The Scoop on Stink Bugs

Published by Bucks Country Gardens in Lawn & Garden

Stink. Bugs.

Two words that can send anyone into a tizzy. But what is it about them that causes so much grief? Is it the subtle and inconspicuous damage they cause in our gardens? Is it because they quietly appear before our eyes, dancing around any light source in our home? Is it because they’re IN our home? Or how about the distinctive scent they give off once they’ve been squished? Or is it simply because we all can remember a time before stink bugs existed in Pennsylvania?

One thing most people can agree upon is the fact that stink bugs, properly known as brown marmorated stink bugs, are a nuisance pest both indoors and out. Much like the voyage of the Japanese Beetle arriving in New Jersey as a stow-away on a shipment of iris bulbs from Japan in 1912, stink bugs are thought to have travelled to Allentown, PA around 1998 in a crate of produce from its native homeland of Asia.

The best way to minimalize the presence of these agricultural and bothersome pests is to understand how they operate.

Life History

The brown marmorated stink bug spends the winter in a protected area (such as inside the warmth of your home) and then emerges and becomes active in May and June, followed by mating. Eggs are laid on the underside of host plants through early September and take about one week to hatch. Over the summer months, nymphs and adults feed on plants in the garden causing damage to a variety of fruit, veggie and flowering plants. One glimmer of good news for plants is that little damage will occur after September in our region as crops are harvested and stink bugs seek shelter (again, in our homes) as they begin their resting phase.

The Problem

One of the biggest problems with stink bugs is their tendency to spread and the ease in which they can do it. As we all know, they survive cold, harsh winters by taking shelter in a warm place (yes, our house again). During their active periods in spring and summer, stink bugs are adaptable and can establish themselves in urban and suburban environments. In addition to being strong flyers, they are hitchhiking pests, enabling them to spread quickly with help of any unsuspecting human’s assistance to other locations throughout the United States. Currently, stink bugs have been found in every county in Pennsylvania and in every state up and down the entire east coast. Sightings have been reported as far away as California, Washington, Nebraska, among other mid-west and west coast states.

Extensive, on-going studies of brown marmorated stink bugs have been conducted since their first appearance in the area in 1998 by the Department of Entomology at Penn State University. Some of their findings indicate that stink bugs tend to feed on peaches, apples and soybeans as well as grapes, raspberries, snap beans, cherries, peppers and tomatoes. Additionally, black cherry, maples, Juneberry, hollies and crabapples are some of the host plants growing in natural areas and it is believed that stink bugs would be able to thrive, not just survive, on native plants.

Unlike the overtly visible damage Japanese Beetles cause to plants, stink bug damage in many cases can be harder to see. For example, stink bugs have been observed feeding heavily on snapdragon plants, seeming to prefer the seed pods with no damage to the flower itself. Feeding on tomato and peppers stems, fruit and flowers caused stippling of foliage and spotting of fruit, according research conducted by the University of Maryland Extension. In essence, the quality of fresh market fruits, vegetables and nursery stock can be reduced due to the feeding habits of stink bugs, but more university research is planned to further evaluate the affects of this pest.

Now what?

Stink bugs will begin their search for warmer homes as the cool, fall weather approaches. The best way to combat the invasion of stink bugs into YOUR home is to seal cracks around windows, doors, siding, utility pipes, behind chimneys and so forth with a good-quality silicone or silicone-latex caulk. Repair or replaced damaged screens on doors and windows. Eliminate the probability of these bugs from gaining entrance into your home in the first place.

Should those pesky bugs make their way into your castle, not all hope is lost. Try to locate the opening where they are gaining access. Typically, they will emerge from cracks around baseboards, around window and door trim and around exhaust fans or lights in the ceilings. Seal openings with caulk. Both live and dead bugs can be removed with the use of a vacuum cleaner. For a contact kill, use St. Gabriel Organic Stink Bug Killer. Made with rosemary, cinnamon, thyme and wintergreen oils, simply spray wherever stink bugs appear in the home. It is safe to apply on many indoor surfaces, but a test spray is always recommended. Do not, however, spray on plants.

To tackle stink bugs on plants, here are a few approaches that can be used. Commercially available stink bug traps are good for removing bugs from the population and to monitor quantity levels. Best to put these out in early spring, around April 1. Another option is to grow early crops of “sacrificial plants” of stink bug favorites such as sweet corn, amaranth and okra. Plant near your vegetable garden and when the “trap” crops become infested with stink bugs, destroy them and the plants. There are a few natural enemies of the stink bug egg masses including ants, ladybird beetles and some lacewings. Plant sunflowers and French marigolds to attract these beneficial predators. And lastly, good old fashioned hand-picking. While wearing gloves, pick off the adults and nymphs from your plants and drop them into a bucket of soapy water.  Also, be sure to destroy clusters of light green, barrel-shaped eggs found on the underside of leaves.

The key to combatting brown marmorated stink bugs is to start early. Don’t wait until there are hundreds in your home or garden. Tackling them while in smaller numbers is essential in eradicating them from your property.

David Jones | Horticulturist, Arborist and Customer Service Specialist

Adriene Vesci | Graphic Designer and Advertising Coordinator