Erythraeus acis (Berlese, 1882) is redescribed basing on type specimen from Berlese Acaroteca deposited in Firenze, Italy. The individual, labelled as ‘Coll. Berlese, Erythraeus acis (tipico) Berl. Acireale’ and registered in the collection as 30/40 is illustrated, measured and described. Diagnosis and description are supplemented with standard measurements, not considered in original description. Differentiating diagnoses comprise Palaearctic species of Erythraeus Latreille, 1806, known from postlarval forms, and satisfactorily described in literature. Concise diagnosis and systematic status of Erythraeus gorcensis Gabryś, 2016, is provided. Neotypes for Erythraeus adpendiculatus (Schrank, 1781), E. opilionoides (C. L. Koch, 1837) and E. rupestris (Linnaeus, 1758) are designated as well. The case of sexual dimorphism, sporadic in Erythraeus, and its influence on synonymy is mentioned in relation to Erythraeus cinereus (Dugés, 1834) (= Erythraeus similis (Canestrini, 1885)).