Plumes
of yellow goldenrod flowers danced in the breeze next to succulent stalks of
common milkweed, and insects buzzed in the warm sunshine. While goldenrod flowers get a bad reputation
for being the cause of summer allergies, their heavy pollen grains do not drift
through the air and into our nostrils. The brilliant yellow heads composed of
many tiny florets and the leafy green stalks provide food and shelter for a
myriad of insects, and insects were what we were hoping to find.
My
first catch, since I was one of the participating “kids” on this bug collecting
expedition, was a beautiful grasshopper with red hind legs. Appropriately named
the red-legged grasshopper, Melanoplus femurrubrum (from femur=thigh, rubrum=red), it is one of
the most common grasshoppers in North America, with the center of its
population directly over the Midwest.
Red-legged grasshoppers have good nutrition down
pat, eating a variety of plant species in a single meal. Those fed on just one
type of plant, even if it is the seemingly nutritious alfalfa, developed health
issues and produced fewer eggs. The way they eat is interesting, too. The poet
Mary Oliver observed a grasshopper “the one who is eating sugar out of my hand,
who is moving her jaws back and forth instead of up and down,” and described it
in her poem “The Summer Day.” It is from that poem that I learned that grasshoppers
do indeed move their jaws back and forth to chew!
The chewing action
of the goldenrod gall fly, Eurosta
solidaginis, does more than
just facilitate eating. After a female gall fly deposits an egg into the stem
of a goldenrod plant, the egg hatches in
about ten days, and the larva immediately starts eating the stem from the
inside out. The chewing action and the larva’s saliva, which is thought to
mimic plant hormones, cause the goldenrod’s stem to thicken into a dense, round
gall.
Sliding my bug net over the top of a goldenrod
flower, I caught a beautiful orange-belted bumblebee, Bombus
ternarius. I was glad to have a closer look,
because I’d seen several on prairie blazing star (pretty purple flowers) at the
Forest Lodge Nature Trail recently, and wondered what they were. These smaller
bees tend to forage at the tips of the goldenrod flower clusters, while letting
bigger bees occupy the cluster’s center.
Looking closely at the center of a goldenrod
flower cluster, I notice a deviation in the pattern of blossoms. As I peered
closer, the smooth round body and eight legs of a goldenrod crap spider came
into focus. This
tiny hunting spider has a short, broad abdomen, and legs that are held
outstretched to the side that enable it to move sideways, forward and back just
like a crab.
Goldenrod
flowers are a great spot for this spider to wait in ambush for bees, wasps,
butterflies, moths and other nectar-seeking insects. To camouflage itself from
the eyes of both predators and prey, crab spiders can change from the yellow to
white, depending on the color of the flower they live on.
Some consider goldenrod a weed, while others plant
it in their gardens. When sorting and identifying the diversity of insects
trapped by our nets, it is evident that no matter what we think, many insects
like goldenrod just fine.
And, just for the record, it is ragweed—not
goldenrod—that makes you sneeze.
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