Luna moths, like all moths, get their energy from eating plants. However, they only eat during their larval stage (as caterpillars).

Here's how it works:

1. Caterpillar Stage: Luna moth caterpillars feed on the leaves of various trees, primarily walnut, hickory, sweet gum, and persimmon. They eat voraciously, storing energy in the form of fat reserves.

2. Pupa Stage: The caterpillar spins a cocoon and transforms into a pupa, a resting stage where it doesn't eat. The stored energy from the caterpillar stage is used for metamorphosis.

3. Adult Stage: When the adult moth emerges from the cocoon, it has no mouthparts for feeding. Its primary focus is on mating and laying eggs. The energy stored as a caterpillar sustains the moth for its short lifespan, which is only about a week.

Therefore, Luna moths are not able to obtain energy from food as adults. They rely entirely on the energy reserves built up during their caterpillar stage.