A possible phylogenetic signal in milliped chemical defenses:: The polydesmidan milliped Leonardesmus injucundus Shelley & Shear secretes p-cresol and lacks a cyanogenic defense (Diplopoda, Polydesmida, Nearctodesmidae)

The nearctodesmid polydesmidan milliped Leonardesmus injucundus Shelley and Shear was found to secrete p-cresol as a defensive fluid, and to lack mandelonitrile, benzaldehyde and hydrogen cyanide, heretofore found to be characteristic of most polydesmidan millipeds. The sympatric nearctodesmid Kepolydesmus anderisus Chamberlin does not secrete p-cresol, but utilizes the usual cyanogenic pathway. These are only the second reports on defensive secretions in the milliped family Nearctodesmidae. p-Cresol may be the characteristic secretion of members of the nematophoran order Callipodida, (p-cresol is reported here from Delophon georgianum Chamberlin [Callipodida, Abacionidae] for the first time) and thus its presence in a polydesmidan may be indicative of a relationship between Callipodida and Polydesmida, which orders share other synapomorphies. Examples of two species of Glomeridesmus (Glomeridesmida, Glomeridesmidae) were examined and found to lack any sign of repugnatorial pores. (C) 2007 Elsevier Ltd. All rights reserved.