An assessment of aphid populations and their natural enemies in a banana field bordered by tomato and pepper plants was conducted from March to October 2012 in the region of Bengamisa, DR Congo. Significant differences in the diversity and the abundance of aphids and aphidophagous populations have been observed between the host plants tested at P<0.05. Three main families (Aphididae, Aphidiidae and Coccinellidae) have been identified in which the Coccinellidae family was the most important in terms of predator species. Out of three host plants tested, tomato attracts the most diversified aphid and aphidophagous insect populations (3 Aphididae species and 9 aphidophagous species). Banana (1 Aphididae species and 7 aphidophagous species) and pepper (3 Aphididae species and 7 aphidophagous species) were less attractive. The results suggest a specific attraction between predators or parasitoids and plants due to the recognition of specific molecules emitted by plants. The tendency to a preferential distribution of insects in relation to host plants has been preserved in both seasons, indicating a differential species allegiance to plants and food specialization in insects.

Keywords: biological control, Aphididae, marginal plant, auxiliary insect.