The small Land snail, Helicella vestalis  (Prieffer) is a considerable harmful pest in citrus orchard, in the northern region of Egypt. The population dynamics and host preference was studied on four citrus species at Behera governorate during two successive years (1998 and 1999). The snail H. vestalis was abundant allover the year with maximum peaks during September and/or October. However, the least snail activity was during January and/or February. the number of snails almost doubled throughout only one year. Summer and autumn seasons showed the maximum snail activity with moderate activity during spring, but the least activity was in winter. The snail activity positively and significantly correlated with the temperature but negatively correlated with the relative humidity. Mandarin orchards harboured the least snail activity than orange orchards. Yet, the maximum snail activity was in navel orange, followed by moderate activity in Baladi orange then Sokkari orange at last.