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What's That Bug? does not endorse extermination

Subject:  Luna Moth Caterpillar
Geographic location of the bug:  Eagle River, Wisconsin
Date: 10/01/2019
Time: 10:19 AM EDT
Your letter to the bugman:  We found this caterpillar on a nearby wooded pathway yesterday, and didn’t know what it was or where it was going–end of September can usher in very cold temperatures here.  So, at home we identified it as a Luna Moth Caterpillar.  We want to properly release it back into the wild.  It would be lovely to have seen it develop into the moth, but we don’t feel confident that we can keep it healthy.  Will it over-winter here in the North?  or Will it still be able to mate yet this autumn?  It was found under a soft Maple tree quite close to a lake and alder bushes near the lake and surrounding wetland.  I was even wondering if it could drown?  Thank you for information so that we can release it soon and get it on its way to the right environment.
How you want your letter signed:  The Rasmussens

Polyphemus Caterpillar

Dear Rasmussens,
Luna Moth Caterpillars and Polyphemus Moth Caterpillars can be difficult to distinguish from one another.  We believe your caterpillar is a Polyphemus Caterpillar.  The identifying feature is a pale yellow band that runs through the spiracles or breathing holes on the Polyphemus Caterpillar.  It is described on BugGuide as:  “Larva: body large, bright green, with red and silvery spots below setae, and oblique yellow lines running through spiracles on abdomen; diagonal streak of black and silver on ninth abdominal segment; head and true legs brown; base of primary setae red, subdorsal and lateral setae have silver shading below; end of prolegs with yellow ring, and tipped in black.”  At this time of year in your location, we speculate this individual is preparing to pupate and it will overwinter in the cocoon.  Caterpillars are not aquatic.  They can drown.

Dear Daniel:?? Thank you for the information.?? It is nice to know what it is– Polyphemus, not Luna, and that it will overwinter.?? It started spinning yesterday between two leaves in the leaf litter at the bottom of the container, currently in our garage.?? So now, we will have to decide the next step:?? possibly to get info on overwintering it in our refrigerator with a constant temperature or it will be subjected to?? subzero temperatures for much of our Northern Wisconsin winter.?? If you had thoughts and time on this, don’t hesitate to drop a line.?? We appreciate and feel fortunate to have had your communication.?? Much of the information we were finding is not specific in details or confusing.???? –Patty & Eric Rasmussen

Dear Patty and Eric,
We do not raise caterpillars, but in captivity, one needs to be cognizant of temperature and humidity.  Too warm and the moth will emerge prematurely.  Too damp or too dry it might not survive.  We would recommend keeping it outdoors in a protected location where it will benefit from precipitation, but not get too wet.

What's That Bug? does not endorse extermination

Subject:  Spiky caterpillar
Geographic location of the bug:  New York State
Date: 09/07/2019
Time: 01:07 PM EDT
Your letter to the bugman:  Hello,
This was taken today in New York State.  I’ve searched trying to indenting this one but it has me stumped. Any info would be much appreciated. Thank you!
How you want your letter signed:  Kat

Buck Moth Caterpillar

Dear Kat,
Based on this BugGuide image, your caterpillar appears to be that of a Buck Moth,
Hemileuca maia.  According to BugGuide:  “Caution, caterpillars can inflict painful sting.”

What's That Bug? does not endorse extermination

Subject:  LARGE green caterpillar
Geographic location of the bug:  Middle Georgia
Date: 08/28/2019
Time: 12:33 AM EDT
Your letter to the bugman:  This guy (girl?) showed up on my patio cover (canvas). It’s about 3 inches long and probably an inch around. (BIG joker). Thought maybe Luna Moth. Some one said maybe Imperial Moth. I know Lunas are endangered and I want to do the right thing. Don’t plan on hurting it or anything just curious about what it is.
How you want your letter signed:  Curious in GA

Imperial Moth Caterpillar

Dear Curious in GA,
This is an Imperial Moth Caterpillar.  Many Giant Silkmoth Caterpillars from the family Saturniidae and Hornworms from the family Sphingidae pass unnoticed on vegetation while they are feeding.  Fully grown caterpillars then hunt for a suitable place for pupation  They leave the food plant and at that time they are frequently discovered by observant humans.  When we receive images of pre-pupal Imperial Moth Caterpillars, they have frequently turned brown or orange as metamorphosis nears.  Your green individual might still be feeding

What's That Bug? does not endorse extermination

Subject:  big silkmoth caterpillar
Geographic location of the bug:  Bangor, Maine
Date: 08/14/2019
Time: 03:47 PM EDT
Your letter to the bugman:  Hi! We rescued this caterpillar who was crossing the highway.  I’ve seen photos of it online with people saying it’s a Luna, but I’m thinking maybe Polyphemus?
How you want your letter signed:  Ryan and Emily

