Several types of insects can enter homes and buildings during late summer and fall as they look for shelter for the winter.
- These insects are generally harmless to people and property and do not reproduce indoors.
- Such insects are called as nuisance or accidental invaders.
- Birch catkin feeders, hackberry psyllids and western conifer-seed bugs are nuisance invaders.
- Pesticides are generally not necessary for control of these nuisance invaders.
Nuisance invaders take shelter in wall voids or cracks and spaces around buildings. You may see them emerging indoors during sunny, mild winter weather and again in spring.
You may not notice them during summer when they feed on plants. But, they become more noticeable during fall when people see them on the outside of buildings or indoors.
How to get rid of nuisance invaders
If you see any nuisance invaders indoors, remove them by physical means, such as a dustpan or vacuum. Pesticides are not necessary to treat these insects indoors.
There is no need to treat the exterior of buildings in most cases. These insects go away on their own as weather grows colder.
If necessary, you can spray the exterior of your home with a residual insecticide, such as permethrin, deltamethrin or bifenthrin. Spray around windows and doors.
CAUTION: Mention of a pesticide or use of a pesticide label is for educational purposes only. Always follow the pesticide label directions attached to the pesticide container you are using. Remember, the label is the law.
Pest-proof building exterior
Seal cracks and spaces around doors, windows, fascia boards and similar places as well as where utility wires and pipes enter buildings.
Install storm windows and 18 mesh size screens to keep out psyllids and other small insects.
Repair or replace damaged window and door screens along with any damaged screens in roof and soffit vents, or bathroom and kitchen fans.
Install door sweeps or thresholds to all exterior entry doors. Install a rubber seal along the bottom of garage doors.
Psyllids are attracted to lights at night. Keep outside lighting turned off or install lights, such as yellow lights, that are less attractive to insects.
If you have hackberry trees in your yard
It is not recommended to cut down hackberry trees in your yard to prevent hackberry psyllid problems.
You could treat your trees before galls are produced because psyllids will not be killed later in the season.
Spray a pesticide such as acephate, when leaves are ½ expanded in the spring.
If hackberry trees are common in your neighborhood, psyllids can fly into your yard even after spraying. Take other control measures mentioned above.
Birch catkin feeders
Birch catkin feeders, are common on birch trees, especially white-barked birch, during August and September.
Also known as birch catkin bugs, they have been found on azaleas, rhododendrons and some other plants.
- They feed on the seeds of their host plants and catkins, in the case of birch.
- These insects do not harm plants and control measures are not necessary in landscapes.
These insects generally move to the sides of buildings on sunny, warm fall days.
- Birch catkin feeders do not seek to enter buildings, but can accidentally fly through open windows or hitchhike indoors on clothing or other objects.
- People usually only see a few birch catkin feeders indoors at a time and those that do get inside do not generally live long.
- These bugs give off a bad smell when crushed.
How to identify birch catkin feeders
- The birch catkin feeder is small, up to 1/8th inch long, and oval.
- It has a reddish-brown head and body.
- Its wings are divided into two areas: the section closest to the head is thickened and reddish brown while the section of their wings away from the head is thin and clear.
- You may see a series of three or four black dots where the membranous section of wings meets the more thickened area.
- The wings are long, extending past the abdomen.
- Birch catkin feeders have well developed scent glands and can emit a strong, unpleasant odor.
Birch catkin feeders spend the winter in sheltered, protected sites such as old catkins, under leaves and in and around buildings.
- During spring, adults mate and lay eggs.
- The nymphs are smaller, less developed versions of the adults that also feed on catkins.
- Nymphs mature into adults by the end of summer.
Hackberry psyllids, are small insects that cause the galls commonly seen on hackberry leaves. These insects only affect hackberry trees and do not develop on any other plants.
- Pachypsylla celtidivesicula is responsible for hackberry blister galls on the upper surface of leaves.
- P. celtidismamma produce hackberry nipple galls on the underside of leaves.
Psyllids are annoying because of their presence.
- They can prick exposed skin as they ‘taste test,’ looking for food.
- Otherwise, they are harmless to people, pets, houseplants, stored products and furnishings.
- They are attracted to the sunny sides of buildings and enter through cracks and spaces around windows, doors or siding.
- They are small enough that they can pass through most screens and are especially common around windows.
- Psyllid numbers vary from year to year.
Without magnification, a psyllid appears gnat-like. When examined closely, a psyllid resembles a miniature cicada.
- It is about 1/8 - 3/16 inch long.
- It has mottled brownish wings with small black and white spots.
- Its wings extend past the abdomen and are held like a roof over its body.
- They are also known as jumping plant lice and can jump and fly away quickly.
Adult psyllids emerge from their winter shelters in early spring and fly to hackberry trees to lay eggs in developing leaves.
- Eggs hatch into tiny nymphs that feed on the leaves.
- This feeding causes the leaves to form abnormal plant tissue (galls) surrounding individual psyllids.
- The psyllids live and feed inside these galls for the rest of the summer.
- Galls affect the appearance of the leaves but rarely harm a healthy, mature tree even when it has large numbers of them.
Psyllids complete their development in late summer and adults exit the galls to spend the winter in protected sites, such as cracks and crevices of tree bark and other sheltered locations.
Western conifer-seed bugs
The western conifer-seed bug, is a type of leaf-footed bug.
- These bugs are common in small numbers in homes during fall as well as winter and spring.
- They don’t bite or sting and are harmless to people and their property.
Because of its large back legs, people sometimes think this bug is a grasshopper.
- The western conifer-seed bug is ¾ inch long, elongate and fairly robust.
- It is reddish-brown with a white zig-zag line across the center of its wings.
- It has long, conspicuous back legs with a leaf-like enlargement on them.
- When this insect flies, it buzzes like a bumble bee and exposes orange and black stripes on its abdomen.
This insect might be mistaken for a cockroach because of their similar size, color and noticeable antennae.
- A cockroach moves quickly, does not fly, hides during the day and has antennae as long or longer than its body.
- A western conifer-seed bug moves slowly, flies readily, is commonly seen during the day and has antennae that extend less than half the length of its body.
Nymphs and adults spend the summer on pines and Douglas firs, feeding on sap from green cones and needles.
- This feeding does not harm landscape trees in the Midwest.
- As the weather cools in September, western conifer-seed bugs search for sheltered places to hibernate.
- These bugs do not normally accumulate in large numbers like boxelder bugs or lady beetles but are typically seen a few at a time.
- It is common to see them during mild days in the winter and spring.
Reviewed in 2018