Sexual Teasing Could Lead Insects to Fatal Attraction

By Rosalie Marion Bliss
February 25, 2003

Even in a tiny bug’s life, the force of cravings such as physical appetite or reproductive drive can lead to serious consequences. At the Agricultural Research Service, entomologist Joseph C. Dickens studies how stimuli, such as plant odors and pheromones, attract insects. He is interested in developing optimal attractants that will coax pests into congregating. When that happens, the possibility of catching or killing them increases.

Dickens now has access to a custom-developed “locomotion compensator” to help him discern more about various insects’ internal desires. Also known as a “servosphere,” the device was developed by SYNTECH, a Hilversum, Netherlands-based manufacturer of custom scientific equipment, following discussions between Dickens and Jan van der Pers, president of SYNTECH. Dickens works at the ARS Chemicals Affecting Insect Behavior Laboratory in Beltsville, Md.

The new equipment looks like an incandescent globe the size of a basketball. Various scents are funneled, using a specially designed attachment, and then blown over the globe in a steady stream. Dickens places a bug on the globe near the path of an odor stream and then teases it with various test stimuli to gauge what interests it.

A test insect’s movements are then tracked by specially developed software and fed into a computer. The computer activates two motors that turn the sphere to compensate for movements by the insect--in effect, keeping the bug in place as it tries to reach its object of desire. Basic behaviors, such as how long the insect will walk toward a given scent, demonstrate the strength of its reaction to the stimulus.

The experiments are aimed at developing optimal attractants that combine chemical and visual signals.

Read more on this in the February issue of Agricultural Research magazine.

ARS is the chief scientific research agency of the U.S. Department of Agriculture.