Writer: Steve Byrns, 325-653-4576, s-byrns@tamu.edu
SAN ANTONIO – They’re “baack!” And after a two-year hiatus, red katydids have returned by the millions to torment Central Texans with their incessant racket and voracious appetite for oak leaves and other desirable plants.
“This is the worst outbreak I’ve ever seen,” said Molly Keck, Texas AgriLife Extension Service integrated pest management specialist for Bexar County. “Our office is being inundated with calls from folks wanting to know if the insects will kill their trees, what can be done to stop them and how long this will last.”
Keck said red katydids, Paracyrtophyllus robustus or Central Texas leaf katydid, can damage landscape and pasture plants through defoliation when numbers are as high as they are now, though the damage they inflict is usually not long-term. Most of the time the katydids are green, but during outbreak years, the red form is predominant.
“They are a tree-dwelling insect that prefer oaks,” Keck said. “They have been described by some as looking similar to grasshoppers except thinner and having long antennae. The katydids sing by rubbing their forewings together. During population explosions like the one we are having now, the pleasant outdoor sound of a few turns into a loud, raspy, pulsating whine that continues day and night.”
“The sheer numbers we are seeing now can decimate oak-tree canopies over many acres,” she said.
“They tend to swarm over everything and eventually die by the thousands, making them a real nuisance, but not a human health threat,” she said. “However, given their numbers, large die-offs can be expected, either through the natural course of events or from pesticides, so cleaning them up and bagging the dead ones is important to keep down flies and odors caused by decomposition.”
Keck said red katydids are tough insects to control on a large scale and that their control depends on where they are found – home landscape, forested area or pastures.
If control is decided upon, Keck said, persons should read and follow the manufactures’ label directions. Insecticides containing acetamiprid, carabryl, indoxacarb, malathion and spinosad are labeled for use on the pest and should provide some level of control.
Older trees will recover from defoliation caused by these voracious pests, she said, so the best strategy may be to protect young trees, less than three years old.
Keck said counties reporting red katydid troubles thus far are Bexar, Bandera, Burnet, Comal, Hays, Kerr, Lee, Medina, Real, Travis and Williamson.
How long will this onslaught last? To some degree, all summer, Keck said, though probably not to the extent being seen now.
“At some point like most everything else in life, there will be some abatement when such things as natural predators, the current insect populations’ age and weather conditions kick in,” Keck said. “What we’re seeing is nothing new. If you’ve lived in this region for very long, you’ve probably seen similar episodes, the one in 2010 and the one in 2007 come to mind. It’s part of living in a generally lush environment with relatively mild winters. And as they say, ‘this too shall pass.’”
Property owners can get more information about the insect and actually report outbreaks at http://www.texasento.net/robustus.htm .
See http://bugguide.net/node/view/93515 for additional images.
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