Gossamer Tapestry

Reflections on conservation, butterflies, and ecology in the nation's heartland

Monday, August 29, 2011

Indiana Metalmarks

Our visit took us to the banks of the Ohio River

Unlike populations further to the north, swamp metalmark butterflies in southern Indiana have two generations annually. The second one flies in mid August. Last year, members of my department visited and found dozens of individuals, the largest population we have yet encountered. A couple of weeks ago, I returned for some further work with this population. My goals were:

1. Do a mark/release/recapture study, incorporating GPS to measure dispersal rates of the species
2. Obtain a few specimens to test for an insect pathogen called Wolbachia
3. Obtain females from which to obtain eggs in order to try to develop methods to hold larvae from this species over the winter

This year, I went down with Andy. a member of the horticultural staff at the museum. We had beautiful weather, but were disappointed to find far fewer metalmarks than we did last summer. We were unable to complete the dispersal study, but did manage to to GPS mapping of the capture location of the 18 or so specimens that we marked. Having been able to mark very few individuals, we recaptured only one. No statistical analysis possible here. Still we got four females and have a bunch of eggs in the lab. We also have sufficient material for Wolbachia testing.

Marked metalmark
These guys are so tiny that it's really hard to mark them

Although we found few metalmarks, we did see lots of other butterflies, including three lifers for me: Hoary-edged Skipper, Goatweed Butterfly, and Gemmed Satyr.

Goatweed Butterfly (Anaea andria)

Hoary-edge Skipper (Achalarus lyciades)

In addition to new species, I was able to get some better photographs of familiar species. I was most pleased with the Tiger Swallowtail and Least Skipper.

Tiger Swallowtail (Papilio glaucus)

Least Skipper (Ancyloxypha numitor)

What do do when the big experiment of a trip for field study turns out to be a bust? I consoled myself with a stop at Falls of the Ohio State Park on the way home to check out the tiger beetles. I got some decent photos, including the Coppery Tiger Beetle, another lifer for me.

Coppery Tiger Beetle (Ellipsoptera cuprascens)

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Saturday, August 20, 2011

Hentz' Red-Bellied Tiger Beetle, Revisited

Three years ago, I made my first visit in many years that took me back to my home town in mid summer. On a walk in the woods, I stumbled upon a tiger beetle subspecies (Cicindela rufiventris hentzii) that is endemic to the Boston area. The beetle was on Agassiz Rock, a large granite outcrop that is owned and managed by the Trustees of the Reservation. Several months later, I was contacted by the Massachusetts Division of Fisheries and Wildlife, informing me that this is a state-listed (Threatened) species, and that this population was not in their database.

Agassiz Rock

For the first time since then, I'm back in Massachusetts at the right time of year to see hentzii. I went back today with several goals. I wanted to see that the population is persisting. I have a much better camera than I did in 2008, and wanted to try for some better photos. I am aware of a second rock outcropping about a half mile away from Agassiz Rock, and wanted to see if the beetle could be found there as well.

I was successful at all three of these goals. The population at Agassiz is small- I've never seen more than one individual per visit, but I did see one this time. I was able to get a series of photos with the new camera. I'm much happier with these pictures than with the ones from my old camera.

Cardinal Flower and Pickerelweed

The walk to the second rock outcropping is lovely. The land is owned by the Manchester-Essex Conservation Trust. A beautiful wetland stretches between Agassiz Rock and the other outcop. The Pickerelweed and Cardinal Flowers were potting on a spectacular display.

The Second Granite Outcrop

I've never been to the second granite outcrop before, though I have seen it from the highway many times. The tiger beetles are very well camouflaged, and fly less than many other species I am familiar with. Perhaps they persist better on the tiny islands of bare-rock habitat if they are reluctant to fly. I managed to see two individuals on this site.

On Wednesday, Leon and I are heading off to Martha's Vineyard. Who knows, maybe we'll see the last Massachusetts population of Cicindela dorsalis.

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