Egg laying habits and structure of egg-batches of pine processionary moth Thaumetopoea wilkinsoni Isparta pine forests

This study was conducted as "Master's Thesis" at Süleyman Demirel University, Graduate School of Applied and Natural Sciences, Department of Forest Engineering. Observations were performed and samples were collected in the research area periodically from 2014 to 2015. In this study, the structure of egg batches laid by T. wilkinsoni, which causes severe damage to the pine forests in Turkey and especially in Isparta and for which a huge amount of money and effort is spent for their control, on the needles of trees and called "egg cob" as they look like corn cobs, rates of hatching and parasitism, egg parasitoids and the egg-laying patterns of insect were investigated. To this end, 654 egg-batches were collected from 16 pine forests located in Isparta. In order to determine the overall structure of egg-batches of pine processionary moth, 164 egg-batches collected from 11 sites were studied. It was found that the average number of eggs in these sites was 221,2; the average number of eggs that hatched was 177,1 (80,0%) and the rate of parasitism was 13,8%. In order to determine the elevation of the land, 128 egg-batches were collected from nine sites at three different elevation steps from three stands at each elevation. The average number of eggs at the upper, middle and lower elevations was found to be 208,1, 223,3 and 226,7, respectively. The rate of hatching was 73,3%, 82,6%, 85,3%, respectively, while the rate of parasitism was found to be 15,9%, 9,8%, and 8,9%, respectively. In order to investigate the structure of egg-batches depending on the location of trees within the stands where the egg-batches were laid, 160 egg-batches were collected from two sites. The average number of eggs in the batches collected within and at the borders of the stands was 203,9 and 217,6, respectively. The rate of hatching was 77,0% and 67,4%, respectively, while the rate of parasitism was 15,7% and 24,9%. The egg-laying habit in both sites was investigated according to the aspect of the egg-batches on trees and lower and upper parts of the canopy of trees. Furthermore, particularities of these egg-batches were revealed. Therefore, 202 out of 654 egg-batches were evaluated for this purpose. The egg-batches were laid on the northern, western, southern and eastern aspects by 6,5%, 14,7%, 16,6% and 62,2%, respectively. 43,5% of the egg-batches were laid in the lower parts of trees, while 56,5% on the upper parts. The average number of eggs in the batches collected from the lower and upper parts of trees was 195,5 and 197,7, respectively. The rate of hatching was 62,5% and 56,5%, respectively, while the rate of parasitism was 29,9% and 35,6%, respectively.