Polydesmid
Guides
Apheloria
cherry millipedes, flat-backed millipedes
Apheloria is a genus of large, chemically defended millipedes in the family Xystodesmidae, distributed across eastern North America. These millipedes are notable for producing hydrogen cyanide and benzaldehyde as defensive secretions, which imparts a characteristic cherry or almond odor. The genus participates in Müllerian mimicry rings in the Appalachian Mountains, with species displaying highly variable aposematic coloration involving black backgrounds with contrasting yellow, orange, red, or white markings. Species-level identification requires examination of male gonopod morphology due to extensive color polymorphism and convergent color patterns among co-occurring species.
Sigmoria bidens
Sigmoria bidens is a species of flat-backed millipede in the family Xystodesmidae, described by Causey in 1942. It belongs to the order Polydesmida, one of the largest orders of millipedes, characterized by their flattened bodies and keeled tergites. The genus Sigmoria is part of the tribe Apheloriini within the subfamily Rhysodesminae. Very few observations of this species have been documented, with only 8 records in iNaturalist as of the knowledge cutoff.