Blattodea

(Cockroaches)

Class Insecta

Order Blattodea

Number of families ca. 7

Evolution and systematics

Fossil cockroaches or cockroach-like species are so numerous in the coal seams of the Upper Carboniferous (350 million to 400 million years ago [mya]) that the period is known as the "Age of Cockroaches." Only about 5% of fossil cockroaches represent entire insects; 90% consist of wings or wing fragments, with the remaining 5% consisting of other body parts. For the most part, these fossils appear to be very similar to the forms living today. However, the females of many fossils from the Carboniferous and Permian deposits (270 to 225 mya) of Europe, Asia, and North America, as well as from the Triassic (225 to 180 mya) and Jurassic deposits (135 to 100 mya) of Russia, had long, external ovipositor valves. This indicates that they probably laid single eggs in soil or soft plant tissue, rather than a number of eggs in an ootheca, which is characteristic of today's forms. During the Jurassic period the ovipositor valves decreased in length and gradually evolved into those found in all present-day species.

The oldest fossil genus in the Blattellidae (one of the largest families), Pinablattella, dates to the Cretaceous (135 mya) of Siberia. The coexistence of fossil cockroaches and fossil plants in the same geological stratum suggests that there was a close association between them during this early period, and it is speculated that the cockroaches fed on these plants. Cockroaches are related closely to termites and mantids, with which they often have been grouped in the order Dictyoptera. This chapter treats cockroaches as comprising the order Blattodea, which does not include termites and mantids. Cockroaches can be divided into two large superfamilies, the Blattoidea and the Blaberoidea. These two groups evolved from oviparous ancestors; the Blattoidea remained oviparous, and the Blaberoidea eventually evolved ovoviviparity and viviparity.

Physical characteristics

The chewing mouthparts are directed downward. The antennae consist of numerous segmented annuli and usually are longer than the body. Compound eyes typically are present, but they may be reduced in size or absent, especially in cavernicolous (cave-dwelling) species. The pronotum is large and often shieldlike and covers the head. When present, the forewings typically are modified into hardened tegmina, which may be abbreviated or absent; hind wings may be reduced in size or absent, if present, they are membranous, with well-developed veins. Legs are adapted for running or sometimes digging. The coxae are adpressed against the body. The tarsi have five segments, often with pulvilli, which may be reduced, or absent. Tarsal claws almost always are present, with or without an arolium between them.

Sizes vary widely, the smallest being about 0.8 in (2 mm) long, the size of a mosquito (e.g., Nocticola species). The largest species generally are in the Blaberidae; the wingless Macropanesthia rhinoceros (Panesthiinae) probably is the bulkiest cockroach known, and it may reach 2.6 in (65 mm) in length and weigh 0.53–1.1 oz (15–30 g) or more. Another wingless blaberid, Gromphadorhina portentosa, may reach a length of 3.1 in (80 mm). Some fully winged neotropical blaberids may have a body length of 3 in (75 mm) (Archimandrita tessellata) or 3.1 in (80 mm) (Blaberus giganteus).

Numerous species are uniformly dark (black, brown, or reddish brown), but many are distinctively marked. A large

Distribution

Cockroaches are worldwide in distribution, although some genera are endemic to certain countries. The greatest number of species occurs in the tropics. Some pest species, if not controlled, may build up huge populations in homes, businesses, and other buildings and in sewers.

Habitat

Feral cockroaches inhabit almost every conceivable habitat, with the exception of extremely cold regions, although Eupolyphaga everestinia (Polyphagidae) was collected on Mount Everest at 18,500 ft (5,639 m); pest species (e.g., the German cockroach) can survive indoors in extreme cold. Cockroaches are found in caves, mines, animal burrows, bird nests, ant and termite nests, deserts, and water (subaquatic). Most cockroaches live outdoors and, during the day, usually are found near the ground and hiding under bark, dead leaves, soil, logs, or stones. Numerous species have adapted to human beings and live in man-made structures (homes, restaurants, food stores, hospitals, and sewers) where temperatures and levels of humidity are relatively stable and the cockroaches are protected from adverse climatic conditions.

Many species are found in association with plants, but the significance of the relationships is obscure. Undoubtedly, most of the associations are accidental, but some damage plants. Not all cockroach/plant associations are harmful. There are some tropical species that live in the canopy and are involved in pollinating certain plants. Numerous species in at least six ovoviviparous genera (Blaberidae: Epilamprinae), are amphibious or semiaquatic. They usually live on land at the edges of streams or pools, but they may spend brief periods of time in the water. About 25 genera and about 62 species of cockroaches have been found in bromeliads, where water collects in the leaf bases. Many of these species are not restricted to this habitat, but some may be truly bromeliadicolous.

