Host Plant Selection by the Wheat Bug, Nysius huttoni (Hemiptera: Lygaeidae) on a Range of Potential Trap Plant Species.

The wheat bug, Nysius huttoni L. is an endemic New Zealand pest. The seedlings of forage brassicas are highly susceptible to direct feeding damage by this insect, and this can reduce plant establishment. Prophylactic use of pesticides is the usual practice for N. huttoni management. These practices have been linked to environmental pollution, biodiversity loss, and pollinator population declines in brassicas and other crops. Habitat management of the bug utilizing potential trap crops can be a better option for its management. A series of choice, no-choice, and paired-choice tests were conducted in a controlled-temperature room to evaluate the pest's preferences on seedlings of eight plant species. Kale plants (Brassica oleracea) were used as a potentially susceptible control, and seven non-kale plants were compared with kale as potential trap-plant species. These were: Lobularia maritima (L.) Desvaux (alyssum), Triticum aestivum L. (wheat), Phacelia tanacetifolia Bentham (phacelia), Fagopyrum esculentum Moench (buckwheat), Coriandrum sativum L. (coriander), Trifolium repens L. (white clover), and Medicago sativa L. (lucerne). In choice tests, wheat was the most suitable followed by alyssum, buckwheat, and phacelia, all significantly more favored than kale. In no-choice tests, alyssum was significantly more favored than kale and the other plant species except wheat and phacelia. First feeding damage was recorded on alyssum in both the above test conditions. For paired-choice tests including kale, wheat, and alyssum were significantly more suitable than brassica. These findings are important for developing agro-ecological management strategies. Alyssum followed by wheat were the most suitable trap plants for N. huttoni. These two plant species can be deployed in and around brassica fields either independently or as in a multiple trap-cropping system to reduce bug damage, minimizing or avoiding pesticides, and delivering a range of ecosystem services.