What's Hot at the PPDL on

October 13, 2015

Hackberry Psyllids 2015

Timothy Gibb, Department of Entomology, Purdue University

Hackberry psyllids are back.  We are getting lots of reports of these tiny black colored, jumping bugs all over houses and especially at window screens.  They are tiny enough to pass through window screens.

Psyllids are a group of small insects called jumping plant lice, and the name fits.  They are tiny, plentiful at times and they do jump when disturbed. 

In the late fall adult Hackberry psyllids emerge from their galls and fly, sometimes congregating on windows and screens.  They are often described as tiny black jumping insects and are quite small - small enough to actually pass through the mesh of many window screens.  That is why homeowners report them as being a nuisance in the home.  They also fly to windows again in the late winter or early spring when temperatures begin to warm.

Under a microscope Hackberry psyllids resemble a miniature cicadas – large eyes and with wings held roof-like over the back. 

They pass the winter as adults and lay eggs again during the spring time on the emerging leaves of hackberry trees. When the eggs hatch, the tiny nymphs act like other gall-making insects by causing the leaves to form the distinctively shaped gall that they are named after. The tiny nymphs live and grow inside this protective gall. As summer progresses, the leaves can sometimes be covered with them.

These are not a serious pest of hackberry trees because the galls, although very conspicuous, do very little damage to the leaf.  Hackberry psyllids are mostly considered to be a nuisance pest when they get into homes.

Chemical treatments are seldom warranted. To prevent them from entering the home simply close the windows during the short period of time when they are active. 



Click image to enlarge



Figure 1



Figure 2