What's eating my moneywort ground cover? - Ask Extension
It's almost June and the moneywort in my yard is bright green and lush---but the now the leaves look like Swiss cheese. We found baby blue grub type t...
Knowledgebase
What's eating my moneywort ground cover? #326526
Asked May 29, 2016, 10:42 PM EDT
It's almost June and the moneywort in my yard is bright green and lush---but the now the leaves look like Swiss cheese. We found baby blue grub type things in the dirt. Could they be the culprit? What are they? Any recommendations for finding better balance in my yard? The only chemicals used are to treat my ash tree to protect from emerald ash borer. Otherwise I am chemical free.
Ramsey County Minnesota
Expert Response
It's a type of sawfly. Because it's feeding on moneywort, I
suspect that the sawfly may be the species Monostegia abdominalis. They are
controlled best by hand picking and dropping them into soapy water. They can also be sprayed with horticultural
oil or spinosad.
http://homebuggarden.blogspot.com/2010/06/sawfly-saturday-creepy-loosestrife.html
Thank you for your help. I have another question for you. If I don't capture all of the bugs of if choose not to treat the groups at all, will they die off once they're done eating the moneywort? Or will they go and try to eat other plants in my garden?
Monostegia abdominalis only feeds on plants in the Primrose Family (Primulaceae) including (Lysimachia) and pimpernel (Anagallis arvensis) so most types of plants in your garden will not be eaten. The female sawfly only lives for a few weeks. There are two generations a year. Each female may lay 30-70 eggs.
