With 4 figures in text)Two new species of Meguseliu Rondani, M. dimotphica Disney and M. praedafura Disney, are described from South America. Their larvae crawl around on the bodies and exuviae of Theraphosidae. Larvae of M. pruedajiira were observed moving on to the spider's prey while it was engaged in feeding from the same prey.

The new genus Neoholothele is herein described based on the results of a recent phylogenetic analysis. This phylogeny, which included representatives of all Theraphosidae subfamilies, showed that the genus Holothele, as hitherto defined, does not comprise a monophyletic group. Neoholothele gen. nov. is diagnosed by the following features: males and females with dark carapace and golden cephalic region; females with striped color pattern on the abdomen dorsum and long and slender spermathecae receptacula; males with retrolateral branch of male tibial spur with apical end wider than proximal end (synapomorphy), with two apical spines. It comprises two species: N. incei (F. O. Pickard-Cambridge, 1898) comb. nov. and N. fasciaaurinigra sp. nov., both from northern South America.

The genus Euthycaelus Simon 1889 is diagnosed based on the examination of type-material and additional material from Venezuela and Colombia. The genus now includes: Euthycaelus colonicus Simon 1889, E. norae sp. nov., E. amandae sp. nov.; Euthycaelus steini Simon 1889 is transferred to Psalistops comb. nov. The genus Schismatothele Karsch 1879 is considered a senior synonym of Hemiercus Simon 1903. Schismatothele includes S. lineata Karsch 1879, S. inflata (Simon 1889) comb. nov., S. modesta (Simon 1889) comb. nov, and S. benedettii Panzera et al. 2011. Hemiercus proximus Mello-Leitão 1923, from Cubatão, São Paulo, Brazil, is transferred to Acanthoscurria proxima (Mello-Leitão 1923) comb. nov. Hemiercus kastoni Caporiacco 1955 is considered a species inquirenda pending the examination of the type material.

A series of adult flies were reared from larvae living on the carapace of a spider, Pamphobeteus vespertinus (Simon), from Ecuador. These are described and named Megoselia tinteri Disney sp. n. This is a sibling species of M. dimorphica Disney and M. praedafura Disney, whose larvae also live on Theraphosidae in South America.

The new genus Agnostopebua Perez-Miles & Weinmann is proposed for the type species A. tota n. sp. and A. gardel n. sp. from Boyaca, Colombia. Agnostopehna build shelters under stones at high elevation. The new genus is unusual in lacking tarsal scopulae on its posterior legs and in having few labial cuspules and short leg tarsi in females.