their thorax is enlarged so that they appear hunch-backed.  The females are bloodsuckers and can become vicious biters.  Their bites may cause swelling or bleeding.  In some parts of North America blackflies become so numerous that their attacks on livestock can cause death.  Even humans have succumbed.  Indeed, in areas of heavy infestation some communities hold "Blackfly Festivals" in late springtime to "celebrate" the end of the worst season of their occurrence.

 

 

          They are associated with moving streams where the larvae develop underneath submerged stones to which they attach themselves with a disk like sucker at the rear end of their body..  The larvae possess gills, attachment hooks and characteristic respiratory horns. 

 

          Blackflies are vectors of animal diseases, especially of poultry, in some parts of the world.  Diseases include onchocerciasis caused by a filarial worm, which may result in partial or complete blindness.

 

---------------------------------

 

     Thaumaleidae (= Orphnephilidae) . -- <Habits>; <Adults> & <Juveniles>  Members of this family are mostly or entirely aquatic in habit.  The larvae feed in part on minute organisms such as diatoms and on small Crustacea.

 

 

---------------------------------

 

     Tipulidae. -- <Habits>; <Adults> & <Juveniles> -- The Crane flies, which contain the largest number of species in the order, are recognized by their long, spindly legs.  They have the appearance of giant mosquitoes, but there are no biting mouthparts in the adults.

 

 

          There is a distinct V-shaped suture between the scutellum and scutum, and the adults lack ocelli.

 

 

          Their habitat is primarily in damp areas with abundant vegetation, the larvae feeding in dead and decaying vegetation.  The larvae of most species are aquatic or semi aquatic, and a few species feed on living plant tissue and thereby may cause damage to crops.  There are even a few predatory species.  Adults derive their nourishment from nectar.

 

= = = = = = = = = = = = = =

 

Brachycera = "short antennae" includes larger flies with large eyes.

 

     Acroceridae. -- <Habits>; <Adults>   This is a small family of odd looking flies most closely related to Nemestrinidae. There are about 520 species in 50 genera. They are characterized by a humpbacked appearance and a small head, sometimes with a long proboscis for nectar. As such, acrocerids are commonly known as small-headed flies or hunchback-flies. Many are bee or wasp mimics. Their eyes are often holoptic; their heads seem to be composed primarily of ommatidia. They are cosmopolitan in distribution but rarely observed in most places; the majority of the over 500 species are known from fewer than 10 specimens. They are found most commonly in semi-arid tropical locations.

         

 

          All small headed flies are parasitoids of spiders. They are most commonly collected when a spider from the field is brought into captivity. The adults do not seek out their hosts; instead the first instar larvae is a planidium that seeks out spiders. When a spider contacts an acrocerid planidium, the larva grabs hold of the spider, crawls up the spider's legs to its body, and forces its way through the body wall, often lodging near the book lung, where it may remain for years before completing its development. Some obsolete names for Acroceridae include "Cyrtidae" and "Oncodidae".

 

---------------------------------

 

     Agromyzidae. -- <Habits>; <Adults> & <Juveniles>  Commenting on host preferences, Clausen (1940/1962) stated that the hosts are all monophlebine Coccidae with the exception of several questionable records from Dactylopius.  Larvae and puparia of the species occurring on Drosicha corpulenta Kuw. in Japan, which had previously been recorded as C. grandicorne Rond., were found by Thorpe (1931) to be distinct from any that had been described.  This species, recorded on Drosicha and Icerya seychellarum Westw. is an effective parasitoid of the latter but does not attack I. purchasi Mask. (Kuwana 1922).  It is probable that two species were involved and that the form from Icerya may prove to be one of those recorded on that genus in other parts of the world.  The Australian C. iceryae Will, which attacks I. purchasi, is the best known of the genus.  It was established in California in 1888 from material shipped by Alfred Koebele, and proved very effective in certain areas.  Its status as a biological control had been somewhat obscured by the more conspicuous Rodolia cardinalis Muls., which was introduced at the same time [please refer to Case History section for cottony-cushion scale work].

 

 

          Agromyzidae is a smaller cosmopolitan family with about 1,010 species known by the year 2000.  They are most numerous  in the Palearctic.  Important characters include a costa which is broken at the end of S-c (or at or near end of R-1, if S-c vestigial or fused with R-1).  The first M-2 cell is usually present, but cross-vein-like M-3 is often close to wing base; femora often with conspicuous bristles.  The abdomen is often depressed, and the female ovipositor is sometimes long and well sclerotized.

 

          Most species of Agromyzidae are phytophagous, usually as leaf or stem miners of broad-leafed plants.  All entomophagous species are primary, solitary or gregarious endoparasitoids of nymphal and adult monophlebid scale insects.  One species, Cryptochaetum iceryae, has been widely used with considerable success in the biological control of cottony cushion scale, being the dominant natural enemy in coastal California (Quezada & DeBach 1973).

 

---------------------------------

 

     Anthomyiidae. -- <Habits>; <Adults> & <Juveniles> -- The root maggots feed on roots up the crown of plants, which allows rots to enter the plants.  The damage is especially severe in cold wet springs.  Adults are attracted to decaying organic matter.  The adults lay their eggs around the bases of plants and the larvae resemble housefly maggots.  They overwinter in puparia.

