Girl of Limberlost and Son of Poseidon

GIRL OF LIMBERLOST AND SON OF POSEIDON  

November/December, 2013 issue  
The  photo of the caterpillar that Scoop editor Angela Saxe sent me, taken   by Isadora Spielmann, was a mystery. Covered in tiny white spiracles,  the  caterpillar’s identity was lost in the carpet of these white  protuberances. So,  I sent the photo to friend Joe Bartok in Tweed who  seldom has been stumped by  other mysteries I have e-mailed him in the  past. Pretty sure that this was an  Imperial Moth, he was however  curious about the white bumps, whether they were  natural or parasites.  He forwarded the photo to a website called BugGuide, and  inquired about  the white spiracles. They replied, “The white bumps you refer to  could  either be the scoli (fancy word for spines) or the spiracles, both  normal  features. This caterpillar looks healthy but could still be  parasitized.”
  
 Moreover,  the caterpillar was identified as Eacles imperialis pini, an  Imperial  moth species that feeds specifically on pine. What was amazing,   attributable primarily to the speed of the Internet and electronic  messages, it  took only the better part of a day to pin an identity on  this creature.  Naturalist Gene Stratton Porter's “A Girl of the  Limberlost” features E.  imperialis prominently in the plot development.
  
 Butterflies  and moths are fascinating, but in the larva or cocoon stage,  their  identity can be a little challenging. Two years ago, I walked into my  home  office to find a huge moth fluttering in front of my face.
  
 Earlier  I had received an e-mail from a Picton farm supply staff member  about a  strange cocoon someone had brought into their store. The store sold  bird  feeders, so surely they must know the identity of a cocoon! It  spent several  days jostled about on a shelf between farm catalogues and  order forms.  I was  quite certain that the object that I now rolled  around in my fingers was the  cocoon of a Polyphemus moth, but I would  need to take it home with me to verify.  The cocoon was placed in the  back seat of the car where it rode around for three  days before I  remembered to bring it into the house where I was able to verify  it as a  Polyphemus moth. 
  
 I  left it in my office, and later placed it atop a fluorescent light   fixture above my desk where it sat for a few more days. I intended to  add the  new acquisition to my box of props that I take along on guided  hikes. Figured it  would be useful on one of those hikes where few  things show up and an emergency  item is required to add interest to the  hike.  
  
 That’s  when I entered my office to do some work and met a large Polyphemus   moth fluttering in front of my eyes which then landed on the light  fixture. Sure  enough, the abandoned cocoon that I had placed on the  light fixture, had a small  opening at one end, where this creature had  emerged, unfolded his wings and  dried off. I carried him outside and  placed him on the sun deck railing so he  could get on with what`s left  of his life – roughly two weeks. Hardly worthwhile  coming out of the  cocoon. What amazed me was the size of this moth and that he  had  somehow been compacted and folded enough to fit in this cocoon that was   barely an inch in width and a little more than an inch in length. The  sundeck  railing is five inches in width, and his wings extended beyond  either  edge.
  
 So,  what’s with the unusual name? Well, Polyphemus was actually the   mythological gigantic one-eyed son of Poseidon and Thoosa in Greek  mythology,  one of the Cyclopes, mentioned in The Odyssey of Homer. The  moth itself is  actually fairly common and, superficially, resembles the  more familiar cecropia  moth somewhat in that it has  two large  eyespots on its hind wings, which give  the Polyphemus its name.  Eyespots also serve as startle patterns, a form of  distraction should a  predator come along. Even its light colouration serves as a  camouflage  to some degree, despite the moth’s huge size. 
  
 This  is not the only animal that uses these startle tactics. Most startle   patterns are brightly colored areas on the outer body of already  camouflaged  animals. A good example of the use of startle patterns is  the gray tree frog. If  you find one, and it is difficult as they change  colour to match their  background, check its leggings. They are bright  yellow. When it leaps, a flash  of bright yellow appears on its hind  legs, usually startling any predator away  from its prey. In the case of  the Polyphemus and the cecropia moths, the false  “eyes” are believed  to be a form of mimicry, meant to misdirect predators. The  predator  thinks it is meeting its prey head on, only to see it successfully   flutter away in the opposite direction.
  
 Insects  have evolved numerous ways to ensure survival. So expertly do some   match their background, it is often difficult to spot them, even after  the  location of an individual has been pointed out. Others are  transparent allowing  the background to filter through so there is no  need for the insect to seek out  habitat that resembles itself. Any old  place will do. Others like the Monarch  butterfly, contain cardenolides,  a toxin that it obtains from milkweed plants,  and carries with it  through the larval stage and into the adult stage. Birds and  other  predators soon learn to avoid Monarchs. The very similar viceroy  butterfly  is not in the least bit poisonous, but uses its resemblance  to the Monarch  butterfly as a defence.  The recently arrived giant  swallowtail butterfly six  years ago – even larger than my Polyphemus  moth – as a larva, has a defence that  is guaranteed to thwart the  efforts of any predator. First, it resembles a large  bird dropping  which is usually sufficient to turn off most birds from pecking at  it.  And, if that doesn’t work, it uses chemical warfare, producing a foul  odour  from its tiny body that permeates the air around it. 
  
 My  moth likely lasted only a few days, having lived out its short  lifespan,  but not before finding a female (mine was a male, obvious by  the feathered  antenna) which will lay its eggs singly, and seemingly at  random, on the lower  surface of leaves. Although the larva feeds  voraciously on leaves, it does not  feed with thousands of others of its  own species like the forest tent  caterpillars do that invaded one  section of forest along Moneymore Road near  Marlbank three years ago.  The Polyphemus is common enough, but certainly not  invasive.  It tends  to scatter eggs here and there, rather than concentrate them  in masses  on individual leaves; consequently, the number of caterpillars on any   one tree is usually low. It feeds in solitude, and then, constructs its   characteristic cocoon wrapped in leaves on the tree. Here, it  overwinters as a  pupa in its large, thick, tough, silken cocoon.
  
 In  late May or early June, the moth emerges from its cocoon where it spent   the winter and commences its short life in the wild – or, in the case  of the  moth I had   – in the office of our home, after being  unceremoniously jostled  about, likely many miles from where it had spun  its cocoon, confident that it  would not be disturbed. 
  
 Meanwhile, if you get a chance, check out Joe Bartok’s website blog,  “Tangled Web”  . Contained in it is some really  fascinating information about plants  and insects that many of us simply overlook  in our travels. I think his  quote from naturalist Louis Agassiz, says it all, “I  spent the summer  travelling; I got half way across my backyard.” 
  
 For more information on birding and nature and guided hikes, check out the  NatureStuff website at www.naturestuff.net 
  
 Terry Sprague lives in Prince Edward County and is self-employed as a  professional interpretive naturalist.