Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2000
Publication Date: 7/20/2000
Citation: Chang, C.L., Kurashima, R.S., Albrecht, C.P. 2000. Effects of limiting concentrations of growth factors in mass rearing diets for Cerititis capitata Larvae (Diptera: Tephritidae). Annals of the Entomological Society of America. 93(4):898-903.
Interpretive Summary: The Mediterranean fruit fly is a worldwide pest of fruits and vegetables. Currently, control measures include the use of insecticides and various biological control methods. One such method (autocidal control) involves the release of sterile males (SIT) that will seek out and mate with non-sterile females. For this to occur, flies are mass-reared, sterilized and released along with the wild population. We are trying to improve the artificial diet used to rear the flies and have come up with a chemically defined diet for this species. The chemically defined diet is made up of vitamins, minerals, amino acids, RNA and an inert substrate. This diet was comparable to the control diet in every aspect except for a slight delay in the developmental period. Furthermore, using this defined diet is to identify precisely the components (such as growth factors or vitamins) that are essential (nicotinic acid) or required (riboflavin, pantothenic acid) to rear the best quality fly and improve SIT.
Technical Abstract: Larvae of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) were reared on nutrient deletion and addition diets based on Medfly #1 defined diet (used as a control diet in this study). Elimination or removal of all nine growth factors (7 water-soluble vitamins and 2 lipogenic factors) from a control diet resulted in prolonged developmental period, decreases in pupal recovery, pupal weight, adult emergence and flight ability, but normal egg hatch. Without nicotinic acid concentration greater than 0.1 mg/50g in Medfly #1 diet, resulted in complete second instar larval mortality. In the absence of riboflavin, larvae reached the third instar and pupated, but the rate of development was slower and the total pupal recovery was not significantly different. Pupal weight and adult emergence were significantly decreased while flight ability and egg hatch remained within normal ranges. The effects of omitting pantothenic acid were similar to those for riboflavin except this was no difference in adult emergence compared to the control diet. The omission either of thiamine, pyridoxine, biotin, folic acid, inositol or choline had no significant effects on the rate of larval development and survival. Nicotinic acid was determined to be indispensable (requires minimum of 0.1 mg/50g diet) while riboflavin and pantothenic acid appear to be required at least >0.01 mg/50g diet for normal growth and development of larvae C. capitata. Addition of ascorbic acid phosphate or a-tocopherol in medfly #1 diet did not improve C. capitata development or growth either.