March is a great month for viewing waterfowl, and while traipsing the backwaters of Metzger Marsh in northwest Ohio and Killbuck Wildlife Area in nearby Holmes County, we have seen this same style of gall on many different willow species along the waters' edge. Since wetlands and willows go hand in hand, these interesting insect galls which infect many forms or willow are quite visible on the dormant trees at this time of year.
This Pine-cone willow gall is created by a little insect called a midge, Rhabdophaga strobiloides. An itty-bitty fly-like guy, or more specifically- gals lay an egg in the leaf buds of the willow in early spring. The insect larva releases a chemical which ultimately causes these cone-shaped growths. The adult insect, having spent winter transforming inside the gall, will be emerging very soon; probably as a primary food for some Eastern Phoebe or Willow Flycatcher!
There are many unique insects that utilize our native plants, and they all contribute to the food chain in one manner or another. Try watching for the micro-fauna on the flora to see where it all begins.
Photo from UBC Botanical garden.