The nymphal instars of two species, Pergalumna myrmophila (Berlese, 1914) and P. striatiprodorsum Ermilov, Alvarado-Rodríguez & Retana-Salazar, 2014, based on materials from Russia and the Antilles, respectively, are described and illustrated. The nymphs of these species are generally similar in their habitus. Basic characteristics of nymphs are the well-developed transverse furrow on the gastronotic shield as well as circumgenital and adanal macrosclerites; the gastronotic setae d-, l-, h- and p-series, which are represented by their alveoli, and the position of famulus ε on tarsus I. Additionally, comparative analyses of juvenile instars of species belonging to Galumnidae are given based on our own data and available literature sources.