Register for an account


Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.


Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Planet Earth

Primordial Pest


Sign up for our email newsletter for the latest science news

Bugs have been eating plants for over 300 million years. But insects that actually live within the plants they prey on are generally assumed to have emerged about 120 million years ago. Now paleobiologist Conrad Labandeira at the National Museum of Natural History in Washington, D.C., has found signs of an insect larva that apparently resided within tree-fern fronds in the swamp forests of Illinois some 300 million years ago. Modern insects like the sawfly deposit their eggs inside a plant’s leaf or stem so that the larvae will have plant cells to feed on when they hatch. Since the plant responds to injury by surrounding the wound with protective cells that also happen to be highly nutritious, the larvae trick their host into providing them with a choice meal. Labandeira recognized the hallmarks of a similar strategy while studying slices of the 300- million-year-old fossilized fronds. Some of the ferns bore scars left by grubs of some kind that had tunneled through the fronds. The grubs chewed their way out before the ferns fossilized, but they left behind feces (dark dots in photo), which, Labandeira found, contained resin-filled cells identical to surrounding plant cells. Says Labandeira, This is a unique window into the behavior of a very early insect.

3 Free Articles Left

Want it all? Get unlimited access when you subscribe.


Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%


Already a subscriber? Register or Log In