Population Density, Food Consumption and Damage Caused by the Land Snail Monacha cantiana to Some Vegetable Crops at Kafr El-Sheikh Governorate

The land snail Monacha cantiana is one of the most serious pests especially at north and east of Delta. It causes considerable damage to the majority of crops at Kafr El-Sheikh Governorate. In this study, a trial was carried out at Kafr El-Sheikh Governorate on the predominant land snail M. canntiana to throw light on its population density, food consumption and damage caused by it under field and laboratory conditions. Trial was conducted on some vegetable crops i.e. parsley, lettuce, onion, garlic, pepper and Jews mallow showed that the highest number of snails was recorded in March for onion and pepper with 65.6 and 19.0 snails/½ m², respectively and in April for parsley, lettuce, garlic and Jews mallow with 68.6, 81.6, 74.6 and 7.0 snails/½ m², respectively during 2015 season. In general, M. cantiana recorded highest infestation levels during March and April as compared to May, but numbers of snails in 2016 season were clearly less than 2015 season. The mean consumption values of M. cantiana snails for fresh leaves of some vegetable plants under laboratory conditions were 0.546, 0.185, 0.320, 0.070 and 0.117 g/10 snails/5 days for lettuce, parsley, onion, garlic and pepper, respectively. It is clear that lettuce leaves were most favorite for snails, while garlic leaves were the least. Concerning determination the damage caused by M. cantiana to fresh lettuce leaves under field conditions, the obtained data showed that the reduction percentage in lettuce leaf area reached its maximum value (4.81%) in the middle of April, while the minimum value (1.17%) was in the end of the same month.