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COLEOPTERA 1 Kingdom: Animalia, Phylum: Arthropoda Subphylum: Hexapoda: Class: Insecta: Order: Coleoptera (Contact) Please CLICK on underlined categories to view and on
included illustrations to enlarge. Also
view <Habits>; <Adults> & <Juveniles> for greater detail. Depress Ctrl/F
to search for subject matter:
Please CLICK on the following <Habits>; <Adults> & <Juveniles>
for greater detail. Coleoptera
include the beetles that have biting mouthparts; the fore wings are modified to form firm
elytra. The hind wings are membranous
and folded beneath the elytra, and they are usually reduced or absent. The prothorax is large and the mesothorax
is greatly reduced. They have
complete metamorphosis. The larvae
are campodeiform or eruciform or generally apodous.
The head of larvae is well developed and the mouthparts are of the
biting type, about like those of the adults. The most primitive larvae are
those of the campodeiform type
(as found among the Cicindelidae (tiger
beetles); Carabidae (ground
beetles) and the Staphylinidae (rove-beetles».
They are very active in movement and usually predaceous, with well-developed
antennae and mouthparts, and a cuticularized exoskeleton. In the eruciform type found among plant-eating
forms like the lamelllcom beetles, the legs are shorter, and the animal is
less active in its foraging for food, the body bulkier and cylindrical. In the apodous type that is found in the Curculionidae (the weevils), in which
not only are the thoracic legs are lost but the antennae and mouthparts are
reduced. Apodous larvae usually live
inside the soft tissues of plants or beneath the soil attached to roots.
The order has two principal suborders, the Adephaga and the Polyphaga. The Adephaga, are mostly carnivorous, and distinguished by filiform
antennae, a five-jointed tarsus, and a larva of the campodeiform type, with a
tarsus bearing two claws. To this group belong those families including the
large water beetle Dytiscus, the
ground beetles Carabus and Calosoma the tiger beetle Cicindela, and the aquatic whirligig
beetles Gyrinus (Borradaile & Potts, 1958).
The
other suborder, Polyphaga, includes
a large number of families grouped into several superfamilies, the members of
which show great variation both in form and habit. There is a tendency
towards reduction in the number of tarsal joints from 5 to 3, and though some
forms have filiform antennae, clavate (clubbed), geniculate (elbowed), and
lamellate (segments extended to form a 'book of closely arranged leaves or
lamellae) antennae occur, as in the Coccinellidae,
Curculionidae and Scarabaeidae respectively. Larvae vary from the campodeiform to the
legless grub, but where a tarsus is present it usually has only one claw.
The family Coccinellidae (lady-birds)
is of great importance, its members being carnivorous in young and adult
stages, aphids and scale insects are included in their diet. The beetle is
smooth and rounded, with the head concealed beneath the prothorax. The
four-jointed tarsus appears to have only 3 joints, due to the small and
hidden third joint, e.g. Coccinella. Novius
(Rodolia) cardinalis is a classical example of a predatory insect being
used in the biological control of the scale insect, Icerya purchasi, of citrus trees (Borradaile & Potts, 1958). ------------------------------------------ Morphology
& Habits of Coleoptera
The Coleoptera contain the largest number of insect species, with over
215,000 or over 40 percent of all known insects. Their habitats include ground litter, underneath rocks, in
logs, etc. They are adapted to almost
any environment on earth except the ocean and polar ice caps. Their feeding habits range from foliage
feeders to general predators.
The greatest variation is shown among the larval stages. Campodeiform larvae are very active, while
scarabaeid larvae are circular and occur in the ground. Elateriform larvae are long, straight and
heavily chitinized, while apodeus larvae have no legs at all. The pupae are of the exarate type and the
mouthparts are all mandibulate or chewing.
The fore wings are highly sclerotized to form elytra in which the
venation has been lost. The hind
wings with venation present are large and folded or tucked underneath the
elytra.
The general body form is shown in Fig. ent60:
The main taxonomic characters used for identification are the antennae
and the tarsal formulae (e.g., 5-5-5, 5-4-3, 3-4-4, etc.) ------------------------------------------ Subdivisions
& Classification of Coleoptera
Hundreds of years of collecting Coleoptera by enthusiasts and
specialists have led to great sophistication in classification. Some of the major groups are presented
here as of 2010, but these may be modified as more information is obtained
and disagreements among specialists are resolved. The following discussion includes only the most common or
important families of Coleoptera. For greater detail please refer to Borror
et al. (1989), and for an expanded treatment of Coleoptera taxonomy with 192
families noted please see <Coleoptera (All Families)>. Additional
information on <Habits>, <Adults> and <Juveniles> is included when available.
The two largest Suborders of Coleoptera are Adephaga and
Polyphaga. The Adephaga has the
smallest number of species. Here the
coxae divide the first abdominal segment.
This group is further divided into Geadephaga and Hydradephaga. The Suborder Polyphaga has the most
species and the coxae do not divide the first abdominal segment. The group is separated according to the
character of the Malpighian tubules, the spiracles on the eighth abdominal segment
and the urogomphi [Please see Glossary for explanation of structures].
Family Cupedidae. --
The reticulated beetles are a small group of
beetles all of which bear dense scales on their bodies. The elytra are reticulated and the tarsi
with five segments. The prosternum
reaches backward as a narrow structure that lies in a groove in the
mesosternum, similar to the click beetles.
Their habitat is primarily under the bark of trees.
------------------------------------------
Family Micromalthidae. --
The micromalthid beetles are a rare group with
only a few species occurring in eastern North America. Adults are small, 1.7-2.6 mm long,
elongated with parallel sides. Their
color is shiny dark with yellow legs and antennae. The tarsi have five segments.
The life cycle is unusual as the larvae are paedogenic, enabling them
to reproduce parthenogenetically, either viviparously or oviparously. Their habitat is in the decaying wood of
chestnut and oak. = = = = = = = = = = = = = = = = = = = Suborder: ADEPHAGA-- Geodephaga
Family Cicindelidae. -- <Habits>; <Adults> & <Juveniles> -- The tiger beetles are very
active and nervous beetles with diurnal habits. They are metallic in color and predaceous as both adults and
larvae. The larvae burrow in the
ground whre they hold themselves fast to their burrows by a hook on the first
abdominal segment. Larvae will leap
out after prey.
------------------------------------------
Family Carabidae. -- <Habits>; <Adults> & <Juveniles> -- The ground beetles are very
active and nocturnal. The bombardier beetle expels smoke when
frightened. Both adults and larvae
are highly predaceous.
------------------------------------------
Family Dytiscidae. -- <Habits>; <Adults> & <Juveniles> -- The diving beetles are mostly
predaceous. They are very rapid
swimmers. Their crescent shaped
mandibles are well developed.
Pupation is in an excavated cell in the earth adjacent to water.
