Effect of tillage process on some biological and ecological aspects of land snail Eobania vermiculata (MüLLER) [electronic resource].

Includes reference.

The present work was carried out under semi-field conditions to study the efficacy of tillage process on some biological aspects, growth and population density of the land snail, Eobania vermiculata (Muller) in lettuce plots in EI-Qanater district at Qualyobiya Governorate during the egg laying period from October 2007 to March 2008. Tillage process of the soil can lead directly to some biological and ecological aspects which affect the entire fecundity pattern as a result of the reduced vitality of the snail individuals. Snail fecundity was highest in untreated area (mean number of clutches was 17.2 and 110.5 eggs/ clutch after six months) compared to 7.2 clutches and 69.2 eggs / clutch in treated area. It was observed that egg clutches laid deeper in treated area (4.2 cm) than in untreated area (2.7 cm). Also, mean hatching percentage of eggs laid in untreated area increased reaching 92.2%, while in the treated area it recorded 67.2% only. Although the effects of tillage process on incubation period was statistically insignificant. It was noticed that as the time elapsed weight and shell diameter of juveniles increased in untreated area more than in treated one. Tillage process is an effective method for reducing the numbers of the land snail E. vermiculata. It is clear that the number of snails was slightly increased till reached the maximum in March (3232.5 individual/plot) of untreated area as compared to populations density in the same month (218.33 individual/plot) of treated area.

Summary in Arabic.

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