By Linda McCandless and Blaine P. Friedlander Jr.
More than 200 scientists affiliated with Cornell attended an information-packed Cornell Community Conference on Biological Control last week, spearheaded by Tony Shelton, professor of entomology.
"It was not your typical meeting where you have report after report," said Michael P. Hoffmann, Cornell assistant professor of entomology and a member of the conference committee. "This conference provided perspective."
Hoffmann said that, although the scientists came from a variety of disciplines and attitudes toward biological control, the prevailing spirit seemed to be one of listening to what colleagues had to say. "We focused on discussion, not our differences," he said.
Wendell L. Roelofs delivered the conference keynote address, a multimedia presentation of slides and video clips titled "Sex Pheromones in Biobased Methods of Insect Control." Using examples from tomatoes, grapes, apples, cotton and turf insect control, he addressed the question, "Are pheromones worthwhile?"
His answer: yes. Roelofs, the Liberty Hyde Bailey Professor of Insect Biochemistry at Cornell's Agricultural Experiment Station in Geneva, cited statistics that demonstrate that "commercial manipulation" of the chemical communication system that female insects use to attract mates is "indeed, a very effective tool for biocontrol." Acknowledging that a strictly traditional definition of biocontrol refers only to using beneficial insects to prey on insect pests, Roelofs showed that biocontrol has already been expanded in research labs and in the field to include pheromone-based behavior modification.
Pheromones are used by female insects to attract males. The chemicals are carried over great distances in "pheromone plumes" and picked up by extremely sensitive olfactory response systems in male antennae. In response, the male takes flight, using the pheromone plume to activate its upflight to the odor source. Mating ensues, which results in thousands of new larvae feeding on the host crop, Roelofs said.
The driving force and financial backing for much of the current research comes from the potential use of synthetic pheromone chemicals in pest control programs. Because a particular pheromone is so species specific, it can be used as bait in monitoring or eradication traps and in pheromone rings, ties, fibers and hollow tubes to disrupt mating and disperse beneficial predators, Roelofs said.
Roelofs demonstrated one of the newest tools in the insect behavior modification arsenal -- a device called a spritzer, developed by Dr. Tom Baker at Iowa State University. Adoption of this reusable timer, which spritzes pheromones onto an evaporation pad at 15-minute intervals -- but only during the few critical hours each night when males and females are mating -- could dramatically decrease the cost of pheromone mating disruption programs, he said.
Pheromones from over 1,000 species of insects have been identified. In commercial agriculture, turf and landscape studies, they are being used to monitor pest populations from 250 species. Commercially, they have been used successfully to disrupt the mating of more than 20 species. Disruption is particularly effective in control programs for pink bollworm, Oriental fruit moth, tomato pinworm, lightbrown apple moth, the codling moth, the peach twig borer and the European grape berry moth.
Other highlights of the conference included Ernest DelFosse, director of the National Biological Control Institute (NBCI), Riverdale, Md., explaining the national perspectives shaping the future of biological control. He went over the ethics and standards being considered in the field.