 

 

          Three very important species are the Seed corn maggot, Hylemya (Delia) platura (Meigen), which is a pest on any vegetable seedling, the Onion maggot, Hylemya antiqua (Meigen) that is a pest primarily on onion, and the Cabbage maggot, Hylemya (Delia) radicum (Wiedemann) that primarily attacks cruciferous plants.

 

          Control has involved the incorporation of insecticide into the soil, the chemical treatment of seed, the removal of culled vegetables from fields and the placement of cheesecloth over seedbeds.

 

---------------------------------

 

     Apioceridae. -- <Adults> These so-called "flower-loving flies" include only about 150 species all in the single genus Apiocera. They may be found in dry, sandy desert locations of America and Australia.  Apiocera species occurring in sandy, arid and semiarid habitats where most do not visit flowers, but rather are found scampering about the ground near sparse vegetation, or feeding on honeydew in association with aphid-infested plants.  They may drink water from damp sand with sponge-like mouthparts.  The larvae may also be found in sand along coastal beaches.

 

 

 

---------------------------------

 

     Asilidae. -- <Habits>; <Adults> & <Juveniles> -- The robber flies are predators of other insects both as larvae and adults.  They have what looks like a beard underneath their mouthparts.  Adults can catch their prey on the wing.

 

 

---------------------------------

 

     Braulidae. -- <Habits>; <Adults>   Braulidae, or bee lice, is a Diptera family that contains eight species in two genera, Braula and Megabraula. These are very unusual flies, wingless and flattened, and barely recognizable as Diptera.Two species of Braula are associated with bees.  Adults are degenerate in form as a result of their mode of life and lack wings and halteres.  The head is large, with vestigial eyes, the scutellum absent, and the thorax not sharply differentiated from the abdomen (Clausen 1940/62).  Braula caeca Nitz, or "bee louse" is a commensal found on honeybees and in their hives in different parts of the world.  This species originally was considered to be parasitic on adult bees themselves, but  Skaife (1921c) and Herrod-Hempsall (1931) showed that the apterous adults feed only on honey regurgitated by the bee.  Worker bees and the queen are frequently very heavily infested, while very few of this species are found on drones.  A maximum of 26 individuals were found on a single queen.  They usually are attached at the juncture of the thorax and abdomen or at the neck.  When feeding, they move to the head of the bee and, by taking up a position on the mandibles, either force or induce the bee to extrude its tongue, and they then feed on the honey.  They will not feed on honey contained in the comb, and very little harm seems to result from this association.

 

 

          Eggs are laid at random over the brood comb or in the cells filled with honey.  Skaife (1921c) found that young Braula crawl into the cells with the bee larvae and consume a portion of the food provided for the.  The larva forms a tunnel for itself from fragments of the cell wall, and pupates within it.  The life cycle takes ca. 3 weeks.

 

---------------------------------

 

     Bombyliidae. -- <Habits>; <Adults> & <Juveniles> -- The Bee flies mimic bees in their appearance.  Their bodies are fuzzy and they have fast flight habits.  They are beneficial as their larvae are predaceous on many insect pests of economic importance. 

 

 

---------------------------------

 

     Calliphoridae. -- <Habits>; <Adults>   The blowflies, bluebottle flies and screwworm flies are flesh feeders.  They lay masses of eggs in dead animal carcasses.  The presence of these flies is indicative of a dead animal.

 

 

          Screwworm flies are attracted to wounds and some species are parasitic and able to penetrate living flesh.  They are especially prevalent in southeastern North America.  Females lay their eggs in wounds and the larvae invade surrounding tissue.  They are especially serious pests of sheep.

 

 

          Screwworms were periodically effectively reduced in number by the liberation of males that have been sterilized with radioactive cobalt.  The females, which copulate just once, cannot produce progeny if their mate is a sterilized male.  The flies were even completely eradicated from one island by the deployment of this technique.

 

 

          Medication of wounds on animals is effective in control, but it is necessary to be on continuous alert for new wounds.

 

          Wool maggots are attracted to soggy and wet wool, especially around the rump area.  Precautionary control measures involve clipping the wool.

 

          The maggots of some screwworm species are able to clean-up dead flesh from wounds and thereby cause rapid healing, especially for very deep wounds.

 

---------------------------------

 

Chamaemyidae (Ochthiphilidae) . -- <Habits>; <Adults> &  <Juveniles>  Martelli (1908) studied an undetermined species which was predatory on the eggs of Filippia oleae Costa in Italy.  During oviposition the female fly stands either on the egg sac or at one side of it, inserts the ovipositor beneath the margin or through the wax covering, and lays an egg among those of the host.  The entire contents of the sac are consumed by one larva,a nd the cycle from egg to adult takes 30 days.  There are 4-5 generations annually.

 

 

          Cottam (1922) studying some unnamed species that are common predators on aphids in Africa.  One was effective in controlling Aphis sorghi Theo.  Cherian (1933) studied the life history of Leucopis sp., an aphid predator in India.  The egg is 0.36 mm long, white and ribbed longitudinally.  First instar larvae lack the integumentary hairs, but the mature form has several fleshy processes on each body segment.  The posterior spiracles of all instars are borne on stalked processes, which are most pronounced on the mature larva and the puparium.  Before pupation the larva exudes a great quantity of mucilaginous substance, which darkens quickly and attaches the puparium to the substratum.  The egg, larval and pupal stages require 2-4, 4-5 and 5-7 days, respectively.

