Effect of larval density and additional anchoring surface on the life‐history traits of a laboratory colonized Anopheles funestus strain

Abstract

Optimal rearing conditions, inclusive of larval rearing density, are critical for sustained mosquito productivity. There is limited information on favourable conditions for the larval rearing of Anopheles funestus, the dominant malaria vector in east and southern Africa. This work investigated the effects of larval rearing densities and additional anchoring surface on An. funestus development using a life table approach. Larval cohorts were reared at four different larval densities using the same rearing surface area, larval food concentrations and temperature conditions. Rearing larvae at high densities extended the larval developmental time and reduced adult productivity. Adding an extra larval anchoring surface when rearing larvae at high density resulted in extended larval developmental time, increased larval survivorship and produced bigger adults. These findings improve our understanding of the relationship between larval density and developmental traits in An. funestus and provides baseline information for An. funestus rearing under laboratory conditions.

Optimisation of laboratory-rearing parameters for Anopheles funestus larvae and adults

“…Interestingly the wing sizes reported in this study were bigger than previously published studies on An. funestus ( Mwangangi et al., 2004 ; Ngowo et al., 2021 ; Zengenene et al., 2022 ). Therefore, it is possible that the quantity of food provided was above the daily nutritional requirements for the larvae.…”

“…Aquatic stages were maintained on a standard powdered larval diet consisting of crushed dog biscuits (Beeno®, South Africa, http://www.beeno.co.za ) and brewer's yeast (Vital®, Vital Health Foods, South Africa), mixed at a 3:1 ratio respectively. The nutritional composition of the dog biscuits is provided in Zengenene et al. (2022) .…”

“…arabiensis ( Gilles et al., 2011 ; Damiens et al., 2012 ; Somda et al., 2017 ). Increased larval densities can also lead to extended larval development periods ( Zengenene et al., 2022 ). This phenomena of extended larval development time and smaller An.…”

“…However, there remains a limited number of larval rearing studies conducted on An. funestus ( Ngowo et al., 2021 ; Zengenene et al., 2021 , 2022 ).…”