------------------------------------------
Family Gyrinidae -- <Habits>; <Adults> & <Juveniles> -- The whirlygig beetles are
small, active beetles that make circular patterns on the water. Their eyes are formed in two parts: one eye is in the air and the other in the
water. They are gregarious and both
adults and larvae are predaceous.
= = = = = = = = = = = = = = = = = = =
Family Sphaeriusidae (Sphaeridae). -- The minute bog
beetles are tiny, their length being only 0.5-0.76 mm. They are oval, convex shining black
beetles that can be found in mud and underneath stones near water, among the
roots of plants and in moss. Their
tarsi have three segments and their abdomen is short and seems to have only
three segments. The first segment is
triangular, the second a narrow band and the third taking up most of the
abdomen. The antennae are short and
do not extend beyond the middle of the pronotum.
------------------------------------------
Family Hydroscaphidae. -- The skiff beetles are small and
only 1.4 mm long with three-segmented tarsi.
The elytra are short in the manner of the Staphylinidae. Antennae consist of nine segments with a
one-segment club. The abdomen has 6-7
visible sterna, the hind coxae are small and separated.
Their habitat is in filamentous algae that occur on rocks in
streams. There are very few species
known for this family. = = = = = = = = = = = = = = = = = = =
Internal morphology distinguishes this group of Coleoptera. The functional characteristics of the
eighth abdominal segment is used for distinctions with special functions
occurring in some species and in others there are none. The ninth abdominal segment may bear
well-developed cercal structures and urogomphi are present in some
larvae. Urogomphi are
fixed or movable cercuslike processes on the last segment of the larvae. Sometimes these are called pseudocerci or corniculi.
The Polyphaga are divided into an additional five Infraorders: (1) Staphyliniformia, (2) Elateriformia, (3)
Bostrychiformia, (4) Scarabaeiformia, (5) Cucujiformia, Infraorder:
Staphyliniformia
Family Staphylinidae. -- <Habits>; <Adults> & <Juveniles> <Identification> -- The rove beetles are
capable of effective flight even though the wings are extensively folded
under extremely short elytra. There
is a simiulated stinging mechanism on the abdomen.
The family is comprised of mainly predatory species, the importance of
which has been stressed for biological control (see <Staphylinidae>). ------------------------------------------
Family Histeridae. -- <Habits>; <Adults> & <Juveniles> -- The hister beetles are small,
0.5-10.0 mm long broadly oval insects that are usually shining black in
color. Their elytra are squared off
at the apex, which exposes one or two apical abdominal segments. They have elbowed and clubbed
antennae. The tibiae are dilated with
spines located the anterior ones.
These beetles are usually found around decaying organic matter in
animal dung, carrion, where they feed on other small insects. Some flat species are found under loose
bark of tree stumps and some live in ant or termite nests. There are also elongated or cylindrical species
found in galleries of wood-boring insects.
When agitated they may draw in their legs and antennae to become
motionless, as these appendages fit tightly into shallow grooves on their
ventrum. ------------------------------------------
Family Hydrophilidae. -- <Habits>; <Adults> & <Juveniles> -- The diving or water
scavenger beetles are often confused with the coleopterous family
Dytiscidae, although the latter have filamentous antennae instead of clubbed
antennae as in this group.
The antennae are used to trap air for these insects when they are submerged
under water. They contain hydrofuge hairs for this purpose. Air is also trapped underneath their
wings.
The adult hydrophilids are scavengers, but their larvae are very
common predators.
The legs are modified with hairs to facilitate swimming. A long spine, which is an elongation of
the prothorax, may prick one's fingers if handled and serves as a defensive
mechanism. ------------------------------------------
Family: Silphidae. -- <Habits>; <Adults> & <Juveniles> -- The carrion beetles are
quite large insects that may be brightly colored and inhabit areas around
dead animals. Their body is soft and
flat. The antennae are clubbed and the tarsi have five segments. Their size ranges from 3-35 mm.
Some species excavate the soil
beneath carcasses thereby accomplishing burial, which also has given them the
name "burying beetles."
After the carcass is buried the females lay eggs on it, and both
adults and larvae feed on the carrion.
Other species occur in fungi and in ant nests, and some species feed
on fly maggots that inhabit carrion. Borror et al. (1989) report that Nicrophorus spp.
larvae are fed carrion that is regurgitated by the parent beetles. = = = = = = = = = = = = = = = = = = = Infraorder:
Elateriformia
Family Elateridae. -- <Habits>; <Adults> -- Among the click beetles the
larvae do not have a closing mechanism for their spiracles. The clicking sound is brought about by a
ventral spine on the prothorax that is inserted in a groove in the
mesothorax. The head is very small,
and there is a much enlarged prothorax.
The larvae are mainly carnivorous, and require 3-6 years to complete
their life cycle.
Some click beetles produce light and are phosphorescent. These lights may flash on and off. Light production in insects involves a
complicated chemical process and the light is almost pure light, consisting
of 98 percent light with only two percent heat.
Much attention has been paid to controlling elaterids. Over planting a field allows for some
destruction by the larvae. Seed treatment
with chemicals has been effective and is inexpensive. Soil treatment is effective and endures
for four or five years. Crop rotation
is a very effective control measure, and although trap cropping has been used
it is not very effective. ------------------------------------------
Family Buprestidae. -- The flat-headed borers
have various metallic colors and very hard bodies. Their antennae are serrate.
The larvae feed on wood exclusively and they are easily recognized by
their very much enlarged prothorax. They mine in the cambium layer and
thereby girdle trees.
The Flat-headed Apple Tree Borer overwinters in
the larval stage. Adults emerge in
springtime and there is one generation per year. Control of this beetle has deployed wrapping a tree's trunk
with paper, fumigation and spraying before the beetle has had a chance to
attack the trees. ------------------------------------------
Family Cantharidae. -- <Habits>; <Adults> & <Juveniles> -- The soldier beetles are
powdery in appearance. The tarsal
formula is 5-5-4. The larvae are
predaceous, feeding on corn borer larvae for example. Adults feed on flowers and pollen and thus
are effective pollinators, especially on such valuable crops as alfalfa in
Midwestern North America.
= = = = = = = = = = = = = = = = = = = Infraorder: Bostrichiformia
Family Dermestidae. -- <Habits>; <Adults> & <Juveniles> -- The carpet beetles and buffalo moths have larvae with a tapering tail and they
are studded with hairs in a "fishlike manner." They are serious pests of stored products,
museum specimens, woolens, grain, feathers, etc.
Dermestids have extreme durability and can withstand long periods of
dryness and an absence of food. They
may go through "regressive molts"
thereby decreasing in size.
Fumigation has been an effective control procedure.
