They are hackberry psyllids (pronounced SILL-ids). Psyllids are very small insects with a dark, mottled, fly or gnat-like appearance. In the fall, psyllids gather in large numbers looking for protected places to overwinter. One of the places they choose to overwinter is in and around homes. Psyllids enter homes around windows and under siding, and are small enough to pass through most window screens. When warm sunny days occur during the winter, they become active and emerge from their hiding places, and find their way into the living spaces of a home. Once emerged, they are attracted to light and are often found in the windows.
Where do they come from?
Psyllids are gall-making insects that come from the leaves of hackberry trees (see figure 2). Galls are abnormal masses of plant tissue that develop in response to feeding injury by psyllids. The tissue grows around the insect, surrounding it in protective tissue. Psyllids complete their development and emerge from the galls in the fall. In the spring, psyllids leave their overwintering locations and return to the hackberry trees to feed and lay eggs.
Do they bite or harm people?
Psyllids do not harm humans and do not harm anything indoors. Sometimes psyllids try to feed on people causing a temporary pinprick sensation. They don't carry disease, feed on stored foods, woolen items, or wood. Psyllids are just an annoyance.
How do you get rid of it?
Use a vacuum cleaner to remove them wherever they occur. No insecticides are suggested to control these insects indoors because they are short-lived and do not cause harm. Psyllids are a temporary problem that ends by spring.
