The field experiment was conducted to study the population dynamics and efficacy of insecticides against curry leaf mite Schizotetranychus baltazari. The experiment was conducted in the orchard (latitude: 11.009945° N and longitude: 76.93108°E), Department of Spices and Plantation Crops, Horticultural College and Research Institute, Coimbatore. The result showed that more mites were recorded in the 16th standard week (37.10/2cm2). The maximum temperature and minimum temperature showed a positive and significant relationship in the development of the mite population, whereas morning relative humidity, evening relative humidity and rainfall showed a negative and non-significant relationship in the development of the mite population. The efficacy of insecticides viz., Metarhizium anisopliae @ 3ml/l, Beauveria bassiana@ 3ml/l, Lecanicillium lecanii@ 3ml/l, Hirsutella thompsoni@ 3ml/l, Spiromesifen 240 SC @ 0.8ml/l, Thiamethoxam 25 WG @ 2g/10l, Fenpyroximate 5 SC @ 2g/10l against curry leaf mite. Among these insecticides Spiromesifen 240 SC @0.8ml/l has highest cumulative per cent reduction of mites over control (86.48%), followed by Fenpyroximate 5 SC @1ml/l (84.31%), Thiamethoxam 25 WG @ 2g/10l (82.49%), M. anisopliae @ 3ml/l (76.60%), B. bassiana@ 3ml/l(70.95%), L. lecanii@ 3ml/l(61.73%) and H. thompsoni @ 3ml/l (46.17%). Curry leaf mites' small size and hidden habitat on leaf undersides make accurate population assessment and effective insecticide application difficult. Fluctuating environmental factors, including temperature and plant health, influence mite populations and interact with insecticide efficacy, requiring precise analysis for effective control strategies.

Population dynamics, Insecticides, Spiromesifen, Thiamethoxam, M. anisopliae, B. bassiana, Curry leaf, Mite

This study revealed that the maximum temperature and minimum temperature have a positive and significant correlation with the development of the population. Whereas morning relative humidity, evening relative humidity and rainfall have non-significant and negative temperature effects on the mite population. Among insecticides, Spiromesifen 240 SC @ 0.8ml/l was found to be effective in controlling the mites with 86.78 per cent reduction followed by Fenpyroximate 5 SC @1ml/l (84.66 %), Thiamethoxam 25 WG @ 2g/10l (82.88 %). Among entomopathogenic fungi, M. anisopliae@ 3ml/l (75.67) % followed by B. bassiana@ 3ml/l (70.64 %) showed the highest reduction. The Hirsutella thompsoni @ 3ml/l has shown the least reduction in controlling the mites in curry leaf with a 48.38 per cent reduction. The Hirsutella thompsoni @ 3ml/l has shown the least reduction in controlling the mites in curry leaf with a 47.17 per cent reduction.

Indujja M., Baskaran V., Sumathi E., Venkatesan K. and Anandham R. (2023). Population Dynamics and Efficacy of Insecticides against Spider Mite Schizotetranychus baltazari (Tetranychidae) in Curry Leaf Murraya koenigii. Biological Forum – An International Journal, 15(8): 501-507.