Apheloria polychroma, a new species of millipede from the Cumberland Mountains (Polydesmida: Xystodesmidae)

A revision of the wilsoni species group in the millipede genus Nannaria Chamberlin, 1918 (Diplopoda, Polydesmida, Xystodesmidae)

“…Previous authors have indicated that many undescribed species, and possibly even genera, remain to be found in the tribe (Hoffman 1999;Hennen and Shelley 2015;Marek et al 2018), and this has been supported in a recent study of the minor species group, in which 35 new species of the genus were named (Means et al 2021b). However, the wilsoni species group has not been investigated, and new species have been uncovered by examination of material in museum collections.…”

“…Millipedes in the family Xystodesmidae encompass a large component of the diplopod fauna in the deciduous forests of the Holarctic, with 539 currently known species (Marek et al 2014;Means et al 2021a, b;Mikhaljova 2021). Many species in the family are strikingly aposematic, with bold hues of yellow, orange, and red that are paired with black, thereby advertising their toxic chemical defenses of hydrogen cyanide and benzaldehyde (Marek and Bond 2009;Marek et al 2018). While all members of the family are chemically defended, a few groups within the family do not appear to rely heavily on chemical defense and aposematism as a main form of defense.…”

“…The small size and comparatively subdued colors are atypical for xystodesmids, and previous authors have termed Nannaria as non-aposematic due to these traits, but speculated Nannaria may be mimicking colorless juveniles of aposematic xystodesmids (Whitehead and Shelley 1992). Additionally, Nannaria do not exhibit as much diurnal surface-level activity, traits typically associated with aposematic organisms, as other xystodesmids do, such as the apheloriine species Apheloria polychroma (Marek et al 2018). More commonly, Nannaria species are collected under forest detritus such as dead leaves and stones, or with passive trapping methods such as pitfall traps.…”

A revision of the minor species group in the millipede genus Nannaria Chamberlin, 1918 (Diplopoda, Polydesmida, Xystodesmidae)

“…Additionally, N. bobmareki sp. nov. was encountered co-occurring with, but not participating in, a putative Müllerian mimicry ring composed of the xystodesmid species Apheloria polychroma Marek, Means & Hennen, 2018 and Brachoria flammipes Marek, 2010(Marek 2010.…”

“…Burrowing, and behavioral concealment, is likely related to their drab coloration as part of an overall cryptic strategy (Ruxton et al 2018). Dominant color patterns of Nannaria, e.g., small red or white spots on either paranota with a dark background and lack of additional pattern elements such as spots on the prozonite (as in some Apheloria polychroma with four large yellow spots [Marek et al 2018]), lend themselves to a cryptic appearance. Red light has been shown to be a dominant color in forest sub-canopies and red body coloration appears to be camouflaged in these habitats (Wilson et al 2007).…”