Lipid and protein loads in pupating larvae and emerging adults as affected by the composition of Mediterranean fruit fly (Ceratitis capitata) meridic larval diets

Abstract

The effects of sucrose and amino acid (aa) composition and concentration in meridic larval diets (e.g., partially defined at the chemical level) was examined on several parameters of Mediterranean fruit fly (Medfly) development. Lipid and protein levels of pupating larvae and emerging adults were examined. Different sucrose concentrations in the diet had small effects upon most of the development parameters. However, sucrose concentration significantly affected the ability of larvae to accumulate lipid reserves and proteins. Adults emerging from the different sucrose diets did not significantly differ in their lipid contents and protein loads. Specific deletions of aa from the diet, and general aa concentration, had a strong effect upon the parameters of development and pupating larvae lipids and proteins. Glycine-deletion was the most deleterious, followed by the deletion of all non-essential aa, and serine. High aa concentration in the diet has a detrimental effect upon development. Lipid contents in pupating larvae, and to some extent protein levels, were affected by aa manipulations in the diet. Lipid and protein loads in emerging adults were not significantly affected by aa manipulations. Based on the analysis of lipid frequency distribution it is suggested that the Medfly seems to regulate the level of lipid content in emerging adults within a certain range, regardless of the larval diet history or lipid contents. Proteins do not seem to be regulated as are lipids. These results point to an interesting and unexpected metabolic regulation of energetic resources during metamorphosis of the Medfly.

Effects of macronutrient intake on the lifespan and fecundity of the marula fruit fly, Ceratitis cosyra (Tephritidae): Extreme lifespan in a host specialist

“…The fact that adult females fed on carbohydrate only were still able to lay eggs suggests that protein may have been stored from the larval stage in a form that can be retrieved by adults. Storing of protein from the larval stage has been observed in C. capitata where protein content measured in emerging adults corresponded with the protein content in pupating larvae (Nestel, Nemny‐Lavy, & Chang, 2004). …”

Trends in lipid and protein contents during medfly aging: An harmonic path to death

“…The rhythmic patterns in lipid contents observed in this study, hence, point to a unique endogenous regulation of lipid reserves that has not been previously described in fruit flies. This unique pattern of lipid regulation throughout medfly adult life adds to a recently described exceptional regulation of lipids during the larval-adult transition of the fly: regardless of the original lipid levels at the time of larval pupation, the pupae seem to regulate lipid loads towards a certain optimum level for adult emergence (Nestel et al, 2004). The metabolic aim of this special regulation of lipid reserves during pupation and adult life is an intriguing question that deserves to be further investigated.…”

“…Their patterns are expected to express the energetic demands of the organism at a given time and situation. Lipid reserves have been shown in previous studies to reflect the energetic status of the medfly: a decrease in lipid levels has been observed when the developing fly is in high demand of energy and its input of energy through food intake is deficient (Nestel et al, 1985(Nestel et al, , 2004 or absent, such as in the pupal stage (Nestel et al, 2003). If lipids are in fact a reflection of the energetic balance of the medfly, the results obtained in this study suggest that the flies throughout their adult life were not in a negative energetic balance, at least regarding the caloric intake provided by sucrose and the energy required for egg-laying and maintenance.…”

Effects of gamma‐irradiation on midgut proteolytic activity of the mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae)

“…Protein availability in nature is a fundamental determinant of male medfly fitness because amino acids are required for both physiological maintenance and reproductive success Nestel et al, 2004). A positive effect of post-teneral protein nutrition on the sexual competitiveness has been established for cases involving competition between wild males Yuval et al, 2002) or mass-reared males .…”