Spatial distribution of Diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), at the field and the regional level in Ethiopia

Pheromone trap catches were used to study the spatial distribution of Diamondback moth (DBM), Plutella xylostella L., at both single field and regional levels. At the field level, the DBM population tended to remain within the cabbage field. At the regional level, DBM captures were highly influenced by geographic location and cropping systems. In highland areas, daily maximum temperatures positively influenced the aggregation index, whereas in the lowland areas, rainfall had a negative influence on the aggregation index. The implications for integrated DBM managements are as follows: at the local level, knowledge on spatial dynamics allows the delimitation of areas with high DBM infestations for consideration in both monitoring and biological control programmes. At the regional level, areas with year-round production of Brassica spp. and intensive use of pesticides should receive priority in the design and implementation of integrated DBM management systems.