Abundance and phenology of Schizomida (Arachnida) from a primary upland forest in Central Amazonia

There were 193 schizomids (hubbardids) collected from the soil (0-7 cm dept h) during a 12 month study of a primary upland forest (37.5 +/- 16.8 ind/m( 2)/month) near Manaus. They were represented by Surazomus brasiliensis (Kra us 1967) and an undescribed species of a new genus (96% and 4% of the total catch, respectively). About 68% of all specimens of S. brasiliensis inhabi ted the organic soil layer (0-3.5 cm depth) where monthly catches of juveni les were positively correlated with soil temperature. Females were twice as abundant as males. The lack of a distinct reproductive period and the pres ence of juveniles (in particular the first nymphal instar) and adults (both sexes) throughout the year indicate a plurivoltine mode of life. Few speci mens were caught on the soil surface, and none were on tree trunks or in th e canopy. Abundance of S. brasiliensis is compared to that of the Palpigrad i (micro-whip scorpions) and Thelyphonida (vinegaroons) from the same study site.