The Khapra beetle, Trogoderma
granarium Everts, a native of India, is a very important
economic pest where it occurs. It
dees on any stored produce. Although
it does not fly it spreads by clinging onto containers. When it entered North America a grand
scale eradication effort eradicated it. ------------------------------------------
Family Bostrichidae. -- The shot-hole borers have a
head that is turned down underneath the prothorax, which is enlarged. They feed on wood products. The lead cable
borer or short-circuit borer bores into
lead cables even though it does not feed on the lead.
------------------------------------------
Family Anobiidae. -- <Habits>; <Adults> <Juveniles> The drugstore beetle
is similar in appearance to the Bostrichidae, but it prefers to feed on
tobacco and other stored products in drugstores. It also bears the name "death
watch beetle," which is taken from the habit of making noise while
boring in wood of churches during wakes, etc.
= = = = = = = = = = = = = = = = = = = Infraorder:
Scarabaeiformia
Family Scarabaeidae. -- <Habits>; <Adults> & <Juveniles> -- The June beetles have larvae
that are curved and adapted to movement in the soil. Their head is heavily sclerotized, but
their body is only lightly so, and they are often referred to as white grubs. The
antennae are lamellate.
Adults fly at night to feed on newly developing leaves of trees
thereby causing serious damage. The
larvae do serious damage to roots of crop plants. They usually build up their numbers in sod and will attack row
crops if these are planted to the site the following year.
Life Cycle: A complete cycle
takes three years. The last winter is
passed as adults in cells in the ground.
Most damage is done in the second year. There are three broods present, one being more serious than the
other two.
Example Species: The Japanese Beetle, Popillia
japonica Newman,
was introduced into North America from Japan in 1916 on nursery
plants. It is not an important pest
in Japan because of natural enemies.
Adults feed on foliage and fruit.
They are quite attractive insects with a bright green head and thorax
and brown tinged with green elytra and white spots along the abdomen
sides. There is one generation a year
and overwintering is in the larval stage in soil.
A soil bacterial disease has effectively controlled this beetle to
some extent. It is most prevalent in
Eastern North America in areas with high annual rainfall.
The Tumble Bug or Dung Beetle
also bears the name of "Sacred Scarab" in
Egypt. These insects accumulate a
mall of manure upon which they lay an egg.
The ancient Egyptians believed that the beetle represented the sun and
the manure the earth, the rolling of the earth from sunrise to sunset being
symbolic. The 5-5-5 tarsal formula
represented the 30 days of the month (15 days on each side of the
beetle). The rays on the back stood
for the sun's rays. They were in
error because they believed that only males were present. The soldiers of ancient Rome used the
beetle as a symbol for their shields in battle. = = = = = = = = = = = = = = = = = = = Infraorder:
Cucujiformia SUPERFAMILY: Cleroidea: All members of
this group have I & II instar triangulin larvae. They hare highly motile and shaped like
Thysanura. They have a hypermetamorphosis.
Family Trogossitidae ( = Ostomatidae).-- <Habits>; <Adults -- Bark gnawing beetles are elongated with a head about as wide
as the pronotum, and the pronotum widely separated from the base of the
elytra. They are oval or elliptical
in shape with the head only half as wide as the pronotum. They resemble the Nitidulidae somewhat.
Many feed on other insects or on fungi under tree bark. Some species feed on insects in grain and
on the grain itself. ------------------------------------------ Family Cleridae. -- <Habits>; <Adults> & <Juveniles> -- The checkered beetles are
pubescent in appearance. Both the
larvae and adults are predaceous.
They are elongated insects, 5-12 mm. long, and many have bright
colors. The pronotum is frequently
narrower than the base of the elytra and sometimes narrower than the
head. The tarsi have five segments,
but in many the first or the fourth segment is very small. The antennae are usually clubbed, but
sometimes serrate, pectinate or infrequently filiform.
They occur on or within tree trunks and logs where they prey on the
larvae of other wood boring insects, mainly bark beetles. Other species occur on flowers and foliage. Some feed on pollen. One species is known to feed on stored
meats. ------------------------------------------
Family Melyridae. (= Malachiidae) -- <Habits>; <Adults> -- The soft-winged flower
beetles are elongated, oval and soft bodied insects of 10 mm. in
length. Many species are brightly
colored with brown or red and black.
Some have strange orange colored structures along the abdomen sides
that may be everted and saclike or withdrawn into the body. In some the two basal antennal segments
are enlarged.
Most adults and larvae are predaceous, with many being common flowers
where they may come in contact with their prey.. SUPERFAMILY: Cucujoidea are flat compressed beetles with brilliant colors. They all have long prominent
antennae. Most families are
rare.
Family Cucujidae (Incl. Passandridae). -- <Habits>; <Adults> & <Juveniles> -- The flat bark beetles are found
under the bark of deciduous tree logs.
Some species are 13 mm. long.
Some genera have the maxillae concealed by large plates that are
formed by the genae on the ventral side of the head.
Most cucujids are predatory on mites and small insects, while others
are parasitic as larvae on species of Cerambycidae and Braconidae. They have a hypermetamorphosis. A few species are destructive to stored
grain such as the saw-toothed grain beetle, Oryzaephilus surinamensis (L.). ------------------------------------------
Family Coccinellidae. -- <Habits>; <Adults> & <Juveniles> -- The ladybird beetles are
primarily predators of aphids both as larvae and adults. The species are distinguished by the
pattern of spots on their elytra.
When they are effective in biological control there must be a close relationship
with the host species, otherwise introduced ladybirds will simply fly off the
premises. However the cottony-cushion
scale that invaded California citrus was controlled effectively by a
host-specific coccinellid, Rodolia (Novius) cardinalis (see Vedalia beetle) Notwithstanding these scientific facts,
they are often sold by plant nurseries for their unproven value as insect
controls.
The Mexican bean beetle, Epilachna
varivestis Mulsant, is an exception to the group in that it is
very destructive to agricultural crops in some areas of North America. Native to Mexico the beetle attacks bean
crops primarily, but sometimes cowpeas and soybeans also. After invasion from Mexico the beetle stayed
in southern Arizona for about 30 years, but by 1920 it began to spread
eastward.
Overwintering is as an adult in protected spots. In springtime the eggs are laid in plant
foliage. The larvae are a fuzzy yellow,
and they feed for 2-5 weeks on foliage.
There are 1-5 generations per year, with most damage being caused in
July and August. Control has
stressed insecticides. ------------------------------------------
Family Rhizophagidae (Rhizophaginae). -- <Habits>; <Adults> -- The root-eating beetles
are small and about 1.4-3.2 mm long.
The antennae have 10 segments with a club. The last tarsal segment is elongated. The tip of the abdomen projects beyond the elytra. The pygidium is exposed and the first
visible abdominal sternum is about as long as sterna 2-4 combined.
These beetles are found underneath bark or in rotting wood, with a few
species living in ant nests and some in bark beetle galleries where they feed
on the eggs and larvae of bark beetles.
