Interação competitiva e capacidade de parasitismo de tetrastichus giffardianus (hymenoptera: eulophidae)

Biological control stands out as a viable alternative for the control of tephritids, using different species of parasitoids. The simultaneous release of parasitoids can result in the efficient control of pest tephritids, while it can also generate competitive responses due to the overlap by resources (food, host and habitat), making it essential to screen for the use of the best combinations of parasitoid species. Therefore, this study aimed to evaluate the interactions between the endoparasitoid Tetrastichus giffardianus and the ectoparasitoid Pachycrepoideus vindemmiae on the host Ceratitis capitata (Wied.) (Diptera: Tephritidae) in laboratory conditions (T = 25 ± 2 ° C, RH = 60 ± 10% and Photophase = 12h). The competition bioassays comprised two stages: In the first stage, third instar larvae of C. capitata were exposed to parasitism to T. giffardianus and P. vindemmiae, in isolation and in competition. In the second stage, pupae previously selected with the oviposition scars of T. giffardianus were exposed to P. vindemmiae and dissected at three time intervals (24, 48 and 72 hours after exposure to ectoparasitoids), to investigate the interactions inside the pupae. The results showed that P. vindemmiae predominates over T. giffardianus. The isolated T. giffardianus parasitism was greater than when this parasitoid was in competition with P. vindemmiae. The parasitism of P. vindemmiae was not affected by competition with T. giffardianus. The dissections confirmed the lethal interference that P. vindemmiae is capable of causing in the survival of T. giffardianus