In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4–6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation.

No abstract

Telenomus busseolae Gahan is the most important egg parasitoid of sugarcane stem borers in Iran. Laboratory experiments were conducted to evaluate the functional response of T. busseolae to egg densities of Sesamia nonagrioides (Lefebvre) under four different temperatures (20, 25, 30 and 358C). Results of logistic regression revealed a type III functional response for all temperatures tested and type of functional response was not affected by temperature. Roger's random parasite equation was fitted to observed data at 358C. In the other data sets (collected data under 20, 25 and 30 8C) Roger's equation could not provide meaningful parameters, therefore Holling's disk equation was used to fit the data. The attack rate for T. busseolae varying from 0.001784 to 0.10704, 0.0026 to 0.152, 0.0024 to 0.144 and 0.000866 to 0.05196 per h and estimated handling times were 0.59, 0.50, 0.53 and 0.29 h at 20, 25, 30 and 358C, respectively. Based on asymptotic 95% confidence intervals, functional response parameters did not differ significantly from 20 to 308C, which indicates that handling time and attack rate are least affected by the temperature changes. The results suggest a similar performance of T. busseolae against S. nonagrioides eggs at temperatures of 20Á308C. These results show that T. busseolae is well adapted to temperature changes during the sugarcane growing season.

No abstract

No abstract