Saturday, July 27, 2013

Is It A Fly, Wasp, or Moth?

This insect stumped me (and others who saw it) for awhile.  Is some kind of fly?  Maybe a wasp?  Something else?  It was hard to see how many wings it had, which would have helped clarify things.  I went with a species of moth, and after some searching through images at the Moth Photographer's Group website, and much somewhat informed guesswork I arrived at an identification.  It is a Virginia Creeper Clearwing Moth, Albuna fraxini.

It is a member of the micromoth family, Sesiidae.  Micromoths are just what the name implies, small moths.  It's not a taxonomic grouping, just a descriptive term.  About half of North America's twelve   thousand or so known species of moths are micromoths, which means a good proportion of our moth biodiversity is easily overlooked and mostly poorly understood.  Their small size and sometimes unmoth-like appearance also makes many of them hard to even recognize as moths.  And because they are small and easily overlooked, they are probably more species to be discovered.  

Sesiidae are one of the moth families commonly known as Clearwing Moths, because the wings scales are mostly absent, leaving the wings transparent.  Many of them are brightly colored or boldly patterned and probably mimic wasps.  The larva burrow into plant tissue to feed, in the case of A. fraxini, the roots of Virginia Creeper, Parthenocissus quinquefolia.

And if you're so inclined, here's a link to the Sesiidae gallery at the Moth Photographer's Group website.  Or better yet, keep an eye out for Clearwing Moths in your neighborhood.  You don't even have to stay up late since many of them fly by day.

Thursday, July 25, 2013

Burrowing Moth Caterpillar

This is a caterpillar of the American Dagger Moth, Acronicta americana.  It's an impressive looking caterpillar.  It's also one of the many species of moths who burrow to pupate.  In this case, it's chewing its way into a well rotted piece of wood.  I

Tuesday, July 23, 2013

Aquatic Moth Caterpillar

I'm assuming this is the caterpillar of the Chestnut-marked Pondweed Moth, Parapoynx badiusalis.  The little moths are all along the trails around Westwood Lake during July.  It's the only moth that I've come across with aquatic caterpillars, though there are definitely others; I'm not sure any can be found around here. 

I think many people are surprised to learn that certain moths have aquatic caterpillars.  For some reason, on first thought, it doesn't seem like a "natural" fit.  But really it's not at all unusual in the insect world for some to almost all of the members of a particular order to have an aquatic component to their life cycle.  So why not moths?

Monday, July 22, 2013

It's National Moth Week

Remember, it's National Moth Week this week.  It's an effort to get people more aware of the biodiversity around them and to do a little citizen science.
The main feature of Moth Week are the nighttime events held around the world where people can help collect data about moths in the area.  
Unfortunately, it looks like there are no moth events scheduled for the Twin Cities area, but maybe there's one near you.
Maybe I'll plan one myself next year.
Even if you don't attend a moth event this week, you can at least keep your eye out for them this week. Maybe leave a porch light on and see what it attracts; every time I do and I actually stop to look, something new and unfamiliar comes to visit.

Saturday, July 6, 2013

Is this a Pearl Crescent or a Northern Crescent?

I spent the morning of July 4th with my parents hiking the Fish Lake Trails, part of the U of MN's Cedar Creek Ecosystem Science Reserve.  I highly recommend a hike there.  We especially enjoyed watching the baby tree swallows, and Red-headed Woodpeckers were seen on multiple occasions.

The orange and black butterfly pictured above was very cooperative.  It's one of two species of Crescents, genus Phyciodes; either the Pearly Crescent, P. tharos or the Northern Crescent P. selenis.  Up until about 25 years ago they were considered one species.  After reading through a number of descriptions, it seems the range is the best way to distinguish between the two species.  However, the Fish Lake Trails are located were the two species overlap.  The Pearly Crescent seems more likely, but only because it is mentioned on the Cedar Creek website, while the Northern Crescent is not.
A field mark mentioned in most descriptions of these two butterflies concerns markings on the underside of the wings, specifically, the outer margin of the hind wing, which in the picture above, is the edge of the wing closest to the lower right side of the photo.  Pearly Crescents have a pearl-colored crescent in the darker smudge of this area of the wing, while Northern Crescents do not.  Well, Pearl Crescent are more likely to have this marking and it depends on whether the butterfly in question is a male or female.

One thing I've learned from reading about these butterflies is that a good picture of the underside of the wing is just as important as the upper side, and while maybe not as brightly colored, still quite pleasing to the eye.

(And by the way, there is third species, the Tawny Crescent, P. batesii, that is also very similar looking, but it's range is more northerly).

I used a lot of sources of information for this post, but my favorite one, and one that was new to me is the Wisconsin Butterflies site.