بررسي ويژگي هاي زيستي شته ي روي گل داوودي در شرايط طبيعي و آزمايشگاهي

Biology of Macrosiphoniella sanborni (Horn.: Aphididae) on Chrysanthemum Flower in Field and Laboratory Conditions

Biology and population parameters of chrysanthemum aphid, !tlacrosrphoniella sanborni (Gillette) were studied in three following conditions laboratory: (24±1°C & 35±5%; RH 28±1°C & 35+5%; RII 28±1°C & 65±5% RH) and in natural conditions (mean 25.91°C & mean 36.05% RH) on chrysanthemum flower var. Yellow Butten. A photoperiod of 16:8 (L:D) h was used at all experiments in laboratory conditions. The nymphal period and longevity of aphid at 24°C was significantly higher compared to other conditions. The least nymphal period and longevity were observed at 28°C (with both humidities). Daily reproduction rate of aphid at 28°C was significantly higher than the other conditions but there was no significant difference between all conditions on aphid total reproduction rate. Intrinsic rate of increase under laboratory conditions of 24°C (35% RH), 28°C (35% RH), 28°C (65% RH) and natural conditions were 0.2239, 0.2965, 0.2961 and 0.2878, respectively. The maximum and minimum rates for the above parameter were obtained at 28 °C and 24°C, respectively. Doubling time for the population of chrysanthemum aphid was more at 24°C (RH 35%) than other studied conditions.