RON HEU, HAWAII DEPT. OF AGRICULTURE
Stinging nettle caterpillars have bristly spines that cause a burning sensation when touched. The sting usually lasts for about an hour. CLICK FOR LARGE
Stinging caterpillars strike at nursery
Stinging nettle caterpillars were found in a Central Oahu nursery, where workers reported getting stung June 1, state agriculture officials say.
Neil Rheimer, an official for the Hawaii Department of Agriculture, said, "Nobody knows for sure, but I suspect it came from plant material from the Big Island."
The workers complained of getting stung from the areca palms that they moved from one site to another. The nursery owner reported it to the University of Hawaii College of Tropical Agriculture and Human Resources, extension agents and the state Department of Agriculture.
The owner was instructed to immediately return the plants to the original site and treat both sites with insecticides.
"The infestation is primarily one spot of the nursery. We've got the HDOA out there working," said Rheimer. He said the Agriculture Department is taking surveys and tests and is making sure that the infestation is under control.
To keep the caterpillars, cocoons and adult moths from spreading, agriculture officials and nursery staff installed Theromon bait stations. The trap is a sticky substance equipped with Theromon, a chemical that the female caterpillars produce and attracts the male moths.
Since the discovery of the caterpillars on the Big Island in 2001, the Agriculture Department is trying to obtain approval from federal and state regulatory officials to release an insect from Taiwan that is a predator of the caterpillars, which also are native to Taiwan. The process will take about six months.
Until then, agriculture officials recommend that people use available chemical insecticides designated for caterpillars. If nontoxic pesticides are preferred, people are recommended to use pesticides with Bt (Bacillus thuringiensis), which is nontoxic to humans, animals and the environment. But according to the Department of Agriculture, Bt is proven to be effective against larvae of various adult moths.
The stinging caterpillars (Darna pallivitta) are white-colored with black stripes and grow to about an inch long. They have bristly spines that cause a burning sensation when touched. The sting usually lasts for about an hour and can be treated by immediately washing the stung area with soap and water, applying ice and consulting a physician. The caterpillars may also cause allergic reactions to those who are sensitive to the venom, in which case seeking immediate medical attention is recommended.
The Agriculture Department asks all Oahu residents and nurseries to report suspected infestations and sightings of the caterpillar to the State's Pest Hotline at 643-PEST (7378).