incapacitating temperatures for hornets

Asked October 9, 2019, 4:26 PM EDT

I have a baldfaced hornet nest hanging in a weeping katsura tree in front yard. Had one removed from the same tree some weeks ago. Can you tell me at what temperature or what time of year the insects will be unable to defend the nest?

Washtenaw County Michigan

1 Response

It definitely depends on the species, but most insects have a hard time maintaining flight at ambient air temperatures below 40 degrees Fahrenheit. To be on the safe side, I would not recommend trying to remove a bald faced hornet nest at any temperature above 40 degrees Fahrenheit. However, the best thing to do would be to just wait until after good hard freeze (overnight temperatures below 29 degrees for several hours). I am often surprised at the ability of insects to tolerate cold temperatures below what our textbooks say they should be able to tolerate. The hornets in that nest will all die this winter and they will not reuse the same nest next year. In other words you might as well wait until January to remove the nest. All of the hornets will have died naturally by then.