The Stinkbug Plague

By Dr. Francis Gouin

A number of Farmers Market customers have complained to me about stinkbugs in their vegetable gardens, and many have brought me tomatoes and peppers marred by punctures from stinkbugs. Some of the tomatoes show the creased cat facing similar to what I have mentioned seeing on peaches. Other tomatoes exhibit a puncture mark with the surrounding tissues turning brown.
Another customer brought me several ears of corn, with the husk on, with much of the silk missing. After husking it, I saw puncture marks on half or more of the kernels.
The symptoms that I found most interesting showed up as wart-like growths on the pods of okra and snap beans. Using a sharp knife, I sliced several of the warts and could easily see puncture marks.

In the Garden this Week

Divide and Conquer Perennials

    Now is the time to divide daylilies, hosta, astilbe and peonies.
   Dig them up with a generous ball of earth so that when you lift it, it falls apart. Then slam the clumps on the ground as hard as you can to shake as much soil from the roots as possible. Next use your hands to pull apart as many divisions as possible. For more difficult divisions, cut from the top down with a hatchet or Japanese gardener’s knife. Cut deep enough that the remaining roots can be pulled apart.
   Keep only the outer divisions and discard the divisions in the center of the clumps. Those are generally the mother plants and with age become infected with rot.

    Many of the pears growing on my Warren pear tree are exhibiting cat facing and visible puncture marks. The only fruits that have not exhibited stinkbug damage are the persimmons and the figs. Yet as the figs ripen, I see stinkbugs crawling on them.
   Stinkbugs have been most severe from Prince George’s County to upper Baltimore County. So far, southern counties like Calvert and St. Mary’s have been largely spared. Next year will be different.
   An entomologist at the University of Maryland warns that we can expect a plague of Biblical proportions in years to come. Next year, they’re anticipated to spread statewide, causing damage three times more severe.
   A number of research projects are under way investigating natural predators of the stinkbug and the use against them of safe pesticides with short residual properties. Until then, swat them, stomp them or drown them in soapy water.

Block the Invasion

    Already, the home invasion is beginning. For under $30, you can buy commercial traps baited with pheromones or light. They work, but only in small areas.
   If you want to try trapping them, it’s cheaper to build your own nighttime trap.
   Here’s how:
   Cut off the top of a two-liter soda bottle just below the curve. Save the top. Insert a battery-operated night light in the bottom of the bottle. Invert the cut top on the bottle to form a funnel. Run masking tape up and down the outside of the bottle in a half-dozen places, from the edge of the funnel down. Use the ends of the tape to secure the bottle to a flat surface.
   The light attracts the stinkbugs, and the vertical strips of masking tape allow them to climb up the sides of the bottle and fall into the funnel, thence into the bottle. Once inside the bottle, they cannot escape.