Comparative effectiveness of plant-derived insecticides against whiteflies Bemisia tabaci Gennadius and thrips, Thrips tabaci Lindeman in tomatoes: A laboratory study

Whiteflies (Bemisia tabaci) and thrips (Thrips tabaci) are significant sucking pests of tomatoes, posing increasing threats to crop health and leading to considerable economic losses, particularly in the context of climate change. These pests are also vectors for viral transmission, further diminishing crop quality and yield. A laboratory bioassay was conducted to assess the efficacy of several plant-derived insecticide formulations, including Adathoda leaf extract soap (10 %) @ 7 g/L, Azadirachtin (1000 ppm) @ 2 mL/L, Neem Seed Kernel Extract (NSKE) (5 %) @ 5 mL/L, Neem soap (10 %) @ 7 g/L and the microbial insecticide Lecanicillium lecanii (1 × 108 cfu/g) @ 5mL/L, along with Thiamethoxam 25% WG @ 0.3g/L as a chemical control. The results indicated that Thiamethoxam 25% WG achieved the highest mortality rate against whiteflies at 72 hr post-treatment (72 %), followed by Adathoda leaf extract soap (10%) (64.00 %), Azadirachtin (63.2 %), L. lecanii (60 %), Neem soap (61.5 %) and NSKE (59.2 %). For thrips, Thiamethoxam 25% WG again demonstrated the greatest effectiveness (71.20 %), with Adathoda leaf extract soap (10%) (65.60 %), Azadirachtin (64.25 %), L. lecanii (58.20%), Neem soap (60.80 %) and NSKE (59.80 %) following. This research highlights the potential of Adathoda leaf extract soap (10 %) as an eco-friendly alternative to traditional neem formulations, suggesting its suitability for integration into future Integrated Pest Management (IPM) programs for tomatoes.