If you have eucalyptus trees, you might have noticed white, crusty growth on the leaves. Or maybe you saw a sticky, blackened mess of fallen leaves under a eucalyptus tree. These are signs of the redgum lerp psyllid, one of the most common psyllid pests that damages eucalyptus trees in California.

The adult psyllid is very small and as nymphs, they are concealed under a waxy cap, or lerp. As they feed, they excrete honeydew which can lead to the growth of black sooty mold, the source of those sticky leaves under the tree.

Although under biological control in coastal areas, this pest is still a problem under some growing conditions and on specific Eucalyptus species. Cultural practices to manage...

[Originally published in the Summer 2022 issue of the UC IPM Green Bulletin]

The three-lined cockroach, Luridiblatta trivittata, (Figure 1) is the smallest cockroach species in California, with adults averaging only 5–7 mm in length. This newly introduced cockroach is native to North Africa and the Eastern Mediterranean. It was first detected in California around 2004 in Marin County, but it was not positively identified until 2009. Since then the three-lined cockroachhas slowly expanded its range to include the entire San Francisco Bay Area, south to San Luis Obispo, east to the foothills of...

When tiny tree-killing beetles first arrived in Southern California several years ago and began destroying urban and riparian forests, they raised widespread concerns among both tree experts and affected communities. More recently, invasive shothole borers have captured far less attention, and many people may think the pest threat is over. Unfortunately, it's not!

While significant progress has been achieved in invasive shothole borer research, surveying, trapping, and management programs, these beetles are still an ongoing threat to the state's urban and wildland trees. Continue reading to find out what you can do to be part of the solution to this invasive pest issue.

What are invasive shothole...