 

          Clausen (1940) referred to an unpublished M.S. Thesis by Maple treating of Leucopis bella Lw. and L. griseola Fall in North America.  L. bella is a common predator of eggs, and possible young larvae, of dactylopine Coccidae, while L. griseola is an effective natural enemy of aphids.  Eggs of both species are ca. 0.5 X 0.16 mm., with the anterior end a bit pointed, and are pearly white, with the surface bearing longitudinal ridges.  They are laid singly among the egg masses or colonies of the host, where they hatch in 3-4 days.

 

---------------------------------

 

     Chloropidae. -- (Oscinidae) -- <Habits>; <Adults> & <Juveniles> -- The chloropids and eye gnats are small shiny black or yellow and black.  They occur commonly in meadows and grassy places.  They feed on grass stems and thus can be pestiferous on cereal crops.  Some species are also scavengers and a few are predators or parasites.

 

 

          The genus Hippelates has members that breed in decaying vegetation and animal dung and are strongly attracted to human and animal secretions.  They have been noted to vector yaws and pinkeye diseases of humans.  Considerable research has been done in California to combat this group of chloropids, either culturally, chemically or biologically (see ch-20.htm)

 

---------------------------------

 

     Conopidae. -- <Habits>; <Adults> & <Juveniles>    Conopidae occur in tropical and temperate regions where more than 500 species are known.  Important morphological characters include a broad head, usually wider than thorax; eyes large (but not as large as Syrphidae); antennae projecting forward, 3rd segment with well-developed style (occasionally aristate).  The ptilinum is present at eclosion; the body is usually bare or slightly hairy.  The abdomen is petiolate, producing a "wasp-like" appearance.  They bear a superficial resemblance to Syrphidae.  Females of several species have the caudal segments of the abdomen modified ventrally into a pincerlike form, which may be an adaptation, similar to the Tachinidae, for grasping the host during oviposition.  Other species, such as Stylogaster spp., have long slender ovipositors (Clausen 1940/62).

 

 

 

           These insects are called thick-headed flies, is a family of flies within the Brachycera suborder of Diptera. Flies of the family Conopidae are distributed worldwide except for the poles and many of the Pacific islands. About 800 species in 47 genera are described worldwide, approximately 70 of which are found in North America. The majority of conopids are black and yellow, or black and white, and often strikingly resemble wasps, bees, or flies of the family Syrphidae, themselves notable bee mimics. Conopids are most frequently found at flowers, feeding on nectar with their proboscis, which is often long.

 

---------------------------------

 

     Cyrtidae. -- <Habits>; <Adults> & <Juveniles>  The Cyrtidae is a small family which is rarely encountered in the field.  Adult flies are distinguished by the large humpbacked thorax, the rather small head, situated markedly ventrally with respect to the thorax, and frequently by a pronounced swollen appearance of the abdomen.  The proboscis is long in several genera, where it is used for sucking the nectar of flowers.  In most forms the proboscis is reduced, and feeding is thought to be rare.  In some species the flies are exceedingly rapid in flight, although in most they are sluggish and may be recognized by an uncertain and undulating movement.  They are clumsy in walking, as if their slender legs were inadequate to support their bodies.  Wings are long, and their tips usually drag on the surface while walking.  Adults of many species can be easily captured while resting or ovipositing.  All species are believed to be internal parasitoids of spiders, mainly of the Clubionidae, Lycosidae and Salticidae (early records of species occurring as predators in egg sacs are thought to be in error (Clausen 1940/62)).  Host preferences of Cyrtidae were noted by Millot (1938), these representing 7 families, the majority of species being arboreal.  The different cyrtid species seem to have a wide host range, each attacking representatives of several families.  Extended studies on behavior are those of King (1916) on Pterodontia flavipes Gray, a solitary internal parasitoid of lycosid and epeirid spiders, and by Millot (1938) on Ogcodes pallipes Latr.

 

 

 

---------------------------------

 

     Dolichopodidae. -- <Habits>; <Adults> & <Juveniles>  The immatures and adults of Dolichopodidae are predators on other insects.  The adults are often found on foliage in shaded areas.  Larvae occur in wet or muddy soil, under bark, in decaying organic matter and in water.  Adults of some species are able to skim over the water surface.  The females move quickly and often have a crab-like manner of locomotion.  Williams (1933) noted that the adults of a few species of Campsicnemus are active on the surface of water pools in Hawaii and that they feed extensively on the collembolan, Salina maculata Fols.  It was also observed that the adults of Hydrophorus pacificus V.D. pulled Chironomus larvae out of shallow water along muddy shores and in marshes.

 

 

 

---------------------------------

 

     Drosophilidae. -- <Habits>; <Adults> & <Juveniles> -- The pomace flies or small fruit flies have been used extensively in research on genetics.  They have a very rapid life cycle, good taxonomic characters and giant chromosomes.  They are especially attracted to fermenting plant juices.  Their size is small, only 3-4 mm. in length and usually yellow in color.

