Biology and Morphometrics of Pulse Beetle, Callosobruchus chinensis (L.) on Chickpea

Abstract

The biology and morphometrics of pulse beetle, Callosobruchus chinensis were studied on chickpea cultivar ICCV 2 under laboratory conditions at ICRISAT, Patancheru, Telangana, India during 2018-19 and 2019-2020. The experiments were carried out in the BOD incubator at temperature of 28 ± 2ºC and relative humidity of 65 to 70%. The life cycle of C. chinensis included four stages egg, grub, pupae and adult. The data revealed that eggs incubation period in 4-5 days, the grub stage consisted of four instars and its development ranged from 20-25 days, pupation lasted for 6-7 days, whereas, female adult longevity ranged from 9-12 days. The morphometric measurements revealed that the average length and breadth of eggs were 0.62 ± 0.03mm and 0.34 ± 0.02 mm respectively. The length and breadth (mm) of four grub instars G1, G2, G3 and G4  were 0.58 ± 0.02 and 0.30 ± 0.01, 1.53 ± 0.06 and 0.92 ± 0.04, 2.71 ± 0.10 and 1.47 ± 0.06, 3.59 ± 0.14 and 1.96 ± 0.08 respectively. The average length and breadth of pupa were 3.72 ± 0.12 mm, 2.15 ± 0.09 mm. Whereas, the length and breadth (mm) of  adult male and female bruchids were 3.87 ± 0.08, 2.07 ± 0.05 and 4.23 ± 0.14, 2.31 ± 0.07 respectively. The total life cycle of C. chinensis ranged from 33-42 days.