Western and northern corn rootworms are serious pests of corn throughout the Corn Belt (Photo 1). We recommend that farmers scout every cornfield every year, regardless of the management tactic(s) used, to evaluate management decisions and prepare for next year. It is a good idea to scout for larvae early in the season, assess root injury when larval feeding wraps up, and monitor adults later in the season. Since beetle emergence is underway throughout most of the state, now is a good time to begin planning for monitoring adults with sticky traps.

Western and northern corn rootworm are serious pests of corn throughout the Corn Belt. We recommend that farmers scout every cornfield every year, regardless of the management tactic(s) used, to evaluate management decisions and prepare for next year. It is a good idea to scout for larvae early in the season, assess root injury when larval feeding wraps up, and monitor adults later in the season. Corn rootworm adults have started emerging throughout Iowa, which is an excellent time to evaluate root injury.

Last year, entomologists and field specialists with Iowa State University Extension and Outreach received many questions about effective management of corn rootworms as populations have increased in the past two years and farmers have experienced enhanced root injury during drought conditions. We teamed up with the ISU extension field agronomists to host corn rootworm management field days at 7 ISU Research and Demonstration Farms in 2022. Come join us this summer to learn about corn rootworm identification, sampling, management, and resistance.

Results summary from abstract: "Results from this study collectively suggest that SmartStax^® PRO may negatively impact WCR life history traits, which may lead to reduced population growth when deployed in an area with WCR resistance to Bt traits."

The 2021 Field Crop Insect and Disease Applied Research Report provides farmers with updated control efficacy and pest distribution information for major pests of corn and soybean. Use these evaluations to guide control decisions, track performance over time, and see trends in pest populations.

The Handy Bt Trait Table provides a helpful list of trait names and details of trait packages to make it easier to understand company seed guides, sales materials, and bag tags.

The purpose of this publication is to take some of the confusion of seed treatments away, giving you a better understanding of what is on your seed. The list covers seed treatments registered in the state of Wisconsin for use on field corn, soybean, small grain and/or alfalfa seed.

Results from the 2021 Ontario trap sites participating in the Adult Corn Rootworm Trap Monitoring Network have been summarized in the infographic. 

Western corn rootworm (WCR) and northern corn rootworm (NCR) continue to dominate as economic pests throughout the U.S. and Canada. In response, the Corn Rootworm IPM Regional Working Group was formed during the spring of 2021 and continues to grow. Currently, we are made up of university, industry, and government personnel from at least 12 U.S. states and 5 Canadian provinces. Recently, high corn rootworm populations and the development of resistance to Bt corn hybrids in some areas has sparked greater interest in scouting and alternative management of corn rootworms.

Results summary from abstract: "The present study confirms the first cases of field-evolved resistance to Cry3Bb1 + Cry34/35Ab1 maize in Nebraska and documents a landscape-wide WCR Cry3Bb1 resistance pattern in areas characterized by long-term continuous maize production and associated planting of Cry3Bb1 hybrids. Use of a multi-tactic integrated pest management approach is needed in areas of continuous maize production to slow or mitigate resistance evolution to Bt maize."

Summary of results from abstract: "Results indicate that as the level of resistance to Cry3Bb1 within field populations increases, mean head capsule width and larval fresh weight also increase. This increases our understanding of western corn rootworm population dynamics and age structure variability present in the transgenic landscape that is part of the complex interaction of factors that drives resistance evolution. This collective variability and complexity within the landscape reinforces the importance of making corn rootworm management decisions based on information collected at the local level."

Corn rootworms are important pests for this crop, especially the larvae that attach to the roots and can indirectly induce yield losses. Good integrated crop management reduces the risk of damage. In this video, you will be able to learn more about: corn rootworms and their biology, the damage caused to corn by these pests, and the different methods of integrated management. This explanatory video is a project of the Grain Research Center (CÉROM). It was funded by the Ministry of Agriculture, Fisheries and Food as part of component 3 of the Prime-Vert program and is linked to the Quebec Phytosanitary Strategy in Agriculture 2011-2021. This video is in French.

The Canadian Bt Corn Trait Tables have been updated for April 2021. The tables list information about trade names, Bt proteins, refuge requirements, and more for products approved in Canada in French.

The Canadian Bt Corn Trait Tables have been updated for April 2021. The tables list information about trade names, Bt proteins, refuge requirements, and more for products approved in Canada.