. ------------------------------------------
Family Nitidulidae. -- <Habits>; <Adults> & <Juveniles> -- The sap beetles vary much in
size, shape and habits. Most species
are 12 mm or less in length. The
antennae usually have a three-segmented club.
Their habitat is around fermenting plant material, such as decaying
fruits. Some occur around animal
carcasses. Others are common around
flowers, underneath loose bark of dead trees in humid environments. The name "picnic
beetles" has been given to them when they are annoying around such
outdoor events. One species, Carpophilus lugubris Murray, the dusky sap beetle, is a pest of sweet corn. The larvae feed on corn kernels and can be
missed during canning operations. ------------------------------------------ SUPERFAMILY: Chrysomeloidea:
Family Chrysomelidae. -- The leaf beetles are related to the Cerambycidae with a
similar tarsal structure. They are
all pests of agricultural crops and the most serious crop feeders of the
Coleoptera. However, they have much
shorter antennae and are smaller than the cerambycids. The adults feed mainly on flowers and
foliage. Some larvae feed on the
surface of plant foliage, while others are leaf miners or feed on roots or
bore into stems. Overwintering is in
the adult stage. Borror et al. (1968) describe in great detail the various subfamilies of
this group.
The Colorado Potato Beetle, Leptinotarsa
decemlineata (Say) is a notorious pest everywhere east of the
Rocky Mountains in North America.
During World War II the United States was accused of introducing this
beetle into Germany. In 1854 it was
the first economic pest of potatoes in North America although it also attacks
tomato and tobacco. It feeds on the
terminal growth of plants and overwintera as an adult in the soil. In springtime the adults feed on residual
tuber shoots. The eggs are laid in a
cluster on the undersides of leaves.
There are two generations per year.
The beetle occurred naturally on wild host plants, but preferred potatoes
when these were introduced. The first
use of an arsenical insecticide, Paris Green, was used
to control it. One company sold a
phony control device, which consisted simply of two boards that were to smash
the beetles.
Flea Beetles, Epitrix spp., cause shot-hole damage
to plant foliage. Damage is most
severe on seedling plants, and only the veins of the lower leaves especially
remain after feeding. With a well
developed femur on the hind legs they are quite active by hopping about on plants.
The Striped or Spotted Cucumber Beetle,
Diabrotica
undecimpunctata howardi Barber, is a pest of squash and
pumpkin. It is necessary to plant an
abundance of seed per hill to compensate for those seeds that are eaten by
these beetles, although insecticidal control is often applied instead.
Some species have been used effectively in the biological control of
weeds, such as St. John's Wort or Klamath Weed (see ch-66). ------------------------------------------
Family Bruchidae. -- The seed beetles feed and pupate within legume seed as
larvae and can attack both in the field and in storage. They are sometimes referred to as
"weevils," the various species given the common name of the crop
they attack; eg., bean weevil, pea weevil.
They often contaminate dried beans and peas that have been packaged
for household use.
They are short, stout-bodied insects, most being less than 5 mm
long. The elytra are shortened and do
not cover the abdominal tip. Their
body may be narrowed anteriorly and is frequently gray or brown in
color. The head is projected forward
into a short broad snout. ------------------------------------------
Family Cerambycidae. -- The longhorn borers and round-headed
borers are pests in orchard and forest plantings. They tunnel into the trees and mine
directly in the heartwood. There are many species all of which are
phytophagous. They are elongated and
cylindrical with long antennae, and many species have bright colors. The tarsi have four segments with the
third segment being bilobed.
The brightly colored species feed primarily on flowers while the more
drab species are nocturnal. The
larvae bore into wood. A few species
attack living trees, but the majority prefer freshly cut logs or weakened and
dying trees and are frequently wrongly blamed for a forest's destruction,
which may be due mainly to environmental stress such as drought or air
pollution. Some girdle twigs. There is a two or three year life cycle, with
adults occurring in late summer. The Round-headed Apple Tree Borer, Saperda candida Fab., is an especially
important pest in North America.. Borror et al. (1968) describe in great detail the various subfamilies of
this group. ------------------------------------------ SUPERFAMILY: Curculionoidea:
Family Anthribidae. -- <Habits>; <Adults> & <Juveniles> -- The fungus weevils vary
considerably in size from 0.4-32 mm. The
antennae are not elbowed and some have slender antennae that extend beyond
the length of the body. The head is
extended interiorly into a broad muzzle.
The elytra cover the pygidium base which is partly exposed when viewed
from the side, but which is not visible from above.
The habitat of adults is in dead twigs or underneath loose bark. The larvae are found in woody fungi or in
fungi that occur on crop plants. Some
species feed on seeds and a few bore into dead wood. The Introduced coffee
bean weevil, Araecerus fasciculatus
(DeGeer) is a pest of seeds, dried fruits and berries. ------------------------------------------
Family Curculionidae. -- The weevils or snout beetles are the largest family of
Coleoptera.
Their head is projected into a long beak with antennae thereon. The mouthparts are located at the tip of
the snout. The lacinia and galea are
still separated.
All species are phytophagous, feeding
in seeds and fruit, but the adults usually feed only on plant foliage. Some species have larvae may that also
feed on roots and twigs.. Plum and
apple curculios are very important pests in North America as they tunnel into
the fruit as larvae. A characteristic
C-shaped slit is cut into the fruit with the snout, and an egg is then laid
therein.
The Alfalfa Weevil, Hypera postica (Gyllenhal), is a
serious pest of alfalfa in the Great Basin area of North America, ranking
high on the pest list with the spotted alfalfa aphid. Its origins are in the Mediterranean area
and was discovered in North America in 1904.
It is most serious on alfalfa, but will also attack clover.
The alfalfa weevil's color is dark gray with fine hairs on the
thorax. Adults begin to feed in
spring and lay eggs in the stems of plants.
One female may lay 500-600 eggs.
The larvae change in color from white to green and they take the form
of a curve without legs. The pupae
mature in June and July. The
generations vary with more produced in warmer climatic regions.
Control has stressed early harvest and the introduction of parasitic
insects.
The Cotton Boll Weevil, Anthonomus grandis
Boheman, is the most serious pest of cotton in North America that can
damage hundreds of millions of dollars worth of cotton each year. The larvae attack only cotton while the
adults attack related plants also, such as okra and hollyhock. This insect attacks both directly in the
larval and adult stage, and there is no recovery of the plant after attack.
The insect is native to North America. It overwinters as an adult in any sheltered place. In springtime it attacks the blossom bud
by depositing a single egg per blossom.
The larvae mature in three weeks, and there are 10 generations per
year.
Control of boll weevil has stressed cultural methods, such as early
planting and the destruction, but frequent insecticide applications have been
the preferred method.
White Fringed Beetles of the genus Graphognathus
are serious agricultural pests in humid areas of the southern United
States. They are usually about 12 mm.
long. They were introduced into
Florida around 1936 after which they spread northward. They are general feeders on over 172
species of broad-leafed plants.
