The biological aspects and life table parameters of the spider mite, Tetranychus urticae Koch were studied under laboratory conditions on two kinds of host plants, tomato leaves and cucumber leaves. The study showed that the incubation period, the total immature stages, life cycle and generation of T. urticae on tomato leaves were higher than them on cucumber leaves. The life cycle was 13.58 and 9.52 days on tomato leaves and cucumber leaves, respectively. The generation period was 15.91 and 11.19 days on tomato leaves and cucumber leaves, respectively. On the other hand, longevity and life span of T. urticae were higher on cucumber than on tomato. Longevity was 15.33 and 19.97 days on tomato leaves and cucumber leaves, respectively. The life span was 28.91 and 29.49 days on tomato leaves and cucumber leaves, respectively. Also, the daily main number of laid eggs was higher on cucumber, 5.36, than on tomato, 4.71. Also, the results demonstrated that the population of T. urticae had the ability to multiply about 1.91 and 2.53 on tomato and cucumber leaves, respectively.

The two-spotted spider mite, Tetranychus urticae Koch is one of the most important pests responsible for yielding losses for many crops. For several years, chemical control of mites has been extensively practiced; a major problem in the control of T. urticae is the response to develop resistance to many acaricides, and so, scientists make efforts to replace the chemical acaricides with natural acaricides, as a mean to reduce negative impacts to human health and the environment. In the search for control alternatives, this study aimed to evaluate the effect of neem essential oil and the aqueous neem extract against adult females of Tetranychus urticae under laboratory conditions. Also, LC 50 of each treatment was established and the obtained results revealed that the active essential oil of neem was more effective than the aqueous neem extract. LC 50 : 33.99 ppm and 260.30 ppm for neem oil and aqueous extract respectively. However, LC 90 value was 238.83 ppm and 1813.70 ppm for neem oil and aqueous extract, respectively.

The predatory mite, Typhlodromus athisae is one of the most important bio-control agents. This work aims to study the efficacy of the predatory mite, T. athisae when fed on the phytophagous mites Teteranychus urticae and Eutetranychus orientalis. The predator mite, T. athisae was collected from mango and citrus trees and reared in Fruit Acarology Department. The biological aspects of predatory mite were studied in the laboratory at 25°Ċ and R.H 70 %. The Life cycle and generation time recorded were 10.5271 & 12.802 day and 12.752 and 15.45 day when fed on T. urticae and E. orientalis.