PPS: What’s in the picture?

In my last post on the evolution of the Pipevine Swallowtail caterpillars I also included three images of a female Ruby-throated Hummingbird that I photographed on the same Harlequin Glorybower bush that harbored the Pipevine butterfly.  A keen 11 year old observer from Maine contacted me, kindness of her grandmother, to point out something in the images I had completely missed.  On the left side of the pictures the head, thorax and powerful front leg of a Praying Mantis are clearly visible:

The Praying Mantis and the Ruby-throated Hummingbird appear to be staring each other down.

This young naturalist took it one more step; she expressed worry that the hummer might fall prey to the preying Praying Mantis, and asked Grandma to query me on that issue.  As I read the email I mused that a child would be so naive as to think that a feisty hummingbird could possibly fall victim to a fierce, but much smaller, insect.  Then I read on; for backup she pointed me to a recent article in the New York Times:

https://goo.gl/jNqVMB

I heartily recommend that all readers of this blog read this Science Times piece, not only for the raft of fascinating information about these critters, and the complete confirmation of my friend’s fears, but also to view spectacular photos of exotic mantid species worldwide.

Speaking of mantid pictures, this is the second time in a week that I have stumbled on, or been led to, a Praying Mantis in a photo I took when I hadn’t noticed it in the field:

With this photo I was documenting a Painted Lady Vanessa cardui butterfly, one of hundreds migrating through Boston right now, on a Butterfly Bush at the Boston Nature Center. Only when I got home and uploaded the image on my computer did I notice the Praying Mantis Mantis religiosa above.  Camouflage or inattention?

As to your concern, Grace, I can’t say for sure that the hummingbird survived to fly south sometime last week, but I do know it flew away from the predator while I was present.  And as the NYT article reports, predation of birds by Praying Mantises is pretty rare; they are prowling around in flowering bushes looking primarily for more reasonably sized fare- bees, wasps and probably butterflies!

Thank you for drawing all of this to my attention.

Butterfly postscript- and fall bird walks

In my last post I promised a followup on the Pipevine Swallowtail caterpillars that the Arboretum staff and I had collected and placed in inclosures back in late July. Here is a shot of some of them in their last stage, or instar;

Three 8th instar Pipevine caterpillars munching on Dutchman’s Pipe

I went away for a brief vacation and when I returned six days later, all three of my cats had pupated and formed complex chrysalides:

Dorsal view of one of the PV chrysalis attached to a vine stem.

The other two chrysalides, seen sideways, attached to the wall of the inclosure.

I had missed the transformation!  When I went to the Visitor’s Center at the Arboretum I discovered that they had about 12 chrysalides in their inclosure as well.  Now the question was whether these pupae would remain as chrysalides and “over-winter” before becoming butterflies (enclosuring), or if they would convert this fall, probably in September.

In mid August I went on another weeks vacation and while there I got a message from the Arb that two of their chrysalides had eclosed!  Upon my return I went immediately to my little cage and found a lovely Pipevine Swallowtail butterfly anxious to escape:

PV butterfly next to it’s empty chrysalis, left and an intact one on the right

Fifteen minutes later it was flying free in the Arboretum!

Over the next several weeks the “rare” Pipevine Swallowtail was being seen all over the grounds, as six of the Arb’s chrysalides had eclosed as well:

Pipevine Swallowtail on Harlequin Glorybower

We were not able to determine if any of them had mated and laid eggs.  There are still eight chrysalides that have not eclosed and we will try to successfully hold them over the winter in a variety of settings- outdoors and exposed, outdoors but covered and protected and indoors in an unheated environment- and await the coming of spring and hopefully another batch of butterflies for release.

On August 25 I had a swallowtail home run; all five species present in a grouping of the same flowering shrub, Harlequin Glorybower Clerodendrum trichotomum.  The Giant Swallowtail that has eluded me in Massachusetts finally appeared, just as the battery in my camera died!  I had to settle for a lousy shot of the lep on my old iPhone:

Giant Swallowtail Papilio cresphontes near Harlequin Glorybower Clerodendrum trichotomum

It has been a BIG butterfly summer!

But now it is time to turn our attention back to birds.  This beauty, captured on the same bushes with the butterflies, helped me make the switch:

Female Ruby-throated Hummingbird, in flight sequence

Female Ruby-throated Hummingbird, in flight sequence

Female Ruby-throated Hummingbird, in flight sequence

Unfortunately, hummingbirds are heading south right now so there won’t be any to be seen on my up-coming fall bird walks. But I’m hoping a few warblers or other late migrants might still be around.  Here are the dates:

Saturday 9/30 8AM starting from the Main Gate on the Arborway.

Saturday 10/14 8AM starting from the Peters Hill Gate on Bussey Street.

Check the Arboretum website for a map or to download a checklist.

Good birding!

How rare is rare? – a butterfly tale

As spring slides into summer birds go quiet; nesting, rearing their young, preparing for their southern migration or just hanging out.  I switch to Lepidoptera and Odontata to keep me busy.  Butterflies and dragonflies have elaborate life cycles; eggs become larvae which grow, sometimes over long time periods, bigger and bigger and finally transform to often spectacular adults who spend their short lives looking for mates, mating- and for the females- laying eggs to renew the cycle.

