Some Biological Characteristics of Hippodamia variegata (Col.: Coccinellidae) rearing on Three Species of Wheat Aphids

Hippodamia variegata is widely distributed in Iran. In this research، biological characteristics of this ladybird feeding on Sitobion avenae، Diuraphis noxia and Schizaphis graminum evaluated under laboratory conditions at 25±1°C، 65±5% relative humidity، and a photoperiod of 16:8 h (Light: Dark). To accomplish the experiments، a cohort of newly laid eggs were randomly selected and transferred into Petri-dishes. After hatching، larvae were transferred individually into test containers and were fed with various stages of each aphids and duration of different stages of H. variegata were recorded. Based on obtained results، total pre-imaginal developmental time for males and females were estimated to be 14. 05±0. 18 and 13. 63±0. 24 days on S. avenae، 13. 58±0. 14 and 13. 42±0. 12 days on D. noxia and 14. 61±0. 21 and 14. 04±0. 12 days on S. graminum، respectively. Adult longevity of males and females were 15. 55±1. 91and 26. 38±3. 28 days on S. avenae، 35. 86±2. 25 and 24. 81±1. 89 days on D. noxia and 25. 78±1. 95 and 19. 88±1. 41 days on S. graminum، respectively.. Daily and total oviposition were determined 4. 86±0. 65 and 55. 4±11. 2 on S. avenae، 23. 37±1. 79 and 476. 1±45. 8 on D. noxia and 13. 95±0. 66 and 158. 0±15. 4 on S. graminum.