Leaf edge eating insect

Question: I'd like to know what might be chomping the edges of our hosta (and other plants) leaves and what to do about it.
Thanks!

responder: D.Lauer Benton County Master Gardener Replied July 13, 2023, 7:07 PM EDT
response: Hello there! This damage looks like root weevil damage. Root weevils overwinter in the soil as larvae. The next year they emerge as adults and crawl up plants and chew holes around the edges of leaves. Meanwhile the larvae are feeding on the roots of your plants. The first step to control these critters is to ensure that they are the ones damaging your leaves. The best way to do this is to go out at night and look for them as they are chewing on your leaves. They are small black or brownish things, do not fly and are slow moving. Wait for dark and go out with a flashlight and look for them. You may want to take something to catch them on and knock them off the leaves into the container as this is one method of controlling them. Since they are slow you can capture them. You may also want to monitor the leaves for more damage over time. Rarely does the notching of leaves cause a health issue for your plants, however the damage to the root system may cause a problem over time as weevil populations continue to rise. Other methods of control are using sticky traps or tanglefoot type substances that trap adults before they can crawl up your plants every night. The best method of control is a soil drench containing nematodes. The best times to use the soil drench with the nematodes are Spring and late August. The nematodes attack the soil dwelling larvae. Kill the larvae, no leaf notching next season. Timing is important. Visit your favorite nurseryman to see if they carry the nematodes. Be sure to follow the directions exactly for the best results. I have attached two links below for more information. https://extension.oregonstate.edu/news/control-sneaky-root-weevils-beneficial-nematodes https://pnwhandbooks.org/insect/hort/landscape/common/landscape-root-weevil

responder: The Question Asker Replied July 13, 2023, 8:26 PM EDT
response: Thank you! It's what I expected. Follow-up question: since some of my hostas are in pots -- Can the weevils move between pots? If we re-pot the hostas with new potting soil, would that rid us of the weevils? Thanks again.   Get Outlook for Android  From: ask=<personal data hidden> <ask=<personal data hidden>> on behalf of Ask Extension <<personal data hidden>> Sent: Thursday, July 13, 2023 4:07:00 PM To: kissidog <<personal data hidden>> Subject: Re: Leaf edge eating insect (#0110418)

responder: D.Lauer Benton County Master Gardener Replied July 14, 2023, 4:49 PM EDT
response: Not sure about whether the weevils can crawl up the side of a pot.  They could crawl from plant to plant if the two plants leaves were touching each other.  Also, they could fall from taller plants they are chewing on or crawling up on.  Changing the soil could certainly reduce their numbers but I am not sure whether you would be able to get all of them.  The grubs are small and the eggs are even smaller.  Since the larvae(grubs) eat the roots of your plants you might not see them, and you may also not see any eggs the adults may have laid that have not hatched yet.  I have used nematode drenches to rid my house plants of fungus gnats with great success.  Having your hostas in a pot may actually be a bonus as the infection is in a limited space. Try changing the soil and if you still have weevils go to the drench.