Roots, Shoots, Fruits & Flowers: Drought-stressed Trees, Leaf-footed Bugs & Male Velvet Wasps

Several homeowners shared concerns about dead and dying trees including pine, magnolia, and crape myrtle. At this writing, our area has a rain deficit of approximately thirteen inches, so drought stress is a contributor of the decline of trees in the landscape. The homeowner with the pine complained about bark beetles killing her tree. If a pine tree is stressed, it tends to become infested with insects because a pine tree, during a drought year, fails to flood the wound and drown the invader with resin.

AHA recommends using a soaker hose to water trees to protect them from drought stress. Soaker hoses are more efficient at irrigating tree because the there is less loss to evaporation. The optimal rate of irrigation is one inch per week. To measure the rate for a soaker hose, use a square container and place it under a section of the hose. Then measure the depth of the water in the container.

The roots of a trees can extend from two to three times beyond the dripline so coiling the soaker hose around a tree will enable thorough watering. Also, mornings are better for irrigating because of the lower evaporation rates.

This type of irrigation requires commitment and effort on the part of the homeowner so the decision to irrigate the tree must be measured against the excessive cost of removing a dead tree.

Olbelina sent s clear photos and this email message, “I am trying to keep an organic garden and i have these bugs in my tomatoes. can you please tell me what they are and how to treat them.”

You have leaf-footed bugs (LFB) in various stages. The orange LFB is a juvenile, and each stage causes damage to tomatoes like stinkbugs.

Here are organic treatments described by various online sources:

• Try to eliminate weedy areas near your garden or keep weedy areas closely mowed.

• The HOD method (“Hand of Death”) is a time-honored approach. They can be removed by hand or with a butterfly net from small plantings in gardens. Or you can handpick the bugs, especially early in the season when the young nymphs are tightly clustered together, especially in the morning. Wear gloves because of the odor they will emit when handled and drop them into a can of soapy water. This is a tedious approach and only provides temporary relief unless you keep at it!

• Also, a DeWalt™ portable shop vac has been helpful in gathering LFBs and stinkbugs.

• Another approach is to plant something that is more attractive to leaf footed bugs than tomatoes – trap crops! Auburn University extension scientists have been investigated this method: A trap crop planted two to three weeks ahead of the main crop worked best in the studies. They have planted grain-type sorghum (specifically, sorghum variety NK300) and sunflowers (specifically, Peredovik-type sunflowers).

• One mechanical insecticide that has shown satisfactory results is made from a finely milled white, edible clay known as kaolin. This organic product coats plants and fruits in a white film, deterring pests. The film is washed off before eating. It is sold under the brand name Surround WP™, though usually must be ordered online or by mail since few local garden centers carry it.

• Pyethrum-rotenone mixes may provide quick “knockdown” but need to be re-applied weekly. This approach works best in killing the nymphs and repelling the adults.

• Insecticidal soap and neem oil sprays have been effective on nymphs as well.

• Later, try to manage overwintering populations of adults that can be found down in the organic mulch. Soapy water can drive adults out of the mulch on a warm winter day and they perish when it gets cold again or you can slay them as they come out.

Mike LaVergne, our 4-H agent in Beauregard Parish, saw this black waspy insect with an orange band on the abdomen. He observed these insects flying over the freshly cut yard at our AgCenter office.

Victoria Bayless, Curator of the LA State Arthropod Museum, responded promptly with an identification of this insect, “That is the male (winged) of a velvet ant… wasp…It is not[emphasis added] the male of the red velvet ant (cow-killer one)… I think you would have to find the female (wingless) to figure out which species. If there are a bunch out, then there must be females in the grass.” The male wasps are unable to sting, and their only task is to mate with female wingless wasps so these males are harmless to people and pets.

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 or .

“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.”


Figure 1. Plastic shelter in forest


Figure 2. Leaf footed bugs Olbelina Letko


Figure 3. Male velvet ant

6/9/2022 4:00:20 PM
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