الفهرس 
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Abstract
The population of the three diaspidid scale insects investigated exhibited three peaks of abundance annually. The parlatoria black scale, Parlatoria ziziphi exhibited the highest population in autumn season, the citrus red scale in spring season, and the purple scale in both winter and spring. The hot and mild conditions of summer seem to be unpreferred for scale insects. Further, the interspecific competition seems to be weak and three species can be coexisted with niche partitioning. On the three diaspidid scale species, the ectoparasitoids Aphytis spp. exhibited three-four peaks annually. Spring and autumn seasons were the most preferred seasons for Aphytis to increase its populations. The populations of all species of Aphytis were almost positively synchronized with those of their host scale insects. Although the population of Aphytis species positively coincided with those of their scale hosts, the relation between the number of living scales and parasitism rates by Aphytis species was only significantly negative in case of the Parlatoria ziziphi. Thus, Aphytis therefore seems to be and inverse-density mortality agent and its releases must be early in the season on low pest populations of P. ziziphi. On both the parlatoria black and California red scales, the population of the endoparasitoid Habrolepis aspidioti exhibited from two to four peaks of abundance annually. Spring and autumn seasons seem to be the most preferred seasons for H. aspidioti to increase its populations. The population peaks of H. aspidioti were synchronized partially with those of P. ziziphi but did not with those of A. aurantii. It seems to be density-independent mortality agent. Parasitism% by Aphytis sp. had from two to four peaks annually with parasitism rales did not exceed 38% on the three diaspidid species. Because Aphytis exhibited inverse density mortality rates on P. ziziphi population, the highest parasitism was during summer season where the population of its host scale was relatively low. Whereas, on the other two scale species, because it was density-independent mortality factor, its seasonal activity differed from season to season and from scale species to another species. Parasitism% by H. aspidioti exhibited two to three peaks annually. The highest parasitism was in winter and autumn with rates did not exceed 37 on P. ziziphi and A. aurantii. Both Aphytis and Habrolepis contributed with the highest fate in the total population mortality of P. ziziphi. However, among them, Aphytis sp. contributed more than H. aspidioti in the total population mortality of P. ziziphi. Thus, both parasitoids can complement together to achieve the higher parasitism activity especially during spring on P. ziziphi and during winter on A. aurantii than other seasons. On P. ziziphi and A. aurantia, parasitism seems to be the key mortality factor among others, whereas on L. beckii populations, predation almost contributed with the highest fate in the total population mortality. Increasing the pH-level of protein- based bait above 7.6 might adversely decline the number of trapped flies of the Mediterranean fruit fly, Ceratitis capitata. Baits composited from Buminal + di-ammonium phosphate mixture can be generalized in IPM programs for C. capitata in Egyptian fruit farms.