Entomology & Plant Pathology Weekly Review, September 6, 2024
Indiana Department of Natural Resources sent this bulletin at 09/06/2024 10:21 AM EDT
Weekly Review for September 6, 2024
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.
Will Drews (Nursery Inspector & Compliance Officer) - WDrews@dnr.IN.gov
It’s that time of year again: kudzu control season. Throughout the month of August and into September, the DNR Division of Entomology & Plant Pathology staff help coordinate kudzu control throughout the state and monitors kudzu populations. Most of the control work is contracted out, and that work is about to finish for this season.
For those that don’t know, kudzu (Pueraria montana var. lobata) is an invasive woody vine that can be found throughout the state of Indiana (see map below). It is referred to colloquially as “the vine that ate the south,” and if you took a drive through some southern states (e.g. Tennessee, Georgia, Alabama, etc.), you’d see why. Kudzu has tremendous growth potential, growing about 1 foot in length per day, and some vines reaching lengths of up to 100 feet. Because of its tremendous growth and detriment to Indiana’s natural resources, kudzu has been listed as a prohibited invasive plant under the DNR’s Administrative Code per 312 IAC 18-3-16 Control of kudzu (Pueraria lobata).
While part of the language includes that the landowner “must take efforts to eliminate this species in such a manner as is consistent with federal and state law,” the Division of Entomology & Plant Pathology has been leading a state-funded control program where sites are treated on a rotating, priority basis to eradicate or suppress further spread with no cost to the landowner. Over the last month, around 40 kudzu sites in Indiana have been treated, and we’ve seen some great progress from last year (see photos below).
If you think you have seen a new kudzu population, please send me that information (photos and GPS coordinates/address) at my above email address. A couple of the sites treated this year are new reports from last year that we were able to address. With your help, we can try to reduce the impact of this incredibly invasive vine and protect our natural resources.
I’ve been seeing a lot of webbing on honeylocust trees from earlier feeding by mimosa webworm caterpillars. The webbing is ugly but the damage from these caterpillars is usually minimal. I’m regularly seeing Japanese maple scale in nurseries and I’ve shown a photo of the scale on paper birch. It could be easy to miss this scale on birch due to the natural features of the wood.
I’ve included a couple of other photos just for fun. One is a viceroy butterfly caterpillar and the other is a mantidfly. Mantidflies are definitely an interesting insect and are a joy to find as they are not commonly seen.
The first thing I wanted to mention was hive beetles. A lot of people feel their populations are up this year and I want to agree with them, but I am wary of it just being confirmation bias in my head. I don’t really have any data to base that statement on, but I’ll take the chance to highlight another aspect of hive beetle behavior. Most people discuss hive beetles as they relate to pollen stores or pollen patties when they cannot be consumed fast enough. Sometimes people will talk about them getting into honey, but I would like to remind everyone that dead bees can be suitable food for hive beetles. I have found several beetle eggs on or near dead bees and brood lately going through colonies.
Second, be sure to always check your feeders for queens. I’m saying that tongue in cheek, but I found a pile of dead bees under a hive top feeder and noticed one was still alive, and she was a queen. The hive below was checked for queen status and I was confirming larvae and eggs when I spotted her. Your guess is as good as mine as to where she came from.
A couple weeks back I had to go do some follow-up on kudzu sites where landowners were treating. One site in particular had gotten away. We get a lot of questions about kudzu when folks don’t realize that kudzu is perfectly at home here in Indiana and not just the south. Indiana has more than 150 known kudzu sites.
Lastly, I was out helping to do an inspection and happened upon some pretty severe planting issues with pines. Planting depth is important when it comes to transplanting, better to be a little high than low in my opinion. But low is what I see pretty consistently. It can be compounded when a grower starts off too deep and then the installer repeats the issue and buries it deeper and the crew doing maintenance just adds insult to injury with a mulch volcano. I’ve also seen this happen with container stock where a plant is stepped up multiple times and buried deeper with each re-potting. None of this bodes well for plant longevity. Take the time to get the root flare at grade and it will pay dividends down the road.
