August 23, 2020: Luna Moth

Back in June a friend sent me a picture of the tremendous Luna Moth that she saw on a tree trunk near Sawyer Pond in Gilmanton.

Luna Moth (Actius luna), June 21, 2020.    (Photo by a good friend.)

These are one of our largest moths and though not rare in New Hampshire, they are not often seen due their nocturnal behavior.  I still remember the first time I saw one of these - it was on the exterior wall of my parents cottage on the west side of Lake Wicwas.  My mom noticed it and called us all out to see it.  I don't know if it was her excitement or just the size and beauty of it, but that moment has stuck with me, and I've been fascinated by them ever since.  I haven't seen one myself in a long time so I was most appreciative of receiving this photo from a friend - thank you!

Luna moths are members of the silk moth family, and are found only in North America.  They are sensitive to light so are often attracted to porch lights.  But this attraction to artificial light is also a problem for them as it affects their navigation and possibly their life cycle.  Light pollution and pesticides are two of the largest risks to these moths, as are naturally occurring parasitic flies and the many birds and animals that hunt them for food.  Their attraction to porch lights and their subsequent landing on illuminated walls makes them highly visible to predators.  

I'm writing about the Luna moth now because Linda found this huge green caterpillar crawling along the ground in one of her gardens this week, and we immediately thought "Luna moth".  

Polyphemus moth (Antheraea polyphemus) caterpillar.

Researching this journal entry I learned wasn't a Luna moth caterpillar, but rather a Polyphemus moth caterpillar.  The Polyphemus moth is equal in size to the Luna, but its adult form is brown rather than green, and it also has the distinctive eye shapes on its wings which help to confuse and scare predators.  The two moths' larval stages are very similar;  I learned the best way to distinguish them is by their face.  The Luna moth has a green face while the Polyphemus moth has a brown, bearded face.  Fortunately we had gotten a good look at its business end.

Linda's friend has the brown face of the Polyphemus moth.

This future-moth will soon wrap itself up in a cocoon made of silk and leaves where it will spend the winter amidst the leaf litter - another reason not to rake the leaves under the trees at the periphery of your lawn!  

Both types of these "macro" moths have one life cycle per year.  The pupa will start to develop in May when the ground warms; the adult moth will emerge a few weeks later.  The adult does not eat, but will find a mate and the female will lays its eggs on the underside of a leaf - mostly birch in our area, but hickory and walnut are also preferred hosts.  The eggs will hatch in about a week and eat and grow until they reach three inches in length.  During this phase both Luna and Polyphemus caterpillars will molt five times as they grow; each of these phases is called an "instar", so these species have five instars.  After their final instar they will form their cocoon and the cycle begins again.  Here are a couple of references to learn more about these giant insects:

Magical Moths, Rick Van de Poll, NH Fish and Game Wildlife Journal, July/August, 2017

Butterflies and Moths of North America

These caterpillars will be all sealed up and safe when the cool weather arrives.  Did you feel the late-summer chill in the air earlier this week?  The lakes sure did, and they showed their displeasure by weeping mist from their still-warm waters.  

Summer is starting to get tired.

July 19, 2015 - Scarlet Tanager

We have had the most stunning bird loitering around our house for the past several weeks:  a Scarlet Tanager.  It is amazing how well a such brilliantly colored bird can melt into its surroundings. 

Scarlet Tanager

It spends its time up in the canopy of oaks and maples, sometimes in the blueberry bushes, picking succulent, protein laden worms and caterpillars off the leaves.  Only when it takes a short flight from tree to tree does it becomes visible for a moment.  As soon as lands, his bright red form most often just disappears in the mass of verdant leaves.

During its residence here for over three weeks I have only been able to get a couple of really good looks at it, and those were fleeting.

I was surprised it spent so much time in a small location, then Friday revealed more of the story.  I was picking a few blueberries near the shore when it winged right over my head, only a few feet away.  I then became aware of a lot of persistent calling from a tree very near me - it was quiet, yet continued without pause in a very insistent manner.  A small fluttering motion caught my eye, and right above me sat a tiny puffball of feathers, white and yellow, rather ragged looking, and the explanation for the resident tanager became clear:  it has a nest in the area and its young had just hatched out.

Newly Hatched Scarlet Tanager Chick

The adults were calling it quietly yet firmly and I watched the chick as it made a couple of feeble flights from one branch to another, each flight becoming a bit more confident and adept than the previous.  The male kept flying in with food for the chick, usually big worms pulled off the leaves, which it devoured happily. 

I never did see the female, which made me wonder if it was off nursing another chick, or perhaps still on the nest.  I doubt I will ever find the nest even though it must be close by;  they are small and built in well hidden locations.  That was only two days ago, but I haven't seem them since - now they are probably moving on around the lake.  Keep your eye out for a happy family of beautiful birds!

Of course, the tanager chick isn't the only new bird on the lake - the two loon chicks are both well and growing rapidly. 

Freedom and Liberty with Mom

Thirteen days old

The family is venturing far and wide around the lake now;  one evening they were all the way down at the far end of the lake, giving Freedom and Liberty a tour of Lake Wicwas during a peaceful sunset cruise. 

A Sunset Cruise

Later in the week we saw mom working diligently to catch fish for the chicks, who seemed to be sharing well - no fighting when she came up with a fish;  they seemed to know who's turn it was. 

We knew it was mom because we saw the band when she did a foot wag.

The aqua-colored band is barely visible on mom's leg

But there was no sign of dad anywhere - until we headed back to Marion Cove.  There has a been a single rogue loon spending a lot time in this cove all summer, and it appeared to me that Freedom and Liberty's dad was standing guard, making sure the rogue didn't leave the cove and threaten the kids.  He was keeping a close eye on it, watching under water whenever it dove.  Then on one dive, dad took off on a wild, fast, splashing, wing-swimming dash to the mouth of the cove. 

Stay away from my family!

It sprinted a couple of hundred yards, stopping at the narrowest part of the cove entrance.  My guess:  it went to blockade the cove to make sure the other loon didn't get out while mom was distracted with her fishing endeavors.  It was quite a show. 

Another unexpected moment gave me a second show, as well as a startle.  I picked my grill cover up where I had left it overnight to dry, and out flew a large creature - I jumped back, my first reaction was, what is a bird doing in there?  The next thought was no, it's shaped like a bat, as it fluttered slowly around me.  But then I settled down and took at good look at it, and saw it was Polyphemus Moth, a member of the Giant Silk Moth family.  It flitted around a bit, and then vanished into the shadows of a dense hemlock tree in search of a dark spot to resume its daytime slumber.  Like most moths, the polyphemus is a nocturnal animal, and it had selected my black grill cover as good spot to hide from the bright summer sun.  No chance for a photo, but here is picture taken by photographer Stephen Lody.

Polyphemus Moth (Antheraea polyphemus) - photo by Stephen Lody Photography

Adult polyphemus moths have wing spans of six inches, and the caterpillar grows to be three to four inches long and as big around as your finger - that would be a feast for the Scarlet Tanager that would feed the chicks for a week!  But alas, all the parents around Lake Wicwas must work tirelessly in the upbringing of their young.  It's nice to think they also take some time to relax now and then, and enjoy the beautiful surroundings in which they live.