HOW TO GET RID OF PINE SEED BUGS

What is a Pine Seed Bug?

This stinky bug is actually the “pine seed bug” (Leptoglossus occidentalis), or the “western conifer seed bug”.  It informally has been referred to as a “stink bug”, which describes the unpleasant odour it emits when squashed.  It is often confused with the brown marmorated stink bug, but is not part of the stink bug family. This herbivore is a true bug (Order Hemiptera, Family Coreidae), and from a small group of insects called the “leaffooted bugs”. This name refers to the flat, leaf-like expansion of the bug’s hind legs.

The pine seed bug is native to the North American West Coast, and made its way eastward, arriving in Ontario in 1985. It is a common Ontario household invader in fall, winter and spring seasons.

Pine seed bug nymphs and adults spend the summer on pine and Douglas-fir trees where they use their piercing-sucking mouthparts to feed on twig and green pinecone sap. Adult pine seed bugs will also eat fruits, seed pulp, flowers, and sometimes needles of certain types of pines, hemlock, spruce and Douglas fir trees.

What does a Pine Seed Bug Look Like?

The average pine seed bug is ¾ of an inch to 1 inch long, with a dull reddish-brown colour. Some have a light white zigzag line across the centre of it’s back. Its elongated shape gives the appearance that it is pointed at both ends. Their antennae are almost the full length of their body.

The Pine Seed Bug Life Cycle

The pine seed bug has a very simple life cycle from egg to nymph to adult. It produces a single generation each season.

Their life cycle begins when adults become active in late May or early June after overwintering. After a long hibernation they feed on one-year old cones and flowering plants. Adults lay their eggs on tree needles (host conifers), which hatch in approximately 10 days. The nymphs first feed on the tender tissue of cone scales and needles, and later feed on developing seeds. By mid-August, nymphs reach adulthood. When the cooler fall weather approaches, they begin to seek shelter for overwintering once again.

Do Pine Seed Bugs Bite?

We get asked often “does a stink bug bite?” The answer is no. Pine seed bugs do not sting, bite or feed on humans or animals. They also do not carry or transmit diseases and pose no serious health concern for people or pets.

Do Pine Seed Bugs Cause Damage?

While the sap and seeds of pine and fir trees are the main diet for nymphs and adults, the impact of their feeding does not harm or destroy the tree.

When squashed, pine seed bugs emit a distinct displeasing smell if they are squished (hence the nick name 'stink bug'. When squished inside homes they often stain walls, curtains or carpets. They cannot reproduce inside the house, as egg laying and development are restricted to the host conifers during the summer months.

Overall, the volume of pine seed bugs that can invade a home can be most alarming and be a tremendous annoyance to homeowners in and of itself.

Why do Pine Seed Bugs Infest Homes and Buildings?

While most pine seed bugs find protective cover in nature, some find safety and warmth within homes and buildings by mistake. In the fall, like the Cluster fly, Asian lady beetle and Boxelder bug, adult pine seed bugs accidently wander into houses and building through cracks and crevices seeking a warm hideout for overwintering. They are not seeking food or a place to mate or lay eggs.

How does a Pine Seed Bug Infestation Happen?

Throughout the spring and summer, the adult pine seed bugs feed on ripening seeds until the onset of colder weather in the fall. This triggers them to seek out warmer shelter to overwinter. Often, they settled in below forest floor leaf litter, under pine bark, in dry or dead Douglas firs, in hawk or rodent nests, in woodpiles or even within stacked lumber.  

A pine seed bug infestation in a home occurs often by mistake. Because they love to bask in the late summer sun, they commonly congregate in masses on the sunny south sides of homes, structures, and buildings. After sunset each day, and as the weather cools off, they search for protective shelter. Your home can offer easy access to warm and protective shelter in attics and wall voids. They most often gain access to these through cracks and gaps around window and doors, in the siding, foundation, soffit, fascia and eaves of homes.

How to Prevent a Pine Seed Bug Infestation

Have you found pine seed bugs in your home? Pest proofing your home or building helps minimize the chances and number of pine seed bugs that gain entry. Here are some tips to prevent stink bugs from entering homes and buildings:

• Inspect your home, structures, and buildings to identify exterior cracks, crevices and gaps, especially around entry points.
• Seal cracks around any openings, including windows, doors, siding, utility pipes, behind chimneys, attic and crawl space vents, and underneath the wood fascia, using a good quality silicone or silicone-latex caulk.
• Replace or repair any damaged screens on doors and windows.
• Replace loosely fitting screens.
• Screen fireplace chimneys and attic and wall vents.
• Seal cracks around electrical outlets, ceiling fans and light switches.
• Replace outdoor lighting with yellow bulbs, which are less attractive to stink bugs.

How to Get Rid of Pine Seed Bugs Effectively

If you need to get rid of pine seed bugs that have already entered a home or building, a vacuum cleaner can help with removal of visible live or dead bugs. Make sure to discard any vacuum bag or empty the vacuum canister outdoors to prevent odor from permeating the infested area.

If an infestation has developed, contact a licensed pest control professional for advice and support.