In the United States, desert species of Arenivaga (Polyphagidae) migrate vertically on plants during the day and avoid the heat of spring, summer, and autumn. Between November and March nocturnal temperatures are lower, and the insects burrow into the sand among roots of shrubs. During the winter, soon after darkness, they become active during peaks of nighttime surface temperatures.

Behavior

There are three types of social behavior and communication: gregarious (aggregation), subsocial (adults care for larvae), and solitary; communication (especially during courtship behavior) is accomplished with pheromones. Vision apparently plays little or no significant role in sexual recognition, courtship, and copulation, in spite of the fact that many species have large, well-developed, pigmented eyes.

There are many records of predation on cockroaches. Among the arthropods, ants and spiders are the most important predators in the tropics. Cockroach remains have been found in the stomachs of fish, salamanders, toads, frogs, turtles, geckos, and lizards. Several species of birds eat these insects, and a Peruvian wren ("cucarachero") apparently specializes in cockroaches. Among mammalian predators on cockroaches are opossums, porcupines, monkeys, rodents, and cats.

Cockroaches are subject to parasites, for example, viruses, bacteria, protozoa, fungi, and helminths. Among the parasite arthropods are wasps, flies, and beetles. One whole wasp family, the Evaniidae, favors only cockroach eggs. Larvae and adult cockroaches are eaten by species in three families of Hymenoptera, two of Diptera, and one of beetles. Species of Ampulex and Dolichurus (Hymenoptera: Ampulicidae) provision their nests only with cockroaches.

Many species burrow into the substrate when disturbed or during periods of inactivity. Some conceal themselves in folded dead leaves, in caves they burrow into guano, or in crevices. Some species run rapidly or fly or become immobile at the approach of an attacker. Cockroaches have mechanoreceptors, especially on their cerci, that respond to the slight acceleration of air that signals the approach of a predator. Some species that become immobile when attacked by ants cling so tightly to the substrate that their vulnerable undersurfaces cannot be harmed. Many species have defensive glands that produce a variety of irritating chemicals, the most common being trans-2-hexenal, which is sprayed forcibly on the attacker. Many immature cockroaches and some adults secrete a sticky proteinaceous substance on their terminal abdominal segments and cerci that gums up ant or beetle attackers.

Some tropical cockroaches have warning coloration that involves mimicry, and they resemble lampyrid beetles (fireflies), coccinellid beetles, or wasps. Virtually nothing is known about the relationships of the mimic (the cockroach) and model; in fact, in many instances the models are unknown.

Cockroaches produce sound in many ways, but two methods, namely, stridulation and expulsion of air through the second abdominal spiracles, have evolved in ovoviviparous Blaberidae: Oxyhaloinae. The stridulating structures consist of parallel striae (thickenings) on the ventral lateroposterior nargins of the pronotum and on the dorsoproximal regions of the costal veins of the tegmina. When disturbed, the insect rubs the pronotum sideways against the modified region of the costal veins.

Under normal periods of light and dark, many pest species are nocturnal and increase their activity just as it begins to get dark; activity ceases after five or six hours, and they remain quiet throughout the following day. Some feral Australian Polyzosteriinae that live exposed are diurnal and are active during the day. Domestic cockroaches may aggregate in large numbers during the day and at night move out and migrate to obtain food and water.

Feeding ecology and diet

Cockroaches seem to eat almost anything, from plants to animals. They may exhibit preferences and discriminate when given a choice. When deprived of food and water, they can live from five days (Blattella vaga) to 42 days (female Periplaneta americana). When given dry food but no water, they live for about the same period of time as insects that are starved; if they are provided with water, most live longer. Some species can live for two to three months on water alone. In bat-inhabiting caves they feed on guano, and in sewers they consume human feces. Some species live in dead trees and feed on wood.

Reproductive biology

Courtship precedes mating and is controlled by pheromones. Some females assume a calling position by raising the wings, expose intertergal membranes, expand their genital chambers, and release a pheromone to attract the male. In many species the newly emerged females, while still white and teneral, attract and mate with older males (e.g., Diploptera punctata).

Some species show little courtship behavior. The female does not mount the male, nor does she feed on or palpate his tergites; he either mounts or backs into her and makes the connection. Many cockroaches have stridulating organs, but in most species their role in courtship, if any, has not been determined. In some wingless species (e.g., Gromphadorhina and Macropanesthia) males hiss during courtship and simply

back into and seize the female genitalia, and the pair remains joined, with their heads facing opposite directions. In all species, while the two are joined, the male forms and transfers a spermatophore to the female's bursa copulatrix.

