demography of hippodamia variegata (coleoptera: coccinellidae) feeding on agonoscena pistaciae (hem.: aphalaridae) under laboratory condition

hippodamia variegata (goeze) (coleoptera: coccinellidae) is one of the most prominent coccinellid predator of common pistachio psylla, in pistachio orchards. the experiment was performed under laboratory conditions i.e. 27±1oc 55±5 rh and 16:8 l: d. a cohort with about one hundred eggs- less than 24h old- was chosen and put in petri dishes. ladybeetle larvae were daily fed with pistachio psylla. fifteen, 24h old, pairs of adult beetles were selected and their daily fertility and longevity were recorded. daily fertility, immature developmental time and mortality were analyzed based on jacknife method using spss statistical software. the results indicated that intrinsic rate of increase (rm) and the finite rate of increase were 0.14 (female/female/day) and 1.16 (days), respectively. the doubling time and mean generation time were 4.7and 28.88, respectively. also, the net fecundity and net fertility rates were 71.19 and 58.9, respectively.