COCKROACH AND ITS TYPESINTRODUCTION TO
COACROACHES:Cockroachesareinsectsof the orderBlattodea, sometimes
called Blattaria, of which about 30 species out of 4,600[1]total
are associated with human habitats. About four species are well
known aspests. Among the best-known pest species are theAmerican
cockroach,Periplaneta americana, which is about 30mm (1.2in) long;
theGerman cockroach,Blattella germanica, about 15mm (0.59in) long;
theAsian cockroach,Blattella asahinai, also about 15mm (0.59in) in
length; and theOriental cockroach,Blatta orientalis, about 25mm
(0.98in).Tropicalcockroaches are often much bigger, and, contrary
to popular opinion,extinct cockroach relativesand 'roachoids' such
as theCarboniferousArchimylacrisand thePermianApthoroblattinawere
not as large as the biggest modern species.The name "cockroach"
comes from the Spanish word for cockroach,cucaracha, transformed by
Englishfolk etymologyinto "cock" and "roach". The
termcucaracha(sp.cuca"bug", andraxa"streak" (modern Spanishraya))
originally was used for the wood louse (the sow bug), but later was
used to mean thepalmetto bug(the flying cockroach). It is from this
later Mexican usage that English-speaking Americans began using the
term for regular (non-flying) cockroachSCIENTIFIC
CLASSIFICATION
Kingdom:Animalia
Phylum:Arthropoda
Subphylum:Hexapoda
Class:Insecta
Subclass:Pterygota
Infraclass:Neoptera
Superorder:Dictyoptera
Order:Blattodea
NOTABLE SPECIESCockroaches are generally rather large insects.
Most species are about the size of a thumbnail, but several species
are bigger. The world's heaviest cockroach is the Australiangiant
burrowing cockroachMacropanesthia rhinoceros, which can reach 9cm
(3.5in) in length and weigh more than 30g (1.1oz). Comparable in
size is the Central American giant cockroachBlaberus giganteus,
which grows to a similar length but is not as heavy. According to
theGuinness World Records, the longest cockroach species
isMegaloblatta longipennis, which can reach 97mm (3.8in) in length
and 45mm (1.8in) across.[16]A Central and South American
species,Megaloblatta blaberoides, has the largest wingspan of up to
185mm (7.3in).[17]Cockroaches have broad, flattened bodies and
relatively small heads. They are generalized insects, with few
special adaptations, and may be among the
mostprimitivelivingneopteraninsects. Themouthpartsare on the
underside of the head and include generalised chewingmandibles.
They have largecompound eyes, twoocelli, and long,
flexible,antennae.The first pair of wings (the tegmina) are tough
and protective, lying as a shield on top of the membranous hind
wings. All four wings have branching longitudinal veins, and
multiple cross-veins. The legs are sturdy, with largecoxaeand five
claws each. Theabdomenhas ten segments and severalcerci Blattella
germanica, German cockroach Blaptica dubia, South American/Peruvian
Dubia cockroach Blatta orientalis, Oriental cockroach Blattella
asahinai, Asian cockroach Blaberus craniifer, true death's head
cockroach Blaberus discoidalis, discoid cockroach or false death's
head Eurycotis floridana, Florida woods cockroach Gromphadorhina
portentosa, Madagascar hissing cockroach Laxta granicollis, bark
cockroach Parcoblatta pennsylvanica, Pennsylvania woods cockroach
Periplaneta americana, American cockroach Periplaneta australasiae,
Australian cockroach1. GERMAN COCKROACHGerman cockroach
Scientific classification
Kingdom:Animalia
Phylum:Arthropoda
Class:Insecta
Order:Blattodea
Family:Blattellidae
Genus:Blattella
Species:Blattella germanica
Binomial name
Blattella germanicaLinnaeus,1767
TheGerman cockroach(Blattella germanica) is a
smallspeciesofcockroach, typically about 1.1 to 1.6cm (0.43 to
0.63in)[1][2]long. In colour it varies from tan to almost black,
and it has two dark, roughly parallel, streaks on
thepronotumrunninganteroposteriorlyfrom behind the head to the base
of the wings. AlthoughBlattella germanicahas wings, it can barely
fly, although it may glide when disturbed.[3]Of the few species of
cockroach that are domestic pests, it probably is the most widely
troublesome example.[4]It is very closely related to theAsian
cockroach, and to the casual observer the two appear nearly
identical and may be mistaken for each other. However, the Asian
cockroach is attracted to light and can fly rather like a moth,
which the German cockroach can not.Biology and pest statusBlattella
germanicaoccurs widely in human buildings, but is particularly
associated withrestaurants,food processingfacilities,hotels, and
institutional establishments such asnursing homes. In cold
climates, they occur only near human dwellings, because they cannot
survive severe cold. However, even though they would soon die in
