Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2006
Publication Date: 4/15/2007
Citation: Chang, C.L., Vargas, R.I. 2007. Addition of Wheat Germ Oil to a Liquid Larval Diet for Rearing Improved Quality Oriental Fruit Flies (Diptera: Tephritidae). Journal of Economic Entomology. 100(2):322-326 Interpretive Summary: Oriental fruit flies are the worldwide pests. In order to achieve SIT (Sterilization Insect Technology) control program, a mass production of insects needed to be reared in the laboratory. It would be the most convenient if the insects possess the high reproductive abilities. The higher the viable eggs are the easier to mass reared fruit flies. We have been working on developing a liquid diet fruit fly larval rearing. The hatchability of eggs from adults Bactrocera dorsalis whose larvae reared on a liquid larval rearing diet was low in the early stage during the liquid diet development. We speculated that there was a lack of fatty acids in the liquid diet formulation due to the replacement of mill feed with sponge cloth as a bulking agent (supporting matrix). Because mill feed diet contains 9.85 times more total fatty acids (including unsaturated and saturated fatty acids) than those in liquid diet based on the nutritional composition assessment (Chang et al. 2004).
Technical Abstract: Wheat germ oil was added into a low waste larval liquid diet for rearing Bactrocera dorsalis (Hendel) to optimize the fruit fly performance. Various concentrations of 0.04, 0.07, 0.15, 0.30, and 0.66 % of wheat germ oil were evaluated. Results showed that the addition of wheat germ oil did not affect the pupal weight, larval developmental period, adult emergence, mating, or the peak time for egg production. An increase in the pupal recovery, percent flier, egg production, and egg hatch were significant in comparison to those from the standard liquid diet without wheat germ oil. The increase in egg hatch is dose dependent. Data was analyzed by multivariate analysis of variance using the ANOVA and Proc Univariate procedure of the SAS statistical analysis software package with honest significant difference (HSD).