Plusiocampa (Plusiocampa) hoelzeli

Plusiocampa (Plusiocampa) hoelzeli (Neuherz, 1984)

Figs 53–58; Table 5

Torocampa hölzeli Neuherz, 1984: 416, figs 1–23, tables i–ii.

Diagnosis (Neuherz 1984)

Troglomorphic species. Antennae with 34–35 antennomeres; 10–12 complex olfactory chemoreceptors in cupuliform organ; protruding frontal process with non-tubercular setae. Pronotum with 1+1 ma, 2+2–3+3 la, 2+2 lp macrosetae; mesonotum with 1+1 sma, 1+1 la, 2+2 lp, 1+1 (0+1) smp macrosetae; metanotum with 1+1 lp macrosetae; long, barbed notal macrosetae; long, abundant notal clothing setae. One ventral tibial macroseta (two and three in Renejevo brezno); unequal claws (1.5) with large lateral crests, posterior claw with a backward overhang. Urotergite IV with 0+0–1+1 la, 1+1 post macrosetae; urotergite V with 1+1 la, 2+2–3+3 post macrosetae; urotergites VI–VII with 1+1 la, 4+4 post macrosetae; urotergite VIII with 5+5 post macrosetae; abdominal segment IX with 7+7–8+8 post macrosetae; urosternite I with 7+7, urosternites II–VII with 5+5, urosternite VIII with 2+2 macrosetae. Male with glandular g 1 setae, slightly enlarged subcylindrical appendages with abundant glandular a 1 setae; female with subcylindrical appendages with glandular a 1 setae.

Remarks

Five specimens (three females, one male and one juvenile) of Plusiocampa were collected at a very deep location,> 1180 m deep in Renejevo brezno, Kanin Mountain, Slovenia (see Table S 2 in Supplementary Material). No other dipluran has yet been found at such a depth, with the exception of specimens of Plusiocampa (Stygiocampa) sp. presently under study from the Lukina jama–Trojama cave system in Croatia, collected by Branko Jalžić (Kazimir Micilinić, pers. obs.). These specimens match the thoroughly described population of P. (P.) hoelzeli found only in Hafnerhöhle, Karawanken Mountains in Carinthia. Nevertheless, there is some variability in important taxonomic features. First, the number of ventral tibial macrosetae on the metathoracic leg, with two (three in one leg) rather than only one; presumably, only the prothoracic legs were observed in the original description. In addition, there is variability in the antennomeres and cercal articles; their mesurements are recorded (Table 5). Body length from 3.4 to 5.1 mm; antennae shorter than body length, with 10–12 complex olfactory chemoreceptors in cupuliform organ; a whorl of gouge sensilla, 34–38 µm long, on each medial and distal antennomere, with an oblique striation (Figs 53–54); small protruding frontal process with slightly tuberculate anterior macrosetae; pronotum with 1+1 ma, 1+1–2+2 la, 2+2 lp macrosetae; mesonotum with 1+1 la, 2+2 lp macrosetae; metanotum with 1+1–0+0 lp (0+1–1+1 slp) macrosetae; unequal claws, posterior claw 1.4–1.5× as long as anterior claw; posterior claw with a large backward overhang (Figs 55–57); urotergite IV with 1+1 la, 1+1 (2+1) post macrosetae; urotergite V with 1+1 la, 2+2–3+3 (3+1) post macrosetae; urotergites VI–VII with 1+1 la, 4+4 (4+3) post macrosetae; urotergite VIII with 6+6 post macrosetae; abdominal segment IX with 7+7–8+8 (8+7) post macrosetae; apical stylus setae with one or two medial thin barbs, subapical and medial setae with a few thin barbs (Fig. 58); cerci longer than body length in adult specimens (Table 5), with several whorls of long, barbed macrosetae on each article in addition to a whorl of smooth, shorter setae in distal position and a characteristic whorl of short, thin setae with a few thin distal barbs in apical position.

Habitat and distribution

Subterranean species found in a cave in Carinthia (Austria) and another one in the Kanin Mountains (Slovenia).