Page Banner

United States Department of Agriculture

Agricultural Research Service

Related Topics

Sci4Kids banner graphic
Title graphic that reads "Trapping Weevisl and Saving Monarchs"
Colored divider bar

Animation of Monarch butterfly landing on flower
Ever see a monarch butterfly?

They have bright orange and black wings, and every year they fly from Canada to Mexico and then back again. Each individual butterfly doesn’t make the trip, but females lay eggs along the way and their offspring continue on.

What a trip!

Some people think monarch butterflies are in danger because they eat milkweed plants, and milkweed plants are getting harder to find. The problem is that an insect called the milkweed stem weevil also likes to eat milkweed plants, and it eats a lot of them.

But an Agricultural Research Service (ARS) scientist made a discovery that could help save milkweed plants and monarchs.

The scientist, Charles Suh, was working on a new boll weevil trap when he made his discovery. Boll weevils are a problem for farmers because they attack cotton plants, so farmers in Texas asked Suh to find out why their boll weevil traps weren’t working. Suh asked the trap manufacturer to make a trap with the exact mix of natural compounds that boll weevils use to sniff out each other. Suh placed the new traps in cotton fields and found that they didn’t catch any more boll weevils, but they did catch a lot of the milkweed stem weevils that eat milkweed plants.

With a little more work, the discovery could lead to traps that control milkweed stem weevils. That would mean enough milkweed plants for monarch butterflies to keep making those long distance trips.

ByDennis O'Brien, Agricultural Research Service, Information Staff

Last Modified: 8/12/2016
Footer Content Back to Top of Page