Parasitic helminth fauna of tree frogs from cocoa plantations at Ugboke, Edo State, Nigeria

Abstract

Cocoa pods are vulnerable to pest and diseases which often cause huge financial losses to farmers. To address this challenge and improve yield, cocoa farmers often resort to pesticide application on the cocoa trees. This leads to deposition of pesticides residues on the cocoa trees, the undergrowth and plantations floor with devastating consequences for amphibians including tree frogs. Previous studies have reported the immune suppressive nature of pesticides on anurans thereby rendering them more susceptible to infection. This study is part of an on-going investigation of the effect of pesticide application on the pattern of helminth parasitic infections of anurans in pesticide-treated cocoa plantations at Ugboke, Edo State. A total of 354 tree frogs belonging to three genera (Leptopelis, Hyperolius and Afrixalus), consisting of 14 species were examined. A high species richness (d=1.971) and diversity (H’=2.215) was recorded. Ten species (71.43%) of these frogs were infected while four (28.57%) were uninfected. The overall prevalence of parasitic infections was 30.23%. Thirteen helminth parasites including three cestodes, two digeneans and eight nematode species were recovered. A significantly higher (P<0.05) prevalence of infection was recorded during the wet season (31.64%) than in the dry (10.53%). There was high parasite diversity with low prevalence and infection intensity of infection as previously reported for other anurans collected from the same cocoa plantations