4.2.1. Trap Crops

Trap crops are plants grown alongside the main crop in order to manipulate insect behavior to prevent pests from reaching the target crop [211]. If a trap crop can be found that lures pests, at least during sensitive growth periods of the main crop, sustainable and long-term managemen<sup>t</sup> solutions can result. Hokkanen [211] describes approximately forty successful cases of trap crop strategies on several crops. As wireworms are very polyphagous [32], a wide range of trap crops are readily available. Despite limited larval mobility, wireworms have been found to be attracted and concentrated in trap crops placed around main crops [212,213]. In 2000, Vernon et al. [213] showed that trap crops of wheat, planted as trap crops a week before strawberry planting, can effectively reduce wireworm feeding and plant mortality. Landl and Glauninger [214] demonstrated the influence of peas as a trap crop on potatoes, and several studies have demonstrated that wheat intercropped with pea and lentil showed significantly less wireworm damage [215,216]. The attractiveness of trap crops, the timing of planting, and the space they occupy are major factors to consider before selecting and using a trap crop.

#### 4.2.2. Companion Plants: Feeding Pests as an IPM Strategy

Companion planting is an agronomic strategy that sees the growing together of two plant species that are known to synergistically improve each other's growth. Companion plants can control insect pests either directly, by discouraging pest establishment, or indirectly, by attracting natural enemies that kill the pest. The ideal companion plant can be harvested, providing a direct economic return to the farmer in addition to the indirect value of protecting the target crop. In maize fields, it has been demonstrated that companion plants lure wireworms away from the crop and lead to a significant reduction (up to 50%) in damage, which is as effective as common chemical products (Belem 13kg/ha) [210,217,218]. Furthermore, meadow incorporation timing, just before crop seeding (e.g., maize), may protect crops from wireworm damage without any further intervention. This effect is due to the fact that soil-incorporated fresh meadow turf is a more attractive wireworm food source than seeds, emerging seedlings, and young plants [219].
