There are three different European corn borer (ECB) areas in southwestern Ontario – a 1-generation (univoltine) area, a 2-generation (bivoltine) area, and an overlap area that has both univoltine and bivoltine populations (Baute, 1999). Degree Days (DD) are heat accumulations using a base temperature (i.e. a minimum temperature required for development). A DD model was validated to predict flight patterns of ECB in southwestern Ontario (Baute, 1999). This model gives us an idea when ECB flight begins, peaks and ends based on moth captures and can be used to guide scouting efforts and management decisions. Below are the estimated accumulated DD for ECB in some regions of southwestern Ontario.

Essex & Chatham-Kent Areas (2-generation/bivoltine area):  As of Sunday, June 25, DD accumulations were approximately 376 in Harrow, 412 in Windsor, and 330 in Ridgetown. Peak flight of the 1^st generation has ended in Harrow and Windsor area and is ongoing in Ridgetown, depending on temperatures. However, flight may continue once peak flight has ended. It will be a couple of weeks before we see the beginning of the 2^nd generation flight. This peak tends to be greater than the first. Be sure to monitor for ECB by getting your black light traps or pheromone traps set up and train your scouts for signs of larval entry holes in the peppers.

London & Sarnia Areas (overlap area):  As of June 25, the DD accumulations were approximately 338 in London, and 292 in Sarnia. For the 2-generation population, peak flight of the 1^st generation is underway in London and will likely begin in the next day or two in Sarnia, depending on temperatures.  Start planning for ECB monitoring by getting your black light traps ready and training your scouts for signs of larval entry holes in the peppers. First flight of the 1-generation population has begun in London and will likely begin in the next day or two in Sarnia, depending on temperatures. It will be a couple of weeks before we see peak flight of the 1-generation population. Be sure to monitor for ECB by getting your black light traps or pheromone traps set up and train your scouts for signs of larval entry holes in the peppers.

Vineland Area (1-generation/univoltine area):  As of June 25, the DD accumulations were approximately 307. First flight has begun. Be sure to monitor for ECB by getting your black light traps or pheromone traps set up and train your scouts for signs of larval entry holes in the peppers.

N.B. Warm, calm evenings are best for flight which usually begins shortly after sundown and ceases by midnight.  High winds, thunderstorms and temperatures less than 18⁰C (65⁰F) can delay or stop egg-laying outdoors. Also, grassy areas or areas of dense vegetation are best for mating activities which usually begins by 10 p.m., peaks at 1 a.m., and ends at dawn. So please remember to clear the areas around the greenhouse of grass and other vegetation.

For more information on pheromone trap catches, the Great Lakes and Maritimes Pest Monitoring Network is a helpful resource (look under moth counts): here

For more information on monitoring for ECB: here