by Carl Strang
My evening of moths at the UV light during the Hills of Gold bioblitz brought back memories of similar nights three decades ago, when I was trying to get a handle on forest insect ecology. Those memories were elaborated as I processed the many photos of the moths that came to the sheet. For example, I was reminded how variable the members of a species can be within a single population.
One example was the friendly probole, a moth in the inchworm family. Here is a relatively pale example.
Here is a somewhat darker one. The previously described members of this genus recently all were combined into the same species, so there was no question of similar conspecifics.
Notice the doubled dark spots on the wings of this third example. These three individuals arrived at different times, and it wasn’t until I studied the photos that I realized that they were related.
Even more surprising was the discovery that 7 different moths all should be regarded as the same species, the yellowhorn. In this case it appears to be different degrees of wear rather than different color patterns that prevented me from recognizing their similarities.
Here is a relatively worn individual. Note the bright yellow antennae that provide its English name.
And here is a fresh one. This one landed on my pants, hence the different fabric color of the background.
There are many species of moths, and they often have similar shapes and color patterns, so some time is needed to sort them out. The yellowhorns are in family Noctuidae. The next photo is of a moth with similar body form and wing shape, but it is not even in the same moth family.
The common gluphisia is in family Notodontidae. This one even shares the yellowhorn’s humpbacked profile.
A final example of within-species variation is a moth called the porcelain gray. This was the least worn of four individuals I photographed at the light.
Some study was required before I was ready to acknowledge that this moth belonged to the same species as the one in the previous photo.
The three-spotted fillip was the most common moth I observed during the day. A few came to the light as well.
It probably is not clear from the photo, but the three-patched bigwing is significantly larger than the three-spotted fillip. Both are in the same genus.
This large mossy glyph was the only representative of its species at my light. It landed on the sheet early in the session, and stayed there until I closed shop.
I don’t know if the light drew this common oak moth caterpillar that crawled along the edge of the sheet. Note the odd abdominal false feet, which shrink progressively back to front.
This one probably is a curve-lined looper moth, Lambdina fervidaria, but that species is practically identical to a congener, Lambdina canitiaria, which is so rare that it has not received an English name.
Such uncertainty and ambiguity is another memory from that earlier moth study.
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