Book Chapter: Spatial Distribution and Damage Dynamics of Major Insect Pests in Rice Field across Three Agroecological Zone in Sierra Leone

Rice production in Sierra Leone is critically affected by insect pest infestations, leading to significant yield losses and food insecurity. This study assessed the prevalence, spatial distribution, and damage caused by major insect pests across three major rice-producing districts (Kambia, Kenema, and Moyamba) representing diverse agroecological zones. A total of 90 rice fields were surveyed using standard sweep net sampling and GPS-enabled data collection. Five key insect pest species were identified: leafhoppers, stem borers, rice ear bugs, and rice gall midges, with leafhoppers being the most dominant. Results revealed notable regional variation, with Kambia exhibiting the highest pest density and damage levels. The panicle initiation and heading stages of rice were the most vulnerable, with pest density peaking at 5.1 pests/m2 and associated damage exceeding 50%. Waterlogged soil significantly increased the likelihood of high pest infestation (OR = 2.01), underscoring the influence of soil moisture on pest proliferation. Logistic regression and generalized linear models identified pest density, crop growth stage, and environmental conditions as significant predictors of infestation severity. Kenema also demonstrated elevated pest pressures, likely due to unique microclimatic and agronomic factors. In contrast, Moyamba showed relatively lower pest incidence. The findings emphasize the need for stage-specific pest control, improved water management, and the promotion of Integrated Pest Management (IPM) strategies tailored to local conditions. Strengthening farmer knowledge and access to IPM tools is essential to reduce pest-induced losses and enhance sustainable rice production in Sierra Leone.