The effect of the two predatory mite species Phytosiulus persimilis Athias-Henriot and Typhlodromips swirskii (AthiasHenriot), fungal entomopathogen, Beuvaria bassiana and the biochemical compound Abamectin (Vapcomic) were investigated against the two-spotted spider mite, Tetranychus urticae Koch on kidney bean (Paulista) and sugar snap pea (Snow wind) in a greenhouse at Behaira governorate during 2013 season. The average number of spider mite population was significantly different among the different treatments on Paulista (F 4,99= 39.025; P < 0.001; Table 1), and on Snow wind (F 4,99= 32.17; P < 0.001). The mean reduction percentage of spider mite populations on both plant varieties by P. persimilis was significantly the highest (95.2%), followed by treating with Vapcomic (90.0 %) and the fungus B. bassiana (84.8%); T. swirskii caused the least (71.9%). Thus, using P. persimilis to control the two spotted spider mite on the two plant varieties (Paulista and Snow wind) is recommended.
This study was conducted to determine the effect of different temperatures and prey type on the biology of Euseius scutalis Athias-Henriot (Acari: Phytoseiidae) fed on Tetranychus urticae Koch and Panonychus ulmi (Koch) (Acari : Tetranychidae) at 20, 25 and 30°C. The incubation period of E. scutalis was shortened with increasing temperature. The mean duration of immature stages was 10.3, 12.7; 7.0, 9.8 and 4.1, 5.7 days when the mite females fed on T urticae and P. ulmi at 20,25 and 30°C, respectively. The life cycle duration was 14.0, 15.5; 9.1, 12.4 and 5.6, 7.9 days when the females were fed on the aforementioned conditions, respectively. Average female longevity on T. urticae and P. ulmi was 27.7& 31.9 days at 20°C, followed by 22.4& 25.7 days at 25°C and 15.7& 20.4 days at 30°C, respectively. The maximum average fecundity (44.2 eggs/female) was observed at 25°C when females fed on T. urticae compared with 35.6 eggs/female on P. ulmi. Obtained relative values for males were generally less than those of females . Effect of temperature on obtained biological values expressed as rates (1/duration) between main aspects and tested temperatures was significant. Obtained R 2 values ranged between 0.90 and 0.655 with P < 0.001 . It was concluded that T urticae was preferred prey than P. ulmi and 30°C was the best for individual developmental rate while 25°C was the best for most fecundity regardless tested prey.
Tetranychus urticae Koch is an emerging pest of solanaceous crops worldwide. Under laboratory conditions (27±1.0°C & 70.0±5% RH), developmental times and reproductive parameters of T. urticae were evaluated on leaves of three plants (eggplant, tomato and pepper). Eggplant was most favorite plant for T. urticae, it recorded shorter life cycle (9.66 days for female), longest life span (19.56 days for female) and richened fecundity (75.72 eggs /female). While pepper was the lowest favorable plant for T. urticae because the pepper leaves when offered as a food for T. urticae longest life cycle (11.99 days for female), and reduced fecundity (19.66 eggs /female). Also Predatory mite Amblyseius hutu was reared on adult stages of T. urticae at 27±1.0 °C, 70.0±5 % RH and 16:8 L: D to evaluate the developmental period, fecundity rate and predatory potential after feeding different prey densities of T. urticae. There were three treatment with ratio two, four and six predator for Each experiment with 60 eggs and ten newly emerged T. urticae females. A. hutu female when fed on adult stages of T. urticae completed the developmental period in 4.90 days. Total of T. urticae females and eggs consumed throughout the whole experiment by 2, 4 and 6 individuals predator of A. hutu were 0.34, 0.75 and 3.00 prey females and, 6.00, 9.00 and 12.27 prey eggs respectively. The treatment three (6 individuals predator) had the shortest extinction time for spider mite (6 days).
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