December 26, 2020
We're reaching into the archives for today's #BenInNature update! The following post was originally published on May 3, 2020.
When I first saw these unusual splotches on a maple leaf, I assumed it was some kind of fungus (and I also had a weird urge to play darts). In fact, this is the work of an insect. The ocellate gall midge (Acericecis ocellaris), also known as the maple eyespot gall midge, is a tiny mosquito-like fly. It lays its eggs on the underside of red maple leaves, and ONLY red maple leaves -- no other tree will do. The midge larva creates a chemical reaction in the leaf that causes a strange "eyespot" to form around it. If you zoom in very closely, you can see a raised tip at the center of each eyespot; the midge larva resides right underneath that raised point.
Adult ocellate gall midges emerge from the soil in April and May to mate and lay their eggs. It takes just eight to ten days for the gall midge larva to drop from their maple leaves; once they hit the ground, they pupate in the soil until the following spring, at which point they emerge from the soil as adults and start the cycle over again.
If you find these eyespots on your maple tree, there's no cause for concern. They don't seem to affect the tree's overall health. Additionally, the gall that the midge larva creates protects it from pesticides, and even if the larva dies, the eyespot remains.
Social distancing can be difficult, but it presents a great opportunity to become reacquainted with nature. In this series of posts, Administrator of Science Ben Williams ventures outdoors to record a snapshot of the unique sights that can be found in the natural world. New updates are posted Monday - Friday, with previous posts highlighted on the weekends.
NEW: TRIVIA CHALLENGE
You've seen the posts. You've learned the facts. Now, it's time to prove you are a #BenInNature Mega Fan! The museum's education team has developed the #BenInNature Trivia Challenge to identify the most devoted fans out there! Everyone who successfully answers each trivia question correctly will be congratulated by having your own nature selfie posted to the museum's #BenInNature Mega Fan Photo Album on the official VMNH Facebook page! Learn more and download the trivia challenge today by visiting www.vmnh.net/research-collections/beninnature-trivia-challenge.
NATURE PHOTO IDENTIFICATIONS
If you discover something in nature that you would like help identifying, be sure to message us right here on Facebook with a picture (please include location and date of picture) and we'll have our experts help you identify it!