Investigations on the damage of Diprion pini (L.) on Pinus nigra forests in Bala and Elmadağ

Insects which affect efficiency of forests and their health have continued their existence for many years due to ensure favorable climate change in Türkey and exist different kinds of plant species, besides some of the insects are harmful constantly, some of them are periodical for forests. One of the harmful ones Diprion pini L. (Hymenoptera: Diprionidae) has increased its population as a result of providing suitable conditions in recent year and has started to make epidemic by earting needles in forest plantations. However, in this reseearch, it is investigated D. pini 's damages in Kaaraçam forests in the research area. It is abserved periodically the population of the mentioned harmful insect in research area; also it is studied about its spread, biology, the ways of damage and amount. Accorrding to this study, it is abserved that the insect has passed the winter in cocoon as a mature larvae, and left cocoon by flying in April-May. Furthermore, it is abserved that the harm insect has avulated and leaving larvaes are abserved first in August-October, not only their growth with nutrition but also their harmful effects. In the some study, it is absserved that D. pini 's larvaes have gone down deep in average 10-15 cm by switching from trees to soil. Finally, it is abserved that the harm insect has passed the winter in its cocoon in the soil as a matured larvae and it is inseminated two times a year.