Mechanical trauma is caused by a variety of arthropods, including bees, wasps, ants, spiders, scorpions, centipedes, and millipedes. Some people have severe allergic reactions to bee and spider venoms. Bee toxins are similar to viperine snake venom because they have a hemolyzing factor; however, bee toxins also contain histamine. Allergic individuals may exhibit symptoms of anaphylaxis and may require antihistamine or epinephrine to stop the reaction if bronchospasm occurs. Wasps, hornets, and bumble bees are capable of multiple stings without losing their stinging apparatus. Honey bees can sting only once because they have a barbed stinger that detaches from the body as the bee flies away.
A discussion of arthropods in relation to disease would not be complete without mention of their obvious and annoying activities of stinging and biting. The bites of fleas, mosquitoes, bedbugs and the like, while always irritating, do not affect every person in the same manner. Some people do not suffer any appreciable harm; others react very strongly to the bites of certain arthropods, exhibiting various allergic manifestations and generalized as well as local effects. Rarely, the bites cause systemic reactions, with ulceration and prolonged healing of the lesions. It is common knowledge that some individuals will not be unduly affected by flea bites but may be very sensitive to the bites of mosquitoes, for example. Conversely, insects of a given kind seem to prefer certain individuals to others. In general, it may be said that the reaction to bites and to stings of certain arthropods will vary with the species of arthropod and with each individual person. Insects such as bees, for instance, while inflicting a painful sting, may not produce any further damage. However, in a person sensitized to bee venom, bee stings may have serious consequences and may even lead to death. It is of interest that bee stings were once used in the treatment of arthritis; the beneficial effects ascribed to this form of therapy may possibly have been due to increased secretion of steroid hormones.
The sting of certain species of scorpions and the bites of centipedes and of spiders such as Latrodectus, the black widow, may be quite dangerous. The reaction to these stings and bites will vary with the amount of venom injected and with the body size and general health of the afflicted individual. While a healthy adult will usually recover, small children or weakened individuals will suffer considerably and may die if proper care is not instituted immediately
39.8. Control of Arthropoda is difficult. Use of chemical sprays is still widespread, but it has very serious consequences for the environment and other life forms because synthetic chemicals are often carcinogenic, are non biodegradable, and remain in the food chain. In addition, many insecticide-resistant species of insects have evolved as a result of spraying.
Other arthropod control methods being tried include increasing natural predators (e.g., flies that lay eggs on fire ants, and hatching larvae eat the ant), destroying breeding grounds, controlling biologically (e.g., releasing artificially sterilized males, as was attempted with screw worm and fruit flies), using pheromones and other types of trap bait, introducing a faster-breeding competitive species, and removing host species on which the insect feeds. All of these methods often lead to only temporary control in local areas.