They have three distinct regions: a head, a thorax and an abdomen. The head bears one pair of antennae, one pair of mandibules and two pairs of maxillae. The thorax has three pairs of walking legs and one or two pairs of wings in most; the abdomen has no appendages.
Several orders of insects are worthy of medical importance:
· The Diptera includes the mosquitoes, flies and gnats. Some larval flies are parasitic in man and animals, while mosquitoes and gnats transmit many different diseases.
· The Heteroptera, or true bugs, The cone-nose bugs are important as vectors of South American trypanosomiasis.
· The Anoplura, or sucking lice, are wingless, dorse-ventrally compressed insects, among which are included the human lice.
· The Coleoptera, or beetles,. Certain grain beetles are intermediate hosts of tapeworms.
· The Hymenoptera include ants, bees, wasps. Bees and wasps are important because of the venom of their stings, and ants may serve as an intermediate host for one of the trematode parasites of man.
· The Siphonaptera, or fleas, are wingless and laterally compressed; in addition to their irritating bites, some fleas act as intermediate hosts of a species of tapeworm.
· The Anoplura, or lice are permanent ectoparasites and live only on the host.
spp. 1. Mechanical vector of many protozoan species
1. Mechanical vector of many protozoan species
1. Mechanical vector of many protozoan species 2. Protozoa—trypanosomiasis (Trypanosoma spp.)
Other Fly Families
Cochliomyia spp. Other genera
1. Myiasis—primary and secondary—screw worm
1. Myiasis—maggots (fly larvae on skin wound), warbles (fly larvae inside tissues)
