Predicting the time to colonization of Diadegma semiclausum using spatial dispersal kernels
Abstract: The time at which natural enemies colonize crop fields is an important determinant oftheir ability to suppress pest populations. This time depends on the distance between source andsink habitats in the landscape and on the dispersal behaviour of the natural enemy. Here weestimate the time to colonization of sink habitats from a distant source habitat using a simulationmodel that was parameterized with mark-capture data of Diadegma semiclausum. Dispersalbehaviour was modelled with spatial probability distributions of dispersal distance, so-calleddispersal kernels. We show that dispersal kernels that receive similar support from the data canproduce a wide range of arrival times. We also demonstrate that the time to colonization increasesmore than proportionally with the distance between source and sink. This result underscores theimportance of proximity of source habitats of natural enemies for early colonization and a largeimpact of natural enemies in crop fields.