Springtails (Hexapoda: Collembola) are one of the most abundant soil arthropods, and many of them play an important role in the decomposition of soil organic matter or may feed on soil pathogenic fungi and nematodes. Some collembolan species can cause damage in greenhouse crops. This study investigates the feeding injury of four different densities of springtails 0 (control), 20, 50, and 100 individuals at 22, 25 and 28 ?C on germinating lettuce, radish, onion, and cucumber, in laboratory (Petri dish) and semi-field pot experiments, with five replications. Also, the effect of soil application of four insecticides i.e. cypermethrin, fipronil, chlorpyrifos and a botanical insecticide, Matrin was determined against collembolan individuals in cucumber and tomato greenhouses. Sampling was carried out from early February to late May from the topsoil of Isfahan greenhouses. Using identification keys, field-collected specimens were identified as Pseudosinella sp. Cyphoderus albinus and Ceratophysella engadinensis with a density of 72.5, 26.5, and 1%, respectively. After laboratory rearing, a mixture of two first species with 60 and 40 percent densities was used in the experiments. The results of both laboratory and pot experiments showed that these two species at low to high densities (20, 50, and 100 individuals per container) significantly reduced the seedling length and caused damage to lettuce, radish, onion, and cucumber plants at 22, 25 and 28 ?C, compared to that of control. In Petri dishes, seedlings exposed to the higher densities (100 individuals at 22 ?C) showed the highest injury percentage as 31.59±2.84, 64.22±2.05, 69.28±1.12 and 68.84±1.96 in lettuce, radish, onion, and cucumber, respectively. In semi-field pot experiments, higher densities (100 individuals per container) caused also higher injuries in relatively low temperatures. Evaluation of soil applied insecticides in the cucumber and tomato greenhouses, showed that cypermethrin, fipronil, chlorpyrifos, and Matrin significantly reduced the population density of collembolan individuals compared to the control. The results of this study demonstrated that the studied springtail species at various densities can cause damage to lettuce, radish, onion, and cucumber seedlings in Isfahan greenhouses. The present study findings can be used in the integrated management of harmful springtails in the greenhouse crops. Keywords est damage assessment, Greenhouse crops, Pest management, Soil pests