The Effect of Pyrethrum and Bacillus thuringiensis Biopesticides on Diprion pini L. and Neodiprion sertifer (Geoffr.) (Hymenoptera: Diprionidae) Larvae

The larvae of the common pine sawfly (Diprion pini L.) and the European pine sawfly (Neodiprion sertifer) can cause epidemic, around the globe. Recently, an outbreak has been reported in young Scots pine (Pinus sylvestris L.) forest in Artvin - Borçka, Turkey. In order to propose effective control measures, this study was conducted to estimate the effectiveness of two biopesticides against D. pini ile N. sertifer larvae. Different doses of Pyrethrum and Bacillus thuringiensis biopesticides (Spruzit® Neu from 150ml to 600ml/100 l, and DiPel® DF BT 100 to 500 g/100 l) were applied against the larvae of D. pini and N. sertifer their impact was monitored under laboratory conditions. The finding of the study revealed that the most effective dosages for larvae of D. pini was Dipel 300 g/100 l and Dipel 500 g/100 l of B. thuringiensis. The efficiency ratio of Pyrethrum doses ranged from 59.5%-78.5% for Spunizet Neu and 85.5%-95.5% for Dipel DF against D. pini larvae. It was observed that the dosage of both pesticides was directly propositional to the death in larvae. Intriguingly, Dipel at the dose rate of 500 g/100 l was the most effective applications for larvae of N. sertifer. While variable impacts were noticed against larvae, both biopesticides were effective against larvae of D. pini and N. sertifer. Taken together, finding of this study propose the use of Pyrethrum and Bacillus thuringiensis biopesticides to control common pine sawfly and the European pine sawfly in the event of an epidemics in Turkey.