This study was carried out in three Local Government Areas in Plateau State, Nigeria located within the Shimankar River Basin. It investigated the impact of some anthropogenic activities on agricultural production and evaluates insect species distribution in the study area, an important agrarian community in Southern part of Plateau State, Nigeria. Questionnaires were administered through focus group discussions. Insects were sampled in April 2014 during the dry season. Insect samples were collected using sweep net along a transect. Five transects of 500 m were placed perpendicular to the river and samples collected at each 100 m section along the transect. Each transect was separated from another by at least 200 m. Insects were collected in irrigated plots of okra, melon, pepper, maize and the flooded Shimankar river. Of all the anthropogenic activities that could affect the ecology of the Shimankar River Basin, slash and burn comprises the highest with 32%, this is closely followed by grazing 18.5%. Other anthropogenic activities include fishing (17.5%), fuel wood collection (16.5%) and hunting (15.5%). Slash and burn is shown to affect the ecology absolutely, while grazing, hunting, fuel wood collection and fishing affect the ecology substantially. The impact of anthropogenic activities based on respondents understanding indicates that soil erosion and loss of soil fertility posed the greatest danger to the ecology of the Shimankar River Basin. Other impacts include loss of vegetation cover and wildlife. In respect to the problems confronting farmers within the river basin in particular, flood is adjudged the greatest threat.
Key Words: Anthropogenic activities, Agricultural production, Flood, Insects