Indiana Department of Natural Resources sent this bulletin at 08/31/2022 07:25 AM EDT
Weekly Review for August 31, 2022
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.
This is our last regularly scheduled Weekly Review of the 2022 season. Like always, we will send out updates throughout the year on this email list as needed. We will be back with weekly updates in spring 2023.
Next, we would like to welcome two new nursery inspectors to the division!
Diane Turner joined the DNR after many years in agricultural educator roles at NC Cooperative Extension, Purdue Extension, and her local Soil and Water Conservation District. She earned a master’s degree in Plant Pathology from University of Tennessee where she developed her interest in plant problem diagnosis. Diane, her husband, and two daughters have lived in central Indiana since July 2012. Diane will be working in and around the Indianapolis area.
Caydee Terrell is a recent Purdue graduate with a master’s degree in entomology. She is no stranger to the division having worked as an insect screener and an assistant with the CAPS program. Caydee will be covering Lafayette and the surrounding counties.
Contact information and territories will be updated on the website this fall as Diane and Caydee get settled in.
Finally, we would like to congratulate Eric Biddinger, the 2022 recipient of the Carl E. Carlson Distinguished Achievement Award in Regulatory Plant Protection. This award, presented by the National Plant Board, is a national recognition of service and contributions made by field level nursery inspectors. Eric is the first inspector from Indiana to receive this award.
I inspected a nursery in Wabash County this past week that was having an issue with hosta that were rotting at the base. I collected samples and sent them into the Purdue Plant Diagnostic Lab and they were found to be infected with southern blight, Sclerotium rolfsii. The blight has a wide host range which includes vegetables, fruit and ornamentals plants. Good sanitation practices like removing infected plants as soon as symptoms appear and removing surrounding soil are helpful; however, prevention is the best strategy.
As fall draws closer, the two big critters are fall webworm and bagworm. Both seem to be on an uptick this year and both do a great job of drawing attention to themselves late in the season when there are few viable control options left. Fall webworm is often cyclical and rarely warrants control measures with the exception of small or newly planted trees where some protection may be needed to minimize further stress. Bagworms are well past the optimal window for chemical treatments. Small populations can be hand-picked and placed in soapy water, but at this point the better strategy might be to mark infestations now and plan for treatment in early June to control newly hatched caterpillars.
I have included a photo of leaf damage from the adult cranberry rootworm beetle. Damage usually appears as chewed out crescent shaped areas on leaves. I have seen this on grape, blackberry, raspberry and jostaberry, but this pest can attack a wide range of fruit bearing plants and ornamentals. More information can be found on this factsheet.
I still often get questions about leaf cutter damage and what insect causes it. I’ve attached a photo. Leaf cutter bees will remove a circle shaped area from around the edges of leaves and then use that plant material to make cells in the nest. This damage is only minor and leaf cutter bees are beneficial pollinators in your landscape. You should not treat them, just let them be.
