Lepidocyrtus instratus Handschin, 1924

Mateos, Eduardo & Álvarez-Presas, Marta, 2022, Integrative taxonomy reveals three new species of European Lepidocyrtus lignorum-group (Collembola, Entomobryidae), Zootaxa 5100 (4), pp. 451-481 : 454-457

Lepidocyrtus instratus Handschin, 1924

Figs 2–7 , Table 2

Material examined. One slide (deposited at the National Museum of Natural History-NMNH, Paris , France) containing one specimen of L. instratus prepared and identified by Gisin in 1948. The slide was labeled with the code “1b:Rr4/2”, and “Autriche, Tirol ” as locality .

Diagnosis based on the original description of Handschin (1924), Gisin (1964a, 1964b) and specimen from the slide “1b:Rr4/2”. Length 2.0 mm (maximum). With dark blue pigment on Ant.II–IV, buccal area, dorsal side of Th.III to Abd.III (and dispersed over Abd.IV–V) and coxae ( Fig. 2 ). Th.II sligthly projecting over head ( Fig. 3 ). Ant. I–II, legs, ventral tube and posterior region of manubrium with scales. Labial chaetae (M 1 M 2 REL 1 L 2) in “p row” well developed and ciliated, M 1 a little shorter than M 2, R half in length than M 2 ( Fig. 4 ). Dorsal cephalic and body macrochaetae formula as A 0 A 2 A 3 Pa 5 /00/0101+3 ( Fig. 5 ). Anterior trichobotrium of Abd.IV with accessory chaetae a, D1 and m fan-shaped, without chaeta s ( Fig. 6 ). Ungues with a small basal tooth at about 40% of the inner edge; unguiculi lanceolate, with smooth and curved outer edge ( Fig. 7 ).

Discussion. In the original description of Handschin (1924) the chaetotaxy was not described and the species was characterised by the colour pattern, the ungues without inner teeth and the unguiculi truncate. The localities of the specimens assigned for the type series are located in the Engadine region of Swiss Alps, at altitudes between 2600 and 2800 m a.s.l.; these specimens were collected under stones on the edge of a snowy field and in groundhog droppings.

Gisin (1964a), based on several topotypes, corrected the original description of Handschin (1924) and noted the presence in the ungues of a small basal teeth (at about 40% of the inner edge) and a tiny tooth (at about 55% of the inner edge), and the lanceolate morphology of the unguiculi rather than truncate. However, Gisin noted that the unguiculi has a curved outer edge, giving the appearance of being truncated. Gisin (1964a) also described the dorsal macrochaetotaxy of head and body, and confirmed the colour pattern of the species as the one described by Handschin in the original description. Both Handschin and Gisin noted the dark pigmented buccal area as characteristic of the species. In the same year, Gisin (1964b) described the chaetotaxy of the basal labium and the accessory chaetae of the anterior trichobothrium of Abd.IV.

The slide from the NMNH revised by the author is, supposedly, part of the material used by Gisin (1964a) for the revision of the species. The specimen was in very bad condition, and the chaetotaxy was completely invisible. However, the morphology of several ungues and unguiculi was visible and was the same as that described by Gisin (1964a).

As noted by the above paragraphs (and also previously noted by Mateos 2008) L. instratus is poorly described in the literature. However, enough characters are known to ascribe the species to the European lignorum -group (sensu Mateos (2011). Several fundamental chaetotaxic characters are still unknown, which makes difficult comparisons between this species and the other species of the lignorum -group with the standards currently required in the genus Lepidocyrtus .

Figures

FIGURES 2–7. Lepidocyrtus instratus: 2, habitus lateral (from Handschin 1924); 3 Head and mesothorax in lateral view (picture from specimen in the slide “1b:Rr4/2”, NMNH); 4, labial chaetotaxy (sensu Gisin 1964b); 5, dorsal cephalic and body macrochaetae (black filled dots), trichobothria (lines) and pseudopores (empty circles) (after Gisin 1964a); 6, anterior trichobotrium of Abd.IV complex (after Gisin 1964b); 7 unguis and unguiculus (after Gisin 1964a).