The paradox of plant preference: the malaria vectors Anopheles gambiae and Anopheles coluzzii select suboptimal food sources for their survival and reproduction

Abstract

Anopheles gambiae s.l. mosquitoes, the primary malaria vectors in sub-Saharan Africa, exhibit selectivity among plant species as potential food sources. However, it remains unclear if their preference aligns with optimal nutrient intake and survival. Following an extensive screening of the effects of 31 plant species on An. coluzzii in Burkina Faso, we selected three species for their contrasting effects on mosquito survival, namely Ixora coccinea, Caesalpinia pulcherrima and Combretum indicum. We assessed the sugar content of these plants and their impact on mosquito fructose-positivity, survival, and insemination rate, using Anopheles coluzzii and Anopheles gambiae, and with glucose 5% and water as controls. Plants displayed varying sugar content and differentially affected the survival, sugar intake and insemination rate of mosquitoes. All three plants were more attractive to mosquitoes than controls, with An. gambiae being more responsive than An. coluzzii. Notably, C. indicum was the most attractive but had the lowest sugar content and offered the lowest survival, insemination rate, and fructose positivity. Our findings unveil a performance-preference mismatch in An. coluzzii and An. gambiae regarding plant food sources. Several possible reasons for this negative correlation between performance and preference are discussed.