Growing Green

By Robin Rott, Extension Educator

As the season cools, box elder bugs begin to gather on warm spaces outside and inside our houses. I invariably receive many calls on how and when to control them. I am fortunate to have many knowledgeable colleagues in Extension.  This is what Marissa Schuh, Integrated Pest Management Educator, has to say about them. 

The box elder bug is an insect that is native to Minnesota, feeding on box elder, maple and ash trees. Box elder bugs tend to have high populations during hot, dry summers (records show their populations skyrocketed during the Dust Bowl in the 1930s), meaning a summer like we just had can produce a lot of box elder bugs. They are now sensing the seasons are changing, and looking for a warm place to hunker down for the winter. 

Fortunately, box elder bugs are nothing more than an annoyance. They don’t cause meaningful damage to plants, they don’t bite people, and they don’t spread disease. The worst they do is give people the heebie-jeebies, and smell a little bad when crushed. 

Keeping the bugs on the outside of your house out of your home

The bugs are looking for somewhere warm to spend the winter. Instead of spending your energy removing bugs, allocate your energy to plugging up the cracks in your home where they can make their way inside.

• Check around window screens and doors for gaps.

• Look at areas where cords, cables, and vents leave your house and seal those areas.

Checking the exterior of your home and making it bug-proof can have other benefits. Mice only need a quarter-inch (think the size of a dime) to get into a house, so by bug-proofing your house, you can keep out pests that actually cause damage to your home.

Don’t cut down your trees

Sometimes people think “I have box elder bugs, I have box elder trees, the trees are my problem!” Trees provide a lot of abstract and concrete benefits to people, so cutting a box elder tree down because of a bug problem every five years isn’t a good solution. Remember, box elder bugs fly (though not necessarily gracefully). They can fly a few miles, so removing a tree on your property doesn’t mean you will never see another box elder bug.

Prevention is fine, 

but I want them gone!

If you want a direct approach, physical removal is a good option. Grab an extension cord and your shop vac and go to town. Sucked-up bugs can be dumped in the garbage. If you decide to use a pesticide, choose a product carefully. This means reading the fine print! Make sure the product you’ve pulled off the shelf says it can be used on the exterior of buildings. 

Before you apply a pesticide, make sure you also read the product’s directions around how to safely spray and what protective clothing to wear. Always follow the pesticide label directions attached to the pesticide container you are using. Remember, the label is the law.

For more information about these and other pests in your home and garden, visit: www.extension.umn.edu.

Until next time, happy gardening!

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“It’s easy to cry ‘bug’ when the truth is that you’ve got a complex system and sometimes it takes a while to get all the components to co-exist peacefully.” ~Doug Vargas