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).