 

 

          Their primary habitat is around decaying fruits and vegetation, where they can cause some damage.  The larvae live in decaying fruits and fungi where they feed primarily on yeasts that are present.  Several species are parasites of Lepidoptera caterpillars and mealybugs.

 

---------------------------------

 

Empididae. -- <Habits>; <Adults> & <Juveniles>  Empidids or "dance flies" are commonly found in damp places, such as along streams.  The adults are predators, and larvae are either predators or scavengers, living in the soil, decaying vegetation and wood, under bark, and in water.  The adult flies are all predaceous on other insects of small size, and the larvae are either predators or scavengers.

 

 

 

          The complete biological control of an infestation of Phytomyza aconiti Hendel was reported through the attack of Tachydromia minuta Meig. on the adult flies (Whitfield 1925).  There is a very unusual feeding habit associated with mating in the genera Empis, Hilara and Rhampomyia.  The male captures its prey, carrying it about until mating occurs, at which time it is transferred to the female.  Males of several species envelop the prey in a frothy web before presenting it to the female (Lundbeck 1910, Clausen 1940).

 

---------------------------------

 

     Hippobosidae. -- The louse flies and sheep ked eggs and larvae develop within the mother fly and are nourished from glands.  The "nits" pupate immediately upon being released.  The adults are either winged or wingless.  The winged species are dark brown and about the size of small houseflies and are common on birds.  The sheep ked, Melophagus ovinus (L.) is wingless and parasitic on sheep.

 

 

          Control of these flies is relatively simple.  Subjecting animals to various sprays, dips and dusts in autumn is usually adequate.  Also by removing sheep from old pens and spraying the pen area with insecticides eliminates the flies.

--------------------------------

 

     Lonchaeidae. -- <Habits>; <Adults> & <Juveniles>    Many species of Lonchaeidae develop in rotting vegetation, but some are also prededors.  Taylor (1929, 1930) found that the larvae of Lonchaea corticis Taylor were predaceous on those of Pissodes strobi Peck and other beetles, the species ranking second among the natural enemies of the pest.  Eggs were laid in clusters of 6-25 in the oviposition burrows of the beetles.  Larvae were not restricted entirely to animal food but also ingested frass, etc.  When the eggs of predator and host occur simultaneously, or if those of the predator precede hatching of the host by a few days to one week, the greatest host destruction occurs.

 

 

---------------------------------

 

     Milichiidae. -- <Habits>; <Adults>   Adult milichiids consistently feed on insects, and thus their feeding habits represent a transitional stage between scavenger and predator.  They cannot kill their own prey but are dependent on other predaceous species for food (Clausen 1940/62).  Knab (1915) and De Peyerimhoff (1917) summarized the food habits of Milichiidae.  Quite a few species of Desmometopa are definitely associated with Asilidae, to which they regularly attach themselves and maintain their hold until a prey is captured.  Other species are more often associated with spiders, although they do not attach themselves to the body but feed on prey that becomes entangled in webs, of which most are bees.  The above types of phoresy is an adaptation relating only to the feeding of adults and thus differs from that found in Scelionidae and other parasitoids, where the object of the association is to reach the freshly laid egg mass for oviposition (Clausen 1940/62)

 

 

---------------------------------

 

     Muscidae. -- The house flies, face flies, horn flies, stable flies, tsetse flies and little house flies are all serious pests of humans and animals.  The family may be identified by fleshy lobes, called squamae, located underneath the halteres on the sides of the thorax.  Many species are also identified by chaetotaxy (arrangement of hairs on the body)

 

          The importance of this family as serious pests and vectors of diseases has led to several biological control projects to contain them (see bc-37.htm).

 

          The housefly, Musca domestica L. lays its eggs in decaying vegetable matter or animal excrement.  .  The legless larvae are maggots with mouth hooks, caudal and thoracic spiracles.  Their filthy habits of regurgitating saliva and food cause them to be vectors of typhoid, cholera, and dysentery. etc.  Either feces or regurgitations cause the flyspecks often found on surfaces.  Houseflies have been the target of biological control in California and elsewhere (see ch-50.htm)

 

 

          The stable fly, Stomoxys calcitrans (L.) can breed in vegetable matter.  The adult's mouthparts are of the biting type, and the adults resemble houseflies, but are grayer in color.

 

 

          The hornfly, Haematobia irritans (L.) is also similar to the housefly but much smaller.  It is a pest of cattle primarily and breeds in cattle dung.

 

          Tsetse flies, Glossina spp., are confined to the African Continent where they are vectors of trypanosomes that cause sleeping sickness and related diseases of humans and animals.  These large, noisy flies may cause severe bites on humans with resultant swellings.  In East Africa they are especially prevalent around streams.

 

          Little house flies, Fannia spp., breed in large numbers in animal dung, and are especially numerous around poultry farms where they breed in such high numbers as to invade surrounding areas causing annoyance to residents.  They appear as small houseflies hovering in huge masses.  They have been the target of biological control in California and elsewhere (see ch-50.htm)

 

---------------------------------

 

Mydaidae (= Mydidae). -- <Habits>; <Adults> & <Juveniles>  The Mydaidae is a small family of American and Australian dipterous insects containing the largest known two-winged flies.   There are about 471 described species.  Many of the species, in addition to their large size, are mimics of stinging insects, especially wasps.  Most mydids are found in arid and semiarid regions but may occur in other habitats as well.

