الفهرس 
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Abstract
The present study on the land snail, Theba pisana which is native to the Mediterranean region, however, it has become an invasive species in many other countries worldwide. Theba pisana is a well-known agricultural pest in numerous parts of the world. The shell color varies from white to yellow-brown with light brown spiral markings.
The distribution of land snail Theba pisana used in the present study, They were collected in May during the period of maximum activity from gardens in Abees area, few kilometers south of Alexandria.
The histological study of digestive gland; showed the presence of two cell types: digestive and excretory ones.
The follow up of the histochemical patterns of distribution and mode of occurrence of certain essential biochemical components in the digestive gland has discerned that :
Positive results were obtained in the present study regarding the mode of occurance of carbohydrate inclusions in the digestive gland cells of normally feeding snails. Also a decline of carbohydrates was observed in the digestive gland after starvation for 15 and 30 days. Concerning the proteinic inclusions in the digestive gland, strong bromophenol blue positive results were detected in case of normally feeding snails. These inclusions have exhibited a weak stain ability in the digestive gland cells as a consequence of starvation.
All cell types elaborate their content in the tubules lumen. Their cytoplasm was acidophilic interrupted with basophilic stain The cytoplasmic vacuoles of the digestive cells increased, and the cells membranes that separate them become thinner where the calcium cells totally ruptured.
The molluscicidal activity of six concentrations of pesticides applied as toxic baits against T. pisana is showed the toxic effect of all tested pesticide baits with mortality percentage increasing with an increase in the period of exposure .Methomyl 5% exhibited the highest mortality percentage(100%) against T. pisana after two days of exposure.