Evaluation of trap crops for their attractiveness to the key caterpillar pest complex and the harlequin bug in cole crops

Traps crops are relatively attractive plants grown to attract, retain, or intercept insect pests resulting in reduced damage to the cash crops. This strategy has shown some success in reducing damage caused by the diamondback moth, Plutella xylostella and the harlequin bug, Murgantia histrionica in cole crops. In this study, we evaluated eight different trap plants [Arugula (Eruca sativa), Broccoli (Brassica oleracea var. Italica), Cabbage (B. oleracea var. Capitata), Kale, Collards (B. oleracea var. Acepahala), Mighty mustard, Mustard greens, (B. juncea) and Rapini (B. rapa)] for their attractiveness to the key caterpillar pests (P. xylostella, imported cabbageworm, Pieris rapae, and cabbage lopper, Trichoplusia ni) as well as M. histrionica. Three field trials (early-, mid- and late season) were conducted during April to November, 2014, at the Lincoln University’s Organic Research Farm. Results showed that while kale was attractive to P. xylostella, collards and broccoli were attractive to P. rapae, and Mighty mustard, Mustard greens, and Rapini were attractive to M. histrionica. Combined results suggest that a mixture of trap plants may be necessary to develop an effective trap cropping system to reduce impacts of key pests in cole crops.