 

 

 

          Not much has been reported on their biology, though Zikan studied the larvae of Gauromydas heros live in the subterranean detritus "pans" of Atta ants in southern Brazil, where they appear to be feeding on detritivorous Dynastinae (Coelosis spp.) larvae.  In North America Mydas brunneus, Mydas clavatus, and Mydas tibialis larvae are predatory on deadwood-feeding scarab beetle larvae (Osmoderma spp.) and can be found in standing and downed trees with extensive heart rot.  Others (e.g. Mydas maculiventris) are subterranean and feed on "white grubs" (Scarabaeidae: genus Phyllophaga) that attack the roots of grasses and could be potential biological control agents of white grubs in sod production areas.   Larvae may require two or three years to mature.   Adults of several species are avid flower visitors and act as pollinating agents. Rattlesnake master (Eryngium yuccifolium) is a favorite nectar source in the Midwest.  They are rarely  collected, as the adult lifespan is usually short.

 

---------------------------------

 

     Nemestrinidae. -- <Habits>; <Adults> & <Juveniles>  This is a rare family of Diptera, several species of which are known to parasitize larvae of Coleoptera and a few are internally parasitic on locusts.

 

 

 

---------------------------------

 

     Odiniidae. -- This is a small family of flies. There are about 58 described species but they occur in all the major biogeographic realms.

 

          Life histories are known for a few species of Odinia, and no biological information is available for the most of the family.  The larvae inhabit in the tunnels of wood-boring larvae of Coleoptera, Lepidoptera, and other Diptera where they feed as scavengers or predators of the host larvae.  One species, Turanodinia coccidarum Stackelberg, has been reared from the egg masses of the mealybug, Pseudococcus comstocki  Kuwana.

 

---------------------------------

 

     Oestridae (Gastrophilidae). -- The warble flies and botflies lay their eggs on the hair of the rear legs of animals.  The larvae burrow into the shanks, pass into the intestines, burrow through the intestinal wall and eventually come to lie in the back of the animal just under the skin.  This results in the hide being reduced in value because of ensuing fly exit holes in the back.  Pupation occurs in the ground.  Systemic insecticides have been used for control.

 

 

          Several serious botflies, Gasterophilus spp., are discussed as follows:

 

          Horse Botflies., -- These flies produce eggs that are swallowed by horses, after which the hatched spiny larvae attach themselves to the wall of the horse's intestines.  Horses lose energy and weight following infection.  The flies overwinter in their alimentary canal and the larvae mature in late winter or spring.  The maggots attach themselves to the stomach lining.  They detach in late spring and burrow into the soil to pupate.  Adults emerge in early summer but do not bite. 

 

 

          Common Botflies. -- Female flies can lay over 800 eggs on hairs in the upper portion of the front legs of animals.  The animal licks the area and the eggs hatch.  The larvae live a short while in the animal's mouth and then are swallowed.

 

          Throat Botflies. -- Eggs are laid on the throat, but stimulation by licking is not required here.  The larvae hatch out and crawl into the animal's mouth where they feed along the gum line.  Later the larvae enter the stomach where feeding continues.

 

          Nose Botflies. -- This is the most serious of all the botflies, although it is less common.  Eggs are laid on the upper lip of the animal.  Moisture there induces hatching.  The larvae then tunnel through the lips and into the mouth, causing severe soreness.  They are then swallowed and enter the digestive tract.  Control has involved keeping animals stabled during daytime, using repellent materials, sponging off areas with warm water and phenol, and providing internal dosages of carbon disulfide.

 

------------------------------

 

          Cattle Grubs and Ox Warbles (Hypoderma spp.). -- Included are the Heel Fly and Bomb Fly.  They are primarily pests of cattle, often infesting over 75 percent of a herd.  The animals will lose weight, the hides are ruined and milk production falls.

 

 

          During their life history in winter the larvae exist as cysts in the backs of animals under their hide.  They feed on secretions from the irritations they cause.  A breathing hole is cut through the hide.  Maturity is in late winter.  In springtime the larvae wiggle through the breathing hole and drop to the soil where they pupate.  Adult flies are found in pastures through the summer and into autumn. 

 

          Adult flies lay eggs on the belly or legs of the animals, which become very annoyed by their buzzing.  Bomb flies prefer to lay the eggs in sunshine on the belly and legs, while heel flies lay eggs in the shade on the heels.  Ensuing larvae of bomb flies go directly to the back of animals, while larvae of heel flies migrate to the gullet area to feed, after which they move up to the back.

 

          Sheep Nose or Bot Flies, e.g., Oestrus ovis L.) -- These attack sheep, goats, deer and rarely humans.  They are responsible for nasal infections, insanity, blindness and even death.  The larvae are deposited in the nostrils of animals after which they migrate to the brain area through the sinuses.  They remain several months in the area underneath the horns.  They then wiggle out through the nostrils and pupate in the ground.  Containment involves painting the animal's nostrils with a repellant, such as pine tar, and to run sheep into dark sheds in daytime at the worst time of the year.

