عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this research, the effect of host instars was evaluated on time allocation to various foraging behaviors in sexual population of the parasitoid wasp, Lysiphlebus fabarum (Marshall) (Hym., Braconidae: Aphidiinae). For this purpose, the parasitoid wasps reared in the second instar of black been aphid, Aphis fabae Scopoli (Hem., Aphididae) were introduced separately to leaf patches that included 15 of the second or fourth instar of the aphid. Next, foraging behaviors of wasp females and host defensive behaviors of aphids were recorded for 30 minutes. According to the results, the host instars did not affect time allocation to various foraging behaviors within a patch. The results also showed that the number of defensive behaviors of two host instars, including kicking and producing droplets of cornicle secretions was significantly different when exposed to parasitoid wasps. The second and fourth instar aphids displayed significantly more kicking and cornicle secretions behaviors, respectively. Frequency of attack orientations relative to the aphid body (anterior, posterior, and lateral) was also tallied. The most attacks on second instar were launched from a lateral orientation, which may present a lower risk of kicking and smearing with cornicle secretions.