The eggs of almost all cockroaches are enclosed in a tan proteinaceous capsule called an "ootheca," which may have as few as four or five eggs or as many as 243. When the ovaries mature, the eggs are extruded through a blob of soft, rubbery, colleterial gland secretion, and, with the help of the ovipositor valves, are lined up vertically and alternately on one side and then the other; when completed, there are two rows of eggs covered by a capsule. The eggs are extruded with the micropylar ends (the region where sperm enter the egg) and oothecal keel (the area that contains the air chambers for egg respiration) upward. The position in which the ootheca is carried at the time it is deposited (i.e., whether or not it is rotated 90°) is significant taxonomically and played an important role in the evolution of blaberid and blattellid ovoviviparity.

There are four types of reproduction: oviparity, false ovoviviparity, true ovoviviparity, and viviparity. In oviparity (all families except Blaberidae), the ootheca is dropped shortly after it is completed and while it still is in the vertical position (all Blattidae and Blattellidae: Pseudophyllodromiinae) or after it is rotated 90° to the right or left (Blattellidae, Nyctiborinae, and Ectobiinae). After the female deposits the ootheca, she leaves and has nothing more to do with the eggs. Initially, these eggs have enough yolk to complete development, but water is obtained from the substrate.

In false ovoviviparity (almost all Blaberidae and four genera of Blattellidae), the ootheca, after it is formed, is retracted into a uterus or brood sac, where it remains during gestation (e.g., Nauphoeta cinerea). The oothecal membrane is greatly reduced in the Blaberidae and less so in the Blattellidae. When first laid, the eggs have enough yolk to complete development and obtain water from the mother during gestation.

True ovoviviparity (only the blaberid Geoscapheinae, specifically, four Australian genera: Geoscapheus, Macropanesthia, Neogeoscapheus, and Parapanesthia) differs from false ovoviviparity in that an ootheca is not formed. The eggs pass directly from the oviduct into the uterus or atrium, where they lie in a jumbled mass until parturition. The eggs have enough yolk initially to complete development but obtain water from the mother as needed.

With viviparity (only one species, that is, Diploptera punctata, Blaberidae: Diplopterinae), the very small ootheca is rotated and retracted into the uterus. It has only about a dozen very small eggs enclosed in an incomplete membrane; the larvae are quite large when born. At first, the eggs lack sufficient yolk and water to complete development, but during gestation the embryos drink water and dissolved proteins and carbohydrates synthesized and transported by the mother's uterus.

Many species that live underground or in dead trees burrow into soil or wood and form a chamber where the insects live and emerge to feed or carry down food (e.g., dead leaves) to the chamber. All the species of Cryptocercus (Cryptocercidae) live in and feed on decaying wood; the cockroaches have special protozoa that digest cellulose. Another group of cockroaches, the Panesthiinae, also eat wood, but their cellulose is digested by bacteria.

The panesthiine cockroaches Geoscapheus robustus and Macropanesthia rhinoceros burrow in sandy areas in Queensland, especially where the cypress pine grows. The adults make a nest of grass, roots, and dead leaves about 2 ft (0.6 m) below the surface and probably play an important role in litter turnover.

In most cockroaches that carry the ootheca externally, the female deposits it soon after its formation; some females dig a hole and cover it with debris or conceal it in some other way. They then leave and have nothing more to do with the eggs. Those species that carry the ootheca externally during gestation probably provide some protection from parasites or predators. The Blaberidae protect their eggs by retracting them into a brood sac. Additional protection is afforded after the ovoviviparous species give birth and the newborn larvae aggregate, usually for relatively short times, under the female until the cuticle hardens. This is true of Byrsotria fumigata, Gromphadorhina portentosa, and Rhyparobia maderae. In Phlebonotus, Thorax, and Phoraspis, the female's tegmina are large and arched; the wings may be reduced and the abdominal tergites depressed, forming a chamber in which the larvae hide, covered by the tegmina.

Conservation status

The greatest threat to feral cockroaches is the destruction of habitats, particularly in the tropics. Those species that are restricted to a particular niche are especially vulnerable. At least one cockroach, Ectobius duskei, the Russian steppe cockroach, has been eliminated as a result of the cultivation of wheat in virgin steppes. Other than conservationists and students of biodiversity, few people probably would object if a cockroach, especially a pest species, were eliminated. Today, support is given for the search for medically and economically important substances that are derived from animals and plants, and it is conceivable that some compounds they produce will be found to be of practical value. No species is listed by the IUCN.