 

 

---------------------------------

 

     Otitidae. -- (Ortalidae) <Habits>; <Adults> & <Juveniles>  Otitids are primarily plant feeders and are often scavengers in decaying plant materials.  However, Lopez (1934) gave a brief account of Elassogaster sepsoides Wlk. as a predator in egg capsules of the migratory locust, Locusta migratoria var. migratorioides R. & F. in the Philippines.  This species was considered as the most important of natural enemies attacking the eggs of Locusta in the islands.  In the insectary, maggots were found in egg capsules within one week after exposure to mated flies.  A maximum of 28 maggots were found in one capsule.  They were not believed to be limited in feeding to a single mass of eggs, but rather to move about in soil searching for others (Clausen 1940/62).

 

 

 

---------------------------------

 

Phoridae. -- <Habits>; <Adults> & <Juveniles>  Megaselia fasciata Fall is a well known parasitic species of Phoridae.  it is gregarious and internally parasitic of the pupae of many coccinellid genera in Europe (Lichtenstein 1920, Menozzi 1927).  The number of individuals developing in each host is dependent on the size, but 8-14 reach maturity in each pupa of Coccinella.  The parasitoid may sometimes act as an important natural control of the increase of these beneficial beetles, as shown by the fact that a parasitization of 48% has been noted on Adalia.  During oviposition the female stands transversely on the thorax of the freshly formed pupa and curves the ovipositor beneath it, and the eggs are laid externally in small clusters between the legs.  Sometimes eggs are also laid on the bodies of larvae that are approaching the time for pupation.  Embryonic development is well advanced at the time of oviposition, and hatching may occur within 3 hrs.  However, Lichtenstein (1920) noted that external incubation took 1.5 to 2.6 days.  The eggshells fall from the host soon after hatching, and thus there is no external evidence of attack.  The newly hatched larvae immediately penetrate the body at the base of one of the legs, and their ensuing development is very rapid.  Feeding is completed in 2-5 days, after which the larvae emerge through an opening between the head and thorax to enter the soil to pupate.  Parasitized pupae retain their normal form, although in death they assume an erect position which contrasts to the horizontal position of healthy pupae.  Female flies feed on body fluids exuding from punctures made with the ovipositor, a habit that seems closely associated with oviposition (Clausen 1940/62).

 

 

          Balduf (1928) found that oviposition of M. aletiae Comst. on Achatodes zeae Harr. usually occurs only when the larvae are sick or feeble, and the species is thus more a scavenger than a parasitoid.  Such larvae enter the body through the anal opening rather than by penetrating the integument.  The mass of larvae that develop causes the posterior 1/3rd of the host body to be much distended.  They enter the body cavity, and the store of adipose tissue is the principal food source.  The larval stage is completed in 11-15 days, and pupation occurs in the host tunnel.  With M. giraudii Egger, a parasitoid of the grasshopper Phasgoneura viridissima L. in Europe, an adult host, fully active at the time of capture, later yielded 12 mature maggots of Megaselia.  These emerged from a large opening in the integument at the side of the mesothorax.  Dissection of the host remains revealed that the muscular tissue of the thorax had been completely consumed (Timon-David 1938).

 

---------------------------------

 

     Pipunculidae. -- <Habits>; <Adults> & <Juveniles>  Pipunculids are primary, solitary endoparasitoids of homopterous nymphs and adults, especially cicadellids, fulgorids, cercopids and membracids.  Pipunculus is the dominant genus.  Perkins (1905e) studied the immature stages of Pipunculus sp. and Keilin & Thompson (1915a) of Ateleneura spuria Meig.

 

 

          During oviposition, the female fly pounces on the host nymph while it is feeding or resting on foliage.  It is then carried into the air.  During this time the parasitoid's abdomen is curved beneath the body and the ovipositor is inserted through the intersegmental membrane of the abdomen.  The egg is thought to lie free in the body cavity.  Clausen (1940) commented that there is no apparent proof for the assertion of several authors that oviposition in some species is external and that the young larva makes its own way into the host body.  Female ovipositors in this family are distinctly of the piercing type.

 

          There were only two larval instars of A. spuria recorded by Keilin & Thompson (1915a), the second having all the characteristics of a normal 3rd instar cyclorrhaphous larva.  The first instar is 1.0 mm. long and a bit elongate.  It bears a vesicle-like organ at the posterior end of the body.  The skin bears no sensory spines nor setae, and no tracheal system is distinguishable until late in the stage when the lateral trunks fill with air.  The second instar, or mature larva, is robust and oval in outline, with the caudal vesicle still present although reduced in size.  The anterior spiracles are elevated, and each has 4-5 openings.  The posterior spiracles, each with three openings, are also elevated and are situated at the lateral margins of a large, black, heavily sclerotized peristigmatic plate.  This single plate, on which both spiracles are borne, is typical of the family.

 

---------------------------------

 

Pyrgotidae. -- <Habits>; <Adults> & <Juveniles>  These flies are of medium to large size, with long often partly clouded wings.  They are solitary or gregarious internal parasitoids of adult scarab beetles.  Davis (1919) studied Pyrgota undata Wied., a nocturnal species attacking nocturnal hosts, Phyllophaga spp.  To oviposit, the female alights on the dorsum of a feeding beetle, causing the latter to fly.  At this time she inserts the ovipositor through the thin exposed integument of the abdominal dorsum.  Female beetles are more often attacked than males, and the host dies 10-14 days after parasitoid oviposition.  The puparium is formed within the dead host.  There is a single generation per year, and winter is passed as pupae.

