DIFFERENT CONTROL METHODS FOR REDUCING POPULATION DENSITY OF Eobania vermiculata (MÜLLER) UNDER FIELD CONDITIONS IN DAKAHLIA GOVERNORATE, EGYPT

Abstract

The use of chemicals to control land snails can lead to environmental pollution, hazards to humans and toxic residues in agricultural products. Therefore, finding safer alternatives for managing these pests has become a priority. Field experiments were conducted to test different methods for controlling Eobania vermiculata snails infested navel orange trees in Dakahlia Governorate. These methods included ploughing during the egg-laying period in January, planting cabbage traps in February, applying attractive materials in March, using pesticides in April during the activity period, and hand collection during aestivation period in June. The ploughing process significantly (P≤ 0.05) reduced the populations of E. vermiculata. One week after ploughing, the number of snails per sample decreased from 29.22 to 11.76, representing 63.87% reduction. After six weeks, the overall reduction in population was 40.73%. Planting cabbage traps also decreased the snail populations, with a maximum reduction of 68.54% after six weeks. Attractive materials had a significant effect on attracting populations. Sugar-cane syrup and barley powder showed the highest effectiveness, with reductions of 66.05 and 54.12%, respectively. Boiled potatoes had a moderate effect, while vanilla powder was the least effective one, with a reduction of 39.92%. Biocides and plant extracts had a significant effect on the suppression of snail populations. Oikous and clove oil had the highest effect, with 46.05 and 42.56% reduction, respectively. Protecto showed a moderate effect, while eucalyptus oil was the least effective one with 28.21% reduction. The application of pesticides also reduced the snail populations to varying degrees. The molluscicidal efficiency of the tested pesticides could be arranged in descending order after three weeks of application as follows: methomyl < fenamiphos < deltamethrin < oxamyl, with reduction percentages of 60.30, 54.41, 48.81 and 39.03%, respectively. Hand collection during the aestivation period in June also significantly (P≤ 0.05) decreased populations, with a 46.41% reduction as a general mean during the six-week experimental period. Generally, all tested control methods significantly reduced the populations of E. vermiculata in navel orange orchard from January to July. Based on the general means of percent reduction, the tested methods can be arranged in descending order as follows: cabbage traps, pesticides, attractive materials, hand collection, ploughing, and using biocides besides plant extracts.