Adults cannot fly but rather cling to moving objects. Their origin is in southern Argentina. Reproduction is by parthenogenesis, with
the female laying over 2,000 eggs in one generation per year.
Control of white fringed beetles has stressed rotation of broad-leafed
crops with grain, the treatment of soil with chemicals and mechanical
barriers. The Granary Weevil,
Sitophilus
granarius (L.) and the Rice weevil, S. oryzae
(L.) are small brownish insects that attack stored grain such as corn,
rice and wheat worldwide. Both adults
and larvae feed on the grain and the larvae develop inside the grains. The granary weevil attacks only stored
grain and does not fly, while the rice weevil attacks both in the field and
in stored grain, and it does fly. The
rice weevil has been considered the most important pests of grain.
The larvae complete development only on while grain. The female deposits one egg in one grain
kernel, and the life cycle lasts about one month. Adults can go without food for over three weeks.
Control of these granary weevils has stressed tight storage
containers, mechanical barriers and fumigation. Sometimes insecticides are also used. ------------------------------------------
Family Scolytidae (Scolytinae). -- The engraver beetles feed
in the cambium just under the bark of trees thereby causing girdling.
Their tunnels have characteristic patterns as shown in Fig. ent64:
Three genera, Dendroctonus,
Ips and Scolytus, are of great economic
importance. Ambrosia
beetles maintain fungus cultures upon which they feed. The fungi, often called blue stain or brown stain
fungi that are introduced by the adult beetles and spread by their
larvae, cause the death of infested trees.
Because the adults and larvae interrupt the flow of nutrients by
feeding in the plant phloem, the fungus spreads inward and clogs the water
transport vessels in sapwood, which suppresses the flow of lethal pitch into
the beetle galleries (Borror et al., 1968).
The destructive bark beetles show a high coordination of their flying
population in a synchronized mass attack, thereby overwhelming a tree's
defenses by their numbers. Both males
and females respond to a combination of odors from the resin of a host tree
and chemical signals from the first colonists. Therefore, thousands of beetles can infest the same tree all at
once. There are usually one or two
generations per year and overwintering is as mature larvae. Dutch Elm Disease fungus was introduced into North America in elm logs from
Europe, and within 75 years spread across the continent attacking the
American elm. The European elm was
desirable for its burls, which gave a good pattern to veneers used in the
furniture industry. By 2010 most
American elm trees had perished The vector Scolytus multistriatus (Marsham)
arrived with the logs and aided in the spread of the fungus.
Control of these beetles is primarily by rogueing out dead trees,
although insecticidal sprays have stopped the spread in some urban
environments. ------------------------------------------ SUPERFAMILY: Tenebrionoidea
Family Anthicidae. -- <Habits>; <Adults>
& <Juveniles> -- The ant-like flower
beetles are small, 2-6 mm long and resemble ants.
Their head is deflexed and constricted behind the eyes. The pronotum of many species has an
anterior hornlike process that extends over the head. They occur on flowers and plant foliage as
well as under stones and logs in debris.
A few species are found on sand dunes. ------------------------------------------
Family Meloidae. -- <Habits>; <Adults> & <Juveniles> -- The blister beetles are
parasites on the eggs of grasshoppers.
They are rather narrow and elongated, and their elytra are soft and
flexible. The pronotum is narrower
than either the head or the elytra.
Their name is derived from the fact that their body fluids contain
cantharadin, a chemical that can cause blisters when contacting the skin.
Some species are destructive pests of tomatoes, potatoes and other
crops. However, because the larvae of
many species feed on grasshopper eggs they are considered beneficial. Some species also live in bee nests as
larvae where they feed on bee eggs and on the food stored in the cells.
They have a rather complex life cycle with a hypermetamorphosis and
different larval instars are very different in appearance. The first triungulin larva usually climbs
on a flower and attaches itself to a bee that visits there. The bee then transports the triungulin to
its nest where the triungulin can attack the eggs. The second instar is similar to the triungulin but its legs are
much shorter. The third through fifth
instars become thicker and scarabaeiform.
The sixth instar has a darker exoskeleton and no functional
appendages. This instar is called the
coarctate larva or pseudopupa and it hibernates. The seventh instar is small, white and active, although it also
lacks legs and dos little if any feeding before pupation. (Please see Borror
et al., 1968 for further details). ------------------------------------------
Family Tenebrionidae. -- <Habits>; <Adults> -- The darkling beetles or mealworms are a varied group that is recognized by the
5-5-4 tarsal formula. The front coxal
cavities are closed behind and the eyes are frequently notched. The antennae usually have eleven segments
and are either moniliform or filiform.
There are five visible abdominal sterna. Most species are black or brown in color with a few having
additional red markings on their elytra.
Darkling beetles in drier areas occupy the habitat of the Carabidae
that are abundant in more humid areas.
They may be found under stones, trash and beneath loose bark, and they
are strongly attracted to light. Most
species feed on plant materials but a few are pests of stored grain. They are easily reared as food for
laboratory animals such as lizards, snakes, etc. ------------------------------------ Additional
COLEOPTERA Families Brentidae. -- <Adults> & <Juveniles>
Brentidae
is a cosmopolitan family of primarily xylophagous beetles also known as
straight-snouted weevils. The concept of this family has been recently
expanded with the inclusion of three groups formerly placed in the
Curculionidae; the subfamilies Apioninae, Cyladinae, and Nanophyinae, as well
as the Ithycerinae, previously considered a separate family. They are most
diverse in the tropics, but occur throughout the temperate regions of the
world. They are among the families of weevils that have non-elbowed antennae,
and tend to be elongate and flattened, though there are numerous exceptions.
The subfamilial classification of the family has been
reorganized by several different authors since 1990 and is not yet stable;
the most recent, and conservative, classification (Oberprieler et al., 2007)
accepts only 6 subfamilies, with many familiar subfamilial taxa (e.g.,
Antliarhininae, Cyladinae, Cyphagoginae, Myrmacicelinae, and Trachelizinae)
now relegated to tribal groups, primarily within the subfamily Brentinae. ------------------------------------------ Colydiidae. -- <Adults>
& <Juveniles>
Some species of "cylindrical bark
beetles" or Colydiidae feed solely on decaying vegetable matter, but a
number are predaceous on wood-inhabiting beetles, and some are
ectoparasitic. Bothrideres geminatus Say is a predator of mature larvae or pupae of
several Cerambycidae, and in one case several larvae were found within a pupa
of Chrysobothris sp. In the latter development was presumably
internal (Craighead 1920). Hopkins
(cited by Clausen, 1940) recorded B.
contractus as an external
parasitoid of Cerambycidae larvae. Bothrideres cactophagi Sc. is parasitic on prepupae of the large
cactus weevil, Cactophagus validus. Deretaphrus oregonensis Horn was found in pupal
cells of Asemum atrum Esch. in pine, the host larvae
being full grown before death (Craighead 1920). The mature larva of this parasitoid is very much modified
because of its host relationships (see Clausen, 1940 for diagram). The body is fleshy, fusiform and wide in
the mid-abdominal area. It has a thin
integument which is glabrous.
