Determination of population fluctuation of american bollworm, Helicoverpa armigera (Hubner) (Lepidoptera:Noctuidae) on cotton fields in Diyarbakir, Turkey

Helicoverpa armigera Hbn. (Lepidoptera: Noctuidae) is one of the most important pests in cotton fields. H.armigera causes crop losses in cotton especially generative organs by doing damage and its damage varies according to months and years. This study was carried out in the years of 2014 and 2015 in Diyarbakır province in order to find out of pheromone traps in observing the population fluctation of H.armigera in the cotton fields. Experiments were conducted in three locations (Bismil, Çınar and Sur) with nine cotton fields. Delta type pheromone traps were used in the experiments. Three of each pheromone traps were placed in the cotton fields. Trapped adults were counted at weekly intervals. In this study was found to have caught more adult in the traps during the in 2014, but it was found that there were fewer catches in the traps in 2015 than in the previous year. The adult of the H. armigera was determined in May and reached to maximum level in end of May pheromone traps in Bismil (Kazancı) (28 moths/trap) and Çınar(Karalar) (23 moths/trap) in 2014 and at the same year reached to maximum level in June pheromone traps in Sur (Tanoğlu) (13 moths/trap). Contrary, the adult population was reached to maximum level at the begining of July pheromone traps in Sur (Tanoğlu) (6 moths/trap) in 2015 and at the same year reached to maximum level in Bismil (Kazancı) (19 moths/trap) and Çınar (Karalar) (15 moths/trap) in mid-July.