|Chang, Chiou Ling|
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2007
Publication Date: 6/21/2008
Citation: Chang, C.L., Caceres, C., Ekesi, S. 2008. Life History Parameters of Ceratitis capitata (Diptera: Tephritidae) Reared on Liquid Diets. Annuals of the Entomological Society of America. 100(6):900-906. 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 which 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. In this study, we evaluated 16 different yeast products to determine the best product for use in the liquid diet formulation 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. 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 Ceratitis capitata was developed. Several yeasts were evaluated and a combination of whole cell yeast (LBI2240) and hydrolyzed yeast (such as FNILS65 and FNI200) in 1:1 to 3:1 ratio was selected for use in the study. Larvae reared in a liquid diet with LBI2240:LS65 (either 1:1 or 3:1 ratios) produced the same pupal recovery as to those reared in the conventional control diet. Larvae reared in a liquid diet with whole cell yeast yielded the lowest pupal production while other parameters such as adult emergence, adult fliers, pupal weight, egg production, percent egg hatch were not affected. In diets fortified with RDA or GSH, there was no enhanced effect on insects while some degrees of detrimental effects were observed in the some of the parameters measured. Therefore, whole yeast and hydrolyzed yeast ratio of 3:1 were found to be the most suitable based on the quality control parameters measured and is recommended for use in liquid diets targeting C. capitata rearing because the cost of whole cell yeast is found to be five times cheaper than that of hydrolyzed yeast. This study also demonstrates that it is possible to rear C. capitata in a liquid diet at the same cost and still maintain the same fly quality as those from the conventional control diets.