Die biologische Bekämpfung von Helicoverpa armigera in Deutschland: Einsatzmöglichkeiten von Trichogramma spp. und anderen Schlupfwespen-Gattungen

Helicoverpa armigera (H.a.) is a pest of growing importance in Germany. First observations of migrating individuals were made one month earlier since 2000 compared to 1975-1995. Due to an increasing mean summer temperature H.a. is migrating to South Germany in the middle of August, attacking tomato and ornamental plants in greenhouses, tobacco, sweet pepper and corn in the field. The monitoring strategy for H.a. has to be improved since pheromone trapping can not control the flight of migrating females. A combination of pheromone and light trapping and the use of attractants will be tested to observe the migrating pest. Egg parasitoids of the genus Trichogramma spp. (Trichogrammatidae) were selected for suitable indigenous strains. Specific strains from T. brassicae, T. cacoeciae and T. evanescens showed highest acceptance. The larval parasitoid Campoletis sp. (Ichneumonidae) was observed as natural enemy with 12% natural parasitism of H.a. larvae in tobacco in South Gemany. Bracon brevicornis (Braconidae) collected from Ostrinia nubilalis in 2006 is available in mass rearing and was successfully tested against H.a. in laboratory. A combined release of Trichogramma with B. brevicornis will be tested in 2007.