Significance to humans

The biology of domesticated species that are pests of humans has been investigated thoroughly, often with the aim of controlling or eradicating them, which is virtually impossible. Some of these species are used in biology classes or in commercial or government laboratories to study physiological problems. University researchers are developing "robotic" cockroaches, using the large, wingless Gromphadorhina portentosa. Engineers and neurologists have developed a wristwatch-sized sensory and video package to control, start, and steer the "Biobot" cockroach. One of the aims for these robots is to make possible remote measurements of environmental conditions where humans cannot easily or safely go (e.g., bombed buildings).

Cockroaches have been used as food by humans and are said to taste like shrimp. The Aborigines of Australia and the Lao Hill tribe of Thailand collect and eat raw cockroaches. The Laos in Korat eat cockroaches, and the children collect the oothecae for frying. In southern China and in Chinatown in New York City, dried specimens of Opisthoplatia orientalis are sold for medicinal purposes. Large nondomiciliary cockroaches are cultured or grown readily, and many have been maintained as pets. Probably one of the most popular is the slow-moving Madagascan hissing cockroach, Gromphadorhina portentosa.

The fact that domesticated cockroaches live in homes, sewers, privies, and hospitals and feed on human foods and feces and cadavers makes it possible for them to be vectors of a variety of human diseases by carrying infectious organisms internally and externally. They have been known to harbor viruses, bacteria, fungi, protozoa, and helminths. At least 18 bacteria that cause human diseases have been found naturally in domesticated pest species, notably the American and German cockroaches. Blattella germanica collected from hospitals and residential areas have been found to carry various species of five genera of fungi of medical importance. The evidence for cockroaches' transmitting human disease organisms is essentially circumstantial, but they have the potential to transmit pathogens indirectly when foods or utensils used to prepare foods are contaminated. Although their importance as vectors of disease is circumstantial, there is no doubt that some people are allergic to cockroaches, and hypersensitive individuals may experience asthma when they are exposed to cockroach allergens. Allergies are common among laboratory workers who study cockroaches. The culprits are commonly the German, American, and Oriental cockroaches, but other species (e.g., G. portentosa) also have been implicated. Many species of cockroaches produce defensive secretions that may cause burning sensations, vertigo, or nausea. Normal cockroach integumental secretions cause dermatitis and conjunctival edema in entomologists who frequently study or work with these insects.

Species accounts

List of Species

Suriname cockroach

Blatta surinamensis

family

Blaberidae

taxonomy

Pycnoscelus surinamensis (Linnaeus), 1758, Surinam.

other common names

None known.

physical characteristics

Medium size, 0.71–0.94 in (18–24 mm) long. Shiny brown to black in color. Tegmina often do not extend beyond the end of the abdomen. Black pronotum, with yellow area along the anterolateral margins.

distribution

Originated in Indo-Malayan region and spread by trade throughout humid and subhumid tropics. In the United States it has been found in Alabama, Florida, Texas, Louisiana, and Iowa.

habitat

In northern states can become established in heated greenhouses and zoos. In the wild frequently burrows into loose soil or sand but also occurs under stones, manure, wood, rubbish, or chicken feces.

behavior

As usually only females are produced, courtship rarely occurs. When it does, the nonfunctional male mounts the female and grasps her genitalia from above.

feeding ecology and diet

Destroys palms and ferns by eating the hearts. In greenhouses, girdles rose bushes and eats aerial roots and orchid petals.

reproductive biology

Parthenogenetic, producing females. Males are produced rarely; when they occur, they are nonfunctional. At about 86°F (30°C), the virgin female deposits her first ootheca in the uterus seven days after emergence and gives birth 34 days later. During an average life span of 307 days she produces three litters, each consisting of about 21 young. Larvae undergo eight to 10 molts and mature in 140 days when reared in groups. The fecundity of clones from different parts of the world varies considerably.

conservation status

Not threatened.

significance to humans

Household pest in the southern United States, Philippines, Tanzania, and Trinidad. Intermediate host of the nematode Oxyspirura mansoni, which causes worm infections and blindness in poultry. Spread simplified by parthenogenesis, because the species can become established through the introduction of a single larva or unfertilized adult female into a suitable habitat.

