SEASONAL ACTIVITY OF LAND SNAILS AND SLUGS ON LEMON AND GUAVA TREES AT DUMYATT AND KAFER EL-BATIKH DISTRICTS, DUMYATT GOVERNORATE. EGYPT.

The present investigation has been achieved as an attempt to study the influence of climatic change on the population density of land snails Monacha cartusiana ,Monacha cantiana , Cochilicella acuta , Succinea putris , Succinea oblonga and gray garden slug Deroceras reticulatum under lemon and guava trees at ElSenania and Kafr El-Batikh districts,Dumyatt Governorate 2011/2012 and 2012/2013 seasons .
      The results revealed that the mean of populations density were higher throughout spring season followed by autumn and lower in winter seasons which estimating by 35.8, 29.3 and  18.5 snails/sample  for M. cartusiana, respectively . C.acuta recorded the higher number on lemon trees 57.2 in spring season while recorded 45.2 in autumn season followed by winter season which recorded 25.6 snails/sample.
       The population fluctuations of land snails varied according to crop , temperature , relative humidity and season to another . The snails were more active during spring and autumn .The snails C.acuta were the highest number of individuals on lemon and guava trees. 
Key words: seasonal, fluctuation of land snails and slugs, lemon , guava                                                     trees , Dumyatt. Temperature.