There are more than 5,000 known cockroaches in the world, and China currently records more than 250 species. Cockroaches are an ancient population that has changed very little over 320 million years. When you first spot a cockroach, there may be 200 cockroaches hiding in their nests. Cockroaches are flattened, dark brown, and usually medium in size. The head is small and can move. The antennae are filamentous and the compound eyes are developed. The wings are flattened, the forewings are elytra and the hindwings are membranous, and the anterior and posterior wings are basically equal in size and cover the back of the abdomen; some species have no wings. Not good at flying, can sprint. Not completely perverted. Spawning occurs in the sheath of the egg, mainly in tropical and subtropical regions, living in the wild or indoors.
Today' big strong to popularize for everyone is the common cockroach species German cockroach, The German cockroach (Blattella germanica), which is the most widely distributed and the most difficult to control a type of world health pest. In addition to stealing food, contaminating food, damaging clothing, books, destroying computers and other sophisticated instruments, causing economic losses, the main harm is the spread of a large number of diseases. Due to the strong adaptability and rapid reproduction of German cockroaches, it is easy to develop resistance to chemical insecticides, so it is very difficult to control them.
The adult German cockroach is a flat oval shape of the dorsal abdomen, divided into 3 parts of the head, chest and abdomen, the small one is only 0.2 to 0.5 cm, most of the body length is 10 to 30 mm, yellowish brown, reddish brown or dark brown, the body length and body color vary from species to species, and the general body surface has a bright luster. Early nymphs are small dark brown and nearly black, wingless, forming a winged nymph with a distinct pale stripe in the center of the dorsal center. Cockroaches are lower mouth head, chewing mouthparts, a pair of developed compound eyes, one pair of single eyes (small and not developed), 2 pairs of wings, leathery forewings, hindwing membranous, but rarely flying, there are 3 pairs of reptile feet of the same shape, the femoral node is developed, strong and powerful, good at speeding, the male has 1 pair of abdominal spines on both sides of the posterior edge of the abdomen, and the female has no abdominal spines, according to which the male and female can be separated. The forecothax is well developed, the dorsal plate is broad and flattened, the middle and posterior thorax is small and indistinguishable, and the abdomen is flattened and broad, divided into 10 segments.
German cockroaches are omnivorous insects, and domestic species not only like to eat clean food in residential households, such as sugar, starch, meat, dairy products, etc., but also like to eat "food" in unhygienic environments, such as rotten food, human sputum and hair, and there are bad habits of eating, pulling and vomiting. German cockroaches are occasionally seen gathering near outdoor garbage during the warmer months, mainly due to too many indoor groups or the use of insecticides to drive them away. German cockroaches are very active insects, preferring to survive in tight seams and inclusions, and often mixed with vegetables, clothing, wood, cloth and other food and items to be brought into the home or transported to other cities and countries, often spreading and invading in a "free-riding" fashion.
German cockroach is the most widely distributed in the cockroach order, closely related to human life and the most difficult to control a class of important pests, it is distributed in the world's tropical, subtropical, temperate, cold zone are widely distributed, in China's Yunnan, Guizhou, Sichuan, Tibet, Guangxi, Guangdong, Fujian, Shanghai, Beijing, Shandong, Liaoning, Hunan, Hubei, Heilongjiang, Shaanxi and Xinjiang are widely distributed.
The integrated control of German cockroaches is to take the pest and its breeding environment as a whole, integrate environmental, physical, chemical and biological methods to control German cockroaches, and minimize the damage to people and the environment.
(1) Monitoring of German cockroaches
Careful and meticulous investigation of the breeding environment of pests, to find out the causes of pest breeding and the nests where they inhabit are half the success of pest control. Most of the failures in the control of German cockroaches are due to the failure to find all the hidden places of German cockroaches in the environment and deal with them thoroughly, so that new German cockroach invasions are constantly discovered and cannot be extinct.
(2) Environmental transformation and physical prevention
Food, water and nests are the 3 basic conditions for the survival of the German cockroach. Measures such as keeping indoors and outdoors clean, controlling food and water, and filling in various gaps and holes in the walls can significantly reduce the amount of environmental accommodation for pests, making it difficult for them to breed. German cockroaches are generally moved in in the summer with food, furniture, etc. transported indoors, so the packaging and various debris should be carefully inspected, and the garbage should be removed in time to avoid the invasion of German cockroaches. During the environmental survey, a vacuum cleaner can be used to capture German cockroaches that gather in the shadows, which is conducive to the next step of prevention and control. The use of sticky cockroach paper is easy to monitor where small cockroaches are moving, both to catch residual pests and to detect problems in time.
(3) Chemical control
Residual spraying and bait are the two basic methods of chemical control of small cockroaches in Germany. Since the residual spraying, the residual agent on the indoor surface can remain for more than 3 months and is difficult to remove [8], so when preventing and controlling German cockroaches, it is necessary to avoid indiscriminately spraying the ground, walls and ceilings, focusing on the activities and habitats of German cockroaches, especially the crevices close to water sources and food. Suitable dosage forms for residual spraying are microcapsule suspension (CS), emulsion (EC), water emulsion (WP), suspension agent (SC), wettable powder (WP) and so on.
Cockroach bait has been rapidly promoted due to its low environmental pollution, safe use and reliable effect. Cockroach bait dosage forms include ointment, glue bait, granular bait, poison bait box, etc., which are suitable for schools, hospitals, offices and other places that are more sensitive to pesticides. Fluorite ant-stomach component cockroach glue bait: more drugs should be applied to cockroach frequent places, so that cockroaches are chronically poisoned and die in the nest after contact with the glue bait of eating fluoride ant-palate components, which has an infectious and gastric killing effect. The duration of effectiveness is long, generally 3-6 months, but moisture should be prevented.
(4) Biological control
The use of insect pathogens to control pests has the advantages of good safety and no pollution of the environment, especially suitable for the prevention and control of indoor urban pests. The black-breasted cockroach concentrated nuclear virus (PfDNV) is the only cockroach virus in the world that has undergone systematic research and can infect and kill black-breasted cockroaches without infecting vertebrates. Insect-specific neurotoxins (AaIT) and essential oils of certain plants also have a good killing effect on German cockroaches. The basic way to prevent resistance of German cockroaches is to rotate different types of insecticides on a regular basis, use poison bait to control low-density German cockroaches, avoid overdosing the abuse of insecticides, and promote integrated control measures.