Most species of the mite genus Winterschmidtia Oudemans, 1923 are associated with bark beetles. These mites are predacious on eggs of their coleopteran hosts and may be potential biocontrol agents for pest species of bark beetles. Here we describe three new species of Winterschmidtia from Peru based on phoretic deutonymphs: W. parallela sp. nov. (from Loganius flavicornis), W. alekhini sp. nov. (from Phloeotribus biguttatus) and W. reducta sp. nov. (from Phloeotribus pilula). The name Calvolia fusiformis Zachvatkin, 1941 was recombined as Winterschmidtia fusiformis (Zachvatkin, 1941) com. nov. An illustrated key to species of the genus Winterschmidtia (phoretic deutonymphs) of the world is provided.