Submitted to: Annals of the Entomological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: 6/20/2007
Publication Date: N/A
Interpretive Summary: The sterile insect technique (SIT) is based on the release of high quality sterile insects. We have recently developed a "liquid" diet that alleviates the need for a bulking agent to replace the currently used "standard" artificial diet for fruit flies consists primarily of sugar, protein and a bulking agent (mill feed) which is consumed by the developing larvae. The impact of this new diet is that costs associated with the disposal of the standard diet can be reduced, as well as potential space saving if the liquid diet is incorporated into a mass-rearing facility. Yeast based products are the main nutritional component in the diet used to mass rear the adults and larvae of fruit flies for sterilization insect technology (SIT) program to control pests. In this study we evaluated 16 different yeast products to determine the best product for use in the larval liquid diet formulation and adult diet and compared various biological developmental parameters to the standard "mill-feed" diet. Our research identified a yeast product which is capable of producing flies of similar quality as the control (mill-feed) diet for larvae and found there are not significantly different in adult diet. These comparison studies are an integral step in bringing this new (liquid-diet) technology into use on a practical scale. Further tests are planned to improve other biological and operational factors involved in mass-rearing of fruit flies.
Technical Abstract: A liquid diet for rearing Bactrocera dorsalis was developed. Three hydrolyzed yeast (LS65, FNI200, FNI210), a glutamine enriched yeast (G, Fermaid SuperRelax, GSH), RDA500 (R, an enriched high vitamins yeast), Korea yeast, and their yeast products (FNI200+G, FNI200+R, FNI200+G+R, LS65 +G, LS65+R, LS65+G +R, FNI210+R, FNI210 +G, FNI210+ G+R, and LBI2240) were evaluated in adult diet for Ceratitis capitata, Bactrocera dorsalis, and B. cucurbitae and larval liquid diet for rearing oriental fruit fly, Bactrocera dorsalis (Hendel). For adult diet, it did not show any discrepancies on egg hatch among these yeast products in comparison to the control while adult flies fed on diet with 210GR produced the most eggs on all three tested fruit fly species. When these yeasts were incorporated into a liquid larval rearing diet, FNI 200 and LS65 showed significantly difference from FNI210 and Korea yeast. Addition of GSH, RDA 500, and/or wheat germ oil into these two hydrolyzed yeasts, LS65GW is selected. In order to select the most cost effective yeast for liquid diet, 65GW then compare with a whole cell yeast LBI2240 series. LBI2240 combine with LS65 in a ratio of 3:1 (224065W) was the final recommendation. Therefore, 224065W (3:1) is the most cost effective yeast for Bactrocera dorsalis liquid larval diet while any yeasts can be used for adult diet depending one’s need.