Lustrochernes grossus (Pseudoscorpiones: Chernetidae) associated with decaying wood in riparian cloud forests

Abstract. We analysed the dead-wood characteristics that determine the presence of saproxylic pseudoscorpion species in remnants of riparian cloud forest. We examined 98 dead-wood pieces (70 logs and 28 stumps), and recorded tree species, decaying wood stages, presence of the pseudoscorpion Lustrochernes grossus (Banks, 1893) (Chernetidae) and the Bess beetle Helicus tropicus. In these wood samples we found 24 L. grossus and one chela. We recorded the highest number of individuals in Clethra mexicana (11), followed by Quercus corrugata (6) and Liquidambar styraciflua (6). In Annona cherimola and Trema micrantha, one chela and one female were recorded, respectively. The presence of this pseudoscorpion is likely due to its relationship with the Bess beetle, which coexists in decaying wood. The distribution of L. grossus in dead wood may also be influenced by tree species and stage of decay. Forest fragmentation and the extraction of firewood from the remnant riparian fragments of cloud forest are factors that could jeopardize the saproxylic pseudoscorpion species and other arthropod diversity associated with decaying wood in this threatened ecosystem.