Cinereous cockroach

Nauphoeta cinerea

family

Blaberidae

taxonomy

Nauphoeta cinerea Olivier, 1789, Isle of France, Mauritius.

other common names

English: Lobster cockroach.

physical characteristics

Large, reaching 0.98–1.14 in (25–29 mm) in length. The sexes are similar, except that male tegmina and wings reach about the fifth abdominal tergite and are slightly longer in the female. Ashy colored. Pronotum with a lobster-like design.

distribution

Apparently a native of East Africa, the species has become distributed widely in the tropics by commerce.

habitat

Found in native huts in the Sudan, in outhouses and stores, and in hospitals in Australia.

behavior

Males stridulate when courting nonreceptive females. Newly hatched larvae crawl under the female or under her wings, remaining there until about an hour after hatching.

feeding ecology and diet

The cinereous cockroach infests mills producing animal feeds in Florida and poultry food sheds in Honolulu. Fond of feeds containing fish oil; known to kill and eat the cypress cockroach, Diploptera punctata.

reproductive biology

At 86–96.8°F (30–36°C), the mated female produces the first ootheca, containing about 33 eggs, in 13 days; gestation lasts 31 days. Larvae undergo seven or eight molts and are reared in groups. Males mature in 72 days and females in 85 days. The adult male lives 365 days, and the female lives 344 days, during which time she produces six litters.

conservation status

Not threatened.

significance to humans

Was implicated in an outbreak of Salmonella poisoning in an Australian hospital.

Madeira cockroach

Rhyparobia maderae

family

Blaberidae

taxonomy

Blatta maderae Fabricius, 1781, Madeira.

other common names

English: Fatula cockroach, knocker cockroach.

physical characteristics

Reaches 1.57–1.97 in (40–50 mm) in length. Sexes are similar in habitus. Pale brown to tan. Tegmina and wings fully developed,

with two black lines in basal region and mottled posterior zones.

distribution

Native of West Africa; introduced into West Indies more than a hundred years ago and through commerce became circumtropical. Abundant in countries that border the Caribbean Sea south of the United States.

habitat

Especially infests food stores. In 1950 became established in basements of buildings in New York City occupied by people from Puerto Rico; spread little since originally reported. Out-door species in tropics found in sugar cane fields and associated with palms, guava, and bananas. Spread from banana ships and intercepted at ports by quarantine inspectors.

behavior

Gregarious; builds up huge colonies. The male may tap the substrate with his thorax, which may be a method of attracting the female. She feeds on secretions on his second abdominal tergite during courtship. The pair remain attached for 20–30 minutes. Young larvae forage with the mother.

feeding ecology and diet

Probably omnivorous. Bananas and grapes are favorite foods.

reproductive biology

At 86–96.8°F (30–36°C), the mated female produces first ootheca, usually containing up to about 40 eggs, 20 days after becoming adult. Eggs develop within the uterus in 58 days. Larvae undergo seven or eight molts and are reared in groups. Males mature in 121 days; females require 150 days. Life expectancy is up to 2.5 years.

conservation status

Not threatened.

significance to humans

Important pest in some areas. Used extensively as an experimental laboratory animal.

Asian cockroach

Blattella asahinai

family

Blattellidae

taxonomy

Blattella asahinai Mizukubo, 1981, Okinawa.

other common names

None known.

physical characteristics

The sexes are similar; fully winged. Reaches 0.31–0.47 in (8–12 mm) in length. Yellowish or yellowish brown. Adult pronotum has a pair of light to dark brown longitudinal stripes. This species is almost impossible to distinguish from the German cockroach but differs markedly in behavior.

distribution

This species is the most recent introduction into the United States. Although it is not distributed as widely as the German cockroach, it has been found (as its synonym Blattella beybienkoi) in Sri Lanka, Andaman Islands, Myanmar, Chagos Archipelago, China, India, Thailand, and Okinawa.

habitat

In Florida, where it was introduced and became established and spread, it occurs outdoors on lawns, bushes, and trees.

behavior

Flies readily. Active at sunset. Adults are attracted to white walls and illuminated buildings. Adults and larvae are active in grass and mulch. In houses adults fly to lights and sit on walls, tables, and dishes. Winged adults are half an inch (12.7 mm) long and have a pair of longitudinal stripes on the thorax; the larvae lack wings but also are striped.

feeding ecology and diet

In Florida it often feeds on aphid honeydew.

reproductive biology

In the laboratory Asian cockroach males cross with German cockroach females and produce offspring. Crosses between male German cockroaches and Asian females did not produce offspring.

conservation status

Not threatened.

significance to humans

Considered a pest on lawns in Florida, sometimes making outdoor activities almost impossible.

