Thursday, September 24, 2009

Goldenrod Season

Autumn officially started this past week, but chilly nights and the turning of the leaves began weeks ago, and the goldenrod has been in full force. Some of it is starting to go to seed already, but from my seat at the computer I can still see bright spots of the yellow flowers out back.

Above is a shot of some of the goldenrod, genus Solidago, that grows at the edge of our rear lawn. I don't know what type of goldenrod it is. There are perhaps a hundred varieties of goldenrod, and I hear that they are difficult to tell apart. All goldenrod is native to North America.

Goldenrod is incorrectly blamed for causing allergies. The real culprit for pollen allergies is ragweed. Goldenrod blooms in vast sweeps of big showy yellow flowers, while ragweed flowers are so uninteresting that they are invisible by comparison. Ragweed is wind-pollinated, but you would have to stick your nose in a clump of goldenrod in order to inhale the heavy pollen.

Below are photos of goldenrod pollinators that Chris took at Idylbrook Field on the same chilly August morning when we got photos of the monarch caterpillars.

The cold weather has slowed down the insects, making them much easier to photograph. Here is some sort of a bee, and a mosquito.

The poor bees were waiting for the sun to warm them up that day. Fortunately for them, we have had several hot days since.

I did a Google search on "goldenrod bug" to identify this beauty, and taa-daa! It came right to the top. This is Megacyllene robiniae, otherwise known as a locust borer. In their pupa form, they eat their way into black locust trees, causing considerable damage to the tree. But, like the black locust, these insects are North American natives.

In their adult form, the locust borer uses goldenrod as its food source. They are easy to spot as well as being fairly common, but at a glance, they do look like big scary wasps. I'm sure that's exactly what the yellow-and-black coloration is for.