Bromodesmus spp.

(Order Polydesmida, family Dalodesmidae)

Above: Adult females of (left to right) B. catrionae, B. militaris, B. riparius and B. rufus. Scale bar = 10 mm.

Bromodesmus is an H+20 genus (formerly code-named 'Rankodesmus') with a very strong-smelling defensive secretion. The secretion can also stain specimens a red-brown colour after long storage in alcohol, as seen with B. catrionae and B. militaris in the image above. Fresh specimens of these two species are pale brown to gray-brown with dark-brown banding around each segment.

All four Bromodesmus species burrow deep in the soil, but B. rufus can sometimes be found in or under woody litter. B. rufus is also a true subalpine millipede, with a known elevation range of ca. 500-1300 m. B. riparius can be abundant in rich organic soil close to shaded streams in the Dial Range, but may be rare elsewhere in its range.

In the distribution map below, note that there appears to be no overlap between the four Bromodesmus ranges. This will help with identification, but be sure to check the male gonopods, shown below. First collections were B. catrionae in 1991, B. militaris in 1988, B. riparius in 1992 and B. rufus in 1980.

Below: Gonopods of B. riparius (head to left). In this specimen the gonopod bases have 'emerged' from the body.

Below: Gonopod tips (left to right) B. catrionae, B. militaris, B. riparius and B. rufus. In some specimens of B. riparius the needle-like structure (technically, the solenomere) points straight up.

Localities for B. catrionae (blue), B. militaris (red), B. riparius (purple) and B. rufus (light green). Scale bar = 100 km.
For an interactive map with more up-to-date localities, go to the mapper page.

More information:
 
Taxonomy - Mesibov (2004b)
Distribution, conservation and general - Mesibov (1997a) (as 'dalodesmid n. gen. 2, n. sp. 2')