German cockroach

Blattella germanica

family

Blattellidae

taxonomy

Blatta germanica Linnaeus, 1767, Denmark; type Brünnich, 1763 [suppressed by the International Commission on Zoological Nomenclature].

other common names

English: Croton bug, steamfly, steambug, Yankee; German: Russische Schabe; Russian: Prussak.

physical characteristics

The sexes are similar; fully winged. Relatively small at 0.4–0.5 in (10–13 mm) in length. Pale yellowish-brown to tawny. Pronotum has distinct dark, parallel, longitudinal bands.

distribution

Cosmopolitan; found in and around human habitations throughout the world. Present in Greenland, Iceland, and the Canadian High Arctic, where it survives indoors.

habitat

Preferring a warm, moist habitat, the German cockroach is a common pest of kitchens, larders, and restaurants. In temperate climates it can be found outdoors, under houses without basements, under rubbish and date palms, and in city dumps. It also has been taken in gold mines and caves in South Africa. It is one of the most prevalent cockroaches in the galleys and storerooms of ships.

behavior

Gregarious and may build up huge populations: a four-room apartment in Texas harbored 50,000–100,000 mostly German cockroaches. It is a poor flier despite having fully developed wings, which it uses to glide downward from a high resting place. The sexually active female assumes a calling position by raising the wings and emitting a pheromone produced in the tenth abdominal tergite that attracts the male. On contact with

the female, the male raises the wings, exposing a pair of glands on his back. The female mounts the male, apparently feeding on a glandular secretion. The male clasps the female genitalia, and the pair remain joined until the male inserts the sperm-filled spermatophore.

feeding ecology and diet

Omnivorous.

reproductive biology

At 86°F (30°C) the mated female produces first ootheca, eight days after adult emergence. Average number of eggs per egg case is 37; the incubation period is 17 days. The male lives 128 days; the female lives 153 days, during which time she produces, at intervals of 22 days, seven oothecae, each of which she carries externally, protruding from the end of the abdomen, until or shortly before eggs hatch. Larvae undergo five to seven molts; they are reared in groups and mature in 40—41 days.

conservation status

Not threatened.

significance to humans

The species causes asthmatic attacks and is known to carry or is suspected of transmitting various bacterial disease organisms.

Oriental cockroach

Blatta orientalis

family

Blattidae

taxonomy

Blatta orientalis Linnaeus, 1758, America, Oriente.

other common names

English: Schad roach, black beetle.

physical characteristics

This dimorphic, shiny, blackish-brown species is 0.71–0.94 in (18–24 mm) long. The tegmina and wings of the male are reduced but cover about two-thirds of the abdomen. The tegmina of the female are small lateral pads that extend only to the middle of the metanotum; hind wings are absent.

distribution

Found in port cities throughout the world and occurs in almost every state of the United States. It also is found in England, northern Europe, Israel, southern Australia, and southern South America.

habitat

Usually found in basements and cellars, service ducts, crawl spaces, toilets, and behind baths, sinks, radiators, ovens, and hot-water pipes; they may congregate in large numbers around sources of water. In north-central states of the United States, they often are found outdoors around homes during the summer and in garbage and trash dumps.

behavior

Often occurs outdoors. In buildings, usually occur below or on ground floor, but small numbers may be found up to the fifth floor.

feeding ecology and diet

Probably omnivorous.

reproductive biology

At 86–96.8°F (30–36°C), the first ootheca is deposited, 12 days after the female becomes an adult; the eggs take 44 days to hatch. The larvae undergo eight to 10 molts. When raised in groups, males require 146 days and females 165 days to mature. The average number of eggs in an ootheca is 16, and the female averages only 2.5 oothecae during a brief average adult life span of 44 days. The life cycle of this species is seasonal; in some areas adults appear in May and June, but some adults can be found in almost all months. Having considerable resistance to cold, they have been found breeding out of doors in England and southern Russia.

conservation status

Not threatened.

significance to humans

A significant household pest.

American cockroach

Periplaneta americana

family

Blattidae

taxonomy

Blatta americana Linnaeus, 1758, America.

other common names

English: Bombay canary, ship cockroach; Dutch: Kakerlac.

physical characteristics

Grows to 1.1–1.7 in (28–44 mm) in length. Tegmina and wings developed in both sexes. Reddish-brown, with pale yellow zone around the edge of the pronotum.

distribution

An important cosmopolitan pest in tropical and subtropical areas, having been distributed by commerce to many regions of the world.

habitat

Its original home was Africa, where it is found commonly both inside and outside human dwellings. In the United States it probably is found in all urban areas. This species prefers a warm, moist habitat and in tropical and subtropical America is common outdoors and may be found in dumps, woodpiles, sewers, and cesspools.

behavior

May fly short distances on occasion. Gregarious and may build up huge populations. After spraying the walls of a trickling filter plant in Florida, over 2.5 cu yd (2.3 m³) of American cockroaches were collected, and several times that quantity died in the adjacent woods. Females produce a pheromone that can attract the male from as far away as 98 ft (30 m).

