An artificial feeder for breeding and infection of mosquitoes.

BONICA M.B; CHUCHUY, A; MUTTIS, E; GOENAGA, S; MARTI G.A; MICIELI M.V

Manaus State of Amazonas Brazil

Congreso; Latin American Society for Vector Ecology - LASOVE,; 2019

Aedesaegypti is the mainurban vector of many flavivirus involved in human diseases, such as Dengue(DENV), Zika (ZIKV) and Yellow Fever (YFV). For this reason, it is subject ofstudy all over the world where Ae.aegypti colonies are well established in insectaries. As a blood meal isrequired by female mosquitoes to produce eggs, this is a critical step whilerearing a colony. In laboratory live animals are usually employed to maintain acolony, while several artificial feeders, which differ for some features weredeveloped for experimental assays. In this study we propose a method ofalimentation which gathers the best qualities in order to eliminate the use oflaboratory animals, improve mass rearing, and obtain a safe and autoclavablefeeder that can be employed for oral infections. According to the available literature and taking intoconsiderations the best characteristics of the artificial feeders previouslydescribed (material, type of membrane employed, method of temperatureregulation) we developed a feeding device characterized by low cost, safety andsterility, together with a practical assembly and disassembly of the unit. Theefficiency of this apparatus was measured by using three reproductiveparameters (hatchability, blood feeding rate, and number of eggs laid by eachcolony) and by performing a vector competence assay. Ae.aegypti eggs from an established colony in La Plata(Argentina) were hatched (Parental line, P). Egg hatchability was recordedafter 48hs. Larvae, pupae and adults mosquitoes were observed daily. Emergedadults were counted and sexed, and a blood meal was offered once a week. Forthis purpose a glass feeder which employs a cattle gut membrane, and bloodmaintained at 37°C due to a hot water circulation system around the device wasemployed. Engorged females were counted to determine the blood feeding rate.The eggs laid during each week were counted and subsequently hatched for thefilial generation (F1) follow up.To evaluate vector competence, Ae.aegypti adults were fed with infected blood. Body, legs andsaliva were harvested and tested by plaque tritation for ZIKV in order tocalculate infection, transmission, and dissemination rates, respectively. Results:After 48hs hatchabilitywas 92% for P and 80.3% for F1. Feeding rates (P=54.4%, F1=72.7%)and the average number of eggs per female per week in each generation (P=5.3, F1=16.6)were calculated at the end of the experiment. The vector competence assay showedthat Ae. aegypti mosquitoes were positivefor ZIKV in body, legs, and saliva. Hatchability, feeding rates and the average number ofeggs per female in each generation were similar or higher compared to thoseobtained with other feeding methods for this mosquito species. The effectivenessof the feeder for vector competence studies was demonstrated by obtainingpositive results for the infection, dissemination and transmission of ZIKV in Ae. aegypti.