Roots, Shoots, Fruits & Flowers: Carpenterworm, Stinkhorn Fungus, Black Willow, and Defoliated Blueberries

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A young oak tree with a carpenter worm infestation. Image: Eric Veuleman, homeowner.

Carpenterworm

Eric sent an email with images of serious wounds in some trees, “I was hoping that you could maybe help me with identifying what is going on with some oak trees in our yard and hopefully getting them back healthy. We have four small (15' tall maybe?) Nuttall oak trees in our back yard that were planted from containers about 2 years ago. I noticed on two of them this past winter that they had some places that looked like sores on the trunks and loose/flaking bark around those places. There are also some small (maybe 3/16") holes in places on the trunks that I have recently noticed. This morning, I saw some bugs on one of them for the first time and am wondering if maybe that is what might be going on with them (pictures attached). All the trees are putting on leaves this spring and appear healthy from a distance. Any help that you could provide would be greatly appreciated." AHA consulted with Wood Johnson, US Forest Service Entomologist, who identified this pest as a carpenterworm. Johnson adds, “The wallowed out, old feeding scars are a signature, as well as the extruding pupal cases on the left and right sides of the tree in [these] pictures. I also think you can see the straw-like frass on the right side of one of the feeding scars.

As far as I know, the attacks are likely associated with [poor] host vigor [due to] offsite/poor soil conditions [or poor] fertilization… Or just drought/flooding [conditions.]” Wood thought an insecticidal soil drench may help control this pest, but he was uncertain if it would be effective.

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A sample of stinkhorn fungus. Image: Lisa Johnson, LSU AgCenter

Stinkhorn Fungus

Lisa found this fungus in her landscape and placed it on a garden sculpture to take a picture of this peach-colored fungus. Lisa had a stinkhorn fungi (SHF), a native fungus which decomposes organic materials. A search about the toxicity of the SHF is unclear. Some online sources say there is toxicity, and others say there is NO toxicity. With this lack of a clear answer about SHF safety , the best path is to treat SHF with fungicides to avoid contact.

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Black willow, a native wetland tree. Image: Niki Wisby, Master Gardener.

Black Willow

Niki sent an email and images for identification, “Hello! Hope you are well. I was wondering if you might be able to help my identity this willow. I am hoping it is native. Thanks for your help!” Niki is correct that this tree is a willow. Specifically, it is a black willow, a native tree. The website of the Lady Bird Johnson Wildflower center described the benefits for wildlife that black willow provides, “The bark, tender twigs and buds are food for browsers such as deer, rabbits, and beaver. Early season harvest for songbirds, waterfowl, and small mammals.” The flowers provide nectar for honeybees, and this tree is a host plant for “the larvae of several butterflies including the Eastern Tiger Swallowtail (Papilio glaucus), Mourning cloak (Nymphalis antiopa), Red spotted purple (Limenitis arthemis astyanax), and the Eastern comma (Polygonia comma).”[Source: NC State Extension website]

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An adult June beetle. Image: LSU AgCenter.

Defoliated Blueberries

Billy contacted the AgCenter because something has eaten all the leaves off his 6 blueberry bushes. He has inspected the bushes and cannot find anything. AHA suspected June bugs as the suspects defoliating Billy’s blueberry plants. The emergence of these insects seems to be lasting longer than in past years. Perhaps, they are compensating for the 2023 drought during which there were very little complaints about these insects. Dr. Mary Helen Ferguson, An AgCenter horticulture agent, discusses treatments for June beetles, “Active ingredients with efficacy against scarab[ or June] beetles include the pyrethroids (active ingredients ending in "-thrin," plus esfenvalerate), imidacloprid, carbaryl, and malathion. To minimize the threat to bees, avoid spraying plants (including weeds around the plants you are targeting) while they are flowering, and spray at times when bees are not active, such as in the late afternoon or evening. Before using an insecticide, be sure to make sure that it is labeled for use on the plant(s) on which you plan to use it and read and follow label instructions.”

If you want to contact Roots, Shoots, Fruits, and Flowers, please send your questions and pictures to Keith Hawkins, Area Horticulture Agent (AHA), 337.284.5188 or khawkins@agcenter.lsu.edu .

“Before you buy or use an insecticide product, first read the label, and strictly follow label recommendations. Mention of trade names or commercial products in this article is for informational purposes only and does not constitute endorsement by Louisiana State University AgCenter.”

“This work has been supported, in part, by the USDA National Institute of Food and Agriculture, Renewable Resources Extension Act Award, Accession Number 1011417.”

5/17/2024 1:32:29 PM
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