Western Farm Press
Unlike the Beach Boys musical group of old, Rodrigo Krugner is picking up bad vibrations.
It’s the sounds that glassy-winged sharpshooters make as they seek to find and mate with each other. That’s the focus of research by Krugner, research entomologist with the U.S. Department of Agriculture’s Agricultural Research Service in Parlier, Calif.
Krugner discussed “Mating disruption of the Glassy-Winged Sharpshooter: How does that sound?” at this year’s Grape Day event at California State University, Fresno (Fresno State). The insect can spread the deadly Pierce’s disease in grapevines faster than its smaller sharpshooter cousins, and Pierce’s costs California more than $100 million per year.
Krugner explained how the insects communicate with each other through seismic vibrational signals produced by their abdominal muscles. He is studying the degree at which “courtship signals” sent in call-response fashion can be disrupted.
Right now, the means for combatting the pest include insecticide applications in citrus orchards where they congregate, and releasing egg parasitoids.
Krugner explained that a laser Doppler vibrometer, a technology used in the aerospace industry to listen for vibrations, figured into his research. Both white noise and female calls reduced mating under laboratory conditions, but did not affect insect aggregation.
The efficacy of these and other signals in disrupting GWSS communication is being evaluated under field conditions in collaboration with Fresno State.
Electrodynamic shakers were attached to plant stems to generate disruptive and-or masking signals. The idea is to learn if the playback of selected GWSS signals onto grapevines will determine whether mating behavior is affected by disruptive signals and whether GWSS individuals can be either attracted or repelled by signals.
Krugner said males sometimes naturally mimic females to lure rivals away, and noted the process of mates locating each other often takes up to three hours.