Indiana Department of Natural Resources sent this bulletin at 08/07/2018 09:26 AM EDT
Weekly Review for August 7, 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.
Inspection Reports Announcements
We would like to remind you that August is Tree Check Month. Please take a few minutes to check out your trees for signs of Asian longhorned beetle (ALB). This highly destructive invasive pest makes round, drill like holes in the trunks of maple, birch, elm, willow, ash, and poplar. While so far never found in Indiana, Hoosiers need to stay vigilant for ALB. Early detection is our most critical tool to protect both woodlands and urban forests from all invasive insects. If you see this beetle or suspicious damage, please report it to the DNR at (866) NO-EXOTIC or DEPP@dnr.IN.gov.
Once again our staff will be manning the Invasive Species exhibit inside the DNR Building at the Indiana State Fair. Please stop in and say, “Hello!” The butterfly exhibit just outside the DNR Building is also fully stocked for the fair.
Ren
Hall (Nursery Inspector & Compliance Officer) - RHall@dnr.IN.gov
At a nursery in Hendricks County, scattered throughout I found several small bur oak trees with these strange growths which I believe to be a type of bud gall but I’m not sure what kind.
I also came across elderberry plants with twisted, deformed tops caused by herbicide injury.
I sent this out last week as a challenge to guess what it was. This is a homemade horse fly trap. I found this while driving a back road in southern Ripley County. The owner of the property had constructed several of these inside their horse pasture. The ball with a black plastic bag serves as a visual attractant to the flies. When the flies take off they have a tendency to fly upward into the funnel which traps them at them in the top container. I have seen another variation of this with a water bath and Plexiglas which drowns the horse flies. Horse fly and deer fly larvae tend to be aquatic, so you generally have the most problem with them around wet areas although they are strong fliers so they can be found some distance from any water. I have seen several versions of both these traps online with the people who built them giving them glowing reviews. I am tempted to build one myself because we get a number of horse fly’s showing up at my house every summer. They seem to be particularly attracted to the area around the above ground pool and will even bite you when swimming. I also have a black inner-tube which floats in the pool which the flies will congregate on. For more information on horse and deer fly biology see Purdue’s webpage on them.
I didn’t turn up much new this past week as far as inspections go. I did go to the State Fair for a special inspection of some turkey legs, ice cream, and Italian sausage. Oh….and the butterflies are in at the DNR exhibit. I did, however, find a couple of interesting things on some of the plant material.
The first thing I found was a fairly heavy infestation of Cypress Twig Gall Midge. If you’re going to be at the fair this is a decent infestation and worth taking a look at. The trees are on the west side of the Glass Barn.
The second thing I found was a first for me. I was playing mini golf with my kids and spotted some rather sad looking euonymus on the north side of the FFA building. Upon further examination it was apparent that mites were taking their toll on the plants but I really didn’t see all that many mites for the amount of damage.
That’s when I noticed the little black dots on almost every leaf. The dots turned out to be a species of lady beetle called the Spider Mite Destroyer (who ever thought of this name must subscribe to my philosophy, “Make entomology fun again.”). According to the University of Wisconsin these little guys (both adult and larvae) can devour 75 mite’s a day.
Over the past week I’ve seen a lot of Fall Webworm in my area, especially in Orange County. I also found long-tailed mealybug on Croton, red headed flea beetle on weigela, bacterial crown gall on ‘Moonshadow’ euonymus, virus symptoms on ‘Key West’ Hosta, daylily leafminer damage on daylily and aphids on river birch.
The critter of the moment seems to be spidermites. I have seen some heavy populations on serviceberry, English oaks, and red maples (especially the Freeman types). We are also starting to see fall webworm popping up here and there in nurseries. Seems they have been most commonly on redbud. Leafhoppers were also causing some noticeable damage. Again on redbuds, the three banded leafhopper seemed to be pretty common this week.
We see a lot of thing in nurseries that, while causing some damage, really don’t matter in the bigger scheme of things. The promethea moth caterpillars I found on yellow poplar were doing some leaf damage, but their numbers just weren’t high enough to do any economic harm to the tree.
