Sevcan (COSKUNTUNCEL) ÖZTEMIZ1 and Serpil KORNOSOR2
1 Plant Protection Research Institute, 01321, Adana, TURKEY.
2 University of Cukurova, Faculty of Agriculture, Plant Protection Department, 01330, Adana, TURKEY.
This study was conducted to determine the biological control possibilities of the main pest of maize, Ostrinia nubilalis Hübner with inundative releases of Trichogramma evanescens Westwood, beside this, natural parasitization rate of T. evanescens Westw. was studied on the maize field in Çukurova region of Turkey during the maize vegetation period in 1995.
O. nubilalis, Ephestia küehniella Zeller (Lepidoptera; Pyralidae) and T. evanescens were reared in a climatic room under constant temperature (25±1°C), relative humidity (65±10%) and appropriate light regime.
T. evanescens was applied in two releases with 10 days interval, at the beginning of the oviposition period of third generation of O. nubilalis in the second crop maize. A total of 1.500.000 parasitoids per 100 da (750.000 parasitoids in each release) were released. Egg parasitism was 89.17 % and the reduction of infested plant with E.C.B. was 63.63 % in this experiment.
Natural parasitization rate of the egg parasitoid (Çukurova region which was assigned to intensity of pesticide use and ease of transportation) was studied in three subregions. The highest natural parasitism rate found in the first subregion (Ceyhan, Kozan, Kadirli, Osmaniye), than the third (Tarsus, Mersin) and the second (Yüreðir, Karataþ) subregion. Even though the parasitism rate of the first and third subregion were 45.93% and 38.26%, second subregion had a lower parasitism rate by 1.45%. In conclusion, natural parasitism by T. evanescens was 38.05% in Çukurova region, in 1995. Natural parasitism was high in the first and third subregion, where pesticide use was minimal; and was low in the second subregion where pesticide use was intense.
Key words: Ostrinia nubilalis, in undative release, Trichogramma evanescens