University of Kentucky Department of Entomology

Mystery Bug Answers

 
Mystery Picture #50

Mystery Picture #50

Tom Barnes,
University of Kentucky
Forestry
Tom Barnes,
University of Kentucky
Forestry
(Mystery Pictures)(Mystery Pictures)
NoviceExpert

Novice

This picture is a close-up of part of an insect.

  • What part of the insect are we are looking at?

    Answer: This is a close-up of the scales on a butterfly's wing. They function in a similar way to the feathers on a bird's wing. Without them, the butterfly would not be able to fly.

  • What kind of insect would have a part like this?

    Answer: a butterfly or a moth


Expert

The Viceroy Butterfly is a mimic. It closely resembles another very common insect, the Monarch Butterfly, that predators find distasteful.

How can you tell the difference? Look at the hind wings of each of the two butterflies pictured below. The Viceroy on the left has a black line that crosses from one side of the wing to the other, whereas the Monarch on the right does not have this line. Although it is hard to see in these particular photos, the Viceroy has only one row of white dots completely within the boundaries of the black wing edges and the Monarch has two rows. Also, the Viceroy's wings are the same shade of orange on both the top and bottom sides of the wing, whereas the Monarch's wings are much lighter orange on the underside.

Viceroy butterfly
P. Lucas,
University of Kentucky Entomology
Monarch butterfly
Corel PhotoCD, used with permission

Extra credit:

1. What is the name of the insect that this one mimics?

Monarch butterfly

2. What advantage does this insect have in looking like another one?

By looking like a monarch butterfly (which tastes terrible to predators and makes them sick!), the viceroy (which is a tasty prey) is avoided by predators who have had a bad experience with monarchs in the past.

By the way, the Monarch butterfly acquires its bad taste as a caterpillar when it feeds on the milkweed plant that is its favorite food. The milky sap of the milkweed contains chemicals called cardiac glycosides that make vertebrate predators such as birds very sick. A young bird may try to eat a monarch butterfly once, but after being sick, it will not touch anything that looks like it ever again. Thus, the viceroy butterfly, which is perfectly good food for a bird, is protected by looking like the monarch.


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This page is maintained by Pat Dillon, Department of Entomology, University of Kentucky. Please send questions or suggestions to: pdillon@uky.edu