I wonder if you’re one of the many in the Montrose and Olathe area who has very small bugs crawling on the outside of your home? If so, this may help you out.
Just when you think things couldn’t get any worse, we hear stories about killer hornets and now the extremely annoying Elm Seed Bugs have shown up. These bugs are native to Europe and the Mediterranean region. They were first identified in Idaho in 2012 and within a year they were found in Oregon. By July 2017, it was also found in Mesa, Delta and Montrose counties.
Now don’t panic. These bugs won’t hurt you or anything that you’re growing. It’s mainly a nuisance insect that feeds on a number of plants including Siberian elms and linden trees. I know of a number of people who were excited when they first heard about the elm seed bugs, thinking we finally have an insect that will get rid of those horrid elm seeds that fall all over the garden and driveway, and blow into the house every time the door opens. While it’s true that the elm seed bugs feed on elm seeds, they won’t begin to make a dent in the number of elm seeds that you have. In fact, they’re attracted to the elm seeds piled around your house and garden.
You may not need to look very closely to see these little guys crawling all over the exterior of your house. At this time, they begin wanting to live with you in your home. They will continue to try to take up residency in your home through September.
These bugs are a lot like the familiar Boxelder bugs. They even look a lot like a Boxelder bug, except these bugs have a strange pungent order when you crush them and they're much smaller.
The adult elm seed bugs will spend the winter in homes or in hidden places on the outside of homes and in the landscape. About around March, they will emerge and move to nearby elm trees where they will lay eggs. Sometime in May the little critters hatch and will go through five growth stages before becoming a winged adult. They think the insects only have one generation per year, which I guess is the good news.
Entomologists think periods of extremely high temperatures, say around 100 degrees, may trigger mass migrations of nymphs and adults to move to more favorable climates, like the inside of your home.
I’d love to tell you that spraying your tree will rid you of all the elm seed bugs, but unfortunately spraying isn’t very effective because the bugs are so mobile. There are a few pesticide products that you can spray on the bugs to kill them if they’re all over the siding of your house, but the bugs will most likely keep reappearing and you’ll need to keep reapplying the spray. The bugs can easily be vacuumed up once they enter your house. Perhaps the best way to deal with them is to seal cracks and crevices, especially in areas around windows, doors and vents where insects can easily gain access.
Just so you know, there is an elm leaf miner bug that’s causing problems in a number of elm trees. This little bug develops between the upper and lower surface of the leaf, feeding on the interior part of the leaf, giving the leaf a hollow appearance. The portion of the leaf that’s affected eventually turns brown and the leaf may drop from the tree. If you look very closely you may be able to see the little insect in-between the surfaces of the leaf. The damage is usually more cosmetic rather than a serious problem. However, if you choose to spray the tree, the pesticide should be applied shortly after the tree has leafed out in the spring. Permethrin, Bifenthren, or Cyfluthrin are sprays that can help. A systemic insecticide drench is also an option that may help control the miners. Just be sure to always read the label and follow the directions.
I remember dealing with a number of various insects over the years that just came and went. They appeared in alarming numbers for a year or two and then just disappeared. Hopefully these insects will also go that route.
Linda Corwine McIntosh, ISA Certified Arborist, Licensed Commercial Pesticide Applicator, Advanced Master Gardener