12 Oct 2014 ID INSIGHTS

The following email from Greg Edgecombe, sent in July this year, wonderfully highlights the intricacies of species identification. It concerns a House Centipede . Today (Sunday) I sought and received Greg’s permission to post it on my blog – all the more impressive because he is a paleontologist specialising in centipedes and Merit Researcher at the Natural History Museum in London. Previously he worked at the Australian Muesum in Sydney for 14 years. Greg was contacted by Bob Mesibov who is based in Tasmania and has helped me with centipede enquries.

Bob and Peter,

Scutigeromorph IDs based on photos are usually highly dubious and I would definitely put this one into that category.  Determining a species requires at least staring at tergite 6 down a microscope at high magnification and working out the relationships of spines, bristles, hairs and whatnot.  If there’s only one species known from a well-surveyed area you can stick your neck out a bit more confidently with a photo alone, but SE QLD harbours multiple species of pretty similar Thereuoneminae.

The name Allothereua maculata has been used for pretty much everything in Australia.  It’s a Western Australian species and can usually be subtly distinguished from eastern populations, and sorts out from them pretty handily based on molecular sequence characters.  When I was doing some morphometric work with students we used the name A. maculata sensu Verhoeff for a particular species that is found in mostly arid parts of eastern Australia, but generally steers clear of rainforest.

The Allothereua we usually find in SE Queensland I called Allothereua serrulata Verhoeff, 1925.  It has clumps of thickened spiculae (slender, spike-like hairs) around the pairs of spines and bristles scattered on its tergal plates.  These are visible in light microscopy in high magnification but are better seen in a slide mount down a compound microscope (as Verhoeff did) or by SEM (as I often have done).  Sorry, they are simply not a user-friendly group of centipedes.

My student Sam Bolton and I sorted the A. serrulata material from NSW and SE QLD into two morphs based on different frequencies of whether the tergal spines were accompanied by a bristle on one side only or by a bristle on each side (not much to go on, but it corresponded to a subtle difference in shape of their female gonopods that we teased out morphometrically).  The ones from around Tamborine Mountain would be in the distribution of the morph we called A. serrulata subspecies 1 (it is all through SE QLD and NE NSW).

Thus with many caveats and football-sized grains of salt, I’d guess that might be what this is but if I were dead wrong I wouldn’t bat an eye.

Cheers,

Greg