Biocontrol potential of Chitosan extracted from Procambarus clarkii (Crustacea: Cambaridae) against Eobania vermiculata snails (Muller 1774) in Egypt

Abstract

BackgroundLand snails, especially the chocolate banded snails, Eobania vermiculata (Muller 1774) are destructive pests of a wide range of field and vegetable crops, and biological treatment appears to be better alternative to the chemical snail control. Therefore, the goal of this work was to assess the molluscicidal activity of chitosan extracted from the crawfish Procambarus clarkii against E. vermiculata using oxidative stress, histopathological and genotoxic biomarkers.ResultsExposure of snails to LC50 (222.4 mg/l) chitosan for 1, 3 and 7 days induced a significant increase in glutathione S-transferase and catalase levels then decline in reduced glutathione content after 1 and 3 days as well as a slight decrease in CAT levels, GSH content and GST of the treated snails after 7 days exposure. Histologically, the stress induced by chitosan exposure leads to deformation of cells, dilatation of the intertubular spaces, and destruction of tubules with increase in lumen size, necrosis of digestive cells with rise in vacuoles number and increase in calcium cells number. Considerably, a great damage was observed with increasing time of exposure. Furthermore, genotoxicity was assessed using RAPD-PCR technique and the results revealed that change in RAPD profiles of E. vermiculata following chitosan treatment included loss of normal DNA bands and appearance of new one compared to control snails. The genomic template stability was 63.6, 36.4 and 18.2% 1, 3 and 7 days of exposure, respectively. The apparent of new bands increased as time of exposure decreased, while GTS values decreased confirming the effect of chitosan-induced DNA damage.ConclusionChitosan may be an ecofriendly acceptable alternative pesticide for snail control.