Corn rootworm (Coleoptera: Chrysomelidae) emergence patterns, survival, and injury in blended refuges and pure stands of short-stature corn and tall corn.

BACKGROUND

Short-stature corn became commercially available in the United States in 2025 and has several desirable qualities including lodging resistance and potential for greater planting density. Corn rootworm, Diabrotica spp., are among the most serious insect pests of corn in the United States. However, information about how corn rootworm interact with short-stature corn is currently lacking. To protect crops from rootworm injury, transgenic corn that produces insecticidal toxins derived from Bacillus thuringiensis (Bt) is frequently grown. An important component of insect resistance management for Bt corn is blended refuges, where non-Bt and Bt plants are planted alongside each other. We conducted a 2-year field study to quantify patterns of corn rootworm survival, emergence, and injury to short-stature corn and tall corn across three treatments: pure stand of Bt corn, pure stand of non-Bt corn, and a blended refuge.

RESULTS

Corn rootworm survival was reduced in Bt corn and in blended refuges, compared to non-Bt corn. Some differences in survival and timing of emergence were detected between short-stature corn and tall corn. However, these were not consistent across years or treatments and typically differed between male and female rootworm. Root injury did not differ between tall corn and short-stature corn across any treatments.

CONCLUSION

Corn rootworm survival, timing of emergence, and injury to corn were generally similar between short-stature corn and tall corn. This suggests that current insect resistance management strategies for corn rootworm in tall corn are likely appropriate for short-stature corn, although additional studies are warranted. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.