2. BROWN RECLUSE SPIDER
(Loxosceles reclusa)
(unlabelled)
Identification. The brown recluse is a medium-sized spider with a 2- to 4-cm (0.8-1.6 in) legspan and a color range from yellow tan to dark brown. The most distinguishing characteristics are six eyes (most spiders have eight eyes) arranged in a semicircle of three pairs on top of the head, and a violin-shaped marking extending from the area of the eyes to the abdomen.
Distribution. Brown recluse spiders occur throughout an area of the Southcentral States, including Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Ohio, Oklahoma, Mississippi, Missouri, Tennessee, and Texas. Localized populations of this spider, probably imported from the Southcentral States, have been reported from Arizona, Wyoming, California, Florida, New Jersey, North Carolina, Pennsylvania, and Washington, D.C. Due to the mobility of the United States citizenry, specimens can be easily transported in household goods from the spider’s home range in the Southcentral United States to any other area of the country. Under favorable conditions the relocated spiders can survive for an extended period of time and possibly become established.
Biology/Behavior. Within its range, the brown recluse spider will readily establish populations inside parts of buildings which are generally dry, littered, and undisturbed for long periods of time. The spider also can be found outside in protected areas (under rocks and loose bark). Members of this species are nonaggressive and normally attempt to escape whenever they are threatened. Thus, most instances of bites occur when the spider is inadvertently trapped, such as when the victim puts on clothing in which the spider is hiding, steps on a wandering spider at night, or cleans closets or other storage areas where the spider resides.
Avoidance/Control. Any of the following actions will help prevent contact with the brown recluse spider: shake out clothing and bedding before use; eliminate collections of papers and unused boxes; thoroughly clean beneath and behind furniture; remove spiders, webs, and egg cases from living and storage areas; and properly use appropriate insecticides.
Envenomization Reaction/Treatment. (See appendix.)
3. CENTIPEDES
(Class: Chilopoda)
(unlabelled)
Identification. Centipedes are multisegmented elongate arthropods with a distinct head and one pair of legs, or appendages, per segment. Size is species dependent, with body length ranging from approximately 2.5 to 25 cm (1-10 in) or more. The number of legs can therefore vary from 15 to 100 pairs or more, depending upon the species.
Distribution. The range of centipedes varies with the species; however, these arthropods are most numerous in the southern half of the United States.
Biology/Behavior. Throughout the day, centipedes hide under rocks, boards, or bark and in cracks, crevices, closets, basements, and other moist, protected locations. At night, they come out of hiding to hunt for prey which usually consists of insects and other small arthropods. Centipedes inject venom through two powerful claws located on the ventral side of the body immediately behind the head. Contrary to popular belief, centipedes cannot inject venom through their numerous legs. The majority of centipedes found in the United States are small and not a threat to man. Human centipede envenomizations occur when a relatively large centipede is accidentally picked up, stepped on, or otherwise trapped against the body.
Avoidance/Control. When camping in a centipede-infested area, carefully invert and shake out sleeping bags, clothes, or other items left in contact with the ground. Always wear shoes when walking about at night, and wear leather gloves when moving rocks or trash from the ground. Usually centipedes are not sufficiently numerous in any one location to warrant chemical control.
Envenomization Reaction/Treatment. (See appendix.)
4. CONENOSE OR KISSING BUGS
(Triatoma spp.)
(unlabelled)
Identification. Species of the genus Triatoma have the elongate (cone-shaped) head which is characteristic of the family Reduviidae. Hence, the name “conenose bugs” is often used to describe these insects. Orange and black markings are usually present where the abdomen extends laterally past the folded wings. These insects are flattened dorsally, and this trait allows them to effectively hide in small cracks and crevices. The size of mature adults varies from approximately 1 to 3 cm (0.4-1.2 in) depending upon the species.
Distribution. Triatoma species that attack humans are generally located in the southern half of the United States.
Biology/Behavior. Conenose bugs are nocturnal insects. They take their blood meals at night and hide in any available crack or crevice between feedings. Triatoma, as a group, normally feed on small mammals; but in the absence of their preferred hosts, several species will readily feed on humans. They are commonly referred to as “kissing bugs” because their blood meals are occasionally taken from the area around the human lips. Some of the common sites of human attack, in order of frequency, are the hands, arms, feet, head, and trunk. This feeding pattern can be expected since kissing bugs have not been found to feed through clothing.30
Avoidance/Control. Since these bugs can feed undetected on a sleeping victim, it is difficult to avoid their attack in heavily infested areas. Exposure to kissing bugs can be minimized, however, by destroying underbrush, rubbish, wood rats’ nests, and any other small-animal habitat located near a residence.27 When an infestation is detected inside a house, two or three treatments with an appropriate insecticide at 10-day intervals should provide control. To obtain the best results, thoroughly treat all windows, baseboards, walls, cracks, crevices, and bedsprings.
Envenomization Reaction/Treatment. (See appendix.)
5. WHEEL BUG
(Arilus cristatus)
(unlabelled)
Identification. Arilus cristatus has the small narrow head characteristic of the Reduviidae family of Hemiptera (true bugs). This insect is mouse gray in color and approximately 2.5 to 4 cm (1-1.6 in) long. A cogwheel-like crest on the dorsal side of the prothorax is distinctive to this insect and accounts for its popular name, “wheel bug.”
Distribution. Wheel bugs are generally found in the southern two-thirds of the United States.
Biology/Behavior. Wheel bugs are predacious on soft-bodied insects. Human envenomizations are usually the result of accidental contact while handling vegetation, boards, or other objects. The bug penetrates the skin with its “beak,” or proboscis, and injects a salivary fluid normally used in killing its insect prey.31
Avoidance/Control. The best way to prevent wheel bug contact is to be able to identify this unusual insect and avoid it. Children should be instructed not to handle it. Wearing leather gloves while working outside will prevent bites which occur when the wheel bug is accidentally picked up with vegetation or other debris. Since wheel bugs are predacious on many harmful insects and are generally considered beneficial, control is not recommended.
Envenomization Reaction/Treatment. Wheel bug bites are characterized by immediate intense pain which usually subsides in 3 to 6 hours. Since all reported bite reactions have been localized and self-limiting, specific treatment measures are not provided for A. cristatus bites. However, anaphylactic shock has resulted from the bite of other Hemiptera and should be considered a possibility with wheel bug bites.12
