Study on Some biological characteristic of Oenopia conglobata by feeding on three aphids, Rhopalosiphum padi, Macrosiphum rosae and Chaitophorus populi

Oenopia conglobata contaminata (Menetries) is an insect predator that has been observed and collected from ornamental trees and Spanner and useful trees in most regions of the world and Iran. Both larvae and adults of this ladybird feed on aphids, scales, psylla and eggs of some insect pests and play important role in control of these insect pests. Identification of biological characteristic of O. conglobata is essential for its use in the field aphids, medicinal plants and in city green space. In this research study, Rhopalosiphum padi (L.), Macrosiphum rosae (A)and Chaitophorous populi (Panzer) were reared on Wheat, Rosa sp. and Populus sp. respectively, as hosts in the greenhouse. According to the results, mean of daily and total feeding rate on R. padi were more than other aphids in both larvae and adults. Longevity immature stages of beetles were shorter since they feed on R. padi and was 2.5±0.2, 2, 2.5±0.1 and 2.5±0.1 for the first, second, third and fourth instar, respectively. Voracity rate of different instar larvaewas direct correlated with instar of larvae. Male and female of coccinellid consumed higher number of aphids (3316±43 and 3390±21 respectively) in comparision with the larvae. Fecundity and oviposition rate of female beetles was more by feeding on R. padi (415±11 eggs)in comparison with the other aphids. Fecundity of coccinellid was placed in next order by feeding on M. rosae and C. populi, respectively. Overall result showed that R. padi regarding to high nutritional quality effect on biological characteristic of O. conglobata.