"Even though the bison reduced the amount of grass by 50% or more, the overall abundance and diversity of arthropod herbivores and carnivores increased significantly, especially among sap-feeders. In addition, Dr. Moran suggests that this may also be beneficial to birds and and other animals that eat insects."
|Goldenrod stem gall - REK|
|Stem gall with larva - REK|
|Larva closeup - REK|
The round goldenrod stem gall above contains the maggot larva of Eurosta solidaginis . These in turn can feed the predaceous beetle larva of Mordellistena (below). According to Bugguide, "Apparently smaller galls are parasitized more often than larger ones; but the largest ones are eaten more often by chickadees and wood peckers." Once again this illustrates the importance of goldenrod in the food web.
|Beetle larva is gall - Beatriz Moisset|
|Flower head or rosette gall - REK|
"In addition to the gall makers we should consider all the parasitoids, predators and inquilines. The total numbers must be quite substantial. In some cases more than fifty percent of galls are parasitized; furthermore, it seems that for each species of gall maker there are at least three or more different species of parasitoids, inquilines, etc." (Bugguide.net)"Inquiline" refers to an organism that lives commensally in the nest or structure of another organism, usually for the purpose of sharing food or resources. This could be a small spider on a larger spider's web or caterpillars living in ant nests while sharing their honeydew, in the common parlance, a type of "friends with benefits." Many inquiline species live in the structures produced by gall making insects.
A wide variety of moths feed on goldenrod, and wasps, spiders, birds and other predators use their larva. A patch of goldenrod can contain a whole microcosm of life. An incredible food web awaits the patient naturalist with curiosity and a hand lens or a good camera. We will look at some goldenrod inhabitants and their predators in a followup blog.
Many of the gall forming species and their predators are found on the Bugguide.net site.