بررسی رفتار تخم‌ریزی سن شکارگر Orius laevigatus روی لوبیاسبز، گل جعفری گلدانی و توت‌فرنگی

The predatory bug, Orius laevigatus Fieber, 1860 (Hemiptera: Anthocoridae) is an omnivore species that preferred thrips than other insects. Plant species affect the oviposition behavior of this predator. Banker plant systems are a form of conservation biological control intended to enhance natural enemy efficacy by providing an alternative source of food when prey items are scarce or absent. This research investigated the acceptability and preferences of a predatory bug for oviposition on castor bean (Phaseolus vulgaris), marigold (Tagetes erecta) and strawberry (Fragaria ananassa) in the laboratory. The purpose of this experiment was to select the best plant for eggs laying of the predatory bug. So plants were examined in non-choice tests with 50 replications. The predatory bug was placed in transparent plastic containers (height 30 and diameter 10 cm) containing pollen grains, western flower thrips with Ephestia kuehniella eggs. Before the test, five female predatory bugs were placed without oviposition site for 24 hours. Then any female bug was entered in a container containing premature strawberry, bee pollen, E. kuehniella eggs and microtube containing moist cotton )to provide moisture(. This was done for castor bean and marigold. Finally, containers were placed in growth chamber (25±1℃, 65±5% RH and 16:8 L:D). Treatment were exposed to oviposition for 48 hours. After 48 hours, the containers were removed from growth chamber, then the females were removed from containers and the number of eggs laid and the oviposition site were recorded and were placed in growth chamber again. After four days, the number of nymph were quantified. Results demonstrated that in castor bean, females prefered to place their eggs most often on the petiole of plant (96%), and rarely laid its eggs on the surface (4%) and the bottom of the leaf (0%). In marigold, it was observed that the predatory bug prefered to place its eggs most often on the flowering area (100%). In strawberries 94% of eggs were laid in calix and 6% was laid on the fruit surface. Assessments of oviposition, egg hatch and number of nymph indicated that there is no significant difference between castor bean, marigold and strawberry for the oviposition of predatory bug, O. laevigatus.