feeding ecology and diet

Probably omnivorous; known to feed on human feces.

reproductive biology

Five-year life-history study under room conditions in Lafayette, Indiana (64.4–80.6°F, or 18–27°C, during winter, with a maximum summer temperature 95°F, or 35°C), found average duration of larval development to be 468 days for females and 551 days for males. Females lived, on average, 441 days and produced 58 oothecae (maximum of 90). Oothecae contained 16 eggs, and the incubation period was 53 days. In another study conducted at 86–96.8°F (30–36°C), larvae went through nine to 13 molts. When reared in groups, females required 161 days and males 171 days to mature.

conservation status

Not threatened.

significance to humans

Together with the German cockroach, probably the most important cockroach pest. Many bacteria, viruses, fungi, and helminths, a number of them pathogenic to man, have been found in the American cockroach.

Brownbanded cockroach

Supella longipalpa

family

Blattellidae

taxonomy

Supella longipalpa Fabricius, 1798, India. Until recently known as Supella supellectilium (Serville).

other common names

English: Furniture cockroach, TV cockroach.

physical characteristics

A small cockroach, reaching only 0.39–0.57 in (10–14.5 mm) in length. Male tegmina completely cover the abdomen; in the female they rarely reach the tip of the abdomen. Color varies widely. Dark pronotum, often with a pale area in the center; chestnut tegmina, with pale areas at base and in middle.

distribution

Probably originated in Africa but, as a domiciliary pest, spread by commerce throughout warm temperate countries; may occur outdoors in subtropical countries. Found in almost every state of the United States.

habitat

In dwellings, it can be found in almost every room: on kitchen chairs; in cupboards and pantries; underneath tables and shelves in closets; behind pictures and picture molding, in TV sets, bookshelves, drawers, and shower stalls.

behavior

Tends to fly when disturbed. The female emits a pheromone that has been identified and attracts the male from a distance.

feeding ecology and diet

Often feeds on gum sizing of books and on paste behind wallpaper, stamps, and gummed labels. Visits kitchens when searching for food.

reproductive biology

Oothecae may be attached throughout the house to walls and ceilings and about kitchen sinks, desks, tables, and bedding. At about 86°F (30°C), larvae undergo six to eight molts. When reared in groups, both sexes mature in about 55 days. Males live 115 days and females 90 days. The female deposits her first ootheca, which usually contains 16 eggs, 10 days after emergence. During her lifetime she produces an average of 11 oothecae, which are deposited at six-day intervals. Eggs hatch in 40 days.

conservation status

Not threatened.

significance to humans

Important household pest that spreads throughout infested homes.

Resources

Books

Asahina, S. Blattaria of Japan. Tokyo: Nakayama-Shoten, 1991. (Japanese, with parts in English).

Bell, W. J., and Adiyodi, K. G., eds. The American Cockroach. London: Chapman and Hall, 1982.

Bey-Bienko, G. Y. "Fauna of the U.S.S.R." In Insects. Moscow: Institute of Zoology, Academy of Sciences of the USSR, 1950.

Carpenter, F. M. Treatise on Invertebrate Paleontology. Part R, Arthropoda. Vol. 3, Superclass Hexapoda. Boulder, CO: Geological Society of America, 1992.

Cornwell, P. B. "The Cockroach." In A Laboratory Insect and an Industrial Pest, vol. 1. London: Hutchinson, 1968.

Gordon, David George. The Compleat Cockroach: A Comprehensive Guide to the Most Despised (and Least Understood) Creature on Earth. Berkeley, CA: Ten Speed Press, 1996.

Roth, L. M., and Alsop, D. W. "Toxins of Blattaria." In Arthropod Venoms. Edited by S. Bettini. Handbook of Experimental Pharmacology, vol. 48. New York: Springer-Verlag, 1978.

Taylor, R. L. Butterflies in My Stomach; or, Insects in Human Nutrition. Santa Barbara, CA: Woodridge Press, 1975.

Vishniakova, V. N. "Mesozoic Blattids with External Ovipositors and Details of Their Reproduction." In Jurassic Insects of Karatau. Edited by B. B. Rohdendorf. Moscow: Akademiya Nauk SSSR, Ordelenide Obschei Biolgii, 1968. (Russian).

Periodicals

Carpenter, F. M. "A Review of Our Present Knowledge of the Geological History of Insects." Psyche 37 (1930): 15–34.

Grandcolas, P. "El Origen de la Diversidad en las Cucarachas: Perspectiva Filogentica de su Gregarismo, Reproducion, Comunicacion y Ecologia." Boletin de la Sociedad Entomologica Aragonesa 26 (1999): 397–414 (English translation, 415–420).

