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

Abstract

There were 193 schizomids (hubbardids) collected from the soil (0-7 cm depth) during a 12 month study of a primary upland forest (37.5 6 16.8 ind/m2/month) near Manaus. They were represented by Surazomus brasiliensis(Kraus 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 inhabited the organic soil layer (0-3.5 cm depth) where monthly catches of juveniles were positively correlated with soil tem- perature. Females were twice as abundant as males. The lack of a distinct reproductive period and the presence of juveniles (in particular the first nymphal instar) and adults (both sexes) throughout the year indicate a plurivoltine mode of life. Few specimens were caught on the soil surface, and none were on tree trunks or in the canopy. Abundance of S. brasiliensis is compared to that of the Palpigradi (micro- whip scorpions) and Thelyphonida (vinegaroons) from the same study site.