DNR - Entomology Weekly Review, May 1


Weekly Review for May 1, 2018

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.

Eric Biddinger (Nursery Inspector & Compliance Officer) - EBiddinger@dnr.IN.gov 

Having a background in plant nutrition sure came in handy this week. During a greenhouse inspection, the growers pointed out ivy geraniums that were showing a lot of burn on the new leaves and growing tips. Geraniums are the one thing this greenhouse excelled at, so it was curious. After searching some more, I noticed a similar burn to a much lesser extent on a couple cultivars of seed geraniums. I asked the grower if they changed anything this year and it turns out a friend of theirs suggested that they needed to add Epsom salts to their nutrient mix to help their tomatoes. So they added it to everything. Turns out that ivy geraniums are more susceptible to high electroconductivity (EC – a measure of soluble salts) than other geraniums. Epsom salt is magnesium sulfate, a soluble salt. In addition, magnesium toxicity in geraniums can reduce calcium uptake. The symptoms of calcium deficiency?  Necrosis of the newest leaf edges and buds…  However, I have to add that the tomatoes have never looked better!  So here’s the lesson. Plant production is all about “dialing in” the growing conditions. If you are going to try to improve production for one species, isolate those changes from everything that is growing well. That way you don’t help one crop and wipe out another!


I also have to comment on Ken’s Photo 8 and Jared’s Photo 17. I saw tons of trees, especially fruit trees, buried too deep today. Often times the graft will be at soil level, but the root flair is 2-6” below that. Trees are often “socked in” so they stand better without support in the nursery. While it’s never good for the tree, the end buyer can go a long way toward improving the survivability of the tree by getting the flair back up where it belongs. 

I’m also seeing heavy freeze damage on apricots, plums, and nectarines in nurseries. Often these trees came from Oklahoma or Tennessee nurseries. They were too far into bud break, brought to Indiana well before our last frost, and not given adequate protection. 

Vince Burkle (Nursery Inspector & Compliance Officer) - VBurkle@dnr.IN.gov

I’ve been inspecting dealers in Allen County over the past week. The main problem I saw was freeze injury on a lot of plants. Other findings include aphids feeding on the new growth of ‘Easy Elegance’ Rose, boxwood mite damage on ‘Winter Gem’ boxwood and botrytis blight on geranium.  I also found an issue with incorrect labeling where sweet bay magnolia was labeled as ‘Royal Star’ Magnolia.


Ken Cote (Nursery Inspector & Compliance Officer) - KCote@dnr.IN.gov

Trees are finally starting to break bud in my area. We still had frost on Sunday morning with scattered locations being below freezing. I have not seen any eastern tent caterpillar. However, I did see boxwood psyllid feeding on boxwoods on a south facing landscape bed. As boxwoods begin to grow, look for leaf cupping and a wax-like material on leaves.  I have not seen much boxwood leaf minor feeding injury. Many boxwoods have severe winter injury and I have some boxwoods on my property that do not appear to be recovering. Aphids were found on magic carpet Spirea. I found a small, white hard scale on arborvitae at a garden center. I believe they may be minute cypress scale (Carulaspis minima) or juniper scale (Carulaspis juniperi). Both of these scale species essentially look the same in the field, but minute cypress scale is said to be slightly smaller according to the literature. Minute cypress scale is also more likely to be found on arborvitae.


During last week’s report I complained about plants that suffered severe winter injury on my property.  However, there are some plants that have done surprisingly well.   Both of my dwarf dawn redwoods were not harmed and my Peve Minaret bald cypress seems to be budding out. Any plant with a small root system, suffered the most damage, but my Chamaecyapris obtusa ‘Nana Lutea’ suffered no winter injury this year despite being in an open area. Once established, this plants seems to be pretty hardy. Sun scald seems to be more of an issue than winter injury with this cultivar. I also have a Japanese snowbell that is doing quite well. No serious injury that I can see. 

I have not found many disease during the last week. Botrytis still continues to be a problem on geraniums and begonias. I am seeing cultural problems in many garden centers. Plants are coming in with loose root balls and in many cases plant are planted too deep in the pot. Garden centers are often overwhelmed with shipments at this time of year and space is limited in garden centers. Remember to keep plants spread out so disease problems do not develop as the weather becomes warmer. It is better to have fewer healthier plants than twice as many plants that are not sellable due to damage caused by spacing issues.


Ren Hall (Nursery Inspector & Compliance Officer) - RHall@dnr.IN.gov

I was out conducting nursery dealer inspections today in Boone County. The main issues I was seeing over and over were freeze/frost damage and drought stress.

At one dealer I saw significant frost injury on Weigela, Hydrangea, Althea, Magnolia, Ninebark, Holly, Willow, Amur Maple, and many other shrubs sitting out on the lot unprotected from the elements, resulting in damage and dieback to the tender new shoots, leaves, and buds. The ‘Endless Summer’ Hydrangeas were hit especially hard. This is a common issue we see at dealers in early spring and especially with this year’s unseasonably cold weather, inspectors have been seeing plenty of cold damage. To avoid damage to plants on cold nights, cover plants with a tarp or sheet, or move them inside (especially plants that are not winter hardy).

At all but one dealer that I inspected today, I also saw significant drought stress and injury. At one dealer in particular this was an issue, with a table of annuals and vegetables in flats and hanging baskets cooking in the afternoon sun on hot asphalt. 


Angela Rust (Nursery Inspector & Compliance Officer) - ARust@dnr.IN.gov


Jared Spokowsky (Nursery Inspetor & Compliance Officer)Jspokowsky@dnr.IN.gov

I don’t have a lot to report. I found some obscure scale on weeping cherry.


I also have some photos of Douglas fir with Diplodia blight. I hadn’t realized that Doug fir was a host for Diplodia and at first glance would have probably attributed the damage to freeze damage unless it hadn’t been pointed out to me.


I have also been seeing a lot of winter burn on southern Magnolias


The most interesting thing I continue to find is root and propagation problems. I have found a number of containers where I will see branches protruding from the soil (these are true branches not suckers). Usually upon further investigation I find that when the material has been stepped up it gets buried deeper than the original soil line. On occasion I have been able to find plants where this has been done multiple times and it has been buried several inches too deep. I’ve also found material that was being girdled by various objects including twine to tie up the ball and nursery tags. As well as having material being held to long in too small of a container.


This Arb was actually a B&B which I assume would have been noticed upon planting (but it serves to illustrate what I have been seeing).


This is a Japanese maple which was starting to be girdled by the tag.


This was a 3.5-4 inch caliper red maple in was I estimate to be a 20 gallon container.

No reports this week

Megan Abraham (Division Director & State Entomologist) - MAbraham@dnr.IN.gov

Eric Bitner (Nursery Inspector & Compliance Officer) - EBitner@dnr.IN.gov

Kallie Bontrager (Nursery Inspector & Compliance Officer) - KBontrager@dnr.IN.gov

Phil Marshall (State Forest Health Specialist) - PMarshall@dnr.IN.gov

Kathleen Prough (Chief Apiary Inspector) - KPrough@dnr.IN.gov

Kristy Stultz (Nursery Inspector & Compliance Officer) - KStultz@dnr.IN.gov