Combining crop resistance and trap plants for cabbage whitefly control

Abstract: The cabbage whitefly Aleyrodes proletella L. is a serious pest of cabbage varietiessuch as Brussels sprouts or kale. As part of a BLE-funded BÖLN joint research project forintegrated management of the cabbage whitefly, a combined approach using two Brusselssprouts cultivars with increased resistance in combination with trap cropping was evaluated,because earlier results showed that plant resistance alone seems not to offer sufficient pestcontrol potential. First the attractiveness of several potential trap plant species and differentcultivars was investigated, followed by a field experiment with selected trap plants in aperimeter enclosing Brussels sprouts plots. The results of greenhouse experiments indicatedthat especially Brassica-crops such as marrow-stem kale (Brassica oleracea var. medullosa),Savoy cabbage (B. oleracea var. sabauda), or kale (B. oleracea var. sabellica), were preferredby adult whiteflies. Therefore in 2015 a field trial with marrow-stem kale and Savoy cabbageas trap plants was completed, where marrow-stem kale performed better in reducing theinfestation of Brussels sprouts with cabbage whitefly especially during the early croppingperiod. In conclusion, host plant resistance and trap plants offer a perspective to cabbagewhitefly control, but only bringing together successful elements of different pest managementtactics to a holistic approach might finally offer a reliable integrated pest managementstrategy.