The Value of Nutrition and Exercise, According to a Moth

Friday, February 24, 2017
The lead author of the study, Eran Levin, gets up close and personal with a moth (Manduca rustica) during nocturnal field work in the Catalina Mountains near Tucson, Arizona. (Photo by Eran Levin)

Quick! Name the top-performing athletes in the animal kingdom. Cheetah? Try again. Blue whale? Nope.

Here's a clue: If you take a walk in the desert on a moonlit night, you might see them, darting from flower to flower and hovering in midair: moths of the hawkmoth family (Sphingidae). 

Nectar-feeding moths, pollinating bats and hummingbirds are masters in sustaining the most intense exercise of all animals. To extract nectar from a flower, they must hover in front of the flower before darting off to the next one. But how can these organisms perform such feats on a diet that's mostly sugar?

New research by University of Arizona biologists not only offers an explanation, but also suggests that these animals stay healthy not despite, but because of, their sugary diet. 

Oxygen, while necessary for life to exist, is a double-edged sword. The more we engage in intense aerobic exercise, such as hovering, the more oxygen reveals its ugly side in the form of reactive oxygen species — small reactive molecules that wreak havoc on cells. 

Researchers in the lab of Goggy Davidowitz in the Department of Entomology in the UA's College of Agriculture and Life Sciences discovered that hawkmoths (also known as Manduca moths) have evolved a strategy that helps them minimize the muscle damage inflicted by the oxidative stress generated during sustained flight. The results are published in the journal Science. 

'Like Drinking 80 Cans of Soda'

"If you wanted to consume the equivalent amount of sugar that a moth takes up in one meal, you'd have to drink 80 cans of soda," says Eran Levin, who led the research as a postdoctoral fellow in Davidowitz's group. "It's amazing that an animal can process such an amount of sugar in such a short time."

Nectar-feeding moths and hummingbirds don't take up any antioxidants with their diet, which begs the question of how they deal with the oxidative damage their muscles are suffering during the moths' nightly foraging flights. 

Read the rest of this February 22, 2017 UA News story here.

Contacts
Goggy Davidowitz
Associate Professor, Entomology, Assistant Research Scientist, Ecology and Evolutionary Biology