Inmature stages of parasitoid wasp Utetes anastrephae (Hymenoptera: Braconidae) reared in two fruit flies of genus Anastrepha (Diptera: Tephritidae)

Utetes anastrephae (Viereck) is a parasitoid species native to America, is an endoparasitoid wasp of several species of tephritid fruit flies larvae. However, immature stages of many endoparasitoids are poorly understood because they develop inside the host. The objectives of this work were to describe the immature stages of U. anastrephae and to determine the principal morphological differences of these immature stages using two distinct species of fruit flies as hosts, Anastrepha ludens (Loew) and A. obliqua (Macquart). The development of the immature was evaluated every 24 hours, recording all stages and changes from the hatching of the larvae to the emergence of the adult. The observations were performed under controlled laboratory conditions, at 26 ± 1° C, 70% RH, and with a 12:12 L:D photoperiod. Preimaginal development takes about 16 days and presented five stages: egg, three larval instars, prepupa, pupa, and pharate adult. The host does not influence preimaginal development time, but in both it was observed that the male emerges before the female. The survival of the parasitoid was lower in A. obliqua, showing a melanization process as a physiological response to the presence of the parasitoid. Finally, the strong intraspecific competition was evidenced in the first larval instars