Life history and voracity of Coelophora inaequalis (Fabricius) (Coleoptera: Coccinellidae) on Aphis craccivora Koch (Hemiptera: Aphididae).

The life history of Coelophora inaequalis (Fabricius) on Aphis craccivora Koch was studied. The eggs hatched within a period of 2-3 days (x = 2.7 plus or minus 0.48 days). The duration of larval instars are: first-instar, one day (x = 1.00 plus or minus 0.00 days); second instar, 1-2 days (x = 1.04 plus or minus 0.19 days); third-instar, 1-2 days (x = 1.14 plus or minus 0.35 days); fourth instar, 2-3 days (x = 2.11 plus or minus 0.31 days). The pupal period was 3-4 days, and the total development period, including incubation, was 10-11 days. The life span of the female adults was 112-126, while that of the male adults was 111-126 days. The number of eggs laid by the female totalled 510-783 for a period of 30 days. The feeding capacities of larvae at different stages were determined using A. craccivora as host. The daily consumption rates of larvae at different stages were: first-instar, 2-7 aphids (x = 4.05 plus or minus 1.04 aphids); second-instar, 4-12 aphids (x = 8.45 plus or minus 2.4 aphids); third-instar, 5-13 aphids (x = 9.20 plus or minus 2.4 aphids); fourth-instar, 10-29 aphids (x = 21.60 plus or minus 5.6 aphids); 20-40 aphids (x = 29.90 plus or minus 9.7), and 31-48 aphids (x = 39.20 plus or minus 5.2) for day 1, day 2, and day 3, respectively. The total consumption from adult emergence to premating was 160-284 aphids per pair (male and female) and 79-115 aphids (per pair) from premating to preoviposition. The total consumption from egg hatching to adult death was 2821-3509 for male and 2959-4779 for female. The results of the functional response test of adults and different larval instar showed that up to a point, consumption rate increased with increasing prey density. Adults and different larval instars also consumed more prey individuals when fed with nymphs of A. crassivora. Body color patterns of both adults and larvae are important key characters to differentiate C. inaequalis from Menochilus sexmaculatus. These characters are useful especially to field researchers and non-taxonomists.