ARTIFICIAL FLOWERS
An insect scientist who fashions fake flowers?
Yes, it's true. But Peter J. Landolt's trick blossom isn't the product of a newfound hobby. It's part of a novel system that annihilates female cabbage looper moths without harming the environment.
The ARS entomologist fashioned a faux flower to resemble a blossom of the tropical night-blooming jessamine shrub, after discovering that female looper moths are attracted to the blossom's scent.
The 'petal' part of Landolt's flower is highly reflective white tape, which mimics the shrub's blossom as the sun begins to set (that's moth feeding time). And, instead of a stamen filled with nectar, Landolt's creation sports a glass capillary tube filled with sugar, synthetic copies of the flower's scents, and an insecticide called methomyl.
The scents were identified and reproduced in the laboratory by chemist Robert R. Heath, who works with Landolt at ARS' Insect Attractants, Behavior, and Basic Biology Research Laboratory in Gainesville, Florida.
Adult females searching for nectar pick up on the scent and follow it to the area. When they are close enough to see the fake blossom, they fly to it and insert their proboscis into the capillary tube, sucking up the deadly mixture.
"Methomyl is a highly toxic chemical," Landolt says. But the beauty of the system is that the poison stays in the tube and in the insect - and doesn't get sprayed into the environment.
In flight tunnel tests - in which adult insects must fly against a wind current to reach the scent and fake flower, the system offered 100 percent control. "Every moth was attracted, fed on our dispenser, and died," Landolt says.
Landolt conducted field tests this past summer and is tabulating results now.
"This promises to be a very effective way to annihilate adult females as they search for nectar," without releasing chemical pesticides into a crop field. By targeting adult females before they lay eggs, a next generation of loopers is thwarted.
Loopers devour cabbage, broccoli, cauliflower, celery, green leafy vegetables, peas, potatoes, tomatoes and other crops, to the tune of at least $100 million per year.
The research project began as a casual observation by Landolt when he lived in Miami several years ago. Like many Floridians, Landolt had two of the beautiful night-blooming jessamine shrubs in his yard, even though "they stink so bad they'll give you a headache."
But that's obviously not the effect the shrub has on several kinds of moths. "When the shrubs were blooming, they were always covered with moths feeding on the flowers. " he says. The moths turned out to be two relatives of the cabbage looper.
Heath and Landolt worked to identify which scents were responsible for attracting the moths to the flowers and then reproduced them. Next, they tested the moths' response to different types of sugar solutions and chose the best one. Then they tested many different formulations of the scents, the sugars, and methomyl to pick the best release rate. "We tested pesticide dosages, because we don't want the lure to have so much methomyl that it becomes a repellant. And yet we wanted the best mortality."
Landolt hopes to adapt the system for soybean loopers and perhaps other pests as well.
Peter Landolt and Robert Health are at the USDA ARS Insect Attractants, Behavior, and Basic Biology Research Laboratory, 1700 SW 23rd Drive, Gainesville, Fl. 32604. Phone (904) 374- 5756.
DATE: Month 19xx
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