
The moths of Philadelphia are an exclusive bunch, numbering only fifty-two species. The 52 species on this list are confirmed to fly around in the City of Philadelphia (Philadelphia County). I am fascinated by moths, but I often don’t venture out moth-hunting. I can go in my garden at night, but for the last week I have been a “walking mosquito buffet”. So, no going outside after dusk.
I think moths are often prettier than butterflies.
Further Moth-flavored Info
There are over 10,500 identified species of moths in North America, north of Mexico. And there very few books on moths except a handful of regional guides. Caterpillars of Eastern North America: A Guide to Identification and Natural History (Princeton Field Guides) by David L. Wagner is one-of-kind and I find it extremely useful. I would like to read Owlet Caterpillars of Eastern North America also by David L. Wagner, but there is only one Owlet moth listed for Philadelphia, the Striped Garden Caterpillar. But, the book may be valuable for your hometown. Create your county list and find out.
Mr. John Snyder’s website is useful for identification http://facweb.furman.edu/%7Esnyderjohn/leplist/
Since this list is for my hometown of Philly, don’t despair. You can generate a list for your county at the website of Butterflies and Moths of North America sponsored by Montana State University at http://www.butterfliesandmoths.org/. Look under “regional lists”.
All the hyperlinks below take you to the species account at the Butterflies and Moths of North America website.

More Posts on Moths
Stalking the Woolly Bear Caterpillar
Bagworm Moth: Little Brown Bags on the Tips of Trees
Clearwing Hummingbird Moth and Its Life Cycle
Polyphemus Moth – Luminous Beauty

I just read a paper from 2015 that concluded that Samia cynthia is now extinct in Philadelphia. I know that for years it was very common in the city. Do you have any first hand accounts that it has been found in Philly recently, and if so, where?
Hi, James
Thanks for contacting me.
When I look for an account of Samia cynthia on the butterfliesandmoths.org website, the moth is listed as extinct.
The moth was brought here from its native China for silk production, The host plant is the Chinese of Heaven, an invasive tree that people have actively been removing from forest, gardens, parks, etc.
When a species is introduced and its host plant is an invasive species, the insect won’t have much of a future. I am not surprised it didn’t last.
Check out these two sites for information.
The Lepidopterists’ Society https://www.lepsoc.org/ – Perhaps if you contact them they may be be able to answer your questions.
Butterflies and Moths of North America https://www.butterfliesandmoths.org/species/Samia-cynthia
Hope this helps.
James, I have no doubts that I had an encounter with the larvae (caterpillars) of the Samia Cynthia moth back around 1978-1979 while I was working in the Northern Liberties section of Philadelphia. The address was 1728 N. 5th St. but is now 1730 N. 5th. There was a blind courtyard with a door out to it from the shop I worked in. Several ailanthus trees were growing in there. One day I went to work at a machine near a window that opened into the courtyard and there were all these huge green caterpillars that found their way inside.
I was a bit creeped out and relocated them outside. The Ailanthus trees were apparently their host tree. i deduce that these were Cynthia moths that somehow managed to survive the “extinction” of them in Philadelphia. On Google maps aerial view, i can see trees still growing in that courtyard. I would love to find out if those caterpillars are there every year.
I bet u saw them. Animals don’t bother with human made range maps. And these moths fly anywhere they want to
And don’t forget to mention that wonderful resource: Bugguide.net, http://bugguide.net/node/view/82.
You can narrow it down to Philadelphia county: http://bugguide.net/adv_search/bgsearch.php?user=&taxon=82&description=&location%5B%5D=PA&county=Philadelphia&adult=&immature=&male=&female=&representative= and you can use a google map from that link.
I use it all the time. I have contributed a few images of moths from Southeastern PA to this site; but I tend to take more pictures of bees and flies than moths.
Thanks for the additional resource. It is a great resource I have surfed the site in the past and will use it more in the future.
Thanks, I can really use these resources. It looks like BAMONA welcomes submissions of pics to help with ID. I just might avail myself.
Glad I could help, Scott.