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Abstract

Observations and video records of live cultures of the parthenogenetic or bisexual Muyudesmus obliteratus Kraus, 1960, from Peru, Brazil and Germany, as well as of the parthenogenetic Poratia digitata (Porat, 1889) (Polydesmida: Pyrgodesmidae) from hothouses in Germany, revealed that the four long setae at the tip of the pre-anal ring represent a spinning apparatus only used by juveniles and subadults. Each seta is located in a pit and separated from the others by a surrounding cuticular wall. All immature stages first build a moulting chamber of soil and/or bark material with their mouthparts. Inside the sealed chamber they produce a silken cocoon inside which they moult. Adult females were not observed to produce silky material during construction of their egg chamber. Our observations represent the first record of spinning ability in Polydesmida, something hitherto thought to be restricted in Diplopoda only to the orders Polyxenida, Chordeumatida, Callipodida and Stemmiulida