Onion is the most important vegetable crops produced on large scale in the world. However, the crops are attacked by several thrips species. In Ethiopia onion thrips, Thrips tabaci L., was considered as the most dominant species of thrips attacking onion while other species of thrips are also involved in the infestation. Farmers manage thrips by applying insecticides several times and this leads to ineffectiveness of most insecticides because of the hiding of thrips between the inner leaves of the onion plant and the pupa in the soil resulting insecticide resistance and also affects the health risks of the grower as well as the environment. Therefore, this study was conducted to evaluate eco- friendly management methods and also species identification to confirm the availability of other thrips species at Koga irrigation scheme, North Mecha district, Ethiopia, under irrigation conditions during 2022/2023. Thrip specimens were randomly collected in eight irrigated onion fields (three plants per field) around the study area and were identified using a dissecting microscope. The experimental treatments included three onion varieties (Bombay red, Nasik red and Nafis) and two mulching materials (white plastic mulch and straw mulch) with a control treatment using a randomized complete block design with three replications in a total of nine treatment combinations. Data (population of thrips/plant, percent thrips reduction, yield parameters were collected and subjected to analysis of variance (ANOVA) using SAS version 9.4 software. The result indicated that, the presence of two thrips species, T. tabaci and F. schultzei, with T. tabaci being the dominant species. The combination of Nafis onion variety with white plastic mulch gave the lowest mean number of thrips per plant (31.17), highest thrips percent reduction (41.1%), highest biomass weight (21934.63 kg/ha), highest marketable yield (19.28 t/ha) and total yield (20.09 t/ha). Generally, the study indicated that the presence of other thrips species and integration of mulch with onion variety gave significant effects on managing onion thrips.