Controlling Harlequin Bugs is No Laughing Matter
How to Keep Your Organic Garden Safe From These Colorful Pests.

Harlequin Bugs are one of the most unique looking bugs that you will ever come across in your organic garden. They are shield-shaped, like their kin, the stinkbug, but they are much prettier to look at: they have a very distinctive mirror image pattern of red and black markings, and lay (dare I say it?) spectacular-looking eggs on the underside of their host plant's leaves. The eggs look like tiny black and white-striped barrels, which they lay about twelve at a sitting, depositing them in a double row.

So, What's the Damage?

Even though harlequin bugs more aesthetically pleasing than your average bug, they will detract from your garden's overall appearance far more than they enhance it. They suck the juices right out of their host plants, stunting them and causing the leaves to become scarred and deformed. In severe infestations, the sheer numbers of harlequin bugs will overwhelm their host plants and kill them.

Harlequin Bugs feed mainly of members of the cabbage family, including kale, mustard greens, broccoli, arugula and Brussels sprouts. They also have been reports of them feeding on other types of plants, including beans, tomatoes and flowers, notably cleome and zinnias.

In warm areas of the U.S., where harlequin bug infestations tend to be the most problematic, the bugs can have up to four generations a year and, in warm weather, their eggs may take as little as four days to hatch. This allows their population to increase dramatically in a short amount of time.

How Can I Control Harlequin Bugs in My Organic Garden?

The most effective way to control harlequin bugs is to refrain from growing cruciferous (cabbage family) crops year-round. This will eliminate the bug's favorite food source, and interrupt their reproductive cycle to some extent. If you take a break from cruciferous crops for at least a few months a year, making sure the you remove all the debris from previous crops so that your garden is a crucifer-free zone, you will discourage the harlequin bugs tremendously.

Tilling your garden beds in the fall, or at least removing the old mulch and plant debris from them will also help you to keep harlequin bugs in check, since adult harlequin bugs tend lurk in plant residue all winter long, just waiting for you to set cruciferous plants out in your garden come springtime.

Covering your young cruciferous plants with floating row cover and growing plant varieties that can tolerate harlequin bug damage (these include Copenhagen cabbage, White Icicle radish and Green Glaze collards) can also reduce your harlequin bug-related headaches.

If you already have a serious infestation, are in the middle of your growing season, and need some immediate help for your plants, there are several things that you can do to help them.

1. If you can stomach it, make sure to smush every harlequin bug egg and any adult harlequin bug that you can get your hands on.
    
2. Provide habitat for spider and ground beetles, two kinds of insects who feed on harlequin bug eggs and nymphs.
    
3. As a last resort, you can try using pyrethrum, sabadilla or rotenone, which are organic insecticides, to control them. Keep in mind the although these particular insecticides are organic, they are still quite toxic, and must be handled with care.

By using a combination of these techniques, you will likely succeed in your attempt to achieve a large measure of harlequin bug control in your organic garden. Once you've achieved that control, you'll be far more likely to welcome a stray harlequin bug as the work of art that it is.

~Tammy Biondi

Tammy Biondi is a former suburbanite who moved to the country in order to dedicate herself to the farm and garden life. She grows and sells organic plants and vegetables and uses the knowledge she gains from her professional experiences to make a beautiful and bountiful home garden for herself and her family.