ABSTRACT: Our knowledge of the recently described genus Eriastichus La Salle is greatly enhanced with the addition of 48 new species: E. acribis sp. nov., E. aphritis sp. nov., E. cluridis sp. nov., E. coelotis sp. nov., E. colenis sp. nov., E. copalensis sp. nov., E. daptilis sp. nov., E. decoris sp. nov., E. denotatis sp. nov., E. derilis sp. nov., E. diadrys sp. nov., E. dotaensis sp. nov., E. drupis sp. nov., E. ebulis sp. nov., E. egrestis sp. nov., E. eleagnis sp. nov., E. ellipsis sp. nov., E. eminis sp. nov., E. facilis sp. nov., E. fenestris sp. nov., E. follis sp. nov., E. galeatis sp. nov., E. geratis sp. nov., E. glanis sp. nov., E. hilaris sp. nov., E. johnlasallei sp. nov., E. johnnoyesi sp. nov., E. maniatis sp. nov., E. nebulis sp. nov., E. neonis sp. nov., E. nexilis sp. nov., E. novalis sp. nov., E. nugalis sp. nov., E. oasis sp. nov., E. ononis sp. nov., E. orestis sp. nov., E. pallidops sp. nov., E. parabilis sp. nov., E. renodis sp. nov., E. rivalis sp. nov., E. sannionis sp. nov., E. scalaris sp. nov., E. sodalis sp. nov., E. taraxis sp. nov., E. tendrilis sp. nov., E. tonioazofeifai sp. nov., E. velaminis sp. nov., and E. vestis sp. nov. All species are known only from males, and all material is from Costa Rica. Females show little morphological variation and are not possible to separate to species or link to conspecific males at present. Apart from the diagnostic features for the genus presented in the original description, two new autapomorphies are introduced here: an inflated pleural membrane between Gt1-4 and Gs1-4, and tufts of pale and flattened setae laterally on Gt4-6. Both features are found on the gaster and are present in both sexes. The distribution of the genus is firmly established as predominantly neotropical. The biology remains unknown.