Tag: European corn borer

Week 15: European Corn Borer

European corn borer, Ostrinia nubilalis, is a generalist pest of a variety of crops, including corn, potatoes, beans, sugar beets, tomatoes, quinoa, and millet. European corn borer is an occasional pest of crops in western Canada; as many of its hosts are grown in western Canada, it is important to monitor for European corn borer. In eastern Canada, European corn borer is an important pest and its populations are monitored by the Great Lakes and Maritimes Pest Monitoring Network and by the Réseau d’avertissements phytosanitaires in Quebec.

European corn borer larva and feeding damage on a plant stem. Picture by Jocelyn Smith, University of Guelph.

In western Canada, European corn borer has one generation per year. Adult female moths lay eggs in clusters on the underside of leaves in June, July and August. Larvae can typically be found feeding on leaves starting in July. Larval feeding continues until the larvae reach the fifth instar, which overwinters.

External plant symptoms of European corn borer feeding damage on corn. Picture by Jocelyn Smith, University of Guelph.

Early instar European corn borer larvae eat the leaves of their host plants. As the larvae grow, they tend to begin feeding on the midrib of leaves and on plant stems by tunneling into these plant structures. In corn, the growing larvae can mine into and feed on the corn tassels. Damage to the leaves and stems caused by European corn borer larvae can cause dieback, especially to young plants. Damage to the stems caused by tunneling larvae can weaken the plants, leaving them prone to breakage during storms or in windy conditions. Damage to the stems also interrupts nutrient cycling in infested plants, which can affect the quality and quantity of yield.

European corn borer damage to millet. Note the pile of frass (insect feces) in a pile below the affected millet plant. Picture by John Gavloski, Manitoba Agriculture.

Later instar larvae often begin feeding on the reproductive structures of the host plant: the pods, fruits, or ear shanks. Larval feeding to these structures affects the marketability of the crop; in many crops, including sweet corn and peppers, there is zero tolerance for European corn borer damage.

The Insect Community of Practice, a committee of the Canadian Plant Health Council has developed a harmonized monitoring protocol for European corn borer. This protocol can be used in any of the many crops that European corn borer can infest, not just corn.

For more information, please read the European corn borer page in Field Crop and Forage Pests and their Natural Enemies in Western Canada, also available in French. You can also find information from Manitoba Agriculture, OMAFRA, and the Canadian Corn Pest Coalition.

Canadian standardized assessment for European corn borer (2.0)

The European corn borer (ECB; Ostrinia nubilalis), can be an important pest of corn. Despite its name, ECB is actually a generalist feeder, having a wide range of hosts.

The recent confirmation of ECB resistance to Cry1F Bt corn in Nova Scotia has increased the need to monitor this pest across Canada. With so many new emerging crops being grown in Canada that are also hosts for ECB (e.g. hemp, cannabis, quinoa, hops, millet and others), there is no better time for us to look at this pest across the Canadian ag landscape.

European corn borer larva.
Photo: J. Smith, University of Guelph, Ridgetown Campus.

To monitor for ECB nationwide, the Insect Surveillance Community of Practice of the Canadian Plant Health Council has developed a harmonized monitoring protocol for European corn borer across all hosts. The protocol can be used to report ECB eggs, larvae or damage in any host crop across Canada. Our goal is to better understand the distribution and abundance of ECB in Canada, detect significant infestations, capture observations on any hosts and determine if ECB is shifting to other emerging crops like hops, quinoa, millet, hemp, and others. This harmonized protocol has been designed to complement protocols that are already in use to make management decisions.

Whether you are scouting corn, quinoa, hemp, millet, potatoes, apples, or other crops susceptible to ECB, we encourage you to try the harmonized monitoring protocol and report the data from your field or research plots using the free Survey123 app (available for both desktop and mobile devices):

European Corn Borer Monitoring for All Host Crops: https://arcg.is/0TLWmS

You do not need a login in to use the survey. Simply download the Survey123 Field App and click on the third option “Continue without logging in”, once on the login screen. To see the French version, click on the button on the top right corner, once in the survey to switch from English to French. A hardcopy version to take out to the field before entering it into Survey123 is also available here in English and French.

Please feel free to contact Tracey Baute (OMAFRA), Meghan Vankosky (AAFC-Saskatoon), Tracy Hueppelsheuser (BC Ministry of Agriculture), James Tansey (Saskatchewan Ministry of Agriculture), John Gavloski (Manitoba Agriculture), Brigitte Duval (MAPAQ), Suqi Liu (PEI Department of Agriculture and Land) or Caitlin Congdon (Perennia, Nova Scotia) if you have questions about this initiative.