Goldenrod Insects

It’s the time of year when fields begin to turn yellow with Goldenrod blossoms. I love to check out the Goldenrods to see what types of creatures have been attracted to this magnificent plant. Goldenrods have been described as being an ecosystem unto themselves because of the diversity of animal life that meets and interacts on these plants.

It’s primarily the old crop fields that support the large stands of Goldenrod at Blue Jay Barrens. Each year the stands are slightly smaller as the native prairie plants crowd in to claim the field as their own. Goldenrod produces a chemical deterrent that makes it difficult for many plants to infiltrate the Goldenrod stands. Many of the native prairie plants are not deterred and actually seem to thrive growing among the Goldenrods. Indian Grass is probably the most aggressive and can eradicate large Goldenrod stands in a matter of five to ten years. There may come a time when I’ll have to take action to save a few remaining Goldenrod blocks.

Goldenrod produces both pollen and nectar that attracts a wide variety of insects. Ctenucha virginica is a common Goldenrod visitor. Its larval food plants are grasses and sedges, but Goldenrod nectar seems to be a favorite of the adults.

Many of these small white moths took flight as I waded through the Goldenrods. At rest they resembled bird droppings.

Of course, there are several species of small bees present. All were filling up on nectar while their bodies collected heavy amounts of pollen.

Flies were by far the most numerous group of insects visiting the flowers. All seemed to be after nectar.

The presence of so many species of flies may be due to an apparent absence of predators hiding in the Goldenrod flowers. I closely examined many flower heads in an attempt to find some spiders or predaceous bugs commonly associated with Goldenrods. I found none. A similar search in September should yield an abundance of predatory species.

There were many of these little Bee Flies visiting the flowers.

This is a small Cylindromyia species of Tachinid fly using a bit of mimicry to look like a wasp. The larvae are parasitic on some type of insect, but the adults are frequent visitors of nectar bearing flowers. I scared it from a flower and thought I wouldn’t be able to use it for a Goldenrod based post until it landed on some Goldenrod leaves.