iarjalsIARJALSIARJALS2708-5104https://doi.org/10.47310/iarjals.2021.v02i01.011Seasonal Abundance and host plant preference of the Tomato Leaf Miner Liriomyza bryoniae (Kaltenbach) (Diptera: Agromyzidae) on three Summer Host Plants in Janzour Region, LibyaAlbasha.MohamedOElkhouly.AlansaryR.NawalSheligDepartment of Zoology faculty of science – Zawia University, Libya.Department of Biology faculty of education – Zolton, Sabratha University, Libya.Background: L. bryoniae is a Palearctic species which probably originates from southern Europe, where it occurs commonly outdoors but has now spread to many parts of central and northern Europe and is also reported in North Africa (Morocco and Egypt), as well as in several countries in Asia. L. bryoniae is polyphagous and as such can feed indiscriminately on plants from a number of different orders, including many vegetables and ornamental species. Objectives: The present study aimed to investigate the population abundance of the tomato leafminer L. bryoniae on three selected host plants. On the other hand, host plant preference by L. bryoniae was investigated. Methods: 100 infected leaves were collected from each host plant. Samples were kept in plastic bags and transferred to be examined in the laboratory. Number of living L. bryoniae larvae were counted and recorded. Results: L. bryoniae larvae recorded low abundance on Kidney bean in early May, then the population increased recording three peaks of abundance recording (127, 158 and 179 individuals/100infested leaves) occurred in 22th of May, the 19th of June, 24th of July. On tomatoes L. bryoniae recorded low numbers in early May, then the population increased recording three peaks of abundance (109, 121 and 104 individuals/100infested leaves) occurred in 22th of May, the 3rd of July, 31th of July. On bell pepper L. bryoniae recorded low numbers in early May, then the population increased recording three peaks of abundance (87, 103 and 88 individuals/100infested leaves) occurred on 29th of May, the 10th of July and the 7th of August. Conclusions: L. bryoniae larvae recorded low numbers in the beginning of the growing season in early May on the three summer host plants, then the population increased recording 3-4 peaks of abundance.