"I'm living proof that people can get over their fear of insects," says Colleen Cannon of Chanhasasen, Minn.
The Flushing, N.Y. native was in art school when she took a book out of the library that had nice illustrations — of insects. In addition to studying the pictures, she read the text. "I learned how interesting insects are." That summer, she took an entomology course that had her in the field collecting bugs. "It was so much fun."
That was it. She'd been 'bitten by a bug' — so to speak — to study the life sciences. Cannon went on to earn a bachelor's degree in biology from Queens College. Then she visited Virginia Tech, enjoyed the camaraderie in the entomology department, and became a graduate student.
Professor of entomology Rick Fell suggested Cannon study carpenter ants.
After doing her master’s degree research on the wintering behavior of carpenter ants, Cannon decided to bring the insects into a Virginia Tech lab to do her doctoral degree research on a more active phase ? the foraging behavior of carpenter ants. Her desire to maintain a colony of carpenter ants in the lab — almost 10 years ago — has resulted in an effective bait for control of carpenter ants.
"To maintain colonies in the lab, we had to develop a diet we could feed them," says Fell.
"We had something that was working well when a visiting industry person commented on the ants’ enthusiasm. I told him that we were working on developing a bait and they asked to become partners in the effort."
That was 1990.
"We were interested in doing this research because baits are safe," says Fell. "They use small amounts of toxins and get directly to the target insect. Baits are the growing insect-control technology, but to be effective, you have to understand the insect. It takes basic research on feed, foraging, and physiology."
Cannon looked at the roles of various compounds in the diet, such as proteins and sugar. "We found that proteins are important all year," says Fell.
For six more years, with funding from the industrial sponsor, Fell and a team of students studied other aspects of the lives and times of carpenter ants to determine their favorite food, how they eat, how they distribute food to the colony, and how an insecticide could be incorporated.
"To determine their preferences, we looked at all types of sugars, the impact of salts, and various fatty acids, to characterize the things that stimulate them to feed," says Fell.
"Then, to determine how big a particle an ant can eat, we fed them different sizes of florescent beads so we could see how small it had to be to pass through their digestive system. We found they can filter particles down to a micron, which is very small," explains Fell.
Carpenter ants do not eat the wood they carve up. "We learned that food has to be in liquid form or a form they can extract as liquid, such as a gel."
Another important facet in understanding the process is how food is distributed among nest members. Byron Dowell used low level radioactivity to trace food distribution in the nest. "His findings were an important piece to developing a feed product," says Fell. (Dowell drowned shortly after completing his research and was awarded his degree posthumously.)
The researchers began to incorporate an insecticide. "Our sponsor had one already approved for indoor use that was the correct particle size. We began to incorporate it at very low levels — parts per million — so the ants would have time to carry it back to the nest."
The researchers created a formula that doesn’t kill the ants for 10 to 12 hours. Fell emphasizes, "We didn’t work on the insecticide, but on attraction, dosage, and delivery."
By 1996, a bait was ready to test. The results made some local homeowners very happy. Household tests were done using people who had had problems with carpenter ants for years.
Blacksburg homeowner Peter Trower sings Fell’s praises. Trower described his home as "infested." "I’d be sitting here, eating, and an ant would fall out of the ceiling. I almost swallowed one. They’re big. You know when one is in your mouth.
"I drilled holes and poured stuff in them. It didn’t work," Trower says. "Finally, Rick came with these ampoules with guck in them. We put them outside on the ant trails and in the locust trees."
Fell explains that the ants may live in the trees and in the house, with the main nest often in a tree.
"The ants take the food home to the wife and kids and they expire," says Trower. "The first year, the ants that fell out of the ceiling were dead. The second year there were much fewer of them. This year, I’ve seen one. And it was dead."
The sponsor was convinced and applied for a patent for an environmentally safe bait to control carpenter ants. Patent No. 5,850,707 was issued to Fell and Cannon in December, less than a week after Cannon graduated. A product will be released initially to the pest control industry this year.
Learn more about carpenter ants at www.ext.vt.edu/departments/entomology/factsheets/carpants.html. Also, Dr. Fell might be able to visit your classroom. Rfell@vt.edu.