Refer to last week's issue about insect pest emergence that coincides with various stages of bloom of Vanhoutte spirea. Be particularly watchful for pine needle scale crawlers. They should be present throughout much of Illinois.
Sawfly larvae have been found on black locust (Robinia psuedoacacia) in northern Illinois. This sawfly will also attack rose acacia (Robinia hispida).
(Other contributors to this article: Staff at The Morton Arboretum)