Indiana Department of Natural Resources sent this bulletin at 07/09/2021 08:46 AM EDT
Weekly Review for July 9, 2021
This informal report by the Division of Entomology & Plant Pathology is a commentary on insects, diseases, and curiosities division staff encounter on a week-to-week basis. Comments and questions about this report are welcome and can be sent to your respective Inspector.
Eric Bitner (Nursery Inspector & Compliance Officer) - EBitner@dnr.IN.gov
I have found false oleander scale on Bracken’s Brown Beauty magnolias at two separate nursery locations in the past week. False oleander scale feeding produces chlorotic spots on leaves and can stunt leaf growth. Heavy infestations can cause leaf loss and general decline of the infested plant.
Cicada damage is showing up along the forest edge, in individual trees and in some nurseries. The damage has been in pockets throughout southern Indiana and not consistently on the same species of trees. I have seen it mostly on beech, maple, and oaks.
I have seen a bit more elongate hemlock scale or Fiorina scale on hemlocks lately. If you are seeing hemlocks yellowing check the underside of the needles for these scales.
I’ve noticed several scattered areas here in Perry County showing Brood X cicada damage to branches, especially on various oaks. I have included a photo of the damage and of the debris after branch tips break and fall off. The damage is caused by the oviposition behavior of the females.
Wooly aphids seem to be having a banner year. I have received a number of questions about floating pieces of fluff that turned out to be the winged adult stage of this insect. The nymphs can do damage if there are enough of them, but I generally see light infestations.
Japanese beetles are out and they seem to be numerous in pockets. Keep an eye out for damage on susceptible plants.
Tar spot is starting to become apparent on my own Norway maples. I remember Joe Boggs from Ohio State last year talking about the fact that there are actually two different tar spots on maple. Rhytisma acerinum is often found on silver and red maples while Rhytisma punctatum infects Norway maples. While there are slight variations in appearance, both fungi cause little lasting damage to the maples. The most effective control is the removal of infected leaves to reduce inoculum for next year. For more information, check out this Buckeye Yard and Garden onLine article.
Keep an eye out for bagworms. They are getting to the point where they are starting to cause noticeable damage on spruce.
Other issues I have run across this past week include an uptick in maple mites, redbud leafhopper adults, powdery mildew starting out on serviceberry, and Taxus mealybug on yews.
