The Diptera fauna colonizing cultivated pepper in Algerian greenhouse was identified and damages were studied. The results let to the identification, of three Diptera species: Scaptomyza pallida, Scaptomyza unipunctum (Drosophilidae) and Scatella tenuicosta (Ephydridae). insects monitoring in Debidibi and El Ogla stations revealed early infestation in March caused by S. pallida and Spodoptera exigua. Dynamic population studies of S. pallida over three generations showed that the duration of the larval stage and pupation is temperature-dependent, with the larval stage decreasing by 2.3 days with a 3.1°C temperature increase. Examination of adult lifetime revealed a significant difference between male and female lifetimes in the first generation (5.87 days for males and 7.26 days for females). The male-female ratio was lowest in the second generation (0.44) compared to the first (0.85) and third generations (0.83). The examination of damaged pepper fruits over three years demonstrated that S. pallida and Spodoptera exigua were responsible for significant damage, with an average infestation rate of 26.17% and 26.15% respectively at El Ogla stations. Their association caused 25.26% infestation at Debidibi station and 21.06% at El Ogla station. However, the association of S. pallida with Ceratitis capitata didn’t exceed 10% at either station. These findings are crucial for implementing integrated control strategies against insects from Drosophilidae, Ephydridae, Noctuidae and Tephritidae family in greenhouses.