Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Photo#51146
Morning calm - Hemaris diffinis

Morning calm - Hemaris diffinis
Fairfield, Wayne County, Illinois, USA
May 4, 2006
At rest in the morning before it warmed up. When I approached to close it started vibrating its wings but didn't take off. Warm-up exercises? Threat response? Nerves? Who knows?

Warming Up
Lepidoptera need to have their wing muscles to a certain minimum temperature before they're strong enough to fly. That's the main reason you see butterflies sunning with their wings spread in the morning.

The main other way of heating up the wing muscles is to vibrate them, but it takes more energy- so they usually do it only if they can't wait.

 
Emergency
takeoff procedure . . . and I was just trying to be friendly.