Helicoverpa armigera (Hübner), a polyphagous moth, is the major cotton pest in Africa. Larvae feed on bolls, flowers and squares, seriously reducing yield. To reduce the use of insecticides and to improve the management of this cotton pest, there is a growing interest in reinforcing the landscape's suppressive properties. The aim of this study was to determine if moth abundance and larval infestation differs among landscapes with different composition (diversity of crops, proportion of bush) to test for a landscape effect on Helicoverpa armigera abundance during peak infestation. In five cotton fields in four landscapes differing in land cover (cotton, cotton+maize, cotton + tomatoes, cotton + bush), measurements of larval infestation were made four times from September 23th to October 18 th 2011. Additionally, adult moth abundance was established using light trapping from September 24 to 1 st November in the four landscapes plus one landscape without any cotton field in the area of the W National Park. Larval infestation was significantly higher in the fields previously cultivated with tomatoes. Results of light trapping of moths did not reveal differences among the landscapes except in the landscape in the W National Park where no moths were trapped. This finding suggests that cotton infestation by Helicoverpa armigera could be related to the proximity of market gardening. Subsequent analyses (analytical chemistry and molecular biology) are underway to investigate this hypothesis.