It will soon be that time of year again, when Japanese beetle adults begin to fly. However, the cooler spring means pupation may take longer. So what does that mean for timing of control products?
This post answers those questions and provides updated infographics for JB control for those exporting to non-JB areas.
This spring, we’ve had several growers ask us to clarify whether Acelepryn can be used as a curative treatment for shipments of ornamentals from Ontario after April 15th.
According to the product label, Acelepryn is efficacious for preventative and curative control when applied early April to early September (with confidence at the higher rate, as indicated on the JB Control Timing chart, below).
However, all pesticides generally tend to be less effective against the pupal stage of insects. As an added safety measure, OMAFRA is recommending that this product should only be applied UP TO the pupation period, but not during. We have confirmation that CFIA agrees with this clarification.
Normally, the pupation window falls from approximately May 15 to June 15th (at which point Acelepryn and Intercept can be applied preventively against young JB larvae). However, given the cold spring in 2020, we have extended the Acelepryn application date to May 21st, since JB pupation will likely be delayed. This is reflected in the updated infographic below.
Note this change might NOT be reflective of conditions in years going forward. ALWAYS check with your OMAFRA Specialist or your local CFIA office for clarification each year.
To decide if you need to spray your crops before shipping to non-JB zones, consult this decision tree:
For more information on Japanese beetle development, product residuals, and how we came up with the dates on our infographic (in collaboration with CFIA), check out this more in-depth post.
You can download the new JB Timing Chart and Decision Tree here: