Lifetime allocation of juvenile and adult nutritional resources to egg production in a holometabolous insect

Abstract

In holometabolous insects reproductive success is strongly determined by the nutritional resources available to the females. In addition to nutrients derived from adult feeding, resources for egg production may come from the limited reserves accumulated during the larval stages. The pattern of allocation of these larval reserves to egg production is expected to be strongly linked to the nutritional ecology of the adult. We investigate the temporal pattern of allocation of larval reserves to reproduction in a hostfeeding parasitoid wasp. As predicted by the dynamics of allocation of an adult meal, larval reserves are the main source of nutrients for four or ¢ve days after emergence. However, despite the high frequency of host feeding and the high nutrient content of a haemolymph meal, which we predicted would lead to larval reserves being conserved in the event of host deprivation, larval reserves contribute to egg production throughout the lifetime of the female. We propose several mechanistic and adaptive explanations for our results, including the possible existence of a limiting or key nutrient for egg production of exclusively larval origin. We make further predictions concerning the pattern of allocation of larval resources in parasitoids with di¡erent adult nutritional requirements.

The relationship between body mass and elemental composition in nymphs of the grasshopper Schistocerca americana

“…From an adaptive standpoint, the patterns of stoichiometric variation with body mass may be needed to fulfill the nutrients requirements of diapause, potentially increasing their fitness. According to our results and some published literatures (Tammaru et al 1996, Wheeler et al 2000, Rivero et al 2001, O'Brien et al 2002, Telfer and Pan 2003, Calvo and Molina 2005, we speculate that the high C:N in larval storage implies that holometabolous insects retain more lipid for survival. For the low C:N and C:S in larval storage, reflecting consumer sequestered more sulfur protein for metamorphosis and reproduction.…”

Translating Available Food Into the Number of Eggs Laid by Drosophila melanogaster

“…How- (Britton et al 2002;Ikeya et al 2002). In addition, ever, in flies that have 20E at physiological concentranutrition has long been known to affect egg production tions injected into their abdomen, apoptosis is observed in many insects (Rivero et al 2001).…”

Testing mechanistic models of growth in insects

“…In general, adult insects do not have access to the same diet available to immature stages, not least of all due to their different morphology [27,28]. This explains why insect reproduction is constrained by resources accumulated during the immature phase and cannot be offset by compensatory feeding in the adult stage [24,25].…”

“…The majority of insects are holometabolous and do not eat during pupation [23], with many even lacking functional mouthparts during the adult phase [23]. For these insects, nutrients acquired during the immature stages strongly determine reproductive effort [24,25]. But even insects that do not metamorphose may be more nutrient limited as they age.…”