Anopheles

Lindane is used predominately as a seed dressing and soil insecticide, for the control of ectoparasites of humans and domestic animals, for the control of locusts and grasshoppers, and as a residual spray to control the Anopheles vectors of malaria. Because of its relatively high volatility it is useful to control wood-boring insects of timber, fmit trees, and ornamental plants. The mode of action is not well understood but is thought to be competitive blocking of the y-aminobutyric acid (GABA) transmitter of synaptic nerve transmission. 

Dieldrin [60-57-1] or l,2,3,4,10,10-hexachloro-l,4,4t ,5,8,8t -hexahydro-6,7-epoxy-l,4- <7o, Aro-5,8-dimethanonaphthalene (34) (mp 176°C, vp 0.4 mPa at 20°C) is formed from aldrin by epoxidation with peracetic or perben2oic acids. It is soluble in water to 27 / g/L. Aldrin and dieldrin have had extensive use as soil insecticides and for seed treatments. Dieldrin, which is very persistent, has had wide use to control migratory locusts, as a residual spray to control the Anopheles vectors of malaria, and to control tsetse flies. Because of environmental persistence and propensity for bio accumulation, registrations in the United States were canceled in 1974. 

Repellents on Cloth. Each candidate repellent is appHed to a knit cotton stocking or cloth patch at 3.3 g/m cloth, usually as a 1% solution of active ingredient (AI) ia acetone. Two hours later, the stock or cloth patch is placed over an untreated nylon stocking on the arm of a subject, the hand covered, and the arm exposed to 1500 female mosquitoes for one minute. If fewer than five bites are counted, the test is repeated at 24 h, then weekly until failure, which is, by definition, five bites per minute. The standard mosquitoes used are Piedes aegppti Anopheles quadrimaculatus or M. albimanus. Candidate repellents ia cloth tests are ia one of the foUowiag classes class 1, effective 0 d class 2, 1—5 d class 3, 6—10 d class 4, 11—21 d and class 5, >21 d. 

Malaria is transmitted by the bite of an infected female Anopheles mosquito, one of the few species of the insect capable of carrying the human malaria parasite. The responsible protozoa ate from the genus P/asmodium of which only four of some 100 species can cause the disease in humans. The remaining species affect rodents, reptiles, monkeys, birds, and Hvestock. The species that infect humans are P/asmodium falciparum Plasmodium vivax Plasmodium malariae and Plasmodium ovale. Note that concomitant multiple malaria infections are commonly seen in endemic areas, a phenomenon that further compHcates choice of treatment. 

Ga.metocytocides. These annihilate the sexual forms of the plasmodia (gametocytes) and also destroy the stages of the parasites in the Anopheles mosquito. 

Four different protozoa of the genus Plasmodium -P. falciparum, P. vivax, P. ovale and P malariae - can cause malaria. P. falciparum is the most virulent, being responsible for virtually all fatal malaria cases. Humans are infected by a feeding female Anopheles mosquito (Fig. 2). The clinical symptoms of malaria are associated with the development of the parasite within human red blood cells, while the liver stages remain asymptomatic. The following dtugs (in alphabetical order) are currently in use for the treatment of malaria [5]. 

Malaria is transmitted from person to person by a certain species of the Anopheles mosquito. The four different protozoans causing malaria are Plasmodium falciparum, P. malariae, P. ovale, and P. vivax. Drugp used to treat or prevent malaria are called anti malarial drags. Three antimalarial drugs are discussed in the chapter chloroquine, doxycycline, and quinine sulfate. Other examples of antimalarial drugs in use today are listed in the Summary Drug Table Antimalarial Drugs. 

Malaria is transmitted by the bites of the Anopheles mosquitoes which introduce into the bloodstream one of four species of sporozoites of the plasmodia (Plasmodium falciparum, P. ovale, P. vivax or P. malariae). Initial symptoms of malaria are nonspecific and may resemble influenza and include chills, headache, fatigue, muscle pain, rigors, and nausea. The onset of the symptoms is between 1 to 3 weeks following exposure. Fever may appear 2 to 3 days after initial symptoms and may follow a pattern and occur every 2 or 3 days (P. vivax, P. ovale and P. malariae). Fever with P. falciparum can be erratic and may not follow specific patterns. It is not unusual for patients to have concomitant infections with P. vivax and P. falciparum. Falciparum malaria must always be regarded as a life-threatening medical emergency. 

Heeds indirectly affect the health of man and animals by harboring animals or insects. Control of aquatic weeds is effective for mosquito (Anopheles quadrimaculatus Say) control by eliminating breeding habitats. In control of the tsetse fly (Glossian spp.) (vector of sleeping sickness in Africa), herbicides are involved to reduce growth of the brush so essential to the survival of the fly. 

Larvae of the yellow fever mosquito, which are shallow feeders, were reared at room temperature by methods similar to those used in culturing Anopheles mosquito larvae (2, 6). Filter papers containing the eggs (furnished through the courtesy of R. E. Heal, Merck Co., Inc., Rahway, N. J.) were placed in tap water in shallow porcelain pans (12 X 7 inches, and 2 inches deep). The eggs hatched within 24 hours. When the larvae had hatched, powdered dog biscuit was added daily at the rate of 100 mg. per liter of water. 

Table II. Dehydrochlorination-Rate Constants and Toxicity to Anopheles quadrimaculatus Larvae of Isomers of Benzene Hexachloride...

Normal routes of exposure Vectors (mosquitoes—Aedes vexans, Culex triteeniorhynchus, Anopheles funestus midges—Culicoides species). 

Normal Routes of Exposure Vectors (mosquitoes—Anopheles funestus, Anopheles gambiae). Infectious Dose Unknown. 

Normal Routes of Exposure Vectors (mosquitoes—Aedes species, Culex species, Psorophora species, Mansonia, species, Deinocerites species, Haemogogus species, Sabethes species, Anopheles species). 

Normal routes of exposure Ingestion (in cats) Vectors (mosquitoes—Culex species, Aedes species, Anopheles species). 

Moore, J.B. and S.G. Breeland. 1967. Field evaluation of two mosquito larvicides, Abate and Dursban against Anopheles quadrimaculatus and associated Culex species. Mosquito News 27 105-111. 

Deonier, C.C., H.A. Jones, and H.H. Incho. 1946. Organic compounds effective against larvae of Anopheles quadrimaculatus — laboratory tests. Jour. Econ. Entomol. 39 459-462. 

Measures taken to control sources of larval emergence of sanitary pests are limited, and excessive treatments frequently induce the development of resistance in disease-transmitting insects. On the other hand, control measures by individuals are becoming a trend. For example, patients with malaria have decreased by the popularization of Olyset mosquito nets, which were developed by Sumitomo Chemical Co., Ltd. to deal with noctumally-active blood-sucking anopheles. 

In a house on Lombok Island in Indonesia, a paper emanator impregnated with 200 mg of Metofluthrin exhibited repellent effects of 80% or greater against C. quinquefasciatus and Anopheles mosquitoes over a period of 4 weeks [6]. In addition, in outdoor conditions on Lombok Island, it exhibited superior repellent effects against C. quinquefasciatus as well as Anopheles balabaciensis and An. sundaicus, which are vector mosquitoes for malaria [7]. 

Kawada H, Maekawa Y, Tsuda Y, Takagi M (2004) Trial of spatial repellency of metofluthrin-impregnated paper strip against Anopheles and culex in shelters without walls in Lombok, Indonesia. J Am Mosq Control Assoc 20(4) 434... 

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