Application of fertilizers in the plant growth medium can affect plant-herbivore interactions by changing plant growth and physiology. Because of the increase in the using vermicompost fertilizer in greenhouse cultivation, the effect of vermicompost application at tomato production on the biological characteristics of the two major tomato pests, tomato leaf miner, Tuta absoluta , and greenhouse whitefly, Trialeurodes vaporariorum , was investigated. Five treatments in eight replications were used in the experiments: control (without vermicompost), 30% and 60% solid vermicompost fertilizer, 40% and 20% aqueous extracts of vermicompost. Results of studied plant parameters showed a significant increase in plant height, leaf number, shoot dry weight and root dry weight in vermicompost treatments and the highest increase was observed in plants treated with 60% solid vermicompost. Also, assessing some elements in the tested plants indicated a significant increase in the amount of nitrogen and potassium in 30% and 60% solid vermicompost treatments. To determine the effect of vermicompost on the insect pests, two different trials, choice and no- choice tests, were used. In the choice test using the greenhouse whitefly, the application of vermicompost reduced the percentage of infested leaves to whitefly eggs and the mean number of eggs per leaf, so that the lowest amounts were in 30% and 60% solid vermicompost and 40% aqueous extract of vermicompost. In the experiments using the tomato leafminer moth, the lowest number of eggs per leaf and the highest mortality in the larval stages were observed in 60% solid vermicompost treatment. Tomato leafminer moth usually oviposit on abaxial leaf surface, however, the percentage of eggs laid on the adaxial leaf surface was increased from 7.09 ± 2.62 in control to 16.68 ± 2.63 in the plants treated with 60% solid vermicompost. In the no-choice experiments, a significant difference was observed in the age-specific mortality. The second instar nymphal mortality of greenhouse whitefly was increased from 0 in control to 1.21 in 60% solid and 40% extract of vermicompost. The larval mortality of tomato leafminer moth was increased from 0.33 ± 0.33 in control to 3.00 ± 0.33 in 60% solid vermicompost. In addition, the number of eggs laid per female of tomato leafminer moths reared on plants treated with 60% solid fertilizer was 16% lower than that of reared on control treatment. According to the results it seems that application of precise amounts of vermicompost in tomato growing media, by increasing the plant growth and reducing the herbivorous insect fitness, can affect the population of these two tomato important pests. Key Words: Tomato Leafminer Moth, Greenhouse Whitefly, Solid Fertilizer Vermicompost, Aqueous Extracts of Vermicomposts, Choice test, No-Choice test