Xanthodasythyreus toohey Walter & Gerson

Xanthodasythyreus toohey Walter & Gerson

Xanthodasythyreus toohey Walter & Gerson is a slow-moving mite hiding in a pincushion of 39 long, barbed setae.  It lives in dry surface soil such as the litter at the base of grass trees (Xanthorrhoea spp.) in the open forests of eastern Australia.

 

In order to capture as much of the mite in focus as possible, 18 separate digital scanning electron micrographs (SEMs) of about 1 mb each were needed.  Each image was made semi-transparent, then overlaid as a separate layer, then restored to full opacity in an image processing program.  The new composite image was then ‘masked’, that is isolated from the background and a new background was created.  Since SEMs are Grayscale, and mites are not, I then tried to recreate the colours of the mite as it was when it was alive.  In all, this image took about 40 hours of intense and concentrated work to produce.  That’s a lot of time in the evening and on weekends to spend on a single mite image, but this one has proven highly popular featuring, e.g. as a full page spread in Popular Science (A mite in a million.  Popular Science, October 2001, p. 44), on the cover of the just released A Manual of Acarology 3rd Edition (Texas Tech University Press), and so I am told, in Maxim under the title ‘A really bad hair day’.

 

Xanthodasythyreus is not found in North America, but another member of the family (Dasythyreidae), Dasythyreus sp. has been found on logs in boreal forest at George Lake in Alberta, Canada.  This may be the same species as Dasythyreus hirsutus Atyeo which bears 179 whiplike setae on its back and was described from tree bark in Arkansas, USA.  Fortunately, I do not have any SEMs of Dasythyreus, because I am sure that trying to layer and mask 179 pairs of dorsal setae (let alone those on the legs) would be a really bad hair month.  Dasythyreus species are known to be phoretic (i.e. hitch rides) on click beetles (aka elater beetles, Coleoptera: Elateridae).

Tags: Prostigmata