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Flea from Red Squirrel

Flea from Red Squirrel
Finland, Lake County, Minnesota, USA
March 29, 2006
Size: 2mm
Louse Flea from a Red Squirrel (Tamiasciurus hudsonica). Shot through my really cheap scope with a Rube-Goldberg lighting apparatus.

Images of this individual: tag all
Flea from Red Squirrel Flea from Red Squirrel

Flea Market
I still have the little blighter and would dearly love to send it to someone who could ID it further.


to order guide page. maybe someday we can ID it further

You want my flea?
If someone wants this flea mailed to them I would be glad to send it. Perhaps you could get better photos and an accurate ID? This one is dead (alcohol poisoning) but I guarantee that I could get fresher specimens. My north woods property is often OVERRUN with these squirrels and I have a rule of only two squirrels at my bird feeders at a time. How long will fleas live in the absence of their host?

This is actually a flea. Maybe a rodent flea, Dolichopsyllidae.
Do you by chance have a higher-res image? A bit of Photoshopping and we might be able to nail down a family ID. It appears that there is a well-developed compound eye, which would not be present in a rodent flea. The only other option would be a Pulicid, and whether or not there are 2 rows of bristles on the abdominal tergites would nail it down. Fleas are actually pretty easy to ID with specimen in hand. The Peterson Guide to Insects is about all you need. You already have a scope.
-Sean McCann

Lousy ID
OK. What's the difference between a louse and a flea? Rooky question, I know. I'm an Odonate guy.

I do have much higher resolution photos (but have dial-up internet access until Monday when I get DSL hooked up) and I have no Peterson Insects book (I have always been so frustrated by those general guides that I don't own one). I do have the older Arnett and will look through it, sometime.

Are these critters species specific or will they utilize a variety of hosts?


Lice are from the orders Anoplura and Mallophaga. They have an incomplete metamorphosis, with juveniles resembling the adults. Fleas (Order Siphonaptera), on the other hand, are holometabolous, with juveniles not in the least resembling adults (like flies and butterflies).
Basically what you are looking for on your flea to tell the family would be: do the upper parts of the abdominal segments have one row of hairs, or two? One row would mean Pulicidae, two would be Ceratophylllidae (which I just learned is the same as Dolichopsyllidae). It does have what is called a pronotal comb (the spines behind the head). The only families of fleas that can have a pronotal but no genal comb are Pulicids and Ceratophyllids.
As for host specificity, yep, most are pretty host-specific. THat doesn't mean they won't bite you if they jump on you, but they cannot usually live successfully without their preferred host type. Sometimes that is a single species, more often several species are suitable hosts.
Anyway, don't worry about the ID, that's why we're here: to help each other learn more. Also, the Peterson is not that bad, as long as you are using it for family ID. The Borror, Triplehorn, and Johnson "Introduction to the Study of Insects" is more comprehensive, and has keys, but does lack the portable size. By all means avoid the Audubon Guides, as I have always found they mess people up with weird made-up common names (but get it if you have the dough).
-Sean McCann

lice feed on blood, but on sk
fleas are insects order (siphonoptera), lice are in a different order depending on the mouth parts, chewing or piercing (Anopulara or Mallophaga).

many other differences, but thats the main one

Maybe it is a Ceratophyllid,
Maybe it is a Ceratophyllid, like Orchopeas howardii. The Peterson guide does not consider this family, but this species is a common inhabitant of gray and red squirrels.
-Sean McCann

Referencing Arnett, there are no Pulicidae that are hosted by "tree squirrels" and very few that reside on rodents at all.
The Ceratophyllidae have several species which are hosted by tree squirrels. The key goes no further than this.


I would say that is probably what you have. That would be a new family for Bugguide (which isn't surprising). If you can get some higher res pics up, I am sure someone would be glad to make a page.
Also, keep finding fleas! They are really interesting little critters, and 99% of what people find commonly are Ctenocephalides felis. Rodent fleas are a great addition to this site.
-Sean McCann

How/where do I post higher resolution photos? I've only been following the 560pix max rule.

You can post larger files.
However, only bugguide editors will be able to see them in more than 560 pixels.

higher res
Couldn't get too much bigger as I had to crop the original photo down so much. Hope it clarifies things a bit.

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