Mystery of the Mangy Squirrel Slurry – solved!

A few posts ago I presented a puzzle – what were the strange arthropod-like creatures I found in a KOH-dissolved slurry of eastern gray squirrel skin? I canvassed colleagues from around the world, and none had a definitive answer (though Terry Galloway from the University of Manitoba guessed the correct order, or suborder depending on your taxonomy). Yesterday I received a second square of skin from the same squirrel, also sent by Jamie Rothenburger. This time I didn’t dissolve it in KOH but rather just plopped it in ethanol and examined it underneath a dissecting scope. Lo! Dozens of the tiny mystery animals were attached to the squirrel’s hairs. Even better, four older instars, including an adult, were also present. So, what did they turn out to be? Sucking lice (Anoplura), most likely Enderleinellus longiceps Kellogg & Ferris based on papers by Kim (1996 a, b). UPDATE: no, it is not E. longiceps, it doesn’t even belong to that genus. I keyed out the adult female today and she turned out to be Neohaematopinus sciuri Jancke based on Kim et al. (1986). I was a bit too eager to get photos of the critters and didn’t wait until the slides were completely cured, so the images below are a little blurry. First are photos of embryonic lice still in eggs, then photos of what I think is a second nymphal instar. The scalloped structure beneath the tarsal claw that was particularly obvious on the legs of the animals in the original post are less striking in the nymph.

Nits on squirrel hair.

Two eggs on a squirrel hair, one occupied.

Enderleinellus in egg B

Close-up of one embryo popping out of the egg.

Enderleinellus nymph habitus B

Nymphal sucking louse, Neohaematopinus sciuri.

Enderleinellus nymph head

Internal mouthparts of the nymph.

Enderleinellus nymph claw with scallop

Tarsus of second leg showing faint scalloped structure.

Enderleinellus nymph scales

A nice scaly patch of integument from the dorsum of the nymph.

Neohaematopinus sciuri female habitus

Adult female Neohaematopinus sciuri.

Neohaematopinus sciuri sternum

Relative sizes of tarsal claws of legs I to III and shape of the sternal sclerite (arrow) helped to identify the female as belonging to the family Polyplacidae and the genus Neohaematopinus.


Kim, K.C. 1966. The species of Enderleinellus (Anoplura, Hoplopleuridae) parasitic on the Sciurini and Tamiasciurini. J. Parasitol. 52: 988-1024

Kim, K.C. 1966 The nymphal stages of three North American species of the genu Enderleinellus Fahrenholz (Anoplura: Hoplopleuridae). J. Med. Ent. 2: 327-330.

Kim, K.C., H.D. Pratt and C.J. Stojanovich. 1986. The Sucking Lice of North America: an Illustrated Manual for Identification. Pennsylvania State University Press, University Park.

Smaller fleas

In his very long poem on the nature of poets, Jonathan Swift famously noted that parasites can themselves be parasitzed. A few weeks ago I came across an interesting case of hyperparasitism. I had washed a recently road-killed Yellow-bellied Sapsucker. It yielded many lovely mites and one feather louse. I slide-mounted the latter and representatives of the former.

Pteronyssus sphyrapicinus male and female ex YPSS HP0929 sml

Pteronyssus sphyrapicinus (Astigmata: Pteronyssidae) feather mites from a Yellow-bellied Sapsucker. Male on left, female on right.

When I looked at the louse under the compound scope I thought its Malpighian tubules had burst out of its abdomen. At higher magnification, the tubules turned out to be hyphae.

Penenirmus auritus with arrows

Fungally infected Penenirmus auritus (Phthiraptera: Philopteridae) from a Yellow-bellied Sapsucker.

I figured it must be a member of the Laboulbeniales, fascinating and highly modified ascomycotan fungi: look here and here! Almost all of the 2000 or so described species are ectoparasites – or perhaps in some cases harmless commensals – of living arthropods. One species has achieved recent notoriety due to its spreading from a native ladybird in the U.K. to an invasive one. I had seen them on various critters before, including beetles and mites, though never on a feather louse. But Googling revealed that in 1951, Wolfdietrich Eichler had published an interesting overview of the Laboulbeniales he’d seen on lice from birds*.Eichler figure

They were all from the genus Trenomyces. I asked my mycologist friend Randy Currah if he could tell whether the fungus on my louse was one that Eichler had identified. He referred me to Meredith Blackwell at Louisiana State University. She identified the images as a Trenomyces sp. (like Eickler’s) and then sent the images I emailed to her to Danny Haelewaters at Harvard University. I’m not sure whether Danny will be able to get it to species based on my bad photos, but if he does I will update. UPDATE (22 Aug 2015) – Danny has just identified the fungus as Trenomyces circinans Thaxter, a new record for Canada. Thanks, Danny!

Penenirmus auritus from YBSS trimmed

Closer view of the Trenomyces showing a big ascocarp, two ascospores (lower right) and juvenile multiseptate things that probably have proper names but I will just call ‘babies’.

*Eichler, W. 1951. Laboulbeniales bei Mallophagen und Läusen. Feddes Repertorium. 54(53):185-206.