Pest to watch (out for): Satin moth.

Adult satin moth

There are more “new” bugs to bug us here in Calgary!  On the weekend, I saw a satin moth for the first time – well, actually, I saw hundreds of them.  These pretty pure white creatures have swept in and are now hanging around outdoor light fixtures everywhere…and posing a threat to many of our trees.

According to the book Garden Bugs of Alberta by Ken Fry, Doug Macaulay and Don Williamson, satin moths (Leucoma salicis) came into North America from Europe in the 1920s, but here in Alberta, they’ve so far tended to stay in the north:  sightings of satin moths began in the Edmonton area a decade or so ago.   The big problem with satin moths is that the adult females will lay hundreds of eggs on host plants and once the larvae show up, they begin to eat.  And eat and eat.  Plus, the little guys hibernate for winter and then wake up and eat some more in early spring.  FUN!  This means that we’re going to have some serious defoliation issues during the tail end of this summer…continuing into next spring.

If only small groups of plants are affected, the book’s authors recommend hand-picking the larvae off of individual plants and disposing of them, which isn’t always an easy thing to do.  (If you can remove these critters at the egg stage, that’s best).  Satin moth larvae have a dietary preference for poplar and willow trees (they may go for alder and Prunus species as well), so the height and spread of the tree could be an issue – it may not be possible to access or control the pests by hand.   We’re going to have to look to birds and beneficial insects to be our allies in getting rid of the larvae…so we’ll need to do everything we can to encourage these helpers to our yards and gardens.  Another thing we can do is to try to keep our trees and plants as stress-free as possible, which means maintaining a consistent watering and feeding schedule, keeping the root zone weed-free, and so on.

Have you ever had satin moths in your yard and garden?  Did they do a great deal of damage?  How did you control them?

 Related posts:

Satin Moths are Here!…and It’s Not a Good Thing (Nora Bryan – Garden Buzz, Calgary Herald)