Parasitismo de Romanomermis iyengari en larvas de tres especies de mosquitos en laboratorio y de anopheles pseudopunctipennis en campo

A laboratory evaluation was carried out to determine the parasitic capacity of the nematode Romanomermis iyengari on III and IV instar larvae of the mosquitoes Aedes aegypti, Anopheles pseudopuntipennis, and Culex quinquefasciatus, applying a dose of 10 nematodes larva ^-1. The effectiveness of R. iyengari in larvae of An. pseudopunctipennis in the field was evaluated in Pochutla, State of Oaxaca, México. R. iyengari efficiently parasitize III and IV instar larvae of the three mosquito species. The III instar larvae of the three species of mosquitoes were more susceptible to parasitism than the IV instar larvae. The larvae of An. pseudopunctipennis were the most susceptible to infestation by R. iyengari (85.8-96.7%) in comparison with Ae. aegypti (80.0-88.3%) and Cx. quinquefasciatus (80.8-91.7%). The adults from larvae parasitized during III and IV died 3-6 d after emergence. The development of the parasitic phase of the nematode normally took place during the pupal and adult stages of the mosquito. Field applications of R. iyengari were made at a density of 3000 nematodes m ^-2 to ten natural larval rearing sites of An. pseudopunctipennis causing 90% to 100% parasitism, infestations ranging from 1.8 to 3.1 nematodes per larvae, and with larval population reductions of 82.2 to 99.0%.