Seventy-one colonies from 24 species of Coleoptera, Passalidae, belonging respectively to the genera Passalus Fabricius, 1792 (14 species), Paxillus Mac Leay, 1819 (three species), Popilius Kaup, 1871 (three species), Spasalus Kaup, 1869 (one species), Verres Kaup, 1871 (one species) and Veturius Kaup, 1871 (two species), were examined from seven municipalities of Amazonas, one of Rondônia and one of Roraima states. Twelve species of psedoscorpions were found, belonging to nine genera and five families, as follows: Chernetidae - Americhernes aff. incertus Mahnert 1979, Cordylochernes scorpioides (Lin. 1758), Lustrochenes similis (Balzan 1892), L. aff. reimoseri Beier, 1932, L. intermedius (Balzan 1892), Phymatochernes crassimanus Mahnert 1979; Chthoniidae - Pseudochthonius homodentatus Chamberlin 1929; Lechytiidae - Lechytia chthoniiformis (Balzan 1887); Tridenchthoniidae - Tridenchthonius mexicanus Chamberlin & Chamberlin 1945; Withiidae - Cacodemonius sp, Dolichowithius emigrans (Tullgren 1907), D. mediofasciatus Mahnert, 1979. Among the most common species, all the development stages of T. mexicanus, L. intermedius and L. aff. reimoseri were found. From one to three species of pseudoscorpions were collected in each colony of passalíd beetles. T. mexicanus, the only species found in all municipalities, was caught in 45 colonies of nineteen species of passalids, the majority of them occurring under bark. L. intermedius, the second most abundant species, was caught in colonies of 11 species of passalids, the majority of them also under bark. Lustrochenes aff. reimoseri was caught in colonies of 13 species of Passalidae under bark and in sapwood and heartwood and was the only species caught exclusively in heartwood.
Pseudoscorpiones; Arachnida; Coleoptera; Passalidae; Amazon; fallen wood
