The milliped family Pyrgodesmidae in the continental USA, with the first record of Poratia digitata (Porat) from the Bahamas (Diplopoda: Polydesmida)

Abstract

The milliped family Pyrgodesmidae in the continental USA comprises eight species: Poratia digitata (Porat), P. obliterata (Kraus), Calpytodesmus sanctus Schubart, Psochodesmus crescentis Cook, Myrmecodesmus formicarius Silvestri, Myrmecodesmus digitatus (Loomis), Myrmecodesmus reddelli new species and ‘Lophodesmus’ bituberculatus Loomis, previously known only from Puerto Rico. They inhabit urban and native environments and caves from northern coastal Georgia and north-central Alabama to south Florida and central and southern Texas, and have been encountered in greenhouses in Illinois. Four species represent human importations, probably from the Neotropics, but the other four appear to be indigenous, and possibly endemic, to certain areas. The occurrence of M. formicarius in south-eastern Louisiana is considered an introduction, but that in Texas is logically the northern part of its natural distribution, which extends southward to Veracruz, Mexico. Likewise, M. digitatus is endemic to the Gulf Coastal states from the eastern panhandle of Florida to western and northern Louisiana, and P. crescentis may be endemic to peninsular Florida. Myrmecodesmus reddelli is known only from the type locality in Kendall County, Texas, and may also be a Mexican form that extends northward into this state. Poratia digitata is recorded for the first time from the Bahamas (Andros Island), Louisiana, and Texas, and M. digitatus and ‘L.’ bituberculatus are newly recorded from Alabama and Florida, respectively; Ilyma colotlipa Chamberlin is placed in synonymy under M. formicarius. A key and illustrations of pertinent somatic features facilitate determinations.