Mandibles are triangular and forked at the apex, and the ventral
mouthparts are fleshy and weak. The
legs are short, weak and widely separated.
Spiracles occur on the 2nd thoracic and 1st 8 abdominal segments. The dorsum of the 9th segment has a pair
of chitinous recurved hooks (Clausen 1940/62).
Dastarcus helophoroides Fairm. is an external parasitoid of the
mature larvae of Xylocopa appendiculata Smith in China (Piel
1938). The 1st instar larva is
elongated, indistinctly segmented and without spines or setae and has minute
rudimentary legs. Development is
completed in ca. 4 days. These larvae
were found on hosts that had been killed by mites and were already undergoing
decomposition, so that is was uncertain whether they were parasitic or
scavengers. Clausen (1940) believed
that the form of the larva would indicate that they were parasitic. ------------------------------------------ Dascillidae. --
<Habits> <Adults>
This family ranges throughout the Northern
Hemisphere and in Australia, but has not been found in Africa and South
America. The greatest diversity is in
Asia. Their length ranges from 4.3–26
mm. The body is slightly flattened to convex, with the sides of the body
being not evenly curved. Upper surfaces of the body are usually glabrous or
clothed with hairs, setae or scales.
The prothorax, metathorax and-or abdomen is without expressible
glands. The antennae are not geniculate; without an apical club, and thare
are 11 antennomeres. The sclerotized
labrum is usually visible. They have
a well-developed scutellum. The hind
wing is well developed and does not have a hairy fringe.
The grublike larvae of species of Dascillus and Notodascillus occur in the soil where
they are believed to feed on roots.. At least some species feed on subterranean
termites
The family has been broadly defined to include many taxa that are now
assigned to the Ptilodactylidae, Psephenidae, Artematopodidae and sine
Scirtidae. Crowson (1971). ------------------------------------------ Drilidae. -- <Habits> <Adults> & <Juveniles>
The larvae of Drilidae feed almost entirely on
snails. Some species show a
remarkable sexual dimorphism, the males being winged and females apterous and
larviform (Clausen 1940/62).
Drilidae oviposit in large masses in shallow burrows in the
soil. Females are able to produce
300-500 eggs, and sometimes the entire quota is laid in a single day. There is a large range in the
exceptionally long periods of incubation recorded for the different species,
varying from 6 weeks to 3 months. First instar larvae are similar in
appearance to the larvae of other Coleoptera. They are very active in their search for their snail prey. When a snail is located, the anal sucker
takes a firm hold on the shell. The
prey is then taken to some sheltered place, after which the larva enters the
shell. The snail's operculum often
proves to be a difficult barrier for the larvae. Feeding is gradual as compared with lampyrid larvae on the same
hosts, and the snail may not die for many days after the larva has entered
the shell. There do not seem to be
any digestive juices or toxic fluids introduced into the snail's body during
this early feeding. The mature larva
is greatly distorted and twisted, due to confinement in a spiral cavity. Drilus
flavescens Rossi appears to
have a distinctive resting stage, induced by adverse conditions such as food
shortage and adverse weather, which is comparable to the coarctate stage of
Meloidae (Crawshay 1903). The
integument of this stage is thin, nearly white, and largely bare, and the
head and body appendages are rudimentary.
They return to the active feeding stage when favorable conditions
prevail. Pupation is within the
snail's shell. The life cycle from egg to adult
takes 3-4 years; during which time 2-4 snails may be consumed each
season. The larva molts after
completion of feeding on each host and immediately before it abandons the
shell. Adult beetles appear in late
spring and early summer (Clausen 1940/62).
Early accounts of the life history and behavior of D. mauritanicus
Lucas and Malacogaster passerinii Bass were given by Cross
(1926, 1930). ------------------------------------------ Ectrephidae. -- <Habits>; <Adults> These beetles are related to Anobiidae or part of them. Species are 2-7 mm long beetles with
elytral length 1.4-5 mm. The base of
the prothorax is not or scarcely narrower than the combined elytral
bases. Beetles are prognathous. The eyes are protuberant and not very
pubescent. A trilobe form with median
lobe long, slender and tubular. The
lateral lobes are long and thin, the rounded tips having hairs. Habitat is in decaying plant material or
under bark or in stored plant products.
They feed on dried animal remains or consume decayed plant material or
other. They may bore into live
wood. Some are destructive to
structural timbers and furniture
------------------------------------------ Eucnemidae. --
<Habits> <Adults>
Eucnemidae occur in all major regions of the
world, although many species are rare in collections.
Adult Eucnemidae are found on the surface of plants, around lights at
night, or in flight-intercept traps. Larvae of most species may be found in
dead wood and are able to move through solid wood, but some are soil
inhabiting as well. The larvae feed
on plant juices and possibly on Myxomycete organisms. ------------------------------------------ Haliplidae. --
<Habits> <Adults> This
family of water beetles swim with an alternating leg motion, but usually move
by crawling. There were ca. 205
species in 5 genera identified by 2011.
They occur in freshwater habitats.
They are also called crawling water beetles.
Adults are usually oval in shape, with a convex
upperside. The size ranges from 1.4–5.2
mm long. The color is yellowish or light brown, often with light and dark
dots. There are usually 10 rows of
punctures on the elytra. The species have large immobile coxal plates on the
hindlegs, which are used for storing air and to add to the air carried under
the elytra. There are protruding
compound eyes and a rather small head, which 11-segmented antennae with a
short scapus. The legs bear long swimming hairs on tibiae and tarsi, but are
not flattened. The hindwings are not
folded under the elytra, but rolled together apically. The larvae have a long
and thin body with a tough integument. They also have specialized mouthparts
that are carried on a small head. The maxillae and labium are adapted for
feeding on algae, while the mandibles contain a channel through which fluids
are sucked. The larval legs are short and have a single claw each, but the
forelegs are adapted to climbing on aquatic plants. There are gills for
respiration. The final instar has functional spiracles on the mesothorax and
the first to seventh abdominal segments. The principal habitat is in aquatic
vegetation around small ponds, lakes, and still streams. Adults are
omnivorous, eating insect eggs, small crustaceans, hydrozoan polyps, and
algae, but the larvae eat only algae. There are three larval instars, and
pupation is on land in a cavity constructed by the larva. ------------------------------------------ Helodidae <Habits>
<Adults>
&<Juveniles> Larvae of marsh
beetles, Helodidae are aquatic and are known to feed on other insects
(Clausen 1940/62). They occur on vegetation
in swamps and in damp rotting trash.
