Parasitization Rate of Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) Eggs After Field Releases of Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) in Cotton in Cukurova Region of Turkey

The control of the noctuid Helicoverpa armigera Hubner (Lepidoptera:Noctuidae) with Trichogramma evanescens Westwood (Hymenoptera:Trichograminatidae) on a cotton (Malvaccae) farm in Turkey is reviewed. Helicoverpa armigera has five generations in a year, but only three attack cotton in the East Mediterranean region of Turkey. Releases of T evanescens are made twice against each of the first three generations of H. armigera in the years of 2004-2005. In each release, 120,000 parasitoids ha(-1) were released, resulting in 62.9% and 71.6% parasitism and the numbers of larvae of H. armigera were reduced by 76.8% and 80.6%, respectively. In fields where insecticides were applied, the numbers of larvae of H. armigera were reduced by 57.1% and 77.1%, respectively. Furthermore, it was observed that population of natural enemies was increased in released parasitoid plots, with an average of 33 to 39 Chrysoperla carnea (Steph.) (Neuroptera:Chrysopidae) were encountered in 25 plants. Pollen-generating plants (maize, okra, weeds, etc.) probably increased the density of the predator. The cultivation of okra as a trap plant can be recommended especially in cotton fields where parasitoid release was conducted. The results of biological control of the noctuid H. armigera by T. evanescens appear promising.