Cost-effective larval diet mixtures for mass rearing of Anopheles arabiensis Patton (Diptera: Culicidae).

BACKGROUND: Larval nutrition, particularly diet quality, is a key driver in providing sufficient numbers of high quality mosquitoes for biological control strategies such as the sterile insect technique. The diet currently available to mass rear Anopheles arabiensis, referred here to as the "IAEA diet", is facing high costs and difficulties concerning the availability of the bovine liver powder component. To promote more affordable and sustainable mosquito production, the present study aimed to find alternative diet mixtures. Eight cheaper diet mixtures comprised of varying proportions of tuna meal (TM), bovine liver powder (BLP), brewer's yeast (BY), and chickpea (CP) were developed and evaluated through a step by step assessment on An. arabiensis larvae and adult life history traits, in comparison to the IAEA diet which served as a basis and standard.

RESULTS: Four mixtures were found to be effective regarding larval survival to pupation and to emergence, egg productivity, adult body size and longevity. These results suggest that these different diet mixtures have a similar nutritional value that support the optimal development of An. arabiensis larvae and enhance adult biological quality and production efficiency, and thus could be used for mass rearing.

CONCLUSIONS: Our study demonstrated that four different diet mixtures, 40 to 92% cheaper than the IAEA diet, can result in a positive assessment of the mosquitoes' life history traits, indicating that this mosquito species can be effectively mass reared with a significant reduction in costs. The mixture comprised of TM + BY + CP is the preferred choice as it does not include BLP and thus reduces the cost by 92% compared to the IAEA diet.