Abstrakt: |
The tomato fruitworm Helicoverpa armigera(Hübner) is regarded as a serious pest that affects a great number of field crops globally. One of the environmentally safe alternatives to the utilization of insecticides is controlling H. armigeravia the release of biological control agents by employing parasitoids, e.g., trichogrammatid species. One of the desired parasitoids indigenous to southwestern Iran is Trichogramma euproctidis(Girault). To anticipate the outcomes of augmentative releases of T. euproctidisin the field, the numerical and functional responses of female T. euproctidisthat parasitizes the eggs of H. armigerawere determined in the laboratory. The densities of host eggs per glass tube arena (length: 10 cm, diameter: 1 cm) were 2, 4, 8, 16, 32, 64, or 128 individuals. The functional response to the eggs of H. armigeraindicated Holling’s type II response. The estimated handling time and attack rate from the random parasitoid equation were 0.6898 h and 0.00823 h, respectively. This indicates that, at the maximum level, each T. euproctidiswas capable of parasitizing 34.79 eggs a day. At the 128 host egg density, the number of eggs laid, that is, the numerical response, ascended as the density of host eggs increased up to a maximum of 89.90 eggs per female. According to the obtained results of the present investigation, T. euproctidiscan serve as an appropriate candidate for augmentative biological control of H. armigera. Nevertheless, it is necessary to conduct complementary experiments in greenhouses and open fields. |