Middle East DVEP - Armed Forces Pest Management Board

found in cellars of buildings, cardboard boxes, storage areas, the folds of clothing, andalso outdoors under rocks and rubble. Members of the genus are shy, nonaggressive, andbite only defensively. They may live as long as two years.The brown recluse bite is usually localized but may produce considerable necrosisresulting in significant scarring. Research on the venom has indicated that its action isnecrotic and hemolytic but not neurologic. The bite is usually painless until 3 to 8 hourslater, when it may become red, swollen, and tender. Later a black scab may develop, andeventually an area around the site may decay and slough away, producing a large ulcerfrom 1 to 25 cm in diameter. Healing can require months. Death is rare but has beenrecorded as a result of systemic effects. Treatment of Loxosceles bites is controversialbecause few controlled studies have been conducted, and the severity of the bite isvariable. A specific antivenin has shown success with patients prior to development of thenecrotic lesion, but currently it is not widely available.Several species of widow spiders occur in the Middle East, but Latrodectus mactansis the one most associated with the name "black widow spider." It is also referred to asthe hourglass, shoe button, or po-ko-moo spider. Considerable variation in coloration andmarkings exists between species and between immature and adult spiders. Widow spidersare found in various habitats in the wild, especially in protected places such as crawlspaces under buildings, holes in dirt embankments, piles of rocks, boards, bricks orfirewood. Indoors, they prefer dark areas behind or underneath appliances, in deep closetsand cabinets. They commonly infest outdoor privies, and these should be routinelyinspected by preventive medicine personnel. Widow spiders spin a crude web and usuallywill not bite unless provoked.Latrodectus spp. inject a potent neurotoxin when biting. The bite itself is mild and mostpatients don't remember being bitten. Significant envenomization results in severesystemic symptoms, including painful muscle spasms, a rigid board-like abdomen, andtightness in the chest. Mortality rates from untreated bites have been estimated at 1 to 5%.Most envenomizations respond quickly to sustained intravenous calcium gluconate.Antivenins are commercially available and very effective.3. Ceratopogonidae (biting midges, no-see-ums, punkies). The Ceratopogonidae are alarge family containing nearly 4,000 species. These extremely small flies can easily passthrough window screens and standard mosquito netting. Their small size is responsiblefor the moniker "no-see-ums." Many species in this group attack and suck fluids fromother insects. Most species that suck vertebrate blood belong to the genera Culicoides(1,000 species) or Leptoconops (about 80 species). In the Middle East these insects do nottransmit human diseases, but they do serve as vectors for several diseases of veterinaryimportance. Many species of Ceratopogonidae are widespread in the region, but little isknown about their biology. Most Middle Eastern species of Culicoides are zoophilic.Leptoconops are more likely to be a major nuisance to man. Blood-sucking speciespredominately feed and rest outdoors, entering houses in much smaller numbers. Onlyfemales suck blood. Leptoconops are active during the day; Culicoides may be eitherdiurnal or nocturnal. Diurnal species of both genera prefer early morning and lateafternoon periods. Despite their small size, they often cause local reactions severe enoughto render a military unit operationally ineffective. In sensitive people bites may blister,134