15. Medical and veterinary entomology
Aside from their impact on agricultural and horticultural crops, insects impinge on us mainly through the diseases they can transmit to humans and our domestic animals. The number of insect species involved is not large, but those that transmit disease (vectors), cause wounds, inject venom, or create nuisance have serious social and economic consequences. Thus, the study of the veterinary and medical impact of insects is a major scientific discipline.
Medical and veterinary entomology differs from, and often is much broader in scope than, other areas of entomological pursuit. Firstly, the frequent motivation (and funding) for study is rarely the insect itself, but the insect-borne human or animal disease(s). Secondly, the scientist studying medical and veterinary aspects of entomology must have a wide understanding not only of the insect vector of disease, but of the biology of host and parasite. Thirdly, most practitioners do not restrict themselves to insects, but have to consider other arthropods, notably ticks, mites, and perhaps spiders and scorpions.
For brevity in this chapter, we refer to medical entomologists as those who study all arthropod-borne diseases, including diseases of livestock. The insect, though a vital cog in the chain of disease, need not be the central focus of medical research. Medical entomologists rarely work in isolation but usually function in multidisciplinary teams that may include medical practitioners and researchers, epidemiologists, virologists, and immunologists, and ought to include those with skills in insect control.
In this chapter, we deal with entomophobia, followed by allergic reactions, venoms, and urtication caused by insects. This is followed by details of transmission of a specific disease, malaria, an exemplar of insect-borne disease. This is followed by a review of additional diseases in which insects play an important role. We finish with a section on forensic entomology. At the end of the chapter are taxonomic boxes dealing with the Phthiraptera (lice), Siphonaptera (fleas), and Diptera (flies), especially medically significant ones.