An Analysis of Diet Quality, How It Controls Fatty Acid Profiles, Isotope Signatures and Stoichiometry in the Malaria Mosquito Anopheles arabiensis

Abstract

BackgroundKnowing the underlying mechanisms of mosquito ecology will ensure effective vector management and contribute to the overall goal of malaria control. Mosquito populations show a high degree of population plasticity in response to environmental variability. However, the principle factors controlling population size and fecundity are for the most part unknown. Larval habitat and diet play a crucial role in subsequent mosquito fitness. Developing the most competitive insects for sterile insect technique programmes requires a “production” orientated perspective, to deduce the most effective larval diet formulation; the information gained from this process offers us some insight into the mechanisms and processes taking place in natural native mosquito habitats.Methodology/Principal FindingsFatty acid profiles and de-novo or direct assimilation pathways, of whole-individual mosquitoes reared on a range of larval diets were determined using pyrolysis gas chromatograph/mass spectrometry. We used elemental analysis and isotope ratio mass spectrometry to measure individual-whole-body carbon, nitrogen and phosphorous values and to assess the impact of dietary quality on subsequent population stoichiometry, size, quality and isotopic signature. Diet had the greatest impact on fatty acid (FA) profiles of the mosquitoes, which exhibited a high degree of dietary routing, characteristic of generalist feeders. De-novo synthesis of a number of important FAs was observed. Mosquito C:N stoichiometry was fixed in the teneral stage. Dietary N content had significant influence on mosquito size, and P was shown to be a flexible pool which limited overall population size.Conclusions/SignificanceDirect routing of FAs was evident but there was ubiquitous de-novo synthesis suggesting mosquito larvae are competent generalist feeders capable of survival on diet with varying characteristics. It was concluded that nitrogen availability in the larval diet controlled teneral mosquito size and that teneral CN ratio is a sex- and species-specific fixed parameter. This finding has significant implications for overall mosquito competitiveness and environmental management.

Evolutionary biology and genetic techniques for insect control

“…Diet utilization Strong selection for high productivity on novel artificial diets, likely to select for adaptation to utilize new food components efficiently and to affect many different life history traits (e.g., Hood-Nowotny et al 2012;Yahouedo et al 2014). Adaptation to artificial, standardized, and simpler diets is expected to reduce gut microbial diversity Chandler et al 2011), reducing host fitness.…”

Analysis of the Transcriptome of Blowfly Chrysomya megacephala (Fabricius) Larvae in Responses to Different Edible Oils

“…Low levels of diet fat can enhance the lifespan of the blowfly, while high-fat diets can cause more rapid death [10]. Diet also has a great impact on the fatty acid profiles of mosquitoes, which exhibit a high degree of dietary routing, characteristic of generalist feeders [11]. Actually, the fatty acids present in dietary lipids could directly affect the tissue phospholipid composition in D. melanogaster [12].…”

Consumer‐resource stoichiometry as a predictor of trophic discrimination (Δ13C, Δ15N) in aquatic invertebrates

“…Here, consumer‐resource imbalances strongly affected isotope discrimination, indicating that imbalances are a more relevant descriptor of nutrient quality than resource elemental concentrations because they relate resource nutrient concentration to consumers’ demand. Furthermore, we showed that P content can be an important descriptor of nutrient quality, a fact that is well established in ecological stoichiometry but so far rarely appreciated in stable isotope ecology (Hood‐Nowotny et al., ). Our work has three major implications.…”