By Erin Hodgson, Department of Entomology, Adam Sisson, Integrated Pest Management, and Laura Jesse, Plant and Insect Diagnostic Clinic.
Black cutworm moths (Photo 1) do not overwinter in Iowa and must migrate north annually. Black cutworm moths have been collected in Iowa since the beginning of April 2015. Seeing significant moth captures in early and mid-April is unusual and could indicate a more frequent incidence of vegetative crop injury compared to other years. There have been reports of black cutworm moth trap catches from other states besides Iowa, including Minnesota, Illinois, Indiana, Missouri, and Kentucky. In some places, such as Indiana, peak flights are being reported. A peak flight is a specific number of moths caught in a trap that signals when to begin adding up temperature data to figure out when to scout for larvae.
Photo 1. Adult black cutworm moth. Notice the characteristic dagger-shaped marks on the forewings of this pest. Image by Adam Sisson.
The Iowa State University Extension and Outreach IPM Program organizes a network of farmers, agronomists, Extension personnel, and others to monitor black cutworm traps around state (Photo 2). At least one county in Iowa has reported a peak flight so far this season, while lots of traps are reporting low numbers. Of the 101 traps placed across Iowa, 46 haven’t caught a single moth as of April 23.
Photo 2. Black cutworm moth traps use a pheromone lure to attract night-flying moths and a sticky board to collect adults. Image by Adam Sisson.
The sporadic nature of this mobile pest makes scouting essential to determine if management is needed. The IPM Program uses this moth capture data and temperature data to estimate when farmers are most likely to see larvae in their fields. Adult moth trap captures do not necessarily mean there will be economically significant black cutworm infestations in a particular location, however. Field scouting is essential to determine if an economically damaging infestation exists.
Look for a future ICM News article including a map for the estimated black cutworm cutting data in Iowa when peak flights are determined.
Erin Hodgson is an assistant professor of entomology with extension and research responsibilities; contact at firstname.lastname@example.org or phone 515-294-2847.
Laura Jesse is an entomologist with the Iowa State University Extension Plant and Insect Diagnostic Clinic; contact at email@example.com or by phone 515-294-0581.
Adam Sisson is an extension specialist for the Integrated Pest Management. He can be contacted by email at firstname.lastname@example.org or by calling 515-294-5899.
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