Diurnal and seasonal rhythm of the melon ladybird - Epilachna chreysomelina (Coleoptera, Coccinellidae) activity in the conditions of the Kashkadarya region of Uzbekistan

¹ Karshi State University, Geography and Agronomy Faculty, Department of Agrochemistry and Ecology, Karshi, Uzbekistan
² Karshi Engineering-Economics Institute, Department of ecology and labor protection, Karshi, Uzbekistan

^* Corresponding author: uzakovzafar40@gmail.com

Abstract

The paper describes that the first signs of beetle movement after night rest in the month of May occur at 8 am at an air temperature of about 20⁰C. Increasing the temperature to 22-29⁰C tends to increase their mobility. By 11 a.m., when the air temperature reached 34⁰C, almost all the beetles went into the shade, into the lower part of the plants, where they remained immobile until almost 4 p.m. After 17 h. the air temperature dropped to 330С, by 20:00 to 200С. By this time, only a small part of the beetles remained active. In summer, the motor activity of beetles intensifies at 8-10 am, when the air temperature rises to 34⁰C. From 11 a.m. to 6 p.m. at a temperature of 34-42⁰C, humidity 34-40%, the beetles were placed in the shade and were inactive. In autumn, after night cooling, the air temperature increased later and the movement of beetles began at 11 am At noon hours (between 12-4 pm) at an air temperature of 20-25⁰C. and humidity 55-60%, beetle activity was maximum. In summer, beetles actively feed in the morning (from 8-9 a.m.) and evening (from 19 to 22 p.m.) hours, when the air temperature was 26-33⁰C. In the middle of the day (13-16 hours) and at night (3-5 hours), their feeding activity is somewhat reduced. The intensity of beetle feeding in the autumn months increases from 9 a.m. and reaches a maximum by 11-13 a.m., and after 5 p.m. it begins to decrease and almost stops at 9 p.m. in the evening.