نرخ شکارگری و ترجیح میزبانی سن Reuter) Nesidiocoris tenuis) روی سه آفت مهم محصولات گلخانه‏ ای

Trialeurodes vaporariorum (westwood) (Hemiptera: Aleyrodidae), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and Tetranychus urticae Koch (Acari: Tetranychidae) are three most important pests of greenhouse crops including tomato and eggplant. Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) has proved a potential agent for biological control of the mentioned pests. To evaluate the efficiency of the predator, an investigation was carried out to calculate the predation rate and prey preference of N. tenuis on the candidate hosts. First, populations of the predator and greenhouse whitefly were collected from infested greenhouses of Isfahan and their colonies were established on tobacco seedlings in separate greenhouses at Plant Protection Research Department, Isfahan. N. tenuis was fed by Mediterranean flour moth eggs and sugar solution (17%). Similarly, tomato leaf miner and spider mite colonies were reared on tomato and eggplant seedlings, respectively. Experiments were performed at 25±2 °C, 60±10% RH, with a 16:8 h (L:D) photoperiod. Predation rates were determined by no-choice method and prey preference was calculated using Manly’s index, respectively. Data was analyzed through SAS software. The results showed that the predation rates of N. tenuis female and male on whitefly 2nd and 3rd instar nymphs, spider mite adults and tomato leaf miner 2nd instar larvae were recorded as 38.1±3.46, 88.6±9.14 and 2.5±0.31 and 28.7±2.69, 68.5±7.16 and 1.65±0.21 per 24 h, respectively. Moreover, N. tenuis demonstrated as high as 62±0.04% preference for feeding on greenhouse whitefly nymphs compared with that on spider mite adults and 58±0.07% compared with that on tomato leaf miner larvae, respectively. Anyhow, adult predators had greater preference (72±0.07%) to feed on spider mite over tomato leaf miner larvae. When predator was exposed to all three prey types simultaneously, Manly’s index was obtained as 46±0.07, 27±0.04 and 26±0.05 on white fly nymphs, spider mite adults and tomato leaf miner larvae, respectively. It is concluded that N. tenuis is able to feed on all three types of prey; however, it prefers to feed on greenhouse whitefly compared with spider mite adults and tomato leaf miner larvae in pest complex scenario.