Indiana Department of Natural Resources sent this bulletin at 06/13/2017 08:03 AM EDT
Weekly Review for June 13, 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.
Division News Cliff Sadof, Purdue University professor of entomology and Purdue Extension pest management specialist, and Carrie Tauscher, state community and urban forester at the Indiana Department of Natural Resources, will lead three workshops on invasive forest pests that pose a significant threat to Indiana’s urban and rural forests.
Each workshop will include presentations on the biology, signs and symptoms, and management of invasive forest pests. Participants will also learn about technology used by citizen scientists to report these pests across the state. There will also be time for participants to ask questions. Light refreshments will be provided.
Gardeners, professional foresters, concerned citizens and anyone interested in learning more about Indiana forest pests - including the emerald ash borer, hemlock wooly adelgid and the Asian Longhorned Beetle - are encouraged to register.
The workshops are free and open to all ages and levels of knowledge. Pesticide applicator CCHs, ISA CEUs, and SAF CFEs will be available.
The workshop schedule: * July 11, 6-8 p.m. EST at the Purdue Extension-Monroe County office, 3400 S. Walnut St., Bloomington. * July 12, 6-8 p.m. EST at the Purdue Extension-Dearborn County office, 229 Main St., Aurora. * July 13, 6-8 p.m. EST at the Brown County Fairgrounds, 802 Memorial Drive, Nashville.
Space is limited, so early registration is encouraged. Sign up online.
For more information, contact Sara Stack at (765) 494-0822 or stack4@purdue.edu
Inspections slowed down a bit this week as I moved over to a few other projects. That being said, I did have a couple of interesting finds.
First, while at a homestead near Peru, I happened to look up and see one of the healthiest tulip tree scale populations I have seen in a while. Judging by the amount of old scales further up the branches, this population had been there a while.
I also came across ‘Yankee Doodle’ Lilac with virus like symptoms at a grower in Elkhart County. The plants originated from Oklahoma. I intend to look into this one further.
Finally, in looking at some older, established willows at a nursery, I noticed what looks to be willow blight. The leaves had black spots and lesions were on the stems. There are several pathogens involved in this complex including an anthracnose, a scab, and a canker.
Photo 1 – Tulip tree scale
Photo 2 – Virus
symptoms on ‘Yankee Doodle’ Lilac
Photo 3 – Willow blight. Note the cankers on branches.
I didn't get a chance to do a lot of inspecting last week, but did go out to look at a potential hogweed report near Hamilton. It turned out to be cow parsnip which is very similar looking. While inspecting a nursery in Dekalb County I came across a burning bush with some unusual yellowing on the foliage. I will be taking the entire plant to PPDL to determine if a virus is present. I also came across four lined plant bug on geranium.
Photo 4 – Cow parsnip
Photo 5 – Burning bush with yellowing
Photo 6 – Four lined plant bug
Photo 7 – Four lined plant bug damage on geranium
Ken Cote (Nursery Inspector & Compliance Officer) - KCote@dnr.IN.gov
It has been 19 days since I received any rainfall at my house. Bagworm have hatched in my area and were found feeding on red maple in Lawrence County. Interestingly I did not see any on evergreens yet. Spruce spider mite injury continues to increase on many Alberta spruce trees in the landscape. Maple mites were found on cultivars of red maple in Lawrence County. Look for stippling on the leaves, especially towards the lowers portion of the tree where mites are protected from rainfall. Spittlebug was found on perennial Hibiscus. This insect causes a spit like mass of foam on a tree. It can be found on pine and herbaceous plants. Damage is usually not the severe from this pest. Aphids are active on birch and I have encountered heavy infestations of aphids on tulip poplar producing honeydew. I have not seen any tulip tree scale so far this year. White pine weevil injury continues to increase in my region and continues to show up as dead or wilting leaders in white pine, Norway spruce and Serbian spruce.
Photo 8 – Maple Mite Injury
Photo 9 -
Spittlebug on Perennial Hibiscus
Photo 10 – Aphids on Tulip Poplar
Root rot symptoms were found on white pine in Lawrence County. Look for white pines that have a faded or off green appearance. Eventually these trees turn brown as they slowly die. Bark beetles and root rot often affect white pines at the same time, especially if those trees are planted in heavy clay soils with poor draining. Remove and destroy these dying trees so that bark beetles do not have an opportunity bread or spread to healthy trees. Leaf spot disease continue to develop on Oak leaf hydrangea, red maple, red bud and many other ornamentals. Recently I saw symptoms of Cercaspora leaf spot on black gum. Remember, to truly know if you have a particular leaf spot disease, you must get laboratory diagnosis. I recently sent samples to the Purdue Lab with leaf spot symptoms and it turned out that the symptoms were a result of something abiotic and the plant pathologist were not able to isolate any fungi from the samples.
Photo 11 – Possible Root Rot on White Pine
Photo 12 – Possible Cercaspora Leafspot on Black Gum
Over the past week in nurseries I’ve found the following: whiteflies generally present in most greenhouse or tropical house areas, aphids on mandevilla, lace bug damage on azaleas, powdery mildew on beebalm, thrips and black spot on ‘Apricot Drift’ roses, apple scab on ‘Golden Delicious’ apple and shot hole type leaf spots on english and cherry laurels.
