Indiana Department of Natural Resources sent this bulletin at 06/19/2018 10:43 AM EDT
Weekly Review for June 19, 2018
Indiana Department of Natural Resources Division of Entomology & Plant Pathology Phone: (317) 232-4120 Our Website Inspector Territories
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.
Links can be found at the bottom of the page to manage your subscription to this list. Comments and questions about this report are welcome and can be sent to Eric Biddinger or to your respective
Inspector.
Seems like we have had a real gypsy moth explosion in northern Indiana. I have scouted a number of sites with 50 to 100% defoliation on white oaks. Most locations are isolated, covering a couple of trees to a few houses. We found areas where the caterpillars have stripped the white oaks and have moved to other trees including maples, pines, and spruce to finish their feeding. Understandably, some property owners are concerned about the vitality of their trees. In most cases, defoliated hardwoods should push out a second flush of leaves in the coming weeks. While gypsy moth does stress the tree, it typically takes two to three years of defoliation before the vitality of the tree is threatened.
Currently the caterpillars are heading to pupal stage, so hang on tight for just another week or so and they will be gone. The time for treating caterpillars is past, so we encourage property owners to prepare now for future actions. Check out Gypsy Moth Management for Homeowners on Small Properties (Virginia Extension) or Management Guide for Homeowners (Wisconsin) for guidelines of what to do and when.
I haven’t had an opportunity to conduct many inspections over the last few weeks, but I do have a couple of noteworthy things to report. Bagworms have hatched in Fort Wayne. I found a small bag on a red maple over the weekend. Hopefully the population won’t be too severe since we had fairly cold weather in January. I also saw Japanese beetle for the first time in my territory. Japanese beetle populations were higher in the northeastern part of the state last year so hopefully there is a decline this year. At one of the Target stores in Fort Wayne I noticed some boxwood that were browning out and dropping foliage so I sent samples in to the PPDL. Test results showed the presence of Volutella leaf blight, Macrophoma leaf spot (typically a secondary infection), suspected spider mite damage and suspected abiotic disorder, but no boxwood blight. The plants were in a raised island next to the store so they would have been under a tremendous amount of stress which probably led to many of the problems.
During this last week, I inspected several locations in Madison and Hamilton counties. It’s hard to believe, but some plants are still struggling to recover from winter damage and as those plants are recovering, the heat and general lack of rain is starting to take its toll. Japanese beetle has been located at most of the inspections I’ve done in the past week. I have not seen feeding damage yet, but the flight season has definitely begun. What I have seen at several evergreen growers is White Pine Weevil damage. In several cases, the tops were just beginning to die indicating a fairly recent infestation.
