Description of an automatic copulation induction system used to establish a free-mating laboratory colony of Nyssorhynchus deaneorum from Brazil

BACKGROUND Nyssorhynchus deaneorum is a potential malaria vector because it has been shown to be competent to transmit Plasmodium vivax and Plasmodium falciparum, and because it exhibits antropophilic and endophilic behaviors in some regions of the Amazon. This profile makes Ny. deaneorum a useful mosquito for experiments that model Plasmodium-vector interactions in the Amazon. OBJECTIVE Herein we describe how a free-mating colony of Ny. deaneorum has been established using an automated light stimulation system. METHODS Mosquitoes were captured in São Francisco do Guaporé, Rondônia. The F1 generation was reared until adult emergence at which point copulation was induced using an automatic copulation induction system (ACIS). FINDINGS After four generations, natural mating and oviposition began to occur without light stimulation. The number of pupae and adult mosquitoes increased from the F5 to F10 generations. The new Ny. deaneorum colony exhibited susceptibility to P. vivax. MAIN CONCLUSIONS Automated light stimulation is an effective method for establishing an Ny. deaneorum colony under laboratory conditions as it produces enough adults to create a stenogamic colony. The establishment of a stable, P. vivax-susceptible colony of Ny. deaneorum makes it possible to model parasite-vector interactions and to test novel drug therapies that target parasite development in mosquitoes.

Brazil's first free-mating laboratory colony of Nyssorhynchus darlingi

Abstract INTRODUCTION: The lack of highly-productive Nyssorhynchus darlingi laboratory colonies limits some studies. We report the first well-established laboratory colony of Ny. darlingi in Brazil. METHODS: Mosquitoes were collected from Porto Velho and were reared at the Laboratory of Fiocruz/RO. After induced mating by light stimulation in the F1 to F6, the subsequent generations were free mating. Larvae were reared in distilled water and fed daily until pupation. RESULTS: In 11 generations, the colony produced a high number of pupae after the F5 generation. CONCLUSIONS: These results demonstrate the potential for permanently establishing Ny. darlingi colonies for research purposes in Brazil.

Laboratory Colonization of Anopheles (Nyssorhynchus) marajoara (Diptera: Culicidae) by Induced Copulation.

Malaria is a serious public health problem, the control of which involves actions directed against its vector, mosquitoes of the genus Anopheles Meigan, 1818. The study of insect biology, ecology, and behavior is simplified when these insects are maintained at the laboratory. However, many of the species are eurygamic and require induced mating. Females of Anopheles marajoara Galvão e Damasceno, 1942 were collected at Mazagão county, State of Amapá, Brazil. F1 eggs were obtained through forced oviposition and raised until mosquito emergence. Around 300 mosquitoes were maintained in each cage and were fed with a 10% sugar solution. Induced mating was made to obtain the other generations. Females had their spermathecae examined for the presence of sperm. The efficacy of coupling in each generation was evaluated. The viability of a sample of generations F5, F9, F12, and F14 was followed from larvae to adult. Two free mating attempts were done. The results demonstrate adaptation of An. marajoara to laboratory conditions over 21 generations, with viability rates temporally increasing. There was no evidence of adaptation to free mating.