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.

Finding Something New in a Place I Know Well

My trip to New England was several weeks ago- but I wanted to do a final post about my last day there before I forgot about it. Before going boating, Leon and I took a quick hike up to Agassiz Rock to try to see the rare red-bellied tiger beetles. No luck, but I did take GPS coordinates and some better habitat photos.


The tiger beetles run over the open expanses of bare granite. I think we may have been a bit too early to see them- the Massachusetts data sheet that I have lists flight times in July and August.

Northern Cloudywing (Thorybes pylades) along the carriage road

That evening, we planned on taking my dad out for an early Father's Day dinner. We got back from boating with plenty of time to spare, and decided to go for a walk in the woods before dressing for dinner. There are old carriage roads all over the woods next to Dad's house, and I wanted to walk there and do some insect photography.

Spangled Skimmer (Libellula cyanea)

Way down one of the carriage roads, we saw an unfamiliar side trail into the woods. We decided to follow it for a while. I vaguely remembered it leading to a pond. It did- but not the pond I remembered. I was absolutely stunned to break out of the woods and find an absolutely gorgeous floating sphagnum bog.



Floating bogs form where sphagnum moss begins growing around the periphery of a pond. The moss forms a floating mat that thickens and begins growing towards the center of the pond. Eventually other plants, including shrubs and small trees, begin growing in the floating mat. Many floating bogs, including this one, retain open water at the center. They can be treacherous to walk on- it's possible to break through the floating mat and become trapped under it.

Sundew! (Drosera rotundifolia)

Sphagnum bogs are home to an amazing array of specialized plants, including orchids and carniverous plants like this sundew. We weren't dressed for slogging our way out into the soggy center (boots, or even hip waders are needed for that sort of thing), so we had to be content with looking in from the edges. I would have loved to have known this was there when I was growing up. I'll definitely have to go back. We were too early in the season to see if the rare bog copper butterfly can be found in this bog.

Hentzii

Growing up on the coast of Massachusetts, I really enjoyed the natural world. I spent a lot of my childhood mucking in tide pools, chasing butterflies, and gardening with native woodland wildflowers. It was a childhood that did a lot to prepare me for my adult life as a biologist and conservationist. I've lived in Illinois over half of my life now, and it is here that these interests have blossomed into my career and resulted in a lot of interaction with the local conservation community. Although my biological family still lives in Massachusetts and I return frequently, I've never had any contact with the environmental community in the Northeast. That may be changing.

Last August, Leon and I spent a few days with my dad. It was the first time in a while that I'd been back home in the summer. The first time since I'd developed my recent obsession with tiger beetles. While visiting a preserve in my old home town, I happened upon a Massachusetts endemic subspecies of the red-bellied tiger beetle, Cicindela rufiventris hentzii. I got some nice photos, blogged about it, and posted the photos to BugGuide.net.

Yesterday I got an unexpected email from an invertebrate zoologizt from the Massachusetts Division of Fisheries and Wildlife. The email read, in part:

I was perusing BugGuide, and was a bit surprized to find your photo of Cicindela rufiventris hentzii from Agassiz Rock. I was even more surprised when I checked the Massachusetts Natural Heritage Program database and realized that this is a new locality record for this critter, which is listed as a Threatened species in Massachusetts.

Wow. And I wasn't even trying to find it. Some further email exchange revealed that there is one extant location in the extreme south of Essex County, an old (1891) record from Gloucester, and my recent find. That's it for Essex County. The habitat that I found it is, however, is one that is very familiar to me from my childhood. I can think of at least half a dozen other locations that could be home to the critter. I'm pretty sure that I know where the Gloucester specimen came from. I'm pretty sure that it's an intact site, so the population may persist. How cool would it be to relocate it after 118 years?

I'm going to be home next June, which is within the flight time for this beetle. The invertebrate zoologist has expressed an interest in having me show him the site where I found it, and scoping out some nearby possibilities. My lack of interaction with the Massachusetts conservation community appears to be ending.

The Gizzy Rock

Big Agassiz Rock

I'm home in Cape Ann, Massachusetts, spending time with my dad in the town of Manchester-by-the-Sea where I grew up. It's been quite a few years since I've been here at the height of summer, and Leon and I have never been here together at this time of year.

Little Agassiz Rock

Today, we walked up to Agassiz rock. It's just off of a route that we traveled regularly when I was a kid, and our family name for this spot was "The Gizzy Rock." It's not one, but two huge glacial erratic boulders, Big Agassiz Rock and Little Agassiz Rock. They are named for Louis Agassiz, Harvard geologist (and creationist) who first postulated that the large boulders that litter the landscape in this part of the country were brought here by the glaciers. The sweet pepperbush (Clethra alnifolia) was in bloom, it's cloying odor wafting through the woods as we began our walk.

The trail through the woods

Sweet Pepperbush (Clethra alnifolia)

The hike up to the boulders is short, no more than about 15 minutes, and leads through some beautiful hemlock/maple woodland, the ecosystem of my childhood. It was great to see some familiar species from back then- things like Indian pipes (Monotropa uniflora), the plant that taught me the word saprophyte (a plant that produces no chlorophyll, but gets it's nutrients from the decaying vegetation that it grows in). I showed Leon the maple-leaved viburnum (Viburnum acerifolium). It was a big favorite when I was a kid, because the leaves turn a fairly vivid purple in the fall.

Indian Pipes (Monotropa uniflora)

Maple-leaved viburnum (Viburnum acerifolium)
These leaves will turn bright purple in the fall.

There were some nice species that I never noticed as a child. An unusual aster with whorled leaves caught my eye. On a whim, I Googled whorled aster after I got home. Yes, indeed, it's woodland whorled aster (Aster acuminoides). I love the Internet- make an educated guess, get an ID!

Woodland whorled aster (Aster acuminoides)

Another of my interests has changed since the last time I was at home during the summer. My entomological interests have expanded way beyond butterflies. The area around Little Agassiz Rock is a large expanse of granite with thin soil. Drought-tolerant plants like bearberry and lowbush blueberries grow there. It's a fairly common habitat type on Cape Ann. It turns out, this is a tiger beetle spot. I only saw one, but I got some nice photos. Better yet, it's a particular subspecies of the eastern red-bellied tiger beetle (Cicindela rufiventris hentzi). It's very narrowly endemic to the area right around Boston, including my home town. Whatt a great species to have as the very forst tiger beetle that I've ever found in New England.

Eastern red-bellied tiger beetle (Cicindela rufiventris hentzi)
Endemic to the Boston area