Effects of plant extracts from needle plants [Pinus nigra L. (Larch), Picea pungens L. (blue spruce)] against some stored pests

In this study carried out in 2023, The insecticidal effects of four different consentration of plant extracts obtained from blue spruce (Picea pungens) and larch (Pinus nigra) were analyzed for Sitophilus oryzae L., Sitophilus granarius L. (Coleoptera: Curculionidae) and Tenebrio molitor L. (Coleoptera: Tenebrionidae). In single-dose screening tests, methanol extracts of larch and blue spruce were applied at 10% (w/v) doses. The highest mortality rates were seen in T. molitor, 11th day every two extracts, and in S. oryzae, 21th day two extracts. 100% seen for extra. In S. granarius, it was seen in 96.60% of the two extracts on the 21st day. In the second part of the study, different doses of extracts of larch and blue spruce were used in dose-effect experiments. In larch; The mortality rate is low, 100% on the 5th day at a 40% dose in S. granarius, 100% on the 19th day in S.oryzae, and 100% on the 3rd day in T. molitor at a 40% dose. On the blue spruce; In S. granarius, the most effective dose was 40% with a 100% mortality rate on day 5. A 20% dose was effective in S. oryzae with a 100% mortality rate on day 19. As for T.molitor, it was concluded that it was effective at a dose of 40% on the 9th day, with a 100% mortality rate.