Development, growth, feeding and reproduction of Ceratomegilla undecimnotata, Hippodamia variegata and Coccinella septempunctata fed on the tobacco aphid, Myzus persicae nicotianae

The demographic parameters and the larval aphid consumption of the predatory coccinellids Hippodamia variegata (Goeze) and Ceratomegilla undecimnotata (Schneider) were examined at five constant temperatures (17, 20, 23, 26, and 29 A degrees C). The same parameters were determined for Coccinella septempunctata L. at 23 A degrees C. A red Myzus persicae nicotiannae Blackman clone reared on tobacco leaves was used as prey. Preimaginal development of H. variegata and C. undecimnotata ranged from 12.4 to 40.6 days and 14.4 to 48.5 days at 17 A degrees C to 29 A degrees C, respectively. The corresponding thermal summation constants were 211 and 256 DD (day-degrees). Total and mean daily larval consumption at 26 A degrees C were 84.2 and 8.7 aphids, for H. variegata and 129.1 and 9.4 aphids, for C. undecimnotata, respectively. At 23 A degrees C, the mean fecundity of H. variegata, C. undecimnotata and C. septempunctata was 882, 656 and 586 eggs, respectively. The duration of the oviposition periods was 47.6, 50.4 and 73.4 days, respectively. The demographic parameters calculated for H. variegata, C. undecimnotata and C. septempunctata, were as follows: intrinsic rate of increase (r (m)) 0.129, 0.084, and 0.061 female/female/day; mean generation time (T) 42.4, 59.1, and 69.3 days; net reproductive rate (R-o) 241.9, 142.7, 67.3 female/female; and population duplication time (DT) 5.4, 8.3, and 11. 4 days. Total aphid consumption by a pair of adult male and female was 2381 aphids in H. variegata and 3242 aphids in C. undecimnotata. The possible role of the three predator species as biocontrol agents is discussed