Section III. ARTHROPOD AND VECTORS
The role of various species of insects, lice, ticks, mites and other arthopods as
vectors of disease, or as agents directly responsible for human discomfort, is of
considerable significance in the study of parasites. Indeed, many of the parasites
presented in the previous sections depend solely upon arthropods as a means of
transmission from one host to another. For example, copepods are the intermediate
hosts in the life cycles of the fish tapeworm, Diphyllobothrium latum, Spirometra species
and the guinea worm, Dracunculus medinesis; the female anopheline mosquitoes are
responsible for carrying the dreaded malarial parasites; African trypanosomiasis could
not be transmitted without the lowly tsetse fly, and Chagas' disease would be nearly
eradicated if it were not for the blood sucking family of reduviid bugs.
Because of their involvement in the establishment of various disease entities, it is
desirable that the parasitology technician recognize the overt appearance of various
arthropod species and be able to identify certain general morphological characteristics.
The following pages contain illustrations of the prominent features of some of the most
important arthropod vectors and agents.
Figure 4-42. Morphology of a Copepod.