University of Kentucky Department of Entomology

Mystery Bug Answers

Mystery Picture #39

Mystery Picture #39

(Mystery Pictures)(Mystery Pictures)


Most everyone recognizes the adult stage of this insect, but did you guess this is a Monarch Butterfly Caterpillar? These larvae are found most frequently feeding on milkweed.

Chemicals in the milkweed plant accumulate in the caterpillars' bodies as they eat the leaves. These chemicals stay in the tissues of the insect for life, so they cause the adult butterflies to taste bad and thus help to protect them from becoming meals for birds. If a bird eats a Monarch butterfly, it will become so sick that it never wants to eat another one! The bright orange and black colors help the bird to identify this as one insect to leave alone!

In early fall, the adult Monarch butterflies can be seen flying overhead as they make their long journey to overwintering grounds in southwest North America. Scientists are interested in the travels of these butterflies and they could use your help! You can get involved in tagging monarchs and recording sightings through Monarch Watch.


locust borer damage
Image courtesy of Virginia Cooperative Extension
One of the common names for this family of insects ("long-horned beetles") is based upon their long antennae. The distinctive yellow and black markings on its hard first pair of wings help the Locust Borer to blend in when it is sitting on a yellow flower.

The larval stages develop in the wood of different types of trees. They are legless, white "worms" that chew long, relatively rounded tunnels in the wood. This particular insect develops in locust.

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