Indiana Department of Natural Resources sent this bulletin at 05/23/2017 12:55 PM EDT
Weekly Review for May 23, 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.
Starting to see a lot of blackspot on roses, especially stock held over from the previous year. At a natives nursery, I was seeing a low level of thrips in the grasses. While thrips damage on grasses is rare, the grasses could become a refuge for the population to move over to something more susceptible. Potato leafhopper damage is also becoming more noticeable on maples, redbuds, and a few perennials.
I’m an amateur when it comes to spider identification, but I love the challenge! I found this one yesterday, but I have yet to make a positive ID. Kind of looks like an orb weaver, but I’m not sure. If anyone has a suggestion, please let me know.
This past week I worked on finish up greenhouse inspections. I saw thrips on various plants such as Hollyhock, Sweet Potato Vine, spikes, Cosmos, Gerber Daisy, Lupine, Lantana, etc. I found Spider Mites on Angel's Trumpet, Verbena Bright eyes and Emerald Green Arborvitae.
At a homeowner I found Peach Curl on a couple of their Peach trees.
Collected from Walnut Twig Beetle traps in southeast Indiana last Wednesday and found June Beetles in most of the traps. During travel to traps, I did not see Sycamore Anthracnose, however there may a small amount as I did not check the trees close up. Have not observed any spring Forest Defoliators – Loopers, Forest Tent Caterpillar or Eastern Tent Caterpillar. Observed a lot of Ash mortality from EAB in Jefferson, Dearborn, Ohio and Switzerland counties.
I’ve been out to a variety of different places this past couple weeks, both growers and dealers. Cold damage was fairly wide spread. I saw cold damage on Norway spruce (pictured), hackberry, tulip poplar, maples, oaks and catalpas. I found aphid populations on the increase on river birch in Dearborn and Union counties. I found some autumn blaze maple with cottony maple scale and taxus with fletcher scale. More Norway spruce which what I believe to be Dothistroma which I sampled again and sent off to the lab to make sure I have the right sight picture when looking for it. I also found some spirea with one of the leaf spot viruses.
Photo 2 – Norway spruce with cold damage.
Photo 3 – River Birch leaf with aphid colony and lady bug eggs.
Photo 4 – Cottony Maple Scale
Photo 5 – Suspected Dothistroma needle blight on Norway spruce.
Photo 6 – Fletcher scale on Taxus
Photo 7 – Spirea virus on Little Princess
Photo 8 – Poorly transplanted blueberry with original root bound container form still visible. The roots did not grow out into the media when this liner was stepped up and much of the media fell out during shipping and or transport.
Over the past week I’ve seen the following: boxwood mite damage on boxwoods, botrytis blight on geraniums and begonias, iris leaf spot on iris, apple scab on ‘Breeze’ apple, aphids on peppermint, black spot on roses, rose slug sawflies and damage on roses and two spotted spidermite on mandevilla and butterfly bush. I saw some Spotted Tiger Beetles the other day and have included a photo of one of them because people often mistake tiger beetles for Emerald Ash Borer adults. Tiger beetles are fast moving, meat eating predators and do not damage trees. One Austrailian species of tiger beetle was clocked at 2.5 meters per second. So if you see these colorful insects running around – no worries. I have also included a photo of a Periodical Cicada that was spying on me while I was looking at a tree trunk!
This past week has been an eventful one. Balsam Twig Aphid is active and causing damage to several species of fir trees, but most of the damage was on Canaan firs. I did see a little Rose Mosaic Virus this last week as well, but it was on plants that did not originate in Indiana. Pine needle scale seems to be a bit of a problem so far this year. While the scale is quite noticeable, I did not see any crawlers and after removing a scale, the eggs were still visible. The first generation should be hatching and crawling soon as it typically happens near the end of May.