the outdoors on their own, German cockroaches have been found
asinquilines("tenants") of human buildings as far north asAlert,
Nunavut.[5]Similarly, they have been found as far south as
SouthernPatagonia.[6]Previously thought to be a native of Europe,
the German cockroach later was considered to have emerged from the
region ofEthiopiain Northeast Africa,[7][8]but more recent evidence
suggests that it actually originated in Southeast
Asia.[4][9]Whatever the truth of the matter, the cockroach's
sensitivity to cold might reflect its origin from such warm
climates, and its spread as adomiciliarypest since ancient times
has resulted from incidental human transport and shelter. The
species now iscosmopolitanin distribution, occurring as a household
pest on all continents except Antarctica, and on many major islands
as well. It accordingly has been given various names in the
cultures of many regions. For example, although it is widely known
as the "German cockroach" in English-speaking countries, in Germany
in turn, it is known as the Russian roach.[10]Diet German
cockroaches areomnivorousscavengers. They are attracted
particularly to meats,starches, sugars and fatty foods. Where there
is a shortage of foodstuffs, they may eat household items such as
soap, glue and toothpaste. In famine conditions they turn
cannibalistic, chewing at each other's wings and
legs.[12]ReproductionThe German cockroach reproduces faster than
any other residential cockroach,[13]growing from egg to
reproductive adult in approximately 123 days.[14]Once fertilized, a
female German cockroach develops anoothecain her abdomen. The
abdomen swells as her eggs develop, until the translucent tip of
the ootheca begins to protrude from the end of her abdomen, and by
that time the eggs inside are fully sized. The ootheca, at first
translucent, soon turns white and then within a few hours it turns
pink, progressively darkening until, some 48 hours later, it
attains the dark red-brown of the shell of a chestnut. The ootheca
has a keel-like ridge along the line where the young emerge, and
curls slightly towards that edge as it completes its maturation. A
small percentage of the nymphs may hatch while the ootheca is still
attached to the female, but the majority emerge some 24 hours after
it has detached from the female's body. The newly hatched 3mm-long
black nymphs then progress through six or seveninstarsbefore
becoming sexually mature, butecdysisis such a hazardous process
that nearly half the nymphs die of natural causes before reaching
adulthood. Molted skins and dead nymphs are soon eaten by living
nymphs present at the time of molting2. ASIAN COACROCHES (Blattella
asahinai)Blattella asahinai
SCIENTIFIC CLASSIFICATION
Kingdom:Animalia
Phylum:Arthropoda
Class:Insecta
Order:Blattodea
Family:Blattellidae
Genus:Blattella
Species:B. asahinai
Binomial name
Blattella asahinaiMizukubo, 1981
Blattella asahinai, theAsian cockroachis aspeciesofcockroachthat
was first described in 1981 from insects collected onOkinaw a
Island,Japan.[1]DescriptionThe Asian cockroach is nearly identical
to theGerman cockroach(Blattella germanica) except for a few minor
morphological differences. Like the German cockroach, it is about
1.6cm (0.63in) long, is tan to brown in color, and has wings.
However, its wings are longer than the German cockroach, and there
is a difference between a groove in the abdomen between the two
species. There are other differences. The quickest way to tell the
difference between the two species is that the Asian cockroach is a
strong flyer (almost like a moth) and is attracted to light, unlike
the German cockroach.[1]This species tends to prefer the outdoors,
whereas the German cockroach prefers living
indoors.DistributionBlattella asahinaiis found
intropicalandsubtropicalclimates, and was first identified in
theUnited Statesin 1986 inLakeland, Florida. It has since expanded
throughout much ofFloridaand is spreading into other southern
states. In addition to Florida, it is reported
inAlabama,Georgia,South Carolina, andTexas.[1]Its population
reaches its zenith in late August and declines rapidly with the
onset of cool weather (Snoddy and Appel 2007). During adverse
weather conditions such as cold weather or dry conditions the Asian
cockroach will burrow down into the leaf litter (Snoddy and Appel
2007).Beneficial insectAccording to entomologist Bob Pfannenstiel
(Beneficial Insects Research Unit, Weslaco, Texas),
thisomnivorousspecies also feeds, under certain conditions, on the
eggs of lepidopteran pests of annual crops. Asian cockroaches
ventured west into Texas in 2006, and became the most common
predator ofbollwormeggs in the state's Rio Grande Valley region.
The bollworm threatens cotton, soybean, corn and tomato
crops.[2]