McKittrick, F. A. "Evolutionary Studies of Cockroaches." Memoir of the Cornell University Agricultural Experimental Station 389 (1964): 1–197.

Moore, Thomas E., Seldon B. Crary, Daniel E. Koditschek, and Todd A. Conklin. "Directed Locomotion in Cockroaches: 'Biobots' Acta Entomologica Slovenica 6, no. 2 (1998): 71–78.

Princis, K. "Zur Systematik der Blattarien." Eos: Revista Española de Entomología 36, no. 4 (1960): 427–449.

Rehn, J. A. G. "Man's Uninvited Fellow Traveler: The Cockroach." Scientific Monthly 61 (1945): 265–276.

Roth, L. M. "Evolutionary Significance of Rotation of the Ootheca in the Blattaria." Psyche 74 (1967): 85–103.

——. "The Evolution of Male Tergal Glands in the Blattaria." Annals of the Entomological Society of America 62 (1969): 176–208.

——. "Evolution and Taxonomic Significance of Reproduction in Blattaria." Annual Review of Entomology 15 (1970): 75–96.

——. "A Taxonomic Revision of the Panesthiinae of the World." I. "The Panesthiinae of Australia (Dictyoptera: Blattaria: Blaberidae)." Australian Journal of Zoology Supplement series 48 (1977): 1–112.

——. "The Mother-Offspring Relationship of Some Blaberid Cockroaches (Dictyoptera: Blattaria: Blaberidae)." Proceedings of the Entomological Society of Washington 83, no. 3 (1981): 390–398.

——. "A Taxonomic Revision of the Genus Blattella Caudell (Dictyoptera, Blattaria: Blattellidae)." Entomologica Scandinavica Supplement no. 22 (1985): 1–221.

——. "Blattella asahinai Introduced into Florida (Blattaria: Blattellidae)." Psyche 93 (1986): 371–374.

——. "New Cockroach Species, Redescriptions and Records, Mostly from Australia, and a Description of Metanocticola christmasensis gen. nov., sp. nov., from Christmas Island (Blattaria)." Records of the Western Australian Museum 19 (1999): 327–364.

——. "Systematics and Phylogeny of Cockroaches (Dictyoptera: Blattaria)." Oriental Insects 37 (2003): 1–139.

Roth, L. M., and G. P. Dateo. "Uric Acid Storage and Excretion by Accessory Sex Glands of Male Cockroaches." Journal of Insect Physiology 11 (1965): 1023–1029.

Roth, L. M., and T. Eisner. "Chemical Defenses of Arthropods." Annual Review of Entomology 7 (1962): 107–136.

Roth, L. M., and H. B. Hartman. "Sound Production and Its Evolutionary Significance in the Blattaria." Annals of the Entomological Society of America 60 (1967): 740–752.

Roth, L. M., and E. R. Willis. "A Study of Cockroach Behavior." American Midland Naturalist 47, no. 1 (1952): 66–129.

——. "The Medical and Veterinary Importance of Cockroaches." Smithsonian Miscellaneous Collections 134, no. 10 (1957): 1–147.

——. "An Analysis of Oviparity and Viviparity in the Blattaria." Transactions of the American Entomological Society 83 (1958): 221–238.

——. "The Biotic Associations of Cockroaches." Smithsonian Miscellaneous Collections 141 (1960): 1–470.

Rugg, D., and H. A. Rose. "Biology of Macropanesthia rhinoceros Saussure (Dictyoptera: Blaberidae)." Entomological Society of America 84, no. 6 (1991): 575–582.

Schal, C., J. Y. Gautier, and W. J. Bell. "Behavioural Ecology of Cockroaches." Biological Reviews 59 (1984): 209–254.

Shelford, R. "Mimicry Amongst the Blattidae; with a Revision of the Genus Prosoplecta Sauss., and the Description of a New Genus." Proceedings of the Zoological Society of London (1912): 358–376.

Sreng, L. "Cockroach Mating Behaviors, Sex Pheromones, and Abdominal Glands (Dictyoptera: Blaberidae)." Journal of Insect Behavior 6, no. 6 (1993): 715–735.

Willis, E. R., G. R. Riser, and L. M. Roth. "Observations on Reproduction and Development in Cockroaches." Annals of the Entomological Society of America 51 (1958): 53–69.

Other

Driscoll, T. M. Insect Pet Care: The Madagascar Hissing Cockroach. 1999. (Video; includes a booklet with directions for housing, and biological information).

Louis M. Roth, PhD