Indiana Department of Natural Resources sent this bulletin at 04/18/2017 02:06 PM EDT
Weekly Review for April 18, 2017
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.
Welcome to the 2017 edition of the Weekly Review. I’m going to start things off with a few housekeeping items.
First, Liza Denman joined the Division of Entomology as our support staff in December. If she sounds familiar, that’s because she has handled our licensing in DNR Customer Service for a number of years. We welcome Liza to the Division.
Second, the Weekly Review has nearly 3,000 subscribers. Thank you! We welcome your comments and feedback – that’s why our email addresses are next to our names!
Third, ever delete the Weekly Review before you read it or want to share an old issue with a colleague? Well, we now have an archive page. All the issues should be up there within a couple of weeks of publication. Subscription information is right on that page, too!
Now on with the show…
I received a photo yesterday from a firewood vendor of an insect that was all over his newly cut locust logs. It is a longhorned beetle called Painted Hickory Borer. Over the last couple of years, I have received several calls of suspected Asian Longhorned Beetle larva in firewood. So far, every time it has actually been these guys. This fall, the wood will be riddled with holes from the larva and there will be very fine sawdust all over the pile. I have personally never seen PHB on locust, but it has a wide host range so I’m not surprised. It looks very similar to Locust Borer, but can be easily distinguished by the time of year. PHB adults emerge in the spring while Locust Borer adults are present in the fall. For more information, check out Purdue’s Hot News article on Painted Hickory Borer.
Photo 1 – Painted Hickory Borer (Photo courtesy of Will Sullivan)
I saw small eastern tent caterpillar tents in cherry along US 231 near McCutcheon High School south of Lafayette on April 17 so Gypsy Moth egg hatch is probably not too far behind.
I haven’t seen eastern tent caterpillar tents in the northeast part of the state yet.
Ken Cote (Nursery Inspector & Compliance Officer) - KCote@dnr.IN.gov
Eastern tent caterpillars were observed feeding on April 13 in Monroe County. I have not seen a large number of eastern tent caterpillar this year. Populations seem to be less than previous years. Boxwood leafminer has caused noticeable injury to the boxwoods on my property this year. Adults are beginning to emerge in southern Indiana. Look for small orange flies hovering around boxwood plants. Yellow sticky cards can be used to detect adults. Residual insecticides such as bifenthrin, avermectin and systemics such as imidacloprid will reduce populations. Recently, I have been conducting nursery dealer inspections. I am seeing powdery mildew on columbine. I have also observed Botrytis on primrose, gerbera daisy and geraniums. This is a cool wet weather disease. Look for blackened areas with fuzzy, gray spores emerging from leaf tissue. I have also seen virus symptoms on peonies and foxgloves. These plants have been sent to Purdue for testing to determine if a virus is present. Last week I found dieback symptoms and cankers on English Roseum Rhododendron. A sample has been sent to the lab to determine the causal agent. It could be Phytophthora or it could be Botryosphaeria, but there is no way to make and accurate diagnosis in the field.
Photo 2 – Foxglove with Viral Symptoms
Photo 3 – Dieback on Rhododendron, Field Diagnosis not Possible
(This is Jared’s report from March 28) Root problems and scale were on the ticket for this week’s inspections. I took a swing by some retailers in central Indiana to get an idea of what material was being shipped into the state and see if the recent cold spell did any significant damage to stock. First, I found a variety of stock with rooting issues. Much of the stock at one location was poorly rooted and I suspect had been held to long as plugs or in smaller liners before being stepped up. The original container size was apparent with most of the stock and you could see where roots had wrapped around on themselves inside the container. Most stock was poorly anchored in the containers and showed a lot of movement when moved around. I also found a Bartlett pear with crown-gall shipped in from Oklahoma which was destroyed.
Photo 4 – Grape showing root bound original plug
Photo 5 – Improperly planted spruce
Photo 6 – Girdling root on river birch
Photo 7 – Crown gall on Bartlett pear
I also found a number of scale while I was out. The first thing I found was oyster shell scale on Autumn Blaze red maple (no photos)
Photo 8 – A small amount of pine needle scale on white pine
I also found some Magnolia scale on Ann Magnolia. The Magnolia crawlers were dispersing which is the prime time to treat for the pest. There was also a colony of pavement ants tending to the scale. Any time I find a column of ants on a tree or in a greenhouse it’s usually a good idea to follow them as I find most of the time they will take you to a problem (i.e. scale or aphids).
I observed Eastern Tent Caterpillar Sunday in Floyd County. One tent on Black Cherry was about 6” length. I have not seen any around the home in Washington County yet.
Also, observed several tents on Black Cherry on my trip to my family house in Tennessee. It looks like a good population is starting. Tents were 6-8” length in Cumberland and Putnam counties, Tennessee. Did not see any along the route in Kentucky.
