Indiana Department of Natural Resources sent this bulletin at 05/04/2022 01:55 PM EDT
Weekly Review for May 4, 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.
I mentioned chili pepper mild mottle virus (CPMMV) on calibrachoa last week. Well, I think I found it in a greenhouse this weekend while doing some shopping. One variety was noticeably stunted and had a very slight chlorotic mottling on the leaves. The owner opted to destroy a couple flats of plants rather than wait on testing.
There are three issues that I have been seeing in nurseries over the last week or so that I want to note. First is cold or frost injury on material that was left outside just a bit too early. Second is Botrytis in the form of leaf spots or stem rot, mostly on impatiens and geraniums due to the higher humidity in closed-up greenhouses. If we could just get a bit of sunshine and warmth, this problem would start to clear itself up. Third, I have seen newly arrived stock with drought injury. I know a lot of places are dealing with labor shortages, but it is so critical to break that newly arrived material out, check it over, and set it up so it can get watered.
Finally, that same cold weather that has been slowing down plant growth is also slowing down insects. We would normally have spongy moth (aka gypsy moth or Lymantria dispar) hatch by now and be looking to treat in early May. Our aerial treatments for this insect in northern Indiana are now delayed to late May. Check out our website or Twitter for updates.
It has been a busy couple weeks. I have had a couple calls about problems from both nurseries and landowners. A landowner asked me to look at a pocket of sugar maples that were in decline which I was concerned could be damage from Asian long horned beetle. Fortunately, what I found was a disease pocket with at least two forest pathogens present (Armillaria root rot and Hypoxylon canker). I was also called by a nursery about some stem swellings in its dogwoods. Upon inspection I found some dogwood club gall midge.
Here is a reminder about Indiana’s Terrestrial Plant Rule (312 IAC 18-3-25) which includes both winter creeper (Euonymus fortunei) and Barberry (Berberis thunbergii). I found ‘Emerald N Gold’ and ‘Moon Shadow’ winter creeper at two locations which were both promptly destroyed.
I think beekeepers can officially say that swarm season has begun. I have seen scattered reports of swarms for the last couple of weeks, but this past weekend that number jumped significantly. I also had several swarm calls forwarded to me which I redirected to the DNR Swarm List. Despite my best efforts to prevent swarming, I can add one of my own hives to the list that swarmed. Fortunately, I had put up a swarm trap which they promptly took up residence in.
I have not seen tents of eastern tent caterpillar in the lower south-central counties. I saw them over the weekend in Tennessee and they were 6 to 8 inches in size. If the caterpillars are present in Indiana, they should be showing up.
District Forester Janet Eger reports balls of cedar apple rust are very evident on her eastern red cedar in Daviess County.
