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Cockroach

Cockroaches are close relatives of termites and are of the Order Blattodea. Fossil evidence suggests that there has been litlle change in their general body form since their origin. There are nearly 4 000 species of Cockroaches (Dictyoptera, Blattodea) in the world, of which only 25 to 30 have any pest status, the rest are innocent members of the earth's fauna (and some make great pets, slightly better than hyenas, cheaper to keep). Cockroach populations have been found to live in a number of diverse habitats, among decaying leaf matter, under bark, in caves and burrows, on shrub foliage, in nests of social insects, boring into wood and even in semi-aquatic environments. A few species have invaded human dwellings and successfully cohabit with people in Australia and around the world. Despite having misleading common names such as American cockroach, most pest cockroaches found in Australia probably originated from tropical or subtropical Africa. These were carried by ships, carriages and later, by trains and airplanes from one country to another, helped by a remarkable degree of adaptation to built environments. Human habitats have provided conditions that make food, shelter and suitable temperatures available to these very opportunistic insects. Their wide distribution and coexistence with humans, added to the high frequency with which they carry human diseases in and on their bodies, have given them a very high pest status in most parts of the world. Body Structure Adult cockroaches are medium to large insects that, viewed from above, are mostly oval-shaped, with the head hidden underneath the pronotum (cap). They are dorsoventrally flattened so they can hide and crawl in tight places like cracks and crevices. Antennae are usually long and thread-like. Legs usually have protective spikes for crawling and running on many different surfaces. Eyes are compound and well developed. They have primitive, chewing-type mouthparts so they can eat most food types and they may have no wings, reduced wings or well-developed wings. Their abdomen is large and has a pair of often prominent cerci (rear protrusions). Life Cycle Most cockroaches reproduce sexually, involving attractant pheremones, courtship procedures and end-to-end copulation. Egss developed in the female are encapsulated in a purse-shaped egg case called an "ootheca", which may contain between 12 and 40 eggs. The oothecae may be dropped or glued onto a surface just before or months before hatching. Disgusting Behaviourisms . cockroaches eat almost any human or animal food or beverage or any dead animal or vegetable materials. . cockroaches are mostly nocturnal insects that hide during the day and actively seek food after dark. . cockroaches are known to rest in tight cracks and crevices for security, spending up to 18 hours a day there. . immature and mature cockroaches mostly congregate and rest together, assisted in some species by an aggregation pheremone found on the cuticle and in the faeces which encourages aggregation during rest. . like many other insects and animals, cockroaches frequently groom themselves and each other, often by running the antennae and legs through the mouthparts with a nibbling action most probably to clean sensory receptors (try that as a family tonight and email us with the results! - ed.). Why Cockroaches Are Considered Pests . they cohabitate with humans . they contaminate food, utensils, etc with droppings, cast skins, empty egg cases, dead cockroaches and vomit marks . where the cockroach population is large, unpleasant odours usually develop from sercretions from mouthparts and the cuticle . cockroaches have been known to bite people, but mainly in the past on ships where the cockroach populations were extremely large . cockroaches carry human diseases on their cuticle and in their gut and faeces and a cockroach typically carries several million bacteria on and inside its body, including Salmonella This health threat from cockroach cohabitation with humans is considered to be very serious and it is likely that cockroaches are responsible for transmission of human diseases, most commonly of the intestinal type, such as Salmonella food poisoning. Important Pest Cockroaches . German cockroach (Blattella germanica): relatively small, probably the most widespread and successful at human cohabitation. Adult German cockroaches are light amber-brown with two dark longitudinal stripes on the pronotum. Winged, but has not been found to fly. . American cockroach (Periplaneta americana): the largest cockroach known to cohabit with humans. Adult American cockroaches are reddish-brown, with pale legs and a pale yellow border around the pronotum. Wings cover the abdomen. . Smokeybrown cockroach (Periplaneta fuliginosa): relatively large. Adults are dark brown to almost black with no pale markings. Wings cover the abdomen. . Australian cockroach (Periplaneta australasiae): relatively large, similar in appearance to the American cockroach. Adults are brown with a clearly defined yellow border around the pronotum and have a yellow foremargin to the forewings. Wings cover the abdomen. . Brownbanded cockroach (Supella longipalpa): relatively small. Adults are pale brown with very pale bands across the thorax and abdomen. Females have reduced wings, but the male is fully winged. . Oriental cockroach (Blatta orientalis): medium-sized. Adults are dark brown to black. Females have much reduced wings which look like wing buds, but the male has wings that cover most, but not all, the abdomen. Cockroach Control Successful control of pest cockroaches in and around buildings requires: 1. a high level of sanitation, tidiness and hygiene, reducing the food and shelter that encourages cockroach breeding and habitation, and 2. the application of insecticides using methods that maximise the probability of contact with the target cockroach populations. There is a real probability of reinfestation after treatment or even after a treatment program. This is due to cockroach egg cases not subjected to treatment hatching after the appication of the insecticides. Cockroach baits and gels are intended to overcome this problem due to their attraction to adult cockroaches and their long-lasting residual action. (Most of this article was extracted from "Urban Pest Control in Australia", Gerozisis, John & Hadlington, Phillip, 1995 3rd edition, pp 111 - 117). For further information on cockroaches, their habitations and treatment methods, please contact us at Westate Pest Control using the Talk to Us selection on the left side of your screen or ring us on 6365 4800 during office hours. We are always pleased to help where we can. Keyword: pest control cockroach

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