File:
<orthoptera.htm> (Entomology), (Invertebrates), (General
Index)> <Invertebrate Bibliography> <Glossary> <Site Description>
< Home>
Entomology: ORTHOPTERA
& BLATTARIA 1 Kingdom: Animalia, Phylum: Arthropoda Subphylum: Hexapoda: Class: Insecta: Orders: Orthoptera
& Blattaria (Contact)
Please CLICK on underlined
categories to view and on included illustrations to enlarge: Depress Ctrl/F to search for
subject matter:
[Section includes new order Blattaria] The order Orthoptera
-- <Adults> & <Juveniles> --, meaning "straight-winged, are large insects
and among the most injurious of all insects.
They have biting mouthparts, and their hind legs have enlarged femora
for jumping. The fore wings are
straight and leathery and are modified as tegmina, which overlap each other,
while the hind wings are fanlike. The
cerci are unjointed and the pronotum has enlarged lobes that hide the pleural
wall. The ovipositor is well
developed, and there are specialized stridulatory organs. This
order includes grasshoppers, locusts and crickets. Among the grasshoppers are
the katydid
or long-horned grasshopper
Tettigoniidae= <Habits>; <Adults> & <Juveniles>
-- with large
sword-like ovipositors consisting of three pairs of valves borne on the 8th
and 9th abdominal segments. By means
of these the eggs, not enclosed in an ootheca, can be deposited in plant
tissues, on which these insects regularly feed. The antennae also are long,
often extending backwards beyond the apex of the abdomen. Stridulation is
brought about by rubbing a toothed ridge on the left tegmen against an
analogous region of its right counterpart. This latter has a smooth tense
membrane and acts as a resonator when the tegmina are in motion and the
noise, produced mostly at night, can be very loud. Auditory organs of some complexity are situated in each fore
tibia. The Mormon cricket, Anabrus simplex Haldeman, can be a serious pest of agricultural crops
in the Intermountain area of western North America. A miracle of sorts occurred in Utah where a serious outbreak of
these crickets was destroying agricultural crops, but which was significantly
reduced by seagulls (Larus californicus)
(Borror, D. J. et al. 1981).
The long established family name Gryllidae -- <Habits>; <Adults> & <Juveniles>
-- has been used for the true crickets, but current changes in classification does
not distinguish them as a clear taxonomic group (see Orthoptera
Classification). They more closely
resemble the long-homed grasshoppers in their antennae, ovipositor and
stridulatory apparatus, and appear to be directly related to them. Gryllus
domesticus, the house-cricket, competes with the
cockroaches for a place in domestic dwellings and leads there a similar life.
Gryllotaipa
gryllotaipa, the mole cricket, is subterranean in
habit. It is possible to estimate ambient
temperature from the rate of their crick crick chirps. [Also
see: Gryllacrididae
<Habits>; <Adults> & <Juveniles>
--]. Members of the Acrididae are noteworthy
for their gregarious and migratory instincts. A species, such as Locusta
migratoria, generally leading a relatively harmless existence as a
solitary grasshopper, may under certain conditions develop in inestimable
numbers which, after traveling long distances, invade cultivated districts
causing enormous harm. Thus in the case of Locusta migratoria, when
environmental conditions favor an increase in numbers, there is an usual
trend towards the production of swarming migrants, i.e. the gregarious phase.
The subsequent decline in numbers leads to the production of solitary
nonmigrants, i.e. the solitary phase. The two phases differ morphologically,
biologically and in distribution so markedly as to have been regarded as
distinct species. Between them are short-lived individuals that form a series
with no set characters, merging barely the gregarious phase at one end and
into the solitary phase at the other.
The Rocky Mountain
grasshopper of North America, Melanoplus
mexicanus, once had a migratory phase, which has since
disappeared. NEW
ORDER: Blattaria (Previously = Superfamily Blattoidea) These are the cockroaches, sometimes called "water bugs",
that have generalized biting mouthparts and a five-jointed
tarsus. They are considered as
probably the oldest group of present day insects. The anterior wings are narrower and stouter than the posterior
ones, which are more membranous and fold like a fan. Jointed cerci &
styles occur in adult males only. The
ovipositor is small or absent. The
metamorphosis is hemimetabolous. Eggs
are laid in beanlike capsules or oothecae that are produced by secretions of
female accessory glands. The female
may deposit these all at one time, or they may be carried around until they
hatch. Blatella germanica
Cockroaches are nocturnal in their habits and omnivorous. They are also gregarious.
The
Phasmatodea are the stick insects,
which resemble twigs or leaves of plants. They are vegetarian and their body
is very slender and long. They do not
have their hind femora enlarged and they do not jump. The tarsi are commonly 5-segmented. The body is elongated and sticklike and
the wings are either reduced or entirely absent. Their eggs are laid singly and there is no ootheca. Some tropical species are called "leaf insects"
because they are flattened and expanded laterally and usually have their hind
wings well developed. They do not
possess tympana and stridulatory organs, the cerci are short and have only
one segment, and the ovipositor is short and hidden. The walking sticks
of North America are slow moving herbivorous insects that occur on trees and
shrubbery. They can emit a strong
odor from glands on their thorax, which is a means of defense. They are also able to regenerate lost legs
to a great extent. At times their
populations can become epizootic on trees, which causes considerable damage. There is usually
only a single generation per year with an overwintering egg stage. Eggs may remain dormant into a second year
and frequently populations are only abundant on alternate years. During the 20th Century the
Chlorinated Hydrocarbons were widely used to control grasshoppers in North
America and Africa, where great damage was inflicted on agricultural crops. The Desert Locust, Schistocerca gregaria, of
Africa has been considered the most destructive insect in the world. It is responsible for periodic
famine. It migrates from central
Africa to more northern regions where the damage caused is severe. With the ban of these insecticides in
North America cultural means of control were substituted, which requires
plowing the fields before springtime. Cockroaches may be controlled with
poisoned baits, but sanitation is the most effective way to reduce their invasion
into home areas. However, neighboring
dwellings that harbor large populations of roaches may pose a threat because
they are able to travel through the sewer systems. ------------------------------- Orthoptera
--Biological Control Projects (1% of total projects) Cockroaches, Blatella, Blatta, Periplaneta, & Supella <ch-27.htm>
============== Borror, D. J., D. M. DeLong & C. A. Triplehorn. 1981.
An Introduction To The Study of Insects, 5th ed. Saunders Publ., NY.
827 p. |