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This research was conducted for three consecutive years, from February 2021 until November 2023. Samples were collected from citrus growing areas in Latakia Governorate in two locations: the first, Jableh Al-Aidiya, orchard area, 7 dunums. Cultivated varieties: Abu Surra and Karmantina, trees age: 22 years, second: Al-Qardaha, Ras Al-Qalouriya, area, 10 dunums. The cultivated varieties Abu Sura and Valencia, the age of the trees is 20 years. The dynamics of insect development was studied in a lemon orchard in the city of Qardaha, covering an area of 10 dunams. Laboratory work was carried out in the Center for Breeding and Propagation of Biological Enemies in Latakia Governorate, and in the Pesticide Laboratory in the Plant Protection Department, at the Faculty of Agriculture, Damascus University. This research aimed to study the development dynamics of the citrus leaf miner, Phyllocnistis citrella Stainton, and to test some management methods for it. The population density of the incomplete stages of the citrus tunneling insect ranged between 0-35 live immature stages/100 leaves. The lowest density of the insect was zero in incomplete stages in January, until mid-February, and it reached the maximum density during May. The results of the study also showed the presence of four generations of the insect. In the study area, two in the spring, and two in the summer. The study also showed a difference in the development period for the various stages of the insect at constant temperatures of 20, 25, 30, and 35 degrees Celsius, a relative humidity of 70%, and hours of lighting of 14 hours. The insect parasites in the study area were isolated and classified, and classified according to specialized classification keys. 4 parasitoids were isolated. All of these insects belong to the order Hymenoptera, Syperfamily Chalcidoidea, the family Eulophidae, and subfamilies Eulophinae, and 3 parasites belong to them: Cirrospilus quadristriatus (Subba) Rao and Ramamani 1966), Semielacher petiolatus (Girault, 1915), and Ratzeburgiola incompleta (Poueek), under the family Tetrastichinae and to which the parasitoid Citrostichus phyllocnistoides belongs (Narayanam, 1960). The percentage of parasitism ranged from 1.5% to 42.5%. In general, the highest percentage of parasitism was in the month of August (37.5-42.5%). The larval age was the third instar of the insect is the most susceptible to parasitism by parasitoids, as the average percentage of parasitism on the third instar was 32.37±2.8, and the highest rates of parasitism were in the months that witnessed an increase in the percentage of third instar larvae. The study showed the importance of predators on citrus leaf miners, as predation was the main mortality factor for larvae and was highest for the third larval instar. In a study determining the effect of the plant variety on the infestation of the citrus leaf miner, the results showed that the rate of infestation by the leaf miner varies according to the acid group to which the variety belongs, and also varies according to the variety within one group. The highest infection rate reached 37% in Abu Sarra oranges, which belong to the group Orange was followed by red grapefruit with a 34% infection rate, which belongs to the Indian lemon group, and the least infected variety was orange, with a 10.5% infection rate, which belongs to the citrus group. A study was also carried out in an orchard of Abu Surra and Kermantina orange trees in the Latakia region, Jableh, Al-Eidiya village, during the 2023 season. The study aimed to study the effect of the pesticides emamectin benzoate, acetamiprid, alphacypermethrin, and the organic fertilizer ellatico on the larvae and pupae of the citrus leaf miner, Phyllocnistis citrella. The study showed that the effectiveness of the studied pesticides on the insect larvae was high and higher than the effectiveness of the biofertiliser. The larvae mortality rate was 100% for both the pesticides alphacypermethrin and acetamiprid, and 98.44% for the pesticide emamectin benzoate, and the death rate decreased to 57.8% for the ellatico fertilizer, with a significant difference between it. Among the tested pesticides. The effectiveness of the tested pesticides on pupae was lower than on larvae, and was: 34.57%, 27.79%, and 18.34% for the pesticides alphacypermethrin, acetamiprid, and emamectin benzoate, respectively, and decreased to 8.92% for the ellatico fertilizer. Some control methods were tested on the insect, and the predatory Chrysoperla carnea, the parasitoid Trichogramma principium, which was brought from the biocenosis laboratory in Hama, was used, and neem oil Nimbecidine EC1% (Azadirachtin). The treatment with the combined effect of the parasitoid Trichogramma principium and summer oil outperformed the rest of the treatments. Then came the treatment with summer oil, then the effect of the parasitized Trichogramma principium, then the combined effect of the predator Chrysoperla carnea and neem oil on the different stages of the insect, followed by the combined effect of the predator Chrysoperla carnea and the parasitoid Trichogramma principium and finally the effect of Predator Chrysoperla carnea.
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