How To Get Rid of Stink Bugs

How to kill Stink Bugs when you have an Stink Bug infestation.

"Uughh! What is that smell? It's these bugs! They smell foul!" We are hearing this more and more these days. The Brown Marmorated Stink Bug (BMSB) has become firmly entrenched here in the U.S. After being accidentally introduced from Asia into Pennsylvania in the late 1990s, it has quickly spread across the country, a significant pest to both homeowners and farmers alike.

When and Where Stink Bugs Are A Problem

The problem for homeowners begins in the fall. As the temperatures begin to drop, the stink bugs try to stay warm by clustering on the sides of homes and other buildings. They are particularly fond of the south and west sides of the building because they are warmed by the afternoon sun. Many stink bugs will congregate there. They will inevitably work their way into the building through small cracks or crevices, door jams, attic vents, and other gaps in the structure. They are seeking a suitable place to stay warm and spend the winter. Once inside the building, they go dormant, and they fully expect to remain dormant until spring. The problem is that every time there is a warm sunny winter day, their hiding spot warms up, and they think it is spring. After spending the winter months tucked away in the walls or the attic, they have forgotten how they got in. In their effort to get back outside, they accidentally end up inside the home. They don't want to be inside at all. They are merely looking for a way to get outside. This action may happen all at once in the spring or be sporadic throughout the winter and spring, depending on the weather.

Stink Bug Damage

Stink bugs feed on plants and shrubbery. Generally thought of as an agricultural pest, stink bugs will take up residence around any garden or landscape rich with plants and flowers. Stink bugs feed on buds and seedpods, sucking the juice from plants. This feeding results from badly formed buds and fruit.

Identify Stink Bugs

Image from Marlin Rice Department of Entomology Iowa State
Image from Marlin Rice Department of Entomology Iowa State
  • Stink bugs can range in colors but are commonly green or brown.
  • They are about 5/8 inch long.
  • The adults have a triangular thorax.
  • All stink bugs have the characteristic five-sided shield shape.
  • Their eggs are barrel-shaped.
  • Sting Bugs nymphs resemble adults in shape but are smaller and have contrasting color patterns.
  • Stink bugs give out a foul odor.

Stink Bug Diet and Life Cycle

Diet

Plants are the primary source of food for stink bugs. They feed by sucking on the sap from pods, buds, blossoms, and seeds. Some species of stink bugs even feed on juices from caterpillars and beetle larva. They are often crop pests on cabbage, cotton, beans, squash, or melons.

Life Cycle and History:

Stink bugs do not reproduce inside. Therefore they invade homes from the outside. They go through a simple metamorphosis: egg, nymph, and adult. There are one to two generations of stink bugs each year.

Peak population sizes occur in late September to early October. It is during these months that stink bugs may become agricultural pests. Adults are sometimes dormant in the winter, overwintering in logs, leaf litter, or other similar habitats where they are unlikely to be disturbed.

Nymphs feed throughout the summer and molt to adults in late summer. The eggs of a stink bug can be found on the underside of leaves in clumps of 20-30 eggs. Adults mate in the spring and females will lay eggs on plants. These eggs will be laid in groups and are not plant-specific. The eggs are oval, ranging from light yellow to a yellowish-reddish color, equipped with tiny spines forming fine lines along with the eggs. The nymphs, similar in appearance to the adult stink bug, are differentiated by their lack of wings.

The stink bug will molt (5 stages) before becoming a full-grown adult from the nymph stage. They take a couple of months to mature. Due to milder temperatures, the South has the highest populations.

Prevent Stink Bugs

The key to eliminating and eliminating indoor stink bugs in the spring is preventing their entry in the fall. Once they have entered the home, there aren't a lot of treatment options inside. The easiest way to remove them once they are indoors is with a vacuum cleaner; however, the vacuum may take on the stink bug's characteristic smell. If you've had them, you know the smell.

Mechanical exclusion is the best method to keep stink bugs from entering homes and buildings. Cracks around windows, doors, siding, utility pipes, behind chimneys, and underneath the wood fascia and other openings should be sealed with good quality silicone or silicone-latex caulk. Damaged screens on doors and windows should be repaired or replaced.

  • Spraying the exterior of the home early in the fall can offer an additional layer of protection.
  • Look for cracks and crevices and holes around your home's exterior to seal them. Seal all holes with a diameter larger than a pencil.
  • Place screens over any attic openings and vents.
  • Turn outside lights off.
  • Spray during the fall months around the home to prevent them from coming inside. Focus on the south and west sides of your home in the exterior spraying. Stink bugs enter around doors, window frames, utility pipes, under siding, under fasicia, in chimneys, attic vents, and crawl spaces.

Get Rid of Stink Bugs

Pest Control Treatment for Stink bugs

Products such as Avesta CS, Bifen IT, Cyper WSP, and Demon WP are very effective insecticides to prevent the stink bugs from congregating on the side of the home, thus preventing their entry.

Timing of the application is important. As the night time temperatures dip into the low 50's or lower you can expect the stink bugs to arrive. Focus on spraying the south and west exposure of the house.

The more surface area you cover the better the results will be. This may require the use of a ladder to reach the uppermost areas around the roof. Remember to use proper ladder safety protocol and, as always, be sure to read and follow all label directions for the pesticide you are using.

So keep in mind that while stink bugs are a nuisance they can be dealt with. It's not easy or fun to do but avoiding the stinky smell they bring is worth the effort.

Key Takeaway

To prevent stink bugs from entering your home in the fall, treat the outside perimeter with a good all-purpose concentrate. Pay particular attention to the south and west exposure of the house.

Stink Bug Control Sprays

Written by our resident pest control expert Ken Martin.