The Effect of Integrated Pest Management Practices on Aquatic Invertebrate Communities in Rice-Fish Systems, Ebonyi State

This study investigated the effect of integrated pest management (IPM) practices on aquatic invertebrate communities and fish productivity in rice-fish farming systems in Ebonyi State, South East Nigeria. Rice-fish farming is practiced across South East Nigeria as an integrated food production system, yet the ecological consequences of different pest management regimes on aquatic biodiversity within these systems have not been well characterised. A replicated field experiment was established across 18 rice-fish plots divided into three treatment groups: conventional pesticide application, IPM with biopesticides, and a no-pesticide control. Aquatic invertebrate communities were sampled bi-monthly using sweep nets and sediment cores, and fish growth and survival were recorded at the end of the rice cultivation cycle. Results showed significant treatment effects on invertebrate community composition. Conventional pesticide treatment plots recorded the lowest invertebrate diversity and abundance, with sensitive taxa including Odonata larvae, Ephemeroptera, and Mollusca virtually absent following pesticide application events. IPM plots maintained invertebrate communities comparable to control plots, with diversity indices 72 percent higher than conventional plots. Fish survival was significantly higher in IPM and control plots compared to conventional plots, with evidence of sublethal pesticide effects on fish behaviour and feeding observed in conventional plots. Rice yields were comparable across all three treatments. The study demonstrates that IPM adoption in rice-fish systems preserves aquatic biodiversity and fish welfare without yield penalty and recommends its integration into rice farming extension programmes in Ebonyi State. Keywords: integrated pest management, rice-fish farming, aquatic invertebrates, biodiversity, Ebonyi State