| Effect of rearing condition (individual vs. dense) on the establishment of Phytoseiulus persimilis (Acari: Phytoseiidae) on Trichoderma harzianum-treated, spider mite-infested bean leaves |
| Paper ID : 1091-IPCA5 (R1) |
| Authors |
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Fatemeh Ebadi *1, Azadeh Zahedi Golpayegani2, Alireza Saboori3, Keivan Behboudi4, Helen mohammadi5, Roghayeh Garibreza6, Navid Sehat7 1College of Agriculture & Natural Resources of University of Tehran, Karaj city, Alborz province, Iran ebadi.fatemeh@ut.ac.ir 2College of Agriculture & Natural Resources of University of Tehran, Karaj city, Alborz province, Iran Zahedig@ut.ac.ir 3College of Agriculture & Natural Resources of University of Tehran, Karaj city, Alborz province, Iran Saboori@ut.ac.ir 4College of Agriculture & Natural Resources of University of Tehran, Karaj city, Alborz province, Iran Behbodi@ut.ac.ir 5College of Agriculture & Natural Resources of University of Tehran, Karaj city, Alborz province, Iran Helenmohamadi@ut.ac.ir 6College of Agriculture & Natural Resources of University of Tehran, Karaj city, Alborz province, Iran gharibreza.ro@ut.ac.ir 7College of Agriculture & Natural Resources of University of Tehran, Karaj city, Alborz province, Iran Navidsehat93@ut.ac.ir |
| Abstract |
| Learning, defined as a behavioral change resulting from experience, is an important phenomenon in arthropods, including insects and mites. The fungus Trichoderma harzianum Tr6 is an important biological control agent that influences host plants and arthropods. Here we have investigated the effect of rearing condition and plant-fungus interactions on the adaptive learning behavior of the predatory mite Phytoseiulus persimilis Athias-Henriot in both “individual” and “dense” situations. Same-aged individuals were reared separately (individual condition) or in groups (dense condition) from the immature stage, without fungal exposure. Bean plants with four fully developed leaves were treated with T. harzianum Tr6 (10⁸ spores/mL) or left untreated. After 72 hours, these leaves were used for predator exposure. Upon adulthood, mites were placed for 24 hours on detached bean leaves (3 × 3 cm) either treated with the fungus or untreated, positioned upside down in 6 cm Petri dishes on water-saturated cotton. For the individual condition, 15 same-aged predators were introduced separately into 15 Petri dishes. For the dense condition, 15 predators were introduced into a larger plastic container with a water-saturated sponge and a plastic plate, and 10 Tetranychus urticae-infested leaves to allow intraspecific interactions. The experiment was initiated using two Petri dishes, both with fungus-treated leaves and spider mites, which were connected by a plastic bridge. One dish had spider mites previously exposed to three predators for 24 hours (predation cues remained), and the other had predator-free mites. A single predator, from either rearing condition, was released onto the bridge, and its presence in either patch was recorded every eight hours over 36 hours. Statistical analyses were conducted using factorial ANOVA followed by LSD post-hoc tests in SPSS 27. Factorial analysis revealed that neither T. harzianum exposure (P = 0.512) nor rearing condition (P = 0.326) had a significant effect on the oviposition behavior. of P. persimilis However, patch type had a significant effect (P = 0.015), with higher oviposition observed in the predator-free patches. Additionally, a significant interaction was found between fungal exposure and rearing condition (P = 0.006), suggesting that early social context in combination with fungal experience can shape adaptive learning and patch selection. These findings highlight the importance of context-dependent learning, suggesting that social experience in combination with environmental microbial cues can shape adaptive foraging strategies in predatory mites. |
| Keywords |
| Adaptive learning, biological control, cue, fungus, host-plant interaction, predator |
| Status: Abstract Accepted |
