BIOLOGY, MORPHOMETRY AND FEEDING POTENTIAL OF COCCINELLA TRANSVERSALIS FABRICIOUS

Abstract

Investigations on biology, morphometry and feeding potential of Coccinella transversalis Fab. (Coccinellidae : Coleoptera) were carried out at ordinary room temperature during 20010-11. Average egg, larval and pupal period were 9.27 ± 0.30, 21.33 ± 0.39 and 8.27 ± 0.15 days, respectively. Of the four larval instars average duration of first, second, third and fourth instar larvae was 4.73 ± 0.23, 3.93 ± 0.28, 5.13 ± 0.19 and 7.53 ± 0.22 days, respectively. Male and female beetle survived for 21.13 ± 1.02 and 22.17 ± 1.27 days, respectively. Female beetle laid 253.85 ± 38.76 eggs on an average during her adult period. Entire life of the predator was completed in 63.50 ± 1.15 (females) and 62.47 ± 1.05 (males) days. Sex ratio (M: F) was 1: 1.32. Average length and breadth of eggs were 1.06 ± 0.01 and 0.47 ± 0.01 mm, respectively. Mean length of first, second, third and fourth instar larvae were 2.49 ± 0.02, 3.47 ± 0.02, 5.72 ± 0.02 and 9.48 ± 0.06 mm, respectively. The corresponding values for breadth of the larvae were 0.76 ± 0.01, 1.03 ± 0.01, 1.47 ± 0.02 and 2.49 ± 0.01 mm, respectively. Average length of female and male beetles was 6.02 ± 0.01 and 5.96 ± 0.02 mm, whereas breadth was 4.62 ± 0.01 and 4.53 ± 0.03 mm, respectively. The beetle predated significantly maximum (528.47 ± 11.79) number of Aphis craccivora Koch. nymphs followed by Aphis gossypii Glover nymphs (402.67 ± 4.75) and Lipaphis erysimi Kalt. (223.27 ± 5.08).