The influence of larval density on triacylglycerol content in Aedes aegypti (Linnaeus) (Diptera: Culicidae)

Abstract

Given the importance of Aedes aegypti as an arbovirus vector, understanding the impact of population density during larval development is fundamental to improve control methods. The aims of this study were to analyze the effects of larval density on the triacylglycerol (TAG) reserves, fecundity, and the size of mosquitos. To evaluate the influence of density on the amount of TAG in the different stages of development of A. aegypti, the larvae were reared in densities of 0.04, 0.32, and 0.8 larvae/ml, represented by D1, D2, and D3, respectively. Larval rearing density affected the amount of TAG in the different developmental stages of this insect. The group reared with the highest population density (D3) presented greater storage of TAG, except when analyzing the amount of TAG μg/protein in the fat body of blood‐fed females. In addition, it was possible to observe higher resistance to fasting and a greater number of eggs laid. Insects reared in D2 and D3 were larger than those in the D1 group. This study provides interesting data for future investigations on how the density of larval rearing affects the lipid metabolism for synthesis and mobilization of TAG stored in A. aegypti and how it influences size and reproduction.

Targeting Aedes aegypti Metabolism with Next-Generation Insecticides

“…Fatty acids stored in lipid droplets within cells in the fat body take the form of triacylglycerols and are mobilized through lipolysis to maintain metabolic activity of cells and tissues, and provide energy needs for long-term flight, oogenesis, and resisting starvation [ 91 , 92 , 93 , 94 ]. Insect adipokinetic hormone (AKH), juvenile hormone (JH), and 20-hydroxyexdysone (20E) act as metabolic switches to promote the mobilization of stored lipids [ 95 , 96 ].…”

The buzz in the field: the interaction between viruses, mosquitoes, and metabolism

“…This suggests that better nutrition at larval stages can impact the adult vectorial capacity. Moreover, studies by Silva et al, 2021 has shown how higher larval rearing densities can elevate stored TAG levels within adult mosquitoes and also influence the size and fecundity of the mosquito (Silva et al, 2021).…”

Differential expression of brummer and levels of TAG in different developmental stages Aedes aegypti (Diptera: Culicidae), including fasted adults

“…Blood meals promote release of a series of signals that activate the metabolism through their action in different targets, including fat body, similar to the liver and fat tissues in vertebrates (Roy et al, 2007). In Aedes aegypti , lipid storage in the form of TAG is particularly important during its life cycle (Silva et al, 2020). The distribution of lipid content in these insects varies according to demand and can enable processes such as oogenesis, flight, diapause, metamorphosis and even fasting.…”

“…In female mosquitoes previously fed with sugar, the formation of TAG reserves is more efficient and has a significant contribution to oogenesis (Ziegler & Ibrahim, 2001). In addition, the reserves established during the larval stages contribute significantly to the formation of TAG reserves (Silva et al, 2020; Takken et al, 2013).…”