Knowledgebase
Invasive Beetles on viburnum shurbs #871331
Asked June 03, 2024, 2:33 PM EDT
Anoka County Minnesota
Expert Response
Apparently we need to deal with the larvae in May and early June and the adult beetles from late June into the summer.
The larvae are visible and abundant when they are present, but they grow rapidly and in many cases they fall to the ground and pupate before the damage is noticed.
The following publications discuss this pest's life cycle, what can be done to control it, and when control measures must be taken.
https://hort.extension.wisc.edu/articles/viburnum-leaf-beetle/
https://ag.umass.edu/landscape/fact-sheets/viburnum-leaf-beetle
In the long run we may need to replace susceptible viburnum species with those that are resistant.
http://www.hort.cornell.edu/vlb/suscept.html
Given the beetles' rapid spread, we don't know whether reports from locations in the Twin Cities area are still needed. In any case, because reports might still be useful, go here to follow up:
https://www.mda.state.mn.us/reportapest