Effects of the Herbivore Induced Plant Volatiles of Four Common Bean Cultivars on the Performance of the Predatory Mite, Phytoseiulus Persimilis (Acari: Phytoseiidae)

Although host plant resistance is the healthiest, most reliable and cheapest way of pest control, to achieve a successful integrated pest management, pest-resistant plant varieties should be compatibity with the biological control agents. Throughout the present study, the performance of the predatory mite, Phytoseiulus persimilis، on four common bean cultivars (Naz, Khomein, Akhtar and G11867) and also, the emission extent of Herbivore Induced Plant Volatiles (HIPVs), (responsible for the attraction of predatory mite to plant), following the plants infestalion with two-spotted spider mite, Tetranychus urticae, were investigated. To this end the seeds of each genotype were planted in pots and grown under greenhouse conditions the plants when at two fully expanded leaf stage, were each infested with 50 T. urticae adult females on each of the plant's primary leaves. After 3 days past, the plants were tested for predatory preference, carryied out through Olfactometery. The test was performed for all possible pairs on the four cultivars. The level of herbivore induced plant volatile compounds was assessed in the spider mite infested plants of common bean cultivars through GC/MS. The results indicated that Khomein cultivar stood at the highest volatile compound emitter and could significantly attract more predatory mites than the cultivars Akhtar and G11867. Also, although there was not any significant difference observed between the levels of volatile compounds emission in of Naz and Akhtar varieties, Naz could attract significantly more predatory mites than Akhtar did. It is understood that both the quantity, and quality of the volatile compounds are responsible for the attraction of the predatory mite to the spider mite infested bean cultivars.