Pristiphora abietina (Hym.: Tenthredinidae) and Thaumetopoea wilkinsoni (Lep.: Notodontidae) are among the most detrimental forest pests in Türkiye. In this study, a prototype oil-based formulation named Pa4-OD was developed to control both P. abietina and T. wilkinsoni . Under laboratory conditions, the mortality rates for P. abietina and T. wilkinsoni larvae were 95.5% and 98.6%, respectively, 14 days after treatment with a...