It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
This image was acquired from
Keywords from Image Description:
Monarch butterfly caterpillar insect danaus plexippus. en br Image title Monarch butterfly caterpillar insect danaus plexippus Image from Public domain images website publicdomainimage html publicdomainimage Singer Ron Fish and Wildlife Service Not given Transferred by on This file is in public domain not copyrighted no rights
Page 2017 Free-images.com. All images are Public Domain