Mostafa Ghafouri Moghaddam - Department of Plant Protection, Faculty of Agricultural and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
Ali Golizadeh - Department of Plant Protection, Faculty of Agricultural and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
Mehdi Hassanpour - Department of Plant Protection, Faculty of Agricultural and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
Hooshang Rafiee-Dastjerdi - Department of Plant Protection, Faculty of Agricultural and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
Jabraeil Razmjou - Department of Plant Protection, Faculty of Agricultural and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.

Lady beetles are the most important predatory species among arthropods, so studying their population parameters gives a clear picture about their life span. The life histories of variegated lady beetle, Hippodamia variegata (Goeze), fed on the English grain aphid, Sitobion avenae Fabricius, on different host plants were studied under laboratory conditions, at ۲۵ ± ۱ °C, ۶۵ ± ۵% Relative Humidity and a photoperiod of ۱۶:۸ (Light: Dark) h. Developmental, survival and fecundity data were analyzed using the age-stage, two-sex life table method. According to the age-stage, two-sex life table, the net reproductive rates (R۰) of ladybird fed on S. avenae reared on Triticum aestivum var. tajan, Hordeum vulgare var. Dasht, Zea mays var. single cross ۷۰۴ and Sorghum durra var. Speed feed were estimated to be ۲۳۵.۳۸ ± ۳۶.۱۵, ۱۹۰.۷۴ ± ۳۳.۳۷, ۲۹۳.۵۴ ± ۴۶.۶۶ and ۱۳۷.۴۶ ± ۲۳.۶۶ female offspring / female, respectively. Based on the results, the intrinsic rate of increase as an index of population increase of H. variegata, was ۰.۱۸۱ ± ۰.۰۰۶, ۰.۱۷۹ ± ۰.۰۰۶, ۰.۱۶۳ ± ۰.۰۰۶ and ۰.۱۶۲ ± ۰.۰۰۶ h-۱ preyed on host reared on T. aestivum var. tajan Z. mays var. single cross ۷۰۴ S. durra var. Speed feed and H. vulgare var. Dasht, respectively. Our findings demonstrate that by using the age-stage, two-sex life table we can accurately describe the growth, survival and development of the predator. Our finding may provide basic information for developing aphid biological control programs.

Two Sex, Demography, Hippodamia variegata, Sitobion avenae, host plant