Body stores of emergent aquatic insects are associated with body size, sex, swarming behaviour and dispersal strategies

Abstract

Dispersal is a determining step in the life cycle of insects and a key factor of their energy budget. If the body stores of terrestrial insects are relatively well‐documented, those of merolimnic insects (i.e., with aquatic larvae and terrestrial winged adults) remain poorly investigated. We assayed the body stores (protein, carbohydrate and lipid contents) of 18 families of merolimnic insects, encompassing a wide diversity of biological and ecological traits. We highlighted allometry between body stores and mass. The proportion of triglyceride and free carbohydrate relatively decreases with an increase in absolute insect mass, whereas protein and glycogen contents are proportional. We found a significant effect of insect order, Diptera having relatively more proteins than Trichoptera. For swarming taxa, males have relatively more triglycerides than their conspecific female. Passive dispersers are characterised by higher protein and glycogen contents Each body store was associated with specific life‐history traits, emphasising the importance of considering each body store independently to better understand the associated functions. Dispersal strategies seem to be the main structuring factor underlying body store patterns of merolimnic insects, being significantly associated with the variation in adjusted triglycerides (30%), proteins (21%), glycogen (29%) and free carbohydrates (17%). However, our study estimated the role of flight only indirectly through the biological traits of insects. Future works should focus on identifying which substrates are used for flight, by comparing the proportion of body stores before and after flight, as well as protein identification to distinguish proteins associated with flight or reproduction. These further studies will help researchers in understanding the link between body stores of emerging merolimnic insects and the various facets of their ecology.

Ageing and mating status affect food utilization efficiencies and assimilation of macronutrients in adults of Parthenium beetle, Zygogramma bicolorata Pallister

“…The results are in agreement with those reported earlier in the oriental armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae), under both fluctuating and constant temperatures (Lv & Xie, 2022), in the coccinellid beetle, C. septempunctata , over a range of geographic locations (Zhou et al, 1995), and in the Mediterranean fruit fly, Ceratitis capitata Wiedemann (Diptera: Tephritidae), over a range of diets (Nestel et al, 2005). Contrary to our findings, Gerber et al (2022) reported more triglycerides in males than their conspecific females in swarming taxa of merolimnic insects.…”

Nutrition and density dependence of spontaneous female-biased dispersal inDrosophila melanogaster

“…There can be at least two potential alternative explanation of the observed pattern of female biased dispersal in our assays. First, females in D. melanogaster are, on an average, larger than males (Horabin, 2005), and are hence expected to have higher amount of stored resources in their body (Gerber et al, 2022). Body size dependent dispersal rate is not unheard of (Bonte et al, 2012, see Anderson and Fahimipour, 2021 for a relatively recent exposition relevant to stability of metacommunity).…”

Impact across ecosystem boundaries – Does Bti application change quality and composition of the diet of riparian spiders?

“…A shift in consumed prey can also involve a change in the available nutrients for the predator (Toft, 2013). In fact, the nutrient content varies depending on the insect order, the mating system and the dispersal strategy (Gerber et al, 2022), which may affect spider performance including the web quality (Blamires et al, 2009) or the reproductive success (Salomon et al, 2008), parameters especially related to the availability of proteins and lipids, respectively. Such an impact on the individual level may, in the long run, have consequences for the development of spider populations: densities of web-building riparian spiders usually decrease with altered or reduced aquatic subsidy (Kato et al, 2003;Marczak and Richardson, 2007;Paetzold et al, 2011) which could lead to propagating effects on consumers feeding on spiders (Recalde et al, 2020).…”