Western and northern corn rootworms are serious corn pests in Iowa and the Corn Belt. These pests readily adapt to management tactics, especially in continuous corn production. The larvae consume corn roots, thereby reducing nutrient and water uptake, and cause stalk lodging. The adults may also feed on above-ground parts of the plant, including silks and pollen, which may interfere with pollination.
Western and northern corn rootworms are serious corn pests in Iowa and the Corn Belt. These pests readily adapt to management tactics, especially in continuous corn production. The larvae consume corn roots, reducing nutrient and water uptake and causing stalk lodging. The adults may also feed on above-ground parts of the plant, including silks and pollen, which may interfere with pollination.
Western and northern corn rootworms are serious corn pests in Iowa and the Corn Belt, primarily due to their feeding habits but also because they can overcome nearly all management tactics available to farmers. The larvae tunnel into and consume corn roots, thereby reducing nutrient and water uptake and causing lodging. The adults may also feed on above-ground parts of the plant, including silks and pollen, which may interfere with pollination.
Moth trapping began April 1 and came to an end May 31. This year, we had more than 45 trap locations and 42 cooperators across the state. These cooperators provide us data on black cutworm (BCW) and true armyworm (TAW) moth captures at their locations, which we use to predict BCW cutting dates and report captures of both species to aid scouting efforts.
This week we begin Week 7 of moth trapping in Iowa. Significant captures of black cutworm (BCW) have occurred in several counties during weeks 3-6 of trapping (bold and * in Table 1). Significant captures occur when 8 or more BCW moths are caught in a wing-style pheromone trap over 2 nights. Another type of trap used to monitor BCW activity is a bucket trap. This type of trap tends to capture more moths, but determinations about significant flights are not made in our table because a reliable threshold does not exist yet.
Each year, Iowa State University’s IPM team monitors field crop pests to help inform farmers and scouting personnel about pest activity in Iowa. This year, our moth trapping network includes black cutworm (BCW) and true armyworm (TAW), two migratory pests of crops in Iowa that are unpredictable year to year and thus require monitoring.
The IPM team at Iowa State University has been monitoring for field crop pests for a long time. The target pests have changed over the years, but the goal always remains the same: help inform farmers about pest activity in Iowa. One long-standing project is monitoring for black cutworm, an erratic field crop pest. In 2017, we also included true armyworm as part of the trapping network. We use adult trap captures to estimate feeding injury in field crops.
In 2017, ISU is reporting black cutworm (BCW) peak flights by county and providing degree day resources for more personalized cutting prediction dates using actual accrued degree days for a specific location. We first reported on BCW peak flights in the ICM News in early May.
