Feeding potential of Coccinella septempunctata (L.) on mustard aphid, Lipaphis erysimi (kaltenbach) and akk aphid, Aphis nerii (Boyer de Fonscolombe)

The feeding potential of Coccinella septempunctata (Linnaeus) on Mustard aphid (Lipaphis erysimi)and Akk Aphid (Aphis nerii) was studied. The larval feeding potential, larval to pupal stage, mortality, adult emergence, and adult feeding potential were observed. The tests revealed 1^st -4^th instar larvae of Coccinella septempunctata passed through the 4^th instar larvae in all predator hosts. The maximum average feeding rate of the 1^st, 2^nd, 3^rd and 4^th instar larvae of Mustard aphid were 5.87 ± 0.96, 9.27 ± 0.34, 12.06 ± 0.32 and 12.07 ± 3.15, respectively, which were similar to those of Akk aphid 3.60 ± 0.19, 7.80 ± 0.30, 9.33 ± 0.53 and 7.06 ± 2.95. The maximum mean durations of the 1^st, 2^nd, 3^rd and 4^th instar larvae were 2.55 ± 0.33, 3.01 ± 0.13, 3.59 ± 0.37 and 4.30 ± 0.84 days, respectively. Similarly, the total survival time of larvae of C. septempunctata to Mustard aphid 13.45 ± 1.76 days and Akk aphid 11.23 ± 2.86 days. The pupal duration of Mustard aphid was 4.37 ± 0.49 days and Akk aphid 3.11 ± 0.33 days, respectively. Ladybird larvae collected from various hosts had a natural mortality rate of 2.15 ± 2.51 on Mustard, and Akk was 5.25 ± 2.50%. The male emergence rate was 50.01% and the female emergence rate was 50% on Mustard aphid. Similarly, 41.66% of male and 58.33% of female recorded on Akk. The data further showed that the occurrence rate of female adults was higher than that of male adults. The maximum feeding consumption of male was on Mustard 76.17 ± 3.67, and that of Akk aphid was 76.17 ± 3.67. Female adults survived on Mustard aphid (32 days) and Akk aphid (27 days).