The test was repeated in small temperature increments, showing how warm a moth thorax must be for maximum flight power about 90 degrees Fahrenheit and that those in the study took off too cool at about 82 degrees Fahrenheit.
Crespo says moths "are well-known for 'scramble competition.' When the female is advertising the pheromone in a field, that pheromone is probably going to be detected by several males, and they're going to try to compete and get to the female first. You can see how it might be advantageous to take off sooner and try to get to the female first."
"However," he adds, "if you take off with a lower temperature, we show you have less maximum power in flight, so we think there is a compromise between heating up faster to a lower temperature to arrive at that female first, or waiting a little longer to heat up to a higher temperature and make sure you're going to make it to the female."
"This is about a decision to get up and go: 'This is the right smell. Let's do it,'" Vickers says. "There are neurons that detect the odor, and they feed that information into the brain, and the brain says, 'This is the right odor, this is a female,' and then processes occur that we don't know much about. But the brain sends instructions to the flight muscles to start warming up. The animal responds to this odor by warming itself at a faster rate than if it's exposed to a non-female odor. At some level, we've moved a little step closer to understanding that black box that's evaluating these inputs and internal conditions and deciding to move."
Vickers adds: "Insect flight muscles are among the most metabolically costly in the animal kingdom. In order to fly, you have to use a lot of oxygen and generate the power. The decision to take flight after a female odor is not one that would be taken lightly by the moth because it's expensiv
|Contact: Lee Siegel|
University of Utah