This study was carried out during two successive years from October 2014 to September 2016. Results showed that the temperature and moisture R.H.% were significantly affected the mean abundance of the phytophagous mite O. mangiferus and its predator A. swirskii associated with mango orchard trees. The highest mean abundance of O. mangiferus was recorded in the summer season (2.96 ± 0.6 indv./leaf) and (1.33 ± 0.05 indv./leaf) for A. swirskii, respectively in the first year (from October 2014 to September 2015). On the other hand, the lowest mean abundance was recorded in the autumn (0.6 ± 0.11) for O. mangiferus, (0.23 ± 0.09 indv./leaf) for A. swirskii. The mean abundance of O. mangiferus populations increased to (3.43 ± 0.7 indv./leaf) in the second year of study in contrast to the populations of its predator. The results stated that the temperature had a significant effect on the population abundance of the phytophagous mite, O. mangiferus and its predator while the relative humidity had a negative effect on both populations.

Field study was carried out on mite species inhabiting some fruit trees in Ismailia Governorate, during the period from October 2014 to September 2016. Survey of mites proved the occurrence of 44 mite species belonging to 36 genera and 21 families belong to 2 orders and 4 suborders. Order: Acariformes include three suborders; Prostigmata, Astigmata and Cryptostigmata. Suborder Prostigmata was represented by 14 families: Tetranychidae (7 species), Tenuipalpidae (8 species), Eriophyidae (one species), Stigmaeidae (2 species), Neophyllobiidae (2 species), Caligonellidae (one species), Raphignathidae (one species), Cheyletidae (3 species), Eupalopsellidae (one species), Bdellidae (one species), Cunaxidae (one species), Eupodidae (one species), Tydeidae (3 species) and Tarsonemidae (one species). Suborder: Astigmata was represented by two families: Acaridae (two species) and Glycyphagidae (one species). Suborder Cryptostigmata was represented by two families: Oppiidae (one species) and Oribatulidae (one species). On the other hand, order: Acariformes include one suborder: Mesostigmata, which represented by three families: Phytoseiidae (4 species), Ologamasidae (one species) and Ameroseiidae (one species).