|Chang, Chiou Ling|
Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2004
Publication Date: 7/5/2004
Citation: Nestel, D., Nemni-Lavy, E., Soroke, V., Chang, C.L. 2004. Lipid and protein loads in pupating-larvae and emerging adult as affected by the composition of a mediterranean fruit fly (ceratitis capitata) meridic larval diet. Archives of Insect Biochemistry and Physiology. 56:97-109. Interpretive Summary: The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), a worldwide pest, has been mass-reared for SIT program worldwide. While of great importance, artificial diets, which have been highly efficient in the development of mass-rearing systems for fruit flies, provide restricted information on the nutritional requirements of the flies. The determination of nutritional necessities requires that the investigations be conducted on holidic diets (e.g., chemically defined diets, where all the constituents are chemically known). These types of diets for larvae fruit flies have been seldom developed. Recently, Chang et al. (2000) reported on the development of an almost chemically defined larval diet (e.g., a meridic diet in which most of the ingredients, except for one or two, are chemically characterized) for the Medfly. This diet is based on corncob as a bulking agent which, although having some trace elements of nutrients, is basically a nutritionally inert substance. This diet was used to manipulate essential nutrients and investigate their effects upon some parameters of development (e.g., development periods of immature flies, pupal recovery and pupal weight, etc.) and adult behavior (e.g., proportion of fliers, and F1 and F2 proportion of egg-hatch). Authors took advantage of this meridic diet to investigate the effect of diet constitution on the ability of Medfly larvae and emerging adult to accumulate lipids and proteins. We specifically investigated the effects of sucrose and amino acids content and concentration on the diet.
Technical Abstract: The effects of sucrose and amino acid composition and concentration in meridic larval diets were examined on several parameters of 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 amino acid form the diet, and general amino acid concentration, had a strong effect upon theparameters of development and pupating larvae lipids and proteins. Glycine-deletion was the most deleterious, followed by the deletion of all non-essential amino acid, and serine. High amino acid concentration in the diet has a detrimental effect upon development. Lipid contents in pupating larvae, and to some extent protein levels, were affected by amino acid 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.