Surprise: it's in the antennae!
Neurobiologists at the University of Massachusetts Medical School have long wondered how monarch butterflies (Danaus plexippus) can migrate from across eastern North America to a specific grove of fir trees in Mexico.
That's 2000 miles, as a crow flies--or as a monarch flies.
The scientists figured that the key mechanism that steers the monarchs is in the brain.
Nope. It's in the antennae. The antennae aren't just "noses" or "odor detectors."
"We've known that the insect antenna is a remarkable organ, responsible for sensing not only olfactory cues but wind directions and even sound vibration." said Steven Reppert, professor and chair of neurobiology and senior author of the study, published today (Sept. 25) in the journal Science.
"But its role in precise orientation over the course of butterfly migration is an intriguing new discovery, one that may spark a new line of investigation into neural connections between the antennae and the sun compass, and navigation mechanisms in other insects," he said in press release.
For those of us who are navigationally challenged and have long admired how insects migrate from Point A to Point B, this is amazing. There are circadian clocks in the antennae.
This study makes us look at monarch butterflies in an entirely different light.Like the monarchs we spotted nectaring last weekend on the grounds of the Luther Burbank Home and Gardens, Santa Rosa.
Their antennal circadian clocks coordinate sun-compass orientation.
Or, in other words, those antennae are necessary for sun-related orientation.
Attached Images:
Monarch Butterfly
It's in the Antennae