A predatory stinkbug, a beneficial insect. Photo: Bruce Lehto
Bruce sent an image of an insect for identification, and it is a juvenile form of a predatory stinkbug. This is a beneficial insect because it is a predator of caterpillars and beetle grubs. Adults have pointy “shoulders” and tend to be brown. This insect has a “beak” to stab its prey, so this is a good insect to keep around.
Two larvae of the grape flea beetle. Photo: Jimmy Earl Cooley, Master Gardener.
Mary in Olla Has a little black worm eating leaves off her tame muscadine vines. Dr. Mary Helen Ferguson, an Area Horticulture Agent in the Florida Parishes helped with identification, “It looks like it’s the larva of the grape flea beetle.”
Dr. Ferguson recommends these insecticides, “Insecticides with carbaryl (Sevin™, Malathion™, or one of the pyrethroids (‘-thrin’ active ingredients, or esfenvalerate) should have good efficacy. It looks like the new liquid Sevin™ with zeta-cypermethrin is labeled for grapes, as is this insecticide/fungicide combo product with both carbaryl and malathion.”
Liriope, in red circles, infesting a bed of mondo grass. Photo: Dave Curry, Alexandria, LA.
Dave from Alexandria sent an email concern, “I noticed the other day in front yard bed and back yard beds of mondo that they have been invaded by a liriope. I know some liriopes are quite invasive and I must have some which send runners out underground and each plant that pops up does the same. I am trying my best to dig them up, sometimes successful with some roots and runners and other times just getting the stalks.
Is there anything I can do other than keep digging to remove or prevent this in future?”
Unfortunately, there are no selective herbicides for treating liriope in the mondo grass so digging is best solution to managing the liriope.
A dense mat of Virginia buttonweed. Photo: Susan Ham, Father's Hope Nursery, DeRidder, LA
Susan, a landscape professional in DeRidder, asked for information, “This is in someone's lawn. How do they treat it?”
The weed in Susan’s image is Virginia buttonweed (VBW), and it spreads by seeds, stems, and roots so it is difficult to control.
Will Afton, an Area Horticulture Agent, addresses the control with these notes, “Severe infestations may require the use of an herbicide to control and suppress Virginia buttonweed. Preemergent herbicides are gaining in popularity, but they have little to no effect on Virginia buttonweed and therefore, are not recommended.
Virginia buttonweed is tolerant of most selective herbicides used for weed control in the home lawn, especially later in the season when plants have matured and hardened off. Spray programs should begin early in the season as the plants emerge from winter dormancy.
Four-way herbicides (2,4-D + dicamba + mecoprop + carfentrazone) can be used during the months of April, May and June before the average hot temperature exceeds 85°F. Some common trade names include Speed Zone Southern™ and Weed Free Zone™.
If applications are needed later in the season, use the active ingredient metsulfuron. It can be found in MSM Turf™. One of the most effective herbicides to control Virginia buttonweed is Celsius™ (iodosulfuron + thiencarbazone + dicamba). Both herbicides can be applied when temperatures exceed 85°F.”
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 firstname.lastname@example.org or email@example.com .
“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.”