Automated trapping for the detection of corn earworm (Helicoverpa zea) and corn rootworm (Diabrotica virgifera virgifera)

Automated monitoring traps provide growers the means to gauge pest activity without leaving their office. But no trap is suitable for detecting the full range of agricultural pests. With the growing threat of Bt-resistant populations of corn earworm (Helicoverpa zea) and corn rootworm (Diabrotica virgifera virgifera), growers need access to dependable trapping technologies to monitor these threats effectively. Therefore, we tested different traps targeting these pests. We deployed Heliothis (Sentry) and DTN Smart Traps at eight field sites for detecting corn earworm. Traps were placed on the field’s edge and spaced 50 m apart. For corn rootworm, we deployed a prototype trap on the edge of 7 field sites alongside DTN Smart Traps and sticky card traps, with a second row of traps placed 200 m in-field and running parallel to the traps on the field’s edge. Trap counts were collected weekly. Paired t-test revealed that total season corn earworm counts were higher for DTN Smart Traps than Heliothis traps (P = 0.03). Two-factor ANOVA showed that there was no significant difference in the number of corn rootworm beetles caught amongst the three traps types (P = 0.64), though we observed a tendency for higher counts of rootworm beetle with Smart Traps and Prototype traps placed deeper in the field. We conclude that the DTN Smart Trap is sufficient for monitoring the presence of corn earworm. However, the benefit of a new trap design targeting corn rootworm, especially its placement position, warrants further exploration.