Effect of releasing different levels of Phytoseiulus macropilis (Banks) predator on Tetranychus urticaekoch [electronic resource].

Includes references.

Under a screen greenhouse conditions the predatory mite, Phytoseiulus macropilis (Banks) (Acari: Phytoseiidae) was released at 4 and 7 predators/pot on bean plants inculcated 7 days prior with different densities of Tetranychus utticae Koch (i. e. 6, 12, 24 and 48 individuals/pot). When the predatory mite, P. macropilis was released at low level (4 predators/pot) on bean plants, the populations of T. utticae increased in the pots with the increase of the initial inoculated mites. Also, populations of T. utticae were comparatively high after 7 and 14 days from the predator release when the predatory mite, P. macropilis was released at the low level than those obtained with the high level. On the other hand, higher reductions of target mite pest were obtained after 7 and 14 days when the predator was released at high rate (7 predators/pot). The same was obtained by decreasing of the initial densities of T. urticae. The prey: predator ratios generally should be increased, in general, with the increase of the initial inoculated T. urticae. It was clearly high after 7 days from the predator release, while obviously decreased after 14 days. According to the previous results is be advisable to release the predatory mite, P. macropilis when the T. utticae population is at low number to achieve suitable situation for the predator to play their role successfully.

Summary in Arabic.

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