Efficiency Evaluation of Two Chemical Pesticides and a Biocide for Controlling Eobania vermiculata Snails Infesting Guava Orchards

Abstract

In recent years, guava cultivation has gained great commercial prominence due to the increasing international demand for its fresh and processed products. The guava trees are subject to affect by many pests, one of which is land snails. The land snail, Eobania vermiculata, is one of the most serious pests in Egypt's agricultural fields and recently reclaimed areas, causing significant damage to plants. Chemical control is considered the best defense against land snails. Therefore, in the present study, the efficiency of two chemical compounds; Agrinate ® (methomyl) and Gastrotox ® (metaldehyde) as well as a biocide Biogard ® (Bt), at a recommended field rates for controlling the land snail E. vermiculata was tested under field conditions in guava orchard at Alexandria Governorate. The obtained results revealed that all tested compounds exerted significant reduction in the number of living snails on guava trees one day after treatment and until the end of the experiment compared to untreated tress. According to reduction percentages, the three tested compounds were found to be toxic to E. vermiculata with various degrees; 79.39, 69.12 and 86.57% for methomyl, Bt and metaldehyde after 21 days of experiment, respectively. Also the average initial kill (%) were 28.67, 16.39 and 41.66 and average residual effect (%) were 67.98, 59.55 and 78.81 for methomyl, Bt and metaldehyde, respectively. In the comparison among the tested compounds, metaldehyde ranked first and showed the highest effectiveness against E. vermiculata infecting Egyptian guava, followed by methomyl and Bt.