Abai, MR

6th International Congress of DipterologyMaking of artificial diets for an aphidophagous hoverfly,Eupeodes frequens (Diptera: Syrphidae)Iwai, H., K. Niijima & M. MatsukaDivision of Applied Entomology & Zoology, Graduate School of Agriculture, TamagawaUniversity, Machida City, Tokyo 194-8610, JapanThe larvae of an aphidophagous hoverfly, Eupeodes frequens are effectivepredators and potential biological control agents of aphids. However,rearing the aphidophagous hoverfly is much labor- and time-consumingbecause of cultivation of 3 organisms is necessary; host plants, prey aphids,and the flies. The development of artificial diets would be indispensablefor a labor-saving technique but there have been few reports of successfulartificial diets for them. We invented an agar-gelled diet containinglyophilized and pulverized drone honeybee brood (drone powder, DP)which offered the minimum nutrition necessary for E. frequens larvaldevelopment, but the larval period and adult body size on the diet wassignificantly inferior to the insects on aphid. In this report we examined theeffect of three fatty acids (myristic, linoleic, and oleic acids) on the larvaldevelopment and adult body size in order to obtain normal size adults. Theaddition of each one of fatty acids to DP improved the adult emergenceratio and significantly shortened developmental period of the third instarlarvae. The combination of linoleic acid and oleic acid was the mosteffective for adult body size. We challenged to make better artificial dietfor the syrphid. Physical property and amount of fatty acids and sugaradded was changed during early stage to the 3 rd instar larval period. Morethan 80% of larvae reach to the adults and their body size was equal toones feeding on aphids. Thus, we succeeded to rear E. frequens larvae onthe artificial diets and this would be a step to develop mass rearing ofsyrphids.Key Words: Eupeodes frequens, Syrphidae, artificial diet, biologicalcontrol agent124