Pre-Pupal Luna Moth Caterpillar

Dear Ryan and Emily,
Distinguishing a Luna Caterpillar from a Polyphemus Caterpillar can be challenging, but we believe your caterpillar is a Luna Caterpillar.  The pink coloration is due to it being pre-pupal, and we have seen numerous images of pink pre-pupal Luna Caterpillars.  Luna Moth caterpillars, according to BugGuide, are:  “Larva lime-green with pink spots and weak subspiracular stripe on abdomen. Yellow lines cross the larva’s back near the back end of each segment (compare Polyphemus moth caterpillars, which have yellow lines crossing at spiracles). Anal proleg edged in yellow. Sparse hairs.”  Your individual is lacking the “yellow lines crossing at spiracles” that are present in Polyphemus Caterpillars.

Thank you so much Daniel.  What a tricky ID!  Much appreciated.
Update:  August 17, 2019
Bugman (Daniel)– our strangely-colored Luna caterpillar has made a cocoon by folding up some birch leaves in its fish tank terrarium.  I’m aware that it should be misted periodically so it doesn’t dry out…how often is that necessary?  How many days can you skip the misting, without it drying out to death?
Thank you again so much for the ID of this creature.  –Ryan
Hi again Ryan,
We do not raise caterpillars in captivity, but the problem with a terrarium is that it is cut off from external conditions.  Outdoors, the cocoon would be exposed to rain and other precipitation.  Another problem with raising caterpillars indoors is the stable temperature that occurs in modern homes, and this can effect emergence time which presents problems when adults emerge at a time of year that prevents release back into the wild (like an indoor emergence in the dead of winter).  The important consideration is not how often you mist, but when you mist.  If the captive conditions get too dry, the pupa might desiccate.  Trying to duplicate outdoor conditions in a protected environment is a goal.  Good luck.  
What's That Bug? does not endorse extermination

Subject:  Caterpillar
Geographic location of the bug:  Gloucester pool on the Trent Severn waterway
Date: 08/14/2019
Time: 01:51 PM EDT
Your letter to the bugman:  A caterpillar like this stung my son last weekend. After it crawled across his hand he had a double track of very itchy sore spots
How you want your letter signed:  Pam

Io Moth Caterpillar

Dear Pam,
We needed to research your location which we mistakenly thought was in the UK.  Now that we know you are in Ontario, Canada, your son being stung by an Io Moth Caterpillar makes sense.  This is a North American species with a well documented history of stinging.  According to Poison Help:  “The nettling organs are borne on fleshy tubercles, and the spines are usually yellow with black tips. The spines are connected to poison glands.”  You may also read about them on Entomology University of Kentucky.  To the best of our knowledge, the reaction is localized and though painful, the sting is not a cause of concern, though we would always recommend seeking medical advice if there are any concerns.

Thank you very much!  Will pass on the info to my son.
Pam
What's That Bug? does not endorse extermination

Subject:  Green Caterpillar
Geographic location of the bug:  Angela, Montana
Date: 08/07/2019
Time: 02:43 PM EDT
Your letter to the bugman:  My daughter found this by some of our grain bins and she loves bugs. Just curious what kind it was. Thanks!
How you want your letter signed:  Hadlie Mae

Glover’s Silkmoth Caterpillar: Hyalophora species

Dear Hadlie,
This is a Giant Silkmoth Caterpillar in the genus Hyalophora, but we are not certain of the species.  BugGuide recognizes three species in North America, and BugGuide reports two of those species, the Ceanothus Silkmoth and the Columbia Silkmoth from Montana, and the third species, the Cecropia Moth, is reported from the nearby Dakotas as well as Wyoming, and since Angela, Montana is in the eastern half of the state, we would not rule out the Cecropia Moth.  We will try to contact Bill Oehlke to see if he can distinguish the actual species.  Here is a BugGuide image of the Glover’s Silkmoth Caterpillar, the western subspecies of the Columbia Silkmoth.  We suspect your caterpillar is preparing to spin a cocoon.

Giant Silkmoth Caterpillar: Hyalophora species

Thank you! He stared to change the night we emailed you.

Giant Silkmoth Cocoon

Hi again Hadlie,
Thanks so much for sending in images of the cocoon spun by your Giant Silkmoth Caterpillar.  We are hoping to hear back from Bill Oehlke regarding a species identification.

I am pretty sure it is Columbia gloveri due to three sets of orangey dorsal scoli instead of two sets in cecropia. Both species are likely present in Rosebud County.
Bill Oehlke

What's That Bug? does not endorse extermination