Spatial population dynamics of a pest and its parasitoid in an oilseed rape crop.
The spatio-temporal distribution of Ceutorhynchus assimilis adults caught in flight traps in a winter oilseed rape [rape] crop in the UK in 1995 was mapped, analysed and compared with the distribution of their larvae and that of the parasitoid, Trichomalus perfectus, using Spatial Analysis by Distance IndicEs (SADIE). Invasion by C. assimilis began at two field boundaries and the two foci almost merged to give a single cluster at the peak of infestation. The spatial distribution was aggregated on all dates. The spatial distributions of adult and larval C. assimilis were strongly associated as were those of C. assimilis larvae and T. perfectus larvae. These distributions are discussed in relation to pest and parasitoid movement, implications for the development of targeted IPM strategies, and pest sampling for risk assessment.