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Population dynamics and species composition of phytophagous and predatory mites in citrus orchards were determined from January to December 2016 at Shenofa locality, Shebin El-Kom, Menoufia governorate, Egypt. The survey revealed the occurrence of phytophagous mites as: Panonychus citri (McGregor), Eutetranychus orientalis (Klein) (Tetranychidae); Phyllocoptruta oleivora (Ashmed) (Eriophyidae); Brevipalpus californicus (Banks) (Tenuipalpidae) and Tydeus californicus (Banks) (Tydeidae), representing the most common phytophagous species found in citrus orchards. In addition, two predatory mite species of two families were recorded as: Amblyseius swirskii Athias-Henriot (Phytoseiidae) and Agistemus exsertus Gonzalez (Stigmaeidae) were found to be the most abundant predatory species inhabiting citrus leaves. The population fluctuation of phytophagous and predacious mites on studied citrus varieties was varied according to citrus varieties and sampling dates reaching its highest peak, in most cases, during September. Navel orange recorded the highest numbers of P. oleivora in comparison with other varieties of citrus (290.31 indiv. /10 leaves), while the highest number of P. citri and B. californicus were 85.63 and 45.3 indiv. /10 leaves on Balady orange. The obtained result indicated that the maximum and minimum temperature and relative humidity expressed as an insignificantly positive during 2016 season on the population of P. oleivora, E. orientalis, B. californicus, T. californicus, A. swirskii and A. exertus, but highly significance difference was obtained between population of P. citri only. Finally, it could be concluded that winter months are suitable for applying different biological control agents including predatory mites where pests are lowest in numbers and the optimum environmental factors are present as well.

To avoid the bad effect of synthetic insecticides, botanical products are useful tools against pests. Therefore, ftve plant extracts were tested to evaluate their toxicity effect against Tetranychtis urticae Koch as pest and its predatory mite Amblyseius swirskii Athias-Henroit. These plants are red pepper, garlic, seena-L, galls, and thyme. The effect of plant extracts on some biological aspects of T. urticae was studied. Five concentrations of each extract were used 1, 2, 3, 5 and 6 %. LCso of both field and susceptible strain was calculated, in addition to slope and tolerance ratio. The effect of LCso and LCso of field strain on some biological aspects was studied. Red pepper extract exhibited a high degree of efficiency against adult female of T. iirticae with overall mean mortality ranged from 24.46 - 98.56 %; while the lowest was thyme recorded overall mean mortality ranged from 0.00 to 66.86 % for 1 to 6 % concentrations, respectively. As for predator A. swirskii overall mean mortality of red pepper was the highest recording 33.99 to 89.52 % with 1.29 % LCso, whilst galls and thyme extracts recorded the least mortality. There are significant differences between red pepper and other extracts in incubation period; where mean of incubation period was 7.27; while there are no significant differences between the other four plant extracts. Duration of larval stage was prolonged to 6 days in red pepper treatment. All hatched larvae died in garlic treatment and can’t develop to protonymph. Females in red pepper treatments can’t deposit eggs and died, while life cycle was prolonged to 14.75, 15.97, and 15.79 days for galls, thyme, seena-L, respectively in comparison with 10.47 days in control. LC30 of tested plant extracts prolonged incubation period of T. urticne especially in red pepper and garlic treatments, in comparison with control. Garlic and red pepper extracts registered the longest period of life cycle compared with control 10.4 days. Females at garlic treatment died after 6 days without laying eggs, while males lived for five days then died. Female longevity was shortened to 10.89 days in red pepper comparing with 14.67 days in untreated females. Furthermore, few eggs were laid in all treatments in comparison with control.

In a field survey, Aceria fictis, Tetranychtis urticae and the predator, Phytoseius finitimtis, were registered on fig trees from mid of March 2013 to mid of January 2014. A. fiicus population reached its peak at mid September with mean number of 29.05 individuals/leaf. T. iirticne at the end of August with mean number of 10.9 individuals/leaf, whereas the predator, P. finitim us reached at mid September. For control, the highest reduction percentages in eriophyid mite population occurred when P. finitimtis was released by 1 predator/3 Eriophyid mite, resulting in reduction of 90.21 %. The tested pesticides: Acaristop, Dumper and High point, recorded reduction percentages 88.14, 86.84, and 85.06 % in eriophyid mite population, respectively, while red pepper plant extract gave 82.39 %. Numbers of T. urticae decreased after all levels of release, where the highest decrease was at the level of 1 predator: 3 preys (0.03, 0.8 individual/ leaf) after 2 and 4 weeks, respectively, when compared with check. The study recommend the efficiency of the predatory mite, P. finitimu8 at release levels of 1: 3 and 1: 5, in addition to red pepper plant extract 10 %.