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The two spotted spider mite (TSM), Tetranychus urticae Koch (Acari: Tetranychidae) is one of the major mite pests on agricultural crops worldwide. The present work aims to study abundance of TSM and the most common predatory phytoseiid species, Typhlodromips capsicum Mostafa (Acari: Phytoseiidae) on four cotton cultivars viz. Giza 45, Giza 86, Giza 87 and Giza 92 mostly cultivated in Egypt during two successive growing seasons 2016 and 2017 at Aga district, Dakahlia Governorate, Egypt in relation to prevailing atmospheric temperature and relative humidity. Also, the synchronization of TSM and T. capsicum under field conditions on the above-mentioned investigated cotton cultivars was investigated. Obtained results showed that TSM populations were significantly (P≤ 0.05) higher on the cotton cultivars Giza 45 and Giza 92 in comparison with the other investigated ones (Giza 86 and Giza 87) during the two investigated seasons 2016 and 2017. Populations of the phytoseiid species, T. capsicum did not significantly affected by the tested cotton cultivars. There were positive correlations between the changes of TSM and T. capsicum populations and temperature while the correlations with relative humidity were positively insignificant during the two investigated growing seasons. Good synchronization between TSM and T. capsicum populations on tested cotton cultivars was detected during the first and second seasons. These results showed that cotton cultivars, predatory mites and weather factors are of the most important factors affecting the populations of T. urticae on the investigated cotton cultivars.

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A survey conducted recently in Sharkia governorate, Egypt indicated the presences of 11 species of predatory mites on grapevines. These species belong to families Phytoseiidae (8 species), Cunaxidae (one species), Cheyletidae (one species), Stigmaeidae (one species). Frequency occurrence of the collected species was discussed. A logistic regression of the proportion of prey consumed as a function of initial prey density was conducted to identify functional response types. Nonlinear least-squares regression and the random predator equation were used to estimate attack rates and handling times. Overall, adult females E. metwallyi exhibited a type 2 functional response to T. urticae. Whereas, attack rate and handling time of E. metwallyi recorded 0.10 , 0.28 and 0.07 and 0.99 , 1.47 and 4.59 when offering eggs , males , females of T. urticae, respectively. Generally, these results indicated that the predator E. metwallyi may be considered as biocontrol agent against the two-spotted spider T. urticae.