Water source most suitable for rearing a sensitive malaria vector, Anopheles funestus in the laboratory

Abstract

The insecticide susceptibility status of one Background:Anopheles funestus, of the main malaria vectors in the Afrotropical regions, remains under-studied due to the difficulty of working with this mosquito species. Collecting their larvae in natural breeding sites, rearing and maintaining them in normal laboratory conditions have been a difficult task. Forced-egg laying technique has been a very good tool to generate eggs from adult mosquitoes collected from the wild but rearing these eggs to obtain satisfying portion as adults has always been the problem. In this study, we optimized the development of mosquito species larvae under standard laboratory conditions for desired production of adult mosquitoes that can be useful for insecticide susceptibility tests.A forced-egg laying technique was used to obtain eggs from gravid Methods: female collected from Kpome locality in Benin. Eggs were Anopheles funestus reared in three different water samples (water from the borehole, and two mineral water namely FIFA and Possotômè) and larvae were fed with TetraMin baby fish food. The physico-chemical parameters of the waters were investigated prior to use for egg incubation (introduction of eggs' batches into water).In contrast to mineral water that had no contamination, the borehole Results: water source was contaminated with lead (2.5mg/L) and nitrate (118.8mg/L). Egg hatching rates ranged as 91.9 ± 4.4%, 89.1 ± 2.5% and 87.9 ± 2.6% in FIFA, Possotômè and borehole water respectively. High emergence of larvae to adult mosquitoes was recorded as in FIFA (74.3%) and Possotômè (79.5%) water. No adult mosquito was obtained from larvae reared in borehole water.This study gave insight on the water sources that could be good Conclusions: for rearing to mass produce in the laboratory. More analysis with An. funestus other local mineral water sources in our environments could be considered in the future, hopefully giving better outputs.

Fitness Characteristics of the Malaria Vector, Anopheles Funestus, During an Attempted Laboratory Colonization

“…Previous studies investigating the impact of different water sources used for larval rearing in an An. funestus colony (FUMOZ) indicated that their egg hatching rate can exceed 70% [59,60]; con rming hatch rates in this study were low. It is known that females of other Anopheles species can produce unviable eggs without successful mating, or after mating with sperm-less males [61].…”

“…The larval development period of F 1 -FUTAZ (11-14 days) was similar to that reported for An. funestus in other laboratory settings [59,60,62], but faster than FUMOZ development period (21-23 days) observed in this study. The duration of larval development in An.…”

Comprehensive characterization of internal and cuticle surface microbiota of laboratory-reared F1Anopheles albimanusoriginating from different sites

“…Our study represents an initial step in filling this knowledge gap and provides further details regarding the dynamics of changes in both the internal and cuticle surface microbial niches. The homogeneity in internal microbiota of F1 adults is suggestive of a loss in field-acquired microbiota, which could pose an additional set of challenges for field or semi-field mosquito microbiome studiesparticularly studies that rely on laboratory progeny in lieu of field populations to circumvent the challenges involved [25,27,28] in obtaining sufficient numbers of wild mosquitoes of uniform physiological characteristics. Previous findings showed that rearing mosquitoes in water from the field could preserve the field-derived internal microbiota in laboratory-colonized adult progeny of An.…”

“…gambiae, breed in sites that are small, temporary and often difficult to find and/or access [22][23][24][25][26], making it hard to obtain sufficient immature field mosquitoes for experiments. Where larval habitats are plentiful and easy to find and/or access, the subsequent rearing of field-collected mosquitoes to obtain uniform characteristics can pose additional challenges [27,28].…”

Improvement of Water Quality for Mass Anopheline Rearing: Evaluation of the Impact of Ammonia-capturing Zeolite on Larval Development and Adult Phenotypic Quality

“…Similarly, nitrate concentrations were higher from day 4 in NCZ compared to NC, indicating greater ammonia conversion to the less toxic nitrate [31]. The cause of overall higher mortality in Anopheles larval trays without-waterchange (NC and NCZ) in comparison to those with water-change (DC and DCZ) could range from hypoxia, ammonia toxicity, inability to transport oxygen, pathogenicity, nutrient enrichment, and competition for food resource [30,[32][33][34]. In addition, the bacterial build-up that typically accompanies waste accumulation could compound these effects, by increasing hypoxia, ammonia production and/or potential direct bacterial toxicity [29,[35][36][37].…”