University of Kentucky Department of Entomology

Mystery Bug Answers

Mystery Picture #62

Mystery Picture #62

R. Bessin, University of Kentucky
R. Bessin, University of Kentucky
(Mystery Pictures) (Mystery Pictures)


The larvae of Japanese Beetles, June Beetles, and several other kinds of common beetles are called grubs. Grubs are often white, very soft, and have a distinctive "C" shape to their bodies. They live underground where they feed on the roots of grasses and other plants, and are sometimes important pests. Some of the largest grubs are over two inches long.

There are also fishing lures called "grubs." They don't look very much like beetle grubs, though. And, if you have ever heard anyone refer to food as "grub", you shouldn't be surprised to know that some people eat beetle grubs. Yummy!


This beautiful insect is an Io Moth. With a wingspan of nearly 6 inches (!), it's just about the biggest moth found in Kentucky. Imperial Moth larvae have chewing mouthparts and feed on many different tree species. Like many moths, though, the adults don't feed at all. They don't even have working mouthparts.

Imperial moths are common in Kentucky forests. They are related to several other large, colorful moths called saturniid moths (from their family name, Saturniidae), also called "giant silkworm moths." These moths aren't very closely related to the silkworm moths of Asia, though.

Read more about Imperial Moths and other giant silkworm moths that live in Kentucky in EntFact 008 -- Saturniid Moths

Answer to Extra Credit Question:

The markings on the hind wings serve to scare off predators that might try to attack this moth. The moth opens its wings and suddenly, instead of a tasty moth, the predator sees what looks like a big scary face with two fierce eyes staring at it! Whoa! I'd back up too, wouldn't you?

Congratulations to all of you who knew the answer! Excellent work!

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