A New Starch-Grafted Gelling Agent for Screwworm (Diptera: Calliphoridae) Larval Diet

Abstract

Larvae of screwworm, Cochliomyia hominivorax (Coquerel), were reared on diets solidified with an inexpensive starch-grafted sodium polyacrylate gel (brown and white formulations) and on a control diet solidified with Water-Lock G-400 gel, the standard gelling agent used for larval diet in the Screwworm Eradication Program (of the United States Department of Agriculture in collaboration with the government of Mexico). Mean pupal weight, number of pupae, percent emergence, sex ratio, adult longevity, fecundity, and fertility recorded from the test diets solidified with the brown starch-grafted gel were compared with the same parameters obtained from diets prepared with Water-Lock G-400 gel. There were no significant differences in any of the parameters examined between the tests and the corresponding control. Diets solidified with the white variety of the starch-grafted gel performed poorly. The brown starch-grafted gel has potential for use in the larval diet for mass production and may effectively replace the more expensive Water-Lock G-400 gel.