the effect of temperature on prey preference of adults and fourth instar larvae of hippodamia variegata (col: coccinellidae) on two aphid species, aphis fabae and acyrthosiphon pisum (hem: aphididae)

prey preference of natural enemies is among the phenomena that should be considered in determining the efficacy of natural enemies. when the predators are faced with a choice between two or more preys, they often show their preference to one from among them. temperature is one of the environmental factors that can affect insect foraging behavior. two aphid species namely aphis fabae and acyrthosiphon pisum are of the ability to attack and damage bean plants. prey preference of iranian native species hippodamia variegata as one of the efficient aphid predators, was examined on bean plants and on the two named species of aphids at different temperatures. the experiment was carried out at 15±1?c, 19±1?c, 23±1?c, 25±1?c, and 27±1?c, plus 70±10% of rh, and a photoperiodism state of 16:8 (l: d). predator preference was analyzed through an application of manly’s index of preference to the data with statistical analysis showing that at all temperatures for fourth instar larvae, male and female (except 15?c for the fourth instar larvae), a. fabae was preferred to acyrthosiphon pisum. this experiment showed that h. variegata does not change its preference in response to temperature and it is assumed that at variable conditions of releasing the same trend be effected