Winter survivor mite: morphological insights into the frost-resistant mite Eustigmaeus absens Doğan (Acariformes: Stigmaeidae)

This study presents morphologically the distinctive characteristics of the adults and all immature stages of Eustigmaeus absens Doğan. Some asymmetrical and numerical variations in the body setae of this species are also presented. E. absens, in addition to other months, was collected from frozen moss moulds in the winter months (November, December and January). This means that this frost-resistant species possesses the capacity to tolerate the formation of ice in its tissues. Additionally, the Turkish specimens previously identified as Eustigmaeus schusteri (Summers & Price) were evaluated and found to belong to E. parakauaiensis Kapaxidi, Stathakis & Papadoulis. Furthermore, additional specimens of E. vacuus Doğan were collected from the Karasu Valley (Türkiye). The morphological characteristics of these specimens are consistent with previous records, although a barely visible lateral incision on the hysterosomal shield was observed in one specimen, suggesting an intraspecific variation. © Systematic & Applied Acarology Society.