Utilização de Larvas de Toxorhynchites no Controle de Formas Jovens de Culicideos Vetores de Doença

Abstract

The family Culicidae comprises three subfamilies: Culicinae, Anophelinae and Toxorhynchitinae. The subfamily Toxorhynchitinae, the object of this study, is represented by a single genus: Toxorhynchites; with three subgeneric categories: Lynchiella lahile, 1904; Ankylorhynchus luts, 1904; Toxorhynchites Teobald, 1901. The genus Toxorhynchites contains 61 species, distributed in all zoogeographic regions of the world. The objective of this work is to verify the predatory potential of Toxorhynchites larvae in relation to other subfamilies of Culicidae. To obtain larvae of Toxorhynchites sp. we searched different environments such as bamboo internodes, spider hedgehogs, Bromeliaceae leaf axils and artificial water reservoirs. Only two species of Toxorhynchites have been recorded so far. The two species collected were Toxorhynchites (Lynchiella) haemorrhoidalis haemorrhoidalis (Fabrici us, 1794) and Toxorhynchites (Lynchiella) theobaldi (Dyar & knab, 1906). A total of 107 Toxorhynchites larvae were captured in three different environments in natural and artificial breeding ponds. Of the 107 specimens found, 70 survived to laboratory rearing and reached the adult stage, 21 did not survive the new environmental conditions, and 16 are still being reared for further identification. All larval stages of Toxorhynchites haemorrhoidalis and Toxorhynchites theobaldi are potentially predatory, with the 3rd and 4th stages being the most voracious. They can feed on larger or smaller larvae and cannibalism among them is quite frequent. As for feeding preference, it was found that both Toxorhynchites haemorrhoidalis and Toxorhynchites theobaldi prefer larvae to pupae. Under laboratory conditions, Toxorhynchites larvae can naturally control mosquito populations, especially Culex, followed by Wyeomyia, Sabetis, Ochlerotatus and Limatus.