Plant nutrient quality promotes survival and reproductive fitness of the dengue vector Aedes aegypti

Abstract

Background In a recent study using DNA barcoding, we identified the plants fed upon by four Afro-tropical mosquito species that vector dengue, malaria, and Rift Valley fever. Herein, we have expanded on this study by investigating the role of three of the plants Pithecellobium dulce (Fabaceae), Leonotis nepetifolia (Lamiaceae), and Opuntia ficus-indica (Cactaceae) on survival, fecundity, and egg viability of the dengue vector Aedes aegypti. Methods We tested these effects using females that received a) an initial three rations of bloodmeal, and b) received no bloodmeal at all. Two controls were included; age-matched females fed on glucose solution with or without initial bloodmeal, and those fed exclusively on bloodmeal. Data was collected daily over a 30-day period. The amino acid content of Ae. aegypti guts and the amino acid content of their respective diets was detected by coupled liquid chromatography – mass spectrometry. Results Females fed on P. dulce and exclusive bloodmeal had a shorter survival than those fed on glucose. On the other hand, females fed on L. nepetifolia survived longer than those fed exclusively on bloodmeal, whereas those fed on O. ficus-indica had the shortest survival time. With initial bloodmeal, females fed on L. nepetifolia laid 1.6-fold more eggs while those fed on the other diets laid fewer eggs, compared to those fed exclusively on bloodmeal. Hatching rates of the eggs laid varied with the diet. Mass spectroscopic analysis of gut contents of mosquitoes exposed to the different diets showed qualitative and quantitative differences in their amino acid levels. Conclusion Our findings highlight the central role of plant nutrients in the reproductive fitness of dengue vectors which may impact their disease transmission potential.

Supplementing Blood Diet With Plant Nectar Enhances Egg Fertility in Stomoxys calcitrans

“…Plant sugar feeding also has neutralization benefit of plant defense (Malka et al, 2020). However, we cannot rule out that feeding on plants will not affect either the number of eggs nor survival if we try other plants that S. calcitrans has a choice of under natural conditions, as plant species vary in the amount and quality of resources (Roulston et al, 2000;Nyasembe et al, 2020). Most plant nectars found in A. gambiae habitats contain sucrose and/or its hexose hydrolysis products, glucose and fructose.…”

Modulation of odour-guided behaviour in mosquitoes

“…Most females oviposit within 96 h of a blood meal. The y-axis denotes the generalised proportion of mosquitoes participating in the associated behaviour based on, e.g., Alto et al 2003;Bohbot et al 2013;Christ et al 2017;Davis 1984b;Foster 1995, references therein;Klowden 1989;Klowden 1994;Klowden and Blackmer 1987;Klowden and Lea 1984;and Vargo and Foster 1982 used to enhance survival and reproduction (Briegel 1990;Briegel 2003;Manda et al 2007;Moller-Jacobs et al 2014;Nyasembe et al 2020;Shapiro et al 2016;Vrzal et al 2010;Yu et al 2016). As for other behaviours, feeding on plant fluids is endogenously regulated with many species displaying a diphasic feeding cycle (Chadee et al 2014;Gillett et al 1962, and references therein).…”