 

 

          In India, Adapsilia flaviseta Ald. commonly parasitizes beetles of the genus Popillia (Clausen et al. 1933).  Adults are dirunal as are the ost.  Oviposition behavior is similar to Pyrgota undata, but male beetles are preferred (ca. 88%) early in the season.  Later only 60% of males are parasitized as their abundance diminishes.  Eggs hatch 3 days after oviposition, and the larval period is 12-15 days.  The beetle is killed by the parasitoid larva soon after its second molt, which is 12-14 days after oviposition.  There is a single generation per year, and hibernation occurs in the puparium within the bodies of dead host beetles in soil.

 

---------------------------------

 

     Rhagionidae. -- (Leptidae) <Habits>;  <Adults> & <Juveniles>  Rhagionidae or "snipe flies" includes two groups that have sometimes been assigned to the families Xylophagidae and Coienomyidae.  They are predaceous in both the adult and larval stages.  Adults are consistently predaceous, their prey being principally adults of other Diptera, and several species have been reported to have developed bloodsucking behavior.  Most are abundant only in very moist habitats, but some occur under arid conditions.  The larvae are usually predaceous, preying on a variety of insects and smaller animals (Clausen 1940/62).

 

 

 

---------------------------------

 

     Sarcophagidae. -- <Habits>; <Adults> & <Juveniles> -- The flesh flies are similar to Calliphoridae, but they are usually black or gray with stripes on their thorax.  Adults feed on sweet foods such as flower nectar, fruit juice and honeydew.

 

 

          Their larvae show diverse habits, but most feed on animal material, with many being scavengers.  Some species are scavengers, some are parasites of other insects and a few are parasites of vertebrates that develop in skin wounds.

 

---------------------------------

 

     Scatophagidae (Cordyluridae). -- Habits;   Adults   Juveniles -- Adult scatophagids are known as "dung flies," and some researchers include them with Muscidae.  Adults may be found in pastures and meadows, swarming over fresh bovine dung.  There are also scavenger species along coastal areas and arctic and boreal types (Cole 1969).  Adults of some species are predaceous on smaller Diptera, especially of families Bibionidae, Simuliidae, Anthomyiidae and Mycetophilidae.  Scatophaga stercoraria L. has been observed to suck the body fluids of its prey through a puncture made in the neck.  A few species attack Cicadellidae, and others are thought to be parasitic in caterpillars, although the latter records are in doubt (Clausen 1940/62).

 

---------------------------------

 

     Scenopinidae. -- <Habits>;  Adults> & <Juveniles>  There are few species known in this family, adults of which have been called "window flies."  Immature stages live in decaying fungi and wood and are at times found in furniture and beneath carpets.  A common species, Scenopinus fenestralis L., is found in carpets where it may prey on carpet beetle larvae.  Larvae of some species live in fungi and decaying wood, where they feed on other insects (Clausen 1940/62).

 

 

---------------------------------

 

Stratiomyiidae. -- <Habits>; <Adults> & <Juveniles>  In this family more than 1,502 species were known as of 2000.  They are distributed mainly in temperate and tropical zones.  Diagnostic characters include variously shaped antennae, usually with contiguous basal segments and a divergent flagella, the club often with aristate tip; wings with discal cell (1st M-2) small; branches of M more slender than those of R; the vein R branches are rather crowded toward costal margin.  The body is small, while the abdomen is usually as wide as the thorax, and frequently flattened.

 

 

 

          Immature stages of Stratiomyiidae are found in many and diverse habitats.  Some species are aquatic, feeding on algae, small Crustacea, etc.  Others live in decaying plant material.  A number of species are scavengers in the nests of insects, and a few are found beneath the bark of trees, where they feed, at least to some extent, on insect larvae.  Adult stratiomyiids usually are found on flowers.  The family is not of much importance in biological control  (Clausen 1940/62).

 

---------------------------------

 

          Syrphidae. -- <Habits>; <Adults> & <Juveniles> -- The Flower flies and Syrphid flies adults are heavy bodied and have larvae that are predators of aphids especially.  The larvae that frequent liquid animal dung are distinguished by having a rat-like tail.  The wing has a spurious vein that is not a true vein, but is very useful in distinguishing species.

 

 

          Adult syrphids are widespread in most habitats where they frequent flowers especially.  Their habit of hovering around plants often gives them appearance of wasps or bees, especially those that are brightly colored. 

 

          The larvae have variable habits and appearances.  Many species are predators of aphids while others occur in the nests of social insects such as termites, ants and bees.  Other species inhabit decaying vegetation and rotting wood or polluted aquatic habitats.  The maggots sometimes cause intestinal myiasis in humans.

 

---------------------------------

 

     Tabanidae. -- <Habits>; <Adults> & <Juveniles> -- The Horse flies and Deer flies are vicious biters, and they inject toxic saliva into their hosts. The larvae are aquatic and predaceous.  The adults may spread diseases such as tularemia and anthrax.  Control measures involve draining swampland where the flies breed.

