How to Identify Western Conifer Seed Bug

One of the nuisance pests in most homes today is none other than the western conifer seed bugs. These bugs tend to enter buildings during early fall, late summer, or once cold weather kicks in. Western conifer seed bugs don’t sting or bite or cause damages to homes. Learning how to identify these bugs will make it easier for you to know how to handle or deal with them properly.

Western Conifer Seed Bug - What Is It?

The western conifer seed bug Leptoglossus occidentalis is a big squash bug of reddish-brown colour that can grow to a length of 2 centimetres or ¾ of an inch long. At the center of the wings of these bugs is white zigzag light. Its hind legs also have expansions that resemble a leaf.

These bugs feed on the sap of pines as well as other conifers, particularly seed cones. These bugs are native to North America, initially reported during the late 1990s in Europe, specifically Italy. It was in 2007 when it reached Britain and spread widely in Wales and England.

Once an adult, these bugs can fly and bright lights at night attract them. As mentioned earlier, they also look for shelter inside buildings once the weather becomes cooler during autumn.

As one of the species of true bugs, western conifer seed bugs are often mistaken for stink bug and leaf-footed bug but they are neither. However, similar to assassin bugs, its relative, the western conifer seed bugs are known for stabbing using their proboscis once provoked. But, this doesn’t cause physical harm to humans.

For these bugs, their first line of defence against predators is spraying a chemical compound with a bitter taste that sometimes smells like pine or apples but often smells unpleasant to humans.

Life Cycle

Female lays its rows of eggs on needles coniferous trees that earned these bugs their name. These include spruce, hemlock, red pine, and white pine trees. Their eggs hatch within 10 days, with the nymphs feeding on cone scales and the needles every now and then.

Eating Habits

These western conifer seed bugs feed mainly on the different species of the conifer evergreens even though they can also survive on other species of trees. They feed primarily on seeds of such trees. Seed crop of commercial pine groves often suffers from the devastating effects of this feeding habit of western conifer seed bugs. They puncture the outer cover of the seed in order to feed on its contents, thus causing the seeds to be malformed or to shrivel. It seems like these bugs also depend on the compounds developed by resinous trees as their line of defence against herbivores.


Again, it is important to remember that the western conifer seed bugs don’t sting or bite but they can become pests in structures. These somewhat large insects can also invade houses, buildings, and offices in the large number seeking shelter from cool temperatures. Outdoors, they look for shelter in areas such as in leaf litter, under bark, or in bird nests.


Preventing their entry into your home is your first line of defence against these bugs. Screen wall vents, overhang, and attic for mechanically blocking entry points for these insects. Caulk or eliminate cracks and gaps around window and door soffits and frames and tighten any loose-fitting doors, windows, or screens. You can use general insecticides or insecticidal soap sprays to kill off insects huddled outdoors during fall. Just hand-remove or vacuum the insects if adults do find their way inside your home.

Difference between Kissing Bugs and Western Conifer Seed Bugs

Just recently, people have become confused between kissing bugs and western conifer seed bugs. Kissing bugs are one specific kind of assassin bugs that belong to subfamily Triatominae. This is the reason why they are also called triatomines.

Kissing bugs are large insects with a length of ¾ to a bit more than one inch. These insects are of black or dark brown colour with black and orange markings. They have an elongated and narrow head. This is the reason why this specific group of insects is also sometimes referred to as the conenose bugs.

The kissing bugs are actually nocturnal blood-feeders on different vertebrate animals that include humans. They were given the name because it is their habit to bite people on the face, although they can also bite other parts of the body.

While it is already bad enough to get bitten by these bugs, the worse thing is that they are also known vectors of Chagas disease, a deadly disease. Good thing kissing bugs don’t occur in Canada. Almost all kissing bugs are subtropical or tropical in distribution, found in Mexico, Central America, South America, and some areas in the southern United States.