BIOLOGY AND PREDATION EFFICIENCY OF LADYBIRD BEETLE ON MUSTARD APHID

Abstract

A laboratory experiment was conducted in the central laboratory of Sher-e-Bangla Agricultural University to find out the biology and predation efficiency of ladybird beetle on mustard aphid. Zigzag ladybird beetle st , 2 nd , 3 rd , 4 th instar grub period, pupal period, adult male and female longevity and ovipositional period of female for zigzag ladybird beetle were 2-3, 1-2, 1-3, 2-3, 2-3, 3-5, 17-22, 19-25 and 19-27 days, respectively; for black ladybird beetle 2-3, 1-2, 1-3, 2-3, 2-3, 3-5, 17-23, 20-25 and 18-27 days, respectively and 5-7, 2-3, 2-4, 3-5, 3-5, 6-10, 27-33, 31-36 and 30-41 days, respectivelyfor transverse ladybird beetle. The length of egg, 1 st , 2 nd , 3 instar grub, pupa and adult male and female were 0.92-1.12, 1.45-2.50, 2.6-3.8, 3.17-5.52, 5.6-7.5, 3.8-5.2, 3.8-4.4 and 4.1-5.4 mm, respectively for zigzag ladybird beetle; 0.96-1.15, 1.502.35,

2.35-4.15, 4.07-5.85, 5.5-6.84, 3.9-5.3, 3.8-4.6 and 4.16-5.5 mm, respectivelyfor black ladybird beetle; and 1.15-1.36, 1.66-2.23, 3.2-3.98, 4.81-6.07, 5.77-7.9, 5.0-6.6, 5.0-5.4 and 5.35-6.7 mm, respectivelyfor transverse ladybird beetle. The breadth of egg, 1 st , 2 nd , 3 rd , 4 th instar grub, pupa and adult male and female were 0.45-0.50, 0.45-0.6, 0.57-0.98, 1.4-2.25, 1.4-2.25, 3.0-4.1, 3.0-3.6 and 3.4-4.1 mm, respectivelyfor zigzag ladybird beetle; 0.47-0.50, 0.45-0.65, 0.59-1.1, 1.51-2.27, 1.51-2.27, 3.0-4.2, 3.0-3.9 and 3.25-4.8 mm, respectivelyfor black ladybird beetle and 0.46-0.54, 0.51-0.7, 0.9-1.2, 1.632.6, 1.63-2.6, 3.7-4.9, 3.8-4.2 and 3.9-5.0 mm, respectivelyfor transverse ladybird beetle. The

predation efficiency of male and female of zigzag, black and transvers ladybird beetle were 847-899 and 972-1010; 835-915 and 958-1020; and 2073-2394 and 24032825

aphids, respectively. In case of predation efficiency, transvers ladybird beetle showed the best performance and zigzag and black ladybird beetle showed more or less similar. But the host range or diversity capacity of zigzag and black ladybird beetle were same and highest than transvers ladybird beetle. rd , 4 th