Strategies for Establishing a Rearing Technique for the Fruit Fly Parasitoid: Doryctobracon brasiliensis (Hymenoptera: Braconidae).

Abstract

Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is the most important pest in South American orchards. When control measures are not adopted, this pest can cause losses of up to 100%. Doryctobracon brasiliensis (Szépligeti) (Hymenoptera: Braconidae) is a larval-pupal endoparasitoid that can be used as a native biological control agent against A. fraterculus. This study aimed to develop a rearing technique for D. brasiliensis in larvae of A. fraterculus. Trials were carried out to: 1) determine the optimal instar for parasitism, 2) define the exposure time of larvae to parasitoids, 3) determine the density requirements of A. fraterculus larvae offered to each parasitoid, and 4) evaluate the effect of diet on adults of D. brasiliensis. In all trials, we evaluated the number of offspring, parasitism rate, and sex ratio. Moreover, in the experiment to investigate the effects of diet, we determined the longevity of males and females. In both choice and nonchoice parasitism tests, the parasitoids preferred third-instar larvae of A. fraterculus over second- and first-instar larvae. An exposure time of 12 h of A. fraterculus larvae produced larger numbers of parasitoids and higher parasitism rates. The density of 15 larvae of A. fraterculus to each female of D. brasiliensis produced a larger number of offspring. A supply of honey solution (20 and 50%) to the parasitoids yielded the highest number offspring and resulted in greater longevity. Our findings can be used to support the development of a mass rearing protocol for D. brasiliensis.