The Invasion of the Stink Bugs!

I know that sounds like a “B” movie but it appears local gardeners are starting to have problems with stink bugs eating their vegetable and fruit crops and that is worrisome to me.

I think a lot of us grew up thinking stink bugs were those large black beetles that smelled nasty if you stepped on them. It turns out true stink bugs look like what I have pictured above. They come in shades of green or brown, with bodies the shape of shields, and are fairly small, ranging from 3/16″ to 1″ long.

According to one of my insect references — “Insects, Spiders and Other Terrestrial Arthropods” (try saying that fast 3 times) by George C. McGavin (Dorling Kindersley Handbooks, 256 pages, $18.95) — the stink bug “is a worldwide pest of fruit, vegetables and cereals.” They are a member of the order Hemiptera and there are 400 species of the little buggers.

For a couple of months, my husband Bill and I have been happily harvesting and consuming perfect artichokes. Yesterday, after picking a couple for dinner, we noticed some brown areas on them (see photo – you can also click on photo for an enlarged view). At first, we suspected earwigs because they can be a problem on artichokes but you generally just see the frass (droppings) they leave behind.

But when we went back out to the artichoke bed and saw a stink bug on one of the plants, we really became suspicious. As we pulled apart some of the petals on an artichoke bud, we found a small larvae. A web search confirmed that it was indeed a stink bug larvae. Not good at all.

So now what? There are a couple of things you can do to try eliminating or diminishing the population:

1. My go-to reference for dealing with insects and diseases organically — “Rodale’s Complete Guide to Organic Gardening”  — states that “adults and nymphs suck plant sap from leaves, flowers, buds, fruit, and seeds of cabbage family crops, squash, beans, peas, corn, tomatoes and peaches. Feeding punctures in fruit cause scarring and dimpling known as cat-facing.”

What’s helpful to know is that the adult stink bug overwinters in weedy areas so it’s important to clean up any weeds surrounding your garden, especially as we head into fall and winter. The Rodale book also recommends attracting “native parasitic wasps and flies by planting small-flowered plants.” And their last-resort method is to dust them with pyrethrin.

2. Set a trap. You’re familiar with those yellow jacket traps made by the Rescue! company, right? Well, they have recently developed a stink bug trap (go to http://www.rescue.com/product/reusable-outdoor-stink-bug-trap for more information) that uses pheromones (natural chemicals) to lure the stink bugs into the traps. I have one that I’m testing. I haven’t caught any in it yet but want to give it a try.

One of my Master Gardener colleagues recently located a helpful article on stink bugs which can be found at http://msucares.com/newsletters/pests/bugwise/2011/bw07_2011.pdf. Well, it’s helpful but also a bit discouraging when you learn how prevalent they are! As you’ll read, there are both chemical and organic methods of control and unfortunately, the chemical methods sound more effective. I, however, only use organic methods so I guess I’ll be doing the hand-picking and foot-stomping method next spring!
I also wanted you to know that there is a type of stink bug that we need to watch for. It’s called the Brown Marmorated Stink Bug and it is far more destructive than the garden-variety stink bugs we’re dealing with now. Several of my Master Gardener colleagues and I were trained earlier this year as “First Detectors” for invasive insect and plant species earlier this year. So it’s something we’re keeping an eye out for. Here is an article on the web that discusses how to identify them: http://njaes.rutgers.edu/stinkbug/identify.asp.

So far, Brown Marmorated Stink Bugs are causing a lot of problems in the northeast and some midwest states but there aren’t large populations on this side of the country… yet. But the damage they cause, particularly to late-ripening crops, is devastating. There is a lot of information on the web about these nasty insects in case you would like to know more.

But in the meantime, keep a close eye on your veggie crops because the stink bugs we’re seeing in our gardens right now can do enough damage as it is. As always, I’d be interested to hear back from you if you are dealing with stink bugs, if you’ve come across any techniques that work and so on. You can post a comment here or email me at inthegarden@live.com.