Chiasmanyssus, Gomes-Almeida & Pepato, 2021

Gomes-Almeida, Brenda K. & Pepato, Almir R., 2021, A new genus and new species of macronyssid mite (Mesostigmata: Gamasina: Macronyssidae) from Brazilian caves including molecular data and key for genera occurring in Brazil, Acarologia 61 (3), pp. 501-526 : 506-507

Chiasmanyssus n. gen.

Zoobank: 1C2CF818-9683-4DB2-BE34-DAD69DC435F5

( Figures 3 –10)

Type species: Chiasmanyssus cavernicola , new species.

Diagnosis — Female large, its sternal shield square, distinctly sclerotized, with a smoother area on central sternal shield X-shaped; sternal shield bearing three pairs of setae and two pairs of pores; without sternal glands; anterior median protusion in epigynal shield extends under the sternal shield; anterior spur on coxa II lacking. Adults with dorsal shield entire, reticulated and with j and J series complete. Adults and protonymphs with setae J5 minute; all setae on idiosoma, legs and gnathosoma slender and smooth, except palp with disto-ventral seta on genu spatulate. Females and protonymphs with chelae simple and slender, without spines or other processes. Male with four pairs of conspicuous pores near setae j3, z4, J3 and one laterally between J4 and J5 setae; peritrema short, extending from posterior margin of coxae II to the anterior margin of coxae IV and peritrematic shield with nodule fused to the middle of the shield.

Etymology — The generic name comes from Greek word chiasma “ ” referring to the distinct X-shaped area on sternal shield and nyssus “ ”, to prick, referring to the parasitic life.

Figures

Figure 3 Chiasmanyssus cavernicolan. sp. female. A – Dorsal shield; B – Tritosternum; C – Sternal shield, note the distinct X-shaped sclerotization and epigynal shield; D – Anal shield. Scale bars: A 20 µm; B, C & D 50 µm.