Herpetomonas

HERPETOMONAS, herpetomonads, elongated flagellates, with a nucleus in the middle of the body and a blepharoplast at the anterior end, in front of the nucleus; they have 1 flagellum. They belong to the family Trypanosomidae. They enter the developmental cycle of trypanosomes, appearing as developmental stages of the latter in the intestines of insect vectors, as well as in cultures of some trypanosomatids, for example, leishmanias. However, some representatives of H. have specialized as independent parasites in various insects, for example, flies (H. muscaedomesticae, see figure), mosquitoes (H. algeriensis), etc. For this reason, the herpetomonads of insects themselves can be a source of errors in identifying the herpetomonad developmental stages of trypanosomes. Cultures of Herpetomonas have been obtained on blood media. For the precise differentiation of various species of Noguchi proposed a biochemical criterion based on the fermentation of various carbohydrates, which in some cases can provide certain benefits. For some insects, for example, for the bug Pyrrhocoris apterus L., a simultaneous infection of the intestine and body cavity with the herpetomonad Herpetomonas pyrrhocoris Zotta has been described. In others, for example, in the silkworm and in the larvae of midges (Simulium), herpetomonads live exclusively in the coelom. Infection of larvae probably occurs through predatory insects. Thus, for example, larvae of Agrotis pronubana become infected with herpetomonads through the agency of ichneumonid wasps (Ichneumonidae). According to the latest data, the causative agent of so-called pendian ulcer (cutaneous leishmaniasis) - Leishmania tropica - is transmitted by the midge Phlebotomus pappatasii and in the intestine of the latter it occurs in the form of a herpetomonad - H. pappatasii. Herpetomonads have also been described in the intestines of head and body lice. This species (H. pediculi) is probably an independent parasite of lice and does not possess pathogenic properties. H. pediculi also forms non-flagellated stages. The latter are excreted with the feces of lice and are ingested by healthy lice, which become infected in this way.