A STUDY ON THE DIFFERENTIATION BETWEEN ORANGE TREES DIRECTIONS ON THE CITRUS LEAFMINER, PHYLLOCNISTIS CITRELLA STAINTON (LEPIDOPTERA: GRACILLARIIDAE) AND THE COMMON PREDATORY SPECIES, IN QALUOBIYA GOVERNORATE

Field studies were carried out to study the
effect of the different four directions (East, West, North and South) and the middle of the orange trees on the occurrence of the citrus leafminer, Phyllocnistis citrella Staint. (Lepidoptera: Gracillariidae), attacking orange orchards during the period extended from the beginning of July, 2015 until the end of June 2016. Also, to determine the common predatory species occurred in navel orange orchards in Qaluobiya Governorate. The warmer months that have the highest temperature degrees and that months having the newly orange leaves, had the highest percentages of infestation by the pest. The obtained results revealed that, the South direction of the orange trees had the highest percentages of leaves damage by the citrus leafminer, P. citrella. Where, there were significant differences between the South direction (68.75%), in comparing with those of the West direction (64.42%), the North direction (60.58%), the East direction (54.58%) and the middle of the orange trees (45.38%). So, it is recommended to firstly begin the Integrated Pest Management (IPM) programs against the pest in this direction and at the suitable time. Moreover, the importance of the natural role of the common predatory species recorded in the orange orchard is obviously shown and must be encouraged and developed. The highest total numbers of all recorded predatory species were during July, 2015 (47 individuals) and April, 2016 (35 individuals). The recorded predatory species were the highest in the South direction (70 individuals), in comparing with those of the North direction (54), the East direction (50), the West direction (37) and the middle of the orange trees (20). True spiders were recorded as the most predators (114 individuals), in orange orchard and also in the same time of pest occurrence. The animal predatory species (true spiders and predatory mites) were the highest in their numbers (167 individuals), in comparing to the insect predatory species: Chrysoperla carnea, Scymnus sp., Coccinella undecimpunctata, Orius sp. and Metasyrphus sp., of lower individuals numbers (64 individuals). In general, from this study, it is also recommended to use the different predatory species such as: Chrysoperla carnea, Scymnus sp., Coccinella undecimpunctata and Orius sp., for P. citrella control firstlyfrom the South direction. Where, this pest controlcan be applied by mass rearing of these predators in the laboratory and releasing them in orange orchards against P. citrella or other related pests (such as the citrus aphids species and mealybugs). This approach is believed to be highly practical for use as one of the means of biological control with the frame work of suitable and safe IPM programs in citrus orchards in Egypt.