Some species have large hind femora, which are used for jumping. The larvae have long slender antennae.
------------------------------------------ Hygrobiidae. --
<Habits> <Adults>
<Juveniles> Hygrobiidae is a small
family that is closely related to Dytiscidae. They are aquatic, living in ponds rather than streams. Food preferences of Hygrobia hermani F. (= Pelobius
tardus Hbst.) were studied by
Balfour-Browne (1922a). Adults are
found in mud at the bottom of ponds, and females lay their eggs in rows on
the submerged stems of aquatic plants.
The larvae feed on worms and the immature stages of the less active
aquatic insects. The mature larva
leaves the water to pupate, and forms a cells in the soil 5 cm. or more
beneath the surface. A single
generation occurs annually, and overwintering is as adults in the mud at the
pond bottom (Clausen 1940).
------------------------------------------ Lampyridae. --
<Habits> <Adults>
& <Juveniles> Members of this family
are the fireflies or glowworms, which are found worldwide, being conspicuous
because of the luminescence produced by certain organs. All stages show luminescence; even the
eggs have a faint glow due to the material with which they are coated at the
time of oviposition. Several species
are diurnal and have the luminescence organs only slightly developed or
entirely lacking. Females of most
species are wingless and somewhat larviform and of much greater size than
males. A few species are considered
phytophagous as adults (Williams 1917), although the majority, both adults
and larvae, seem to limit feeding to snails, with some evidence that cutworms
and earthworms also form part of the diet.
The amount of food consumed by the larvae is much greater than that
consumed by adults, with many of the latter not feeding at all. Larvae are thought to inject a powerful
toxic agent into the body of the snail host, for death occurs quickly after
attack, even though the mechanical injury is usually very light (Clausen
1940/62). ------------------------------------------
Lathridiidae. -- <Habits>
<Adults>
& <Juveniles> These
are called "minute brown scavenger beetles," which are found in
moldy places and debris and occasionally on flowers. Adults of Enicmus
minutus L. feed extensively on
the beech scale, Cryptococcus fagi Baer, in England. The South American Coccidophilus citricola Brethes, is predatory in its active stages on
diaspine Coccidae (Flanders 1936b).
Females lay their eggs beneath the host scale covering, and hatching
occurs in 8-9 days. The larvae feed
for 10 days, but the stage persists for 13-20 days. They pupate in crevices, and adult beetles emerge 5 days
later. The life cycle from egg to
adult is 27-35 days at 24-27°C. (Clausen 1940/62).
Latridiidae is a family of very small (1.1-3.4 mm) mycophagous and
myxomycophagous beetles. At present, the family includes 35 genera and
approximately 1100 species (including fossil taxa). Latridiidae is
divided into 3 subfamilies (2 extant and 1 extinct): Latridiinae,
Corticariinae and Tetrameropsinae. Although latridiids are best known
from the temperate regions of the world, the family is truly cosmopolitan
with several genera widely introduced as stored product pests (e.g., Corticaria, Melanophthalma,
Latridius).
------------------------------------------ Leptinidae. --
<Habits> <Adults>
& <Juveniles> These "mammal
nest beetles," are sometimes parasitic on ants. It is very small family, closely related
to the rove beetles. The various
species live in the nests or ectoparasitic in the fur of small mammals
(mostly rodents, e.g. beavers, shrews and moles). They feed on on other
insects or mites. Two species in Europe are, Leptinus
testaceus (on small rodents)
and Platypsyllus castoris (on
beavers). Both lack eyes and are
adapted to the life in the fur of their host. The family includes four genera
with palearctic, nearctic or holoarctic distribution.
------------------------------------------ Lycidae. --
<Habits> <Adults> These are also known
as the "net-winged" beetles."
The species are elongated
and usually found on flowers or stems. Adults of some species feed on nectar
while some adults are short lived and may not feed at all. The head is
triangular and the antennae are long, thick, and serrated. Most dark reddish
in color. They are toxic to predators which gives them protection. The predaceous larvae grow under bark or
in leaf litter.
------------------------------------------ Melandryidae. --
<Habits> <Adults> The species vary from 3.2–16
mm long. Both larvae and adults are probably
not predacious but rather prefer to feed on vegetation, rotting wood and some
fungi that occur in older wood.
The base of the prothorax is usually narrower than the combined
elytral bases, or much narrower than the combined elytral bases. The greatest prothoracic width is not
narrower or only slightly narrower than the greatest elytral width, or
distinctly narrower than greatest elytral width. These beetles have an
elongated oval shape. There is no "neck" and their waist is either
not present or barely visible. The
top surfaces of body may be glabrous in some species. There are neither bristles nor setal
scales present. The
species are not prognathous, and the eyes do not protrude. The variable sized filiform antennae have
10-11 segment and are not housed in a notch but they may have bristles. The scape is not swollen. Antennal insertions are either visible or
not, but they are not hidden by lateral extensions of the frons. The mandibular prosthecae is well developed. ------------------------------------------ Mordellidae. --
<Habits> <Adults> <Juveniles>
Certain species of Mordellidae have been
reported predaceous on larvae of stem- and wood-boring insects, even though
there is some disagreement among researchers (Clausen 1940/62). Hill (1922) found larvae of Mordellistena erythroderes Hill in termite nests. He asserted that they are predaceous on
these insects. Clausen (1940) citing
Balduf, noted that the form of the larvae in this family is not one which
would be adapted to an aggressive life style, such as a predator, however.
------------------------------------------ Mycetophagidae. -- <Habits>
<Adults> <Juveniles> The
"Hairy Fungus Beetles: are broadly oval, flattened and quite hairy. They range from 1 to 6 mm long and are
either brown or black in color and frequently brightly marked with red or
orange coloration. They occur under
bark, in shelf fungi and molding vegetable matter.
------------------------------------------ Ostomatidae. -- <Habits>searching;
<Adults> The family includes species that are useful predators of destructive
bark beetles, consuming all life stages.
They live underneath the bark of trees and in higher fungi and dry
vegetation.
------------------------------------------ Ostomidae. -- These are the "Bark Gnawing Beetles." To estimate the
influence of N. elongatum on
bark beetle (Pityogenes chalcographus),
regulation information about the biology of this species was necessary. In
the laboratory, embryonic development depended on temperature and averaged 12
days at alternating temperatures (25/15°C), mean duration of the
postembryonic period was 58 days at this temperature. Prey consumption of the N. elongatum larvae was 30 bark beetles (larvae, respectively,
pupae) per individual. Adult
longevity averaged 3–5 months and mean fecundity was 63.6 eggs per female at
alternating temperature (20/10°C) and 58.4 eggs at constant temperature
(22°C). The prey consumption of the N. elongatum imagines also depended on
temperature. At alternating temperatures (20/10°C) the mean prey consumption
was almost one bark beetle adult per day.