 

 

---------------------------------

 

     Tachinidae. -- <Habits>; <Adults> & <Juveniles> -- The tachinid flies are a large family with representatives widespread in almost every habitat.  They are valuable in natural control because their larvae are parasitic on other insects.

 

 

          Tachinids tend to lay their eggs on the body of their host.  The larvae then burrow into the host to feed internally.  They leave the host to pupate.  Some species that lay their eggs on plant foliage give rise to flattened larvae that are known as planidia.  These remain on foliage until they are able to attach themselves to a host when it comes near.  In other species the eggs must be ingested by a host caterpillar before hatching.  These larvae then feed on the internal organs.

 

---------------------------------

 

     Tephritidae (Trypetidae). -- The fruit flies are a group that has many economically important species.  The apple maggot and Mediterranean fruit fly are just two examples.  The tephritids are fruit and vegetable feeders that may spread bacterial diseases to the fruit on which they feed.  Their picturesque wings, which bear dark areas, identify the adults.  Many species have been attacked with biological control because of the great difficulty in using other means of containment. (see bc-44.htm)

 

 

          The Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) has been imported repeatedly into North America and was twice eradicated in 1926 and 1956.   It attacks citrus and other fruits in subtropical areas.  Although California has experienced an incipient population through the 20th Century, there has never been damage to fruit reported there.  Climatic limitations have been thought to be the reason for this.  Nevertheless, there have been repeated eradication attempts with no data other than a reduction in bait trap collections following widespread insecticidal treatments.

 

          The Apple Maggot, Rhagoletis pomonella (Walsh) tunnels into apples and other orchard fruits, while some other species of Rhagoletis are serious pests of cherries (see ent181).

 

          The Oriental Fruit Fly, Dacus dorsalis Hendel, invaded Hawaii during World War II.  It caused widespread damage to fruits growing on the islands.  Biological control projects have been launched to control this pest (see ch-82.htm)

 

          The Walnut Husk Fly, Rhagoletis completa Cresson, invaded California from Texas causing widespread damage to the walnut industry.  Parasites from the Davis Mountains area of West Texas have been imported for biological control (see efl231).

 

---------------------------------

 

     Therevidae. -- <Habits>; <Adults> & <Juveniles>    This is a small family, the adults of which are predaceous mainly on other Diptera.  Larvae live in sandy soil where they feed on earthworms and various soft-bodied insects.  Larvae of Phycus brunneus Wied. occurring in bat dung in India feed on dermestid larvae (Isaac 1925).  However, Goetze (1932) questioned the supposed predaceous habit of therevid larvae when he noted that a rye field showed extensive root injury in which only therevid larvae were present in large numbers.  However, laboratory tests failed to confirm this kind of damage.

 

 

          Immature stages of Therevidae are similar to Asilidae.  First instar larvae are vermiform, with 20 apparent segments, due to "intersegments" between the first 6 true abdominal segments.  Prothoracic and caudal spiracles are present.  Mature larvae of Psilocephala sequa Wlk. are also elongate and bear spiracles at the posterior margin of the first thoracic segment and at the anterior margin of the 4th "segment" from the abdomen's end.  Pupae have heavily sclerotized processes on the antennal sheaths and at the base of each wing sheath.  Abdominal segments each have a ring of long spines at the posterior margin, and the final segment is developed into a pair of large, heavily sclerotized processes (Clausen 1940/62).

 

--------------------------------

 

     Misc. Orthorrhapha. -- <Habits>; <Adults>   Clausen (1940) noted that the families Blepharoceridae, Limnobiidae and Orphnephilidae are mostly aquatic in habit, with larvae feeding in part on minute organisms such as diatoms and on small Crustacea.  Adult Blepharoceridae feed extensively on midges and other small, soft-bodied insects.

 

= = = = = = = = = = = = = = = = = = = =

 

Diptera --Biological Control Projects (11.2% of total projects)

 

Apple Maggot, Rhagoletis pomonella (Walsh) <ch-5.htm>

Aquatic Diptera  <ch-118.htm>

Aquatic Midges <aqamidge.htm>

Bush Fly, Musca sorbens Wiedemann  <ch-119.htm>

Chironomid Midges, Chironomus spp. <ch-19.htm>

Chloropid Gnats (Hippelates, Leptoconops, etc.) <ch-20.htm>

Flies in Accumulated Wastes, Musca domestica L., Stomoxys spp.  <ch-50.htm><ch-50.ref.htm>

Flies in Field Dung, Musca autumnalis, Musca vetustissima, Haematobia spp. <ch-51.htm>

Fruit Flies, Ceratitis, Dacus, Rhagoletis, etc.  <fruit.htm>

Melon Fly, Dacus cucurbitae Coquillett <ch-73.htm>

Mosquitoes, Culex, Aedes, Anopheles, etc. <ch-74.htm>

Oriental Fruit Fly, Dacus dorsalis Hendel <ch-82.htm>

-------------------------------------------

 

Details of Insect Taxonomic Groups

 

          Examples of beneficial species occur in almost every insect order, and considerable information on morphology and habits has been assembled.  Therefore, the principal groups of insect parasitoids and predators provide details that refer to the entire class Insecta.  These details are available at <taxnames.htm>.

 

==============

 

References & <biology.ref.htm>, [Additional references may be found at:  MELVYL Library ]

 

            Introduction                                                                                                                                        Contents