Diversity, Seasonal abundance and diurnal-nocturnal activity of spider population under 8 vegetable crops were studied in an agro­ecosystem in Menoufyia governorate, Southern part of Nile Delta, Egypt. A Total of 516 individuals were caught using pit-fall traps during the study period. Six species belonging to six families were identified. Lycos­idae was the dominant family (86.42%) of the populations, followed by Philodromidae, Linyphiidae. and Gnaphosidae, while Theridiidae and Sal­ticidae were clearly the rare families in occurrence. Thanatus albini (Philodromiclae) was the dominant species (5.43%). The peak of activity (19 ind/hr) and higher values of diversity (9 species) were recorded in summer, while the lowest were in winter. 0.08 ind/hr and 3 species, re­spectively. Lycorma ferox (Lycosidae) is active only in night-time as well as Setaphis subtilis (Gnaphosidae) which showed majority of activity (75%) in night-time against 25% in daytime. Erigon dentipalpis (Linyphiidae) and Sanatus albini are completely active in daytime, Lycosidae (except Lycorma ferox), Linyphiidae (except Erigon dentipalpis) showed majority of activity in daytime (91.10, 84.21%, respectively). The 3 different daytime parts (the early, mid day and the later one third) showed similar values of activity, diversity, as well as the nocturnal activity in summer, while winter recorded the low­est values and notable fluctuations between night and daytime. The high abundance of spiders in August seems to be a result of a combination of 3 factors, dense vegetation cover, high temperature and enough relative humidity.