Q: I found this growing on a Japanese maple and camellia bush in my front entryway. It looks like a tiny blob of bird poop but is attached to the plant at the joints and seems to be a deposit of some sort. It’s soft and when you pull it off the branch the underside has a tiny hole in the middle. If feels like putty when you squeeze it. The plants seem unbothered but is this a problem I should spray for?
A: Your plants have a fine family of wax scale insects sucking sap from the stems. The insects suck sap from the small branches of holly, quince, camellia and several other shrubs. The waxy covering they secrete looks like bits of white chewing gum stuck to the twigs.
The females (there are no males) lay their eggs in March. Tiny “crawlers” emerge in May, all looking for a spot to settle and begin drinking from their host.
Control is two-fold: pick off and destroy now all of the waxy adults you can find. In June, spray the plants with carbaryl (click for sources) or horticultural oil. This will kill the defenseless crawlers.
Practice the two controls for two years and you’ll eliminate the scale population.