ENVIRONMENTAL STUDIES ON CERTAIN LAND SNAILS UNDER DIFFERENT CONDITIONS AT SHARQUIA GOVERNORATE

Abstract

The present work was carried out to study ecology, food consumption and bioassay of using several plants parts, biocides and chemical compounds on land snails infesting some field, vegetable and horticultural crops at Sharquia Governorate. Ecological studies indicate that three species belonging to three families of order: Stylommatophora were identified on field, vegetables and horticultural crops. Survey revealed that the identified species varied in their incidence and level of infestation according to locality and host plant type. Monacha cartusiana snails have the superior on snail's incidence compared to other species; it was recorded in all surveyed localities. The population dynamics of M. cartusiana carried out throughout two growing seasons at three distracts, belonging to Sharquia Governorate. On some field and vegetable crops indicated that Egyptian clover highest numbers followed by cabbage, while onion was the lowest one in this respect. Importance value of land snail species can be arranged discerningly at Sharquia Governorate as follows: Monacha cartusiana>Succinea putris and Eobania vermiculata. On the other hand, food consumption of the snail, M. cartusiana and E. vermiculata under laboratory conditions showed that the highest values of feeding damage on lettuce and cabbage for M. cartusiana and E. vermiculata respectively. The lowest value (0.014 gm) was recorded on M. cartusiana when fed on Egyptian clover. Conversely, E. vermiculata consumed the lowest value (0.031 gm) when feeding on wheat leaves. Concerning with general mean it can be arranged food consumption for M. cartusiana and E. vermiculata as a follow (lettuce, 0.09, 0.318 gm), (cabbage 0.086, 0.272 gm), (wheat 0.038, 0.031 gm), (broad bean 0.033,