SWD development has been related to temperatures (degree days) by researchers in Oregon. We used their model, and weather data from Environment Canada, to see how it predicted SWD population development in Ontario.
SWD populations are most advanced in Essex county, where third generation adults are now emerging and peak egg laying by this generation is expected next week.
Otherwise, in most of Ontario, this is a peak time for egg laying by second generation SWD. Third generation SWD emergence will peak next week.
In the cooler regions ( Kingston, Coburg) 2nd generation SWD is still predominant. It is important to remember that although pest pressure is not as extreme in these cooler regions it is still high!
The take home message is : this is an important time for SWD control everywhere in Ontario . Reference http://uspest.org/cgi-bin/ddmodel.us.
All degree days calculated in Celsius, base 10. You can calculate the degree days in your area to see how your location compares to the ones on the chart below.
This data was compiled by Abbie Wiesner, OMAFRA Vineland