Sunday, May 23, 2010

Millipede

Larry Whiteley (yes, the Bass Pro one) came up with this millipede.  Insect identification used to be difficult to impossible but the Internet has made it easier- or has it?  Insect experts (entomologists), like botanists, frequently debate species and come up with new names, seemingly to confuse those of us in the laity.
You can see a similar creature at Whatsthat bug.com which is identified as a flat-backed millipede in the Polydesmida order, subsequently modified to Apheloria tigana Chamberlin, 1939 (Polydesmida: Xystodesmidae).  They reassure us that "many species like this secrete a cyanide compound to defend themselves. As long as you don’t eat one or lick it, you should survive.”.  Wikipedia confirms that "members of this order have the ability to produce hydrogen cyanide to ward off predators. 
The posting in Bugguide.net illustrates the some of the problems in identification. Here it is identified as "probably a species of Harpaphe". a subsequent expert opinion states "This may be Harapaphe haydeniana but I am not sure with the color variation in the paranota".
Satisfied with the Harpaphe family, more information is available at Wikipedia. Its cousin, Harpaphe haydeniana (Yellow-spotted millipede or cyanide millipede) has similar characteristics. The family produces cyanide and you have to be careful in handling it. (Don't lick it Larry!) They break down leaf litter, producing soil and nutrients for other organisms.
Millipedes are vegetarians,distinguished by having 2 pair of legs per segment rather than one pair like the predatory centipedes. Even this generalization breaks down as this genus has only one pair of legs in the seventh segment, the other pair having been transformed into gonopods for sperm transfer. Didn't Adam give up a rib for the same cause?
There are way to many bugs on the planet to rely on color and the number of legs. Even the aficionados of the sport of entomology can be stifled without examining the detail of microscopic parts. We interested naturalists may have to be satisfied with a few generalizations. To me, its a Flat-backed Millipede- period!
An excellent resource from the Kansas School Naturalist is available at this site.

P.S.
Thanks to Dr. Chris Barnhart for contacting Neal Youngstead who studies millipedes.  He has a pair of similar appearing millipedes which have not reproduced.  He says
"I have no specific identification for them; Polydesmida, Xystodesmidae, is as far as I can go, but I have not really tried to go farther. This usually gets into the realm of the taxonomic specialist before the species level. The attached paper may be of interest and the photos show how similar some of the species can be."
  (See the pictures on page 2 of the PDF in the right hand column of this PNAS- Procedings of the National Academy of Science
site.
Like I said- Flat-backed Millipede.

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