I’ve discussed dragonflies in two previous posts.  Recently however, I went in search of a butterfly that has eluded me for more than ten years.  The Pipevine Swallowtail is one of five species of Swallowtails, Papilionidae, that can be seen in the Boston area.  Perhaps the most common of this group is the Eastern Tiger Swallowtail:

Eastern Tiger Swallowtail Papilio glaucus

There are two other relatively common swallowtail species in the area; one is the Spicebush Swallowtail:

Spicebush Swallowtail, Papilio troilus, on Swamp Milkweed

It can be tricky to distinguish that predominantly black butterfly from the named Black Swallowtail:

The small yellowish/whitish single spot near the top of the forewing is one way to differentiate this female Black Swallowtail, Papilio polyxenes, from the Spicebush species

To make matters worse, there is a notable gender difference in this last species:

Note the broad yellow median band on the wings of this male Black Swallowtail, and the sub-apical spot characteristic of the species.

Early in July I went to the area where I thought I would have the best odds of finding a Pipevine Swallowtail.  Pipevines, like most butterflies, have specific plants on which they lay their eggs, so called host plants.  Most plants produce toxic substances to reduce their chance of being eaten by predators like the caterpillars of moths and butterflies.  To get around this defense, butterflies evolved over time a resistance to the toxins of one or more plant types; they aren’t deterred by the poison and in fact benefit from eating it because they in turn take the nasty toxin into their bodies thus protecting them from being eaten by birds or other predators.  Many butterflies have several host plants; the Pipevine has only one, the genus Aristolochia or Dutchman’s Pipe, named for it’s flower which is thought by some to resemble a meerschaum pipe:

Aristolochia macrophylla in bloom

The Editor of the Arboretum’s scientific publication Arnoldia has recently written a great post on her blog ARblog which describes this symbiotic relationship in detail.

The Arboretum has a number of these vines growing on the chain link fence surrounding the garage near the main entrance.  I’ve searched them every summer since I learned of the swallowtail connection- in vain.  But this time I spotted something interesting fluttering around the massive leaves of Aristolochia macrophylla:

Pipevine Swallowtail, Battus philenor, on Pipevine

Could this be my illusive lep?  A moment later it perched and I got a closer look:

Female Pipevine Swallowtail, ovipositing on Dutchman’s Pipe

The butterfly was laying eggs on a stem of the vine!  Identity confirmed!

When I returned home I tried to determine just how special my sighting was.  I went to the website Butterflies and Moths of North America and focused in on sightings in Suffolk County, Massachusetts.  There was only one historical listing in over 23 years, a sighting verified in 2004.  Another check on sightings for the entire state since 2010 uncovered only 28 reports.  I was on to a big time rarity!  I emailed some friends who work at the Arboretum, posted the sighting on MassLep (a local list server), and reported it to the above website along with some images.

A week later the Manager of Plant Records at the Arb, and fellow naturalist, emailed me an image of a Pipevine Swallowtail he caught nectaring on an azalea flower at the top of Bussey Hill:

Pipevine Swallowtail Battus philenor on Rhododendron arborescens Photo by Kyle Port

So this was now the third sighting of this swallowtail in Suffolk County?  And as if that wasn’t enough, the next day I received word that two seasoned horticulturalists on the AA staff had discovered Pipevine Swallowtail caterpillars on the same vines near the garage back in 2010, and had even over-wintered one which emerged from it’s chrysalis the following spring!  They have found one or more as caterpillars almost every year since then.  But they record stuff in botanical journals.

Suddenly my rare discovery seemed mundane.  Maybe this swallowtail was pretty common, but no one bothers to report it to obscure websites.  I backed off my high to gather some perspective.  I had never seen it, and I’ve been looking at butterflies for many years.  A cursory review of MassLep reports in the last few years revealed only 3 reports, and they were HIGHLIGHTED in each case.  So yes, this was a rare sighting, but perhaps the Arboretum, with it’s abundant pipevine plantings, may be a local mecca for this lep.  In fact, when I made a presentation on site about my find recently, one of the attendees reported he had seen what he thought might have been a Pipevine Swallowtail as he approached the meeting site.  I pointed out that other more common black butterflies were more likely.  But after the meeting some in the group went with him to where he had his sighting and found and photographed the creature.  After review, the image turned out to be our index swallowtail!  I’ve been back a number of times to follow the development of the eggs and have seen several more likely suspects in flight but have not been able to confirm their identification.

Speaking of the eggs, they have hatched:

About 20 of the 50 or so eggs that were laid by the female butterfly

Five days later most of the eggs have hatched into first instar cats.

A dozen second or third instar cats still hanging out together a few days later.

This little guy has a delineated head at one week of age, and has wandered away from the herd.

Another colleague at the Arboretum has agreed to share her Monarch caterpillar inclosure on display in the Visitors Center, and we have put about a dozen of the Pipevine caterpillars inside along with host plant offerings.  Will they pupate?  Stay tuned, or better yet, come and visit the display when you’re nearby.

The butterfly inclosure at the Visitor’s Center in the Hunnewell Building.

Four of the transplanted Pipevine caterpillars seen through the screen inclosure.

As I mentioned at the beginning of this long post, there are five swallowtail species that can be seen on the Arboretum grounds.  I still have one to go, although I did see it a few years ago while vacationing in Pennsylvania:

Giant Swallowtail Papilio cresphontes. Although this is a very poor photo, it is enough to confirm the identity of the specimen. The yellow spot within the tail, seen to the right of the lower berries, is diagnostic.

Giant Swallowtails have been reported in the Arboretum for the last two years; it is a species that seems to be increasing in our area.  Their host plants are Prickly Ash and Hop Tree; both are represented in the collection.  I’ll be keeping a look out!

Good butterflying!