Indiana Department of Natural Resources sent this bulletin at 08/04/2020 09:17 AM EDT
Weekly Review for Aug. 4, 2020
This informal report by the Division of Entomology and Plant Pathology is designed to update the Nursery and Greenhouse industry of insect and disease pests the Division has been encountering on a week to week basis and as a way to give a “heads up” of things to be on the lookout for. Comments and questions about this report are welcome and can be sent to your respective Inspector.
Ren Hall (Nursery Inspector & Compliance Officer) - RHall@dnr.IN.gov
Last week I found a heavy infestation of galls produced by cypress twig gall midges on bald cypress trees in Tippecanoe County. I’m including a picture of a bald cypress cone to show the difference between these and the galls produced by the midge. The galls house the larval midges which can be seen if the gall is cut open.
I also found tulip tree scale insects on tulip trees at a nursery in Tippecanoe County. In addition to the scale insects themselves there was also black sooty mold and honeydew on the leaves and bark of the tree and ants crawling all over, which are other signs that scale insects or other honeydew-producers are present.
Tar spot is coming along on some of the red and Norway maples. There’s a lot of difference between cultivars in susceptibility. I can find Japanese beetle damage when I look for it, but the populations were way down, even for nurseries that traditionally have issues. Frost damage is still apparent on many species. It is important to remember how hard some of these plants were hit when diagnosing injuries three to four months later. We often only look at things once per year. It is easy to miss the progression of symptoms or the remarkable amount of recovery that can occur in a single growing season.
