wall of moths
As I was returning to my office after a bird survey yesterday, I found a number of small gray moths on the cinder block wall of our building. There were at least 30.
The pattern of the individual moths varied a bit, but they blended in really well with the wall. The wavy lines their wings would have been an even more perfect match for tree bark.
I took some photos, but know bettter than to be optimistic about identifying small, bark-colored moths. I wouldn't have bothered, except that I thought that their numbers and early emergence might be more characteristic than their appearance, and enable me to clinch an ID. I figured I might have some luck going to the moth section of BugGuide and browsing recently submitted photos.
I was right. I only had to click through 4 or 5 pages before I hit on a ringer: Phigalia titea, the Half-wing Moth (a.k.a. Spiny Looper, Eastern Oak Looper). It's one of the geometrid moths; the "inchworm" larvae eat a wide variety of hardwoods.
There are two other Phigalias that fly early in the season: P. strigataria (Small Phigalia) and P. denticulata (Toothed Phigalia). I took a second look at the walls today, and there may have been a few Small Phigalias in the mix, which are smaller, often darker, and tend to show less hing wing when perched.
I didn't find out anything really compelling about the natural history of these moths, except it was kind of interesting to learn that they were all males -- females are flightless and have only vestigial wings.
Despite their apparent ordinariness, I'm sure the early emerging adults are a really important food source for insectivorous birds arriving during this period of fickle weather. The eggs the moths are now laying will also provide a welcome protein source for bark gleaning species both resident and migrant, such as Brown Creepers, chickadees, and nuthatches. And of course, the larvae will be out just in time for the big wave of northbound migrants still to come, with some caterpillars left over for hungry nestlings.
On second thought, their role in the forest food web makes these modest moths anything but ordinary.
I took some photos, but know bettter than to be optimistic about identifying small, bark-colored moths. I wouldn't have bothered, except that I thought that their numbers and early emergence might be more characteristic than their appearance, and enable me to clinch an ID. I figured I might have some luck going to the moth section of BugGuide and browsing recently submitted photos.
I was right. I only had to click through 4 or 5 pages before I hit on a ringer: Phigalia titea, the Half-wing Moth (a.k.a. Spiny Looper, Eastern Oak Looper). It's one of the geometrid moths; the "inchworm" larvae eat a wide variety of hardwoods.
There are two other Phigalias that fly early in the season: P. strigataria (Small Phigalia) and P. denticulata (Toothed Phigalia). I took a second look at the walls today, and there may have been a few Small Phigalias in the mix, which are smaller, often darker, and tend to show less hing wing when perched.
I didn't find out anything really compelling about the natural history of these moths, except it was kind of interesting to learn that they were all males -- females are flightless and have only vestigial wings.
Despite their apparent ordinariness, I'm sure the early emerging adults are a really important food source for insectivorous birds arriving during this period of fickle weather. The eggs the moths are now laying will also provide a welcome protein source for bark gleaning species both resident and migrant, such as Brown Creepers, chickadees, and nuthatches. And of course, the larvae will be out just in time for the big wave of northbound migrants still to come, with some caterpillars left over for hungry nestlings.
On second thought, their role in the forest food web makes these modest moths anything but ordinary.
Just photographed one of these on my back porch not 30 minutes ago!
Posted by: Jenn | 09 April 2008 at 09:55 PM
Very cool. I've been seeing what I thought were Geometrid type moths recently. I'll have to get a closer look.
Posted by: Patrick | 10 April 2008 at 10:40 AM