Etymology : The specific epithet is a patronym in honour of arachnologist Radan Kaderka (Czech Republic) who collected the type specimens, and has contributed significantly to the knowledge of Peruvian theraphosid spiders.
The holotype of Hapalotremus albipes Simon, 1903 is
redescribed. Four new species of the genus Hapalotremus
Simon, 1903 are described: Hapalotremus apasanka sp. nov.,
Hapalotremus hananqheswa sp. nov., and Hapalotremus
kaderkai sp. nov. from Peru, and Hapalotremus yuraqchanka
sp. nov. from Bolivia. Discussion on palpal bulb morphology,
ontogenetic spermathecal morphology, and biogeography is presented.
Historical information about collectors and comments
on the accession numbers and other label information of historical
specimens is also presented.