The efficacy of Serratia nematodiphila and Neem Azal T/S on Macrosiphum rosae: new approaches in biological control

The rose aphid, Macrosiphum rosae (L.) (Hemiptera: Aphididae), is one of the most common pests of rose plants. This study evaluated the effects of four different doses of Neem Azal-T/S, containing the active ingredient Azadirachtin A, and a dose of Serratia nematodiphila (1x108 cfu/ml) on M. rosae over 72 hours. The experiment was conducted in a climate chamber under controlled conditions (25±1 °C, 60±5% relative humidity, and a 16:8 light-dark photoperiod). The results showed that Neem Azal-T/S led to mortality rates of 12.5%, 17.5%, 60%, and 77.5%, respectively, while S. nematodiphila resulted in a 78% mortality rate after 72 hours. In the control group, mortality was 0.75%, while mortality rates for the treatment groups were 1.25 (Neem_1), 1.75 (Neem_2), 6.00 (Neem_3), 7.00 (Neem_4), and 8.25 (S. nematodiphila). Statistical analyses showed significant differences between all treatment groups and the control. In conclusion, this study demonstrated that both Neem Azal-T/S and S. nematodiphila significantly increased mortality rates in M. rosae compared with the control. Additionally, this study is the first record of the presence of S. nematodiphila in Türkiye and the first information on its entomopathogenic effect on M. rosae in the worldwide, supporting the potential of biological methods in managing rose aphids and emphasizing the importance of biological control strategies in agricultural pest management.