Coptera haywardi females discriminate puparia of Anastrepha obliqua treated with Beauveria bassiana

Abstract

The capacity of a parasitoid to discriminate hosts can favor the survival of its progeny as well as improve its efficacy as a biocontrol agent when it is used with another natural enemy, as this may result in greater control of the pest. Our aim was to characterize the discrimination ability of Coptera haywardi (Oglobin) (Hymenoptera: Diapriidae) females with respect to puparia of Anastrepha obliqua (Macquart) (Diptera: Tephritidae) treated with the fungus Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae), under three conditions: (1) no choice, separately exposing A. obliqua puparia, treated at 0, 24, 48, or 72 h prior to exposure, to the parasitoid and without application of the fungus (absolute control); (2) with the possibility of choosing between untreated and treated puparia with the same times after fungus application; and (3) multiple choice, where parasitoids could select among puparia treated at different times. Observations were made to determine the discrimination behavior of the wasps as well as the number of ovipositions by each female parasitoid; 14 observations were made. Coptera haywardi exhibited different levels of discrimination depending on the test. In the no‐choice test, discrimination was not observed; in the two‐choice test, females significantly discriminated the puparia treated at 0, 24, and 72 h prior to exposure; and in the multiple‐choice test, females preferred the untreated puparia – behavior that was corroborated in the direct observations. Oviposition time ranged from 9 to 86 min and differences in average time among treatments were not significant. We conclude that the discrimination ability of C. haywardi allows the simultaneous use of B. bassiana, as females prefer healthy, untreated puparia without interfering with the fungus.