These data suggest that this predator should be considered as an
important and effective antagonist of Pityogenes chalcographus.
------------------------------------------ Paussidae. --
<Habits> <Adults>
A
family of small beetles that are related to the Carabidae. They live in ant nests and have thick
antennae with the joints fused to form a large club. These beetles are difficult to locate
whilst their association with ants in their nests. They possess glandular hairs that give secretions, which the
ants covet. The pygidial glands give
off explosive secretions, which is why they are sometimes called
"Flanged Bombadier Beetles".
Their biology has not been thoroughly studied, but it seems that the
ants gain little from their association.
Although the beetles will feed on ant eggs, larvae and adults they are
still tolerated by the ants.
Stridulatory structures include alary-elytral, abdomen-femur and
thorax-femur combinations of surfaces.
------------------------------------------ Phalacridae. --
<Habits> <Adults> These are called the
"shining flower beetles," which are common on goldenrod flowers and
other composites. Their larvae
develop in the flower heads. Eustilbus apicalis Melsh is a common predator of the pea aphid, Illinoia pisi Kalt. in Wisconsin.
These beetles were especially abundant in alfalfa fields where younger
aphids were most frequently attacked (Fluke 1929).
------------------------------------------ Phengodidae. --
<Habits> <Adults>
<Juveniles> One American species, Phenogodes sp., is known to prey on
myriapods. In other species both the
larvae and adults have light-producing organs (Clausen 1940/62)
------------------------------------------ Pselaphidae. --
<Habits> <Adults> The
"Short-Winged Mold Beetles are small yellowish or brownish, 1/2 to 6 mm
long and may be found under stones and logs in rotting wood and in moss. Several occur in ant, termite and mammal
nests. They have short truncate
elytra and are similar to rove beetles but with only three tarsal
segments. The pronotum is narrower
than the elytra, and the antennae are generally clubbed. This is a la large group with over 500
species found in North America. Some
species have two-segmented antennae and their tarsi with only one claw. They occur in ant nests where they are
kept by the ants for a coveted secretion.
------------------------------------------ Pythidae (= Salpingidae) <Habits>
<Adults>
<Juveniles> Clausen (1940) noted
that several species of this small family have been recorded as predators of
bark beetles in Europe. Some species
have very active larvae which are generally similar in form to those of
Carabidae
------------------------------------------ Rhipiceridae. --
<Habits> <Adults>
<Juveniles> The mature larva of Sandalus niger Knoch was taken from a pupa of Cicada that had constructed its
emergence burrow and reached the soil surface (Craighead 1921). it was thought to have developed as a
parasitoid, and its body showed modifications, such as a reduction in the
legs. The larva was robust and the
9th tergum had a sclerotized tip and bore a pair of broadly conical cerci.
------------------------------------------
Rhipiphoridae. -- <Habits>
<Adults>
<Juveniles>
Adult beetles are rather striking with a
markedly streamlined body, pectinate male antennae, but the color pattern of
many species is variable. Females of Macrosiagon pusillum Gerst. may be completely red or black, or the
thorax may be of one color and the elytra and abdomen of the other. Silvestri (1905) described the genus Rhizostylops as having certain
characters and habits that seem to place it as an intermediate form between
Rhipiphoridae and Strepsiptera, and the adult females bear a striking
resemblance to those of the genera Mengenilla
and Eoxenos of
Strepsiptera. Adult females of Rhizostylops as well as those of several
species of Ripidius are
apterous, degenerate and larviform (Clausen 1940/62).
All species seem to be parasitic,
passing at least a portion of the larval period internally in the host
body. This adaptation is virtually unknown
elsewhere in the Coleoptera.
Development is accompanied by a hypermetamorphosis that is comparable
with that in Meloidae and certain parasitic Staphylinidae. ------------------------------------------ Rhysodidae. --
<Habits> The "Wrinkled Bark Beetles" belong to a group that are slender, light brown in
color and 5 8 mm long with more or less deep longitudinal grooves on the pronotum
and with moniliform antennae. The
pronotal grooves are complete in some species but present on only about the
posterior one-third of the pronotum in others. They are usually found under the bark of decaying ash, elm,
beech or pine trees. Eight species
are known in the United States.
------------------------------------------ Throscidae. --
<Habits> A small group of only two North American species. They are oblong-oval, light brown in color
or even black. Most are 5 mm long or
less. They resemble Elateridae, but
are more oval shaped. Some genera have clubbed antennae. The prosternum is lobed anteriorly and is
quite strongly fused to the mesothorax.
Some are able to click and jump like elaterids. Adults occur mainly on vegetation and leaf
litter especially during cool weather.
They fly or climb onto vegetation in warm weather but are not
particular about the plant species.
------------------------------------------ Trogidae. --
<Habits> <Adults> Most
species are wingless or with reduced wings.
Several may be found in buildings, granaries, houses and barns. A few are the common booklice. The females may produce a sound by tapping
their abdomen on a hard surface.
------------------------------------------ Trogossitidae
(Ostomidae).
-- <Habits> <Adults>
------------------------------------------ Misc.
Families <General Habits> Clausen
(1940) reported on several families of Coleoptera that are associated in
varying capacities with ants, some are definitely known to be predaceous on
the ant broods, and others that are principally scavengers. These were Clavigeridae, Brentidae,
Pselaphidae, Leptinidae and Paussidae.
Park (1929) considered that Leptinus
testaceus Muell., and possibly the entire Leptinidae, exhibit a
facultative parasitism. Some
Brentidae and Cryptophagidae are found in bark and wood under conditions that
indicate they might be predaceous on other insects occupying the same
habitat. ------------------------------------ Coleoptera --Biological Control
Projects (11.2% of total projects) Alfalfa Weevil, Hypera postica (Gyllenhal) <ch-2.htm> Boll Weevil, Anthonomus grandis Boheman <ch-13.htm> Cereal Leaf Beetle, Oulema melanoplus (L.) <ch-18.htm> Coconut Leaf-mining Beetle, Promecotheca reichei Baly <ch-28.htm> Elm Leaf Beetle, Xanthogaleruca luteola (Müller) <ch-40.htm> Eucalyptus Pest Insects: Longhorn borers, Tortoise & Snout
beetles <ch-41.htm> Eucalyptus Snout Beetle, Gonipterus scutellatus Gyllenhal <ch-42.htm> Greater European Spruce Beetle, Dendroctonus micans (Kugelann) <ch-56.htm> Hispid Beetle, Promecotheca cumingi Baly <ch-62.htm> Japanese Beetle, Popillia japonica Newman <ch-65.htm> Rhinoceros Beetle, Oryctes rhinoceros (L.) <ch-93.htm> Sugar-cane Beetle Borer (Coleoptera), Rhabdoscelus obscurus (Boisduval) <ch-102.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>. ==============
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