Hypogastrura cretensis, Skarżyński & Gwiazdowicz, 2022

Skarżyński, Dariusz & Gwiazdowicz, Dariusz J., 2022, A redescription of Hypogastrura gisini Strenzke, 1954 (Collembola: Hypogastruridae) and description of a new related species from Crete (Greece), Zootaxa 5155 (1), pp. 52-60 : 56

Hypogastrura cretensis sp. nov.

Figs 12–16

Hypogastrura cf. gisini: Ellis, 1976: 247

Type material. Holotype: female, verge of the road near the city, comparatively damp, heightened rather recently with coarse sand, overgrown with scanty grass, Rethymno , Crete, Greece, 22.x.1972, leg. A.C. & W.N. Ellis (972.225, ZMA.COL.P 20557) ( NBCN) . Paratypes: 1 male, same data as above ( NBCN) ; 1 female, upper 2 cm compact bare loam, with ephemerous vegetation with liverworts ( Fossombronia sp. ) and seedlings, along roadside, Marathos , Crete, Greece, 26.x.1972, leg. A.C. & W.N. Ellis (972.231, ZMA.COL.P 20583) ( NBCN) ; 1 male, litter under large Quercus coccifera on south slope, Drosia , Crete, Greece, 23.x.1972, leg. A.C. & W.N. Ellis (972.226, ZMA.COL.P 20568) ( NBCN) ; 1 female, wet sandy loam, trodden and ruderal, with some perennial grasses, Fortetsa , Crete, Greece, 19.x.1972, leg. A.C. & W.N. Ellis (972.230, ZMA.COL.P 20579) ( NBCN) ; 1 female, 1 juv., bark of Zelkova abelicea trees, slope of Mt. Kedros near Gerakari village (35.194829 N, 24.606713 E), 1255 m a. s. l., Crete, Greece, 11.x.2018, leg. D.J. Gwiazdowicz ( DIBEC) .

Description. Habitus typical of the genus. Body length 0.7–1.1 mm. Color light greyish-blue. Tegumental granulation coarse and uniform, 5–6 granules between setae p 1 on Abd. V ( Fig. 12 ).

Body setae short (slightly longer on last abdominal segments), fine and smooth. Body sensilla (s) about two times longer than microsetae, fine and smooth. Chaetotaxy of head typical of the genus, with complete set of v-setae ( Ellis 1976: Fig. 9 e ). Dorsal chaetotaxy of Th. I–III and Abd. IV–VI as in Ellis (1976: Figs 10 , 12b–d ). Th. I with 3 + 3 setae. Th. II with setae m 2, m 3 and m 4 present. Th. III with setae m 2 and m 3 absent and setae m 4 present. Abd. IV with setae p 3 and p 7 present. Abd. V with setae p 2 present and setae m 1 and m 3 usually present ( Fig. 12 ). Subcoxae I, II, III with 1, 2, 3 setae, respectively. Microsensillum on Th. II present.

Ant. IV with simple apical vesicle, subapical organite, microsensillum, 6–8 weakly differentiated cylindrical, curved sensilla (3 lateral and 3–5 dorsal) ( Fig. 13 ) and 5–7 short pointed setae in ventral field. Ant. III-organ with two long (outer) and two short (inner) sensilla. Microsensillum on Ant. III present. Ant. I with 7 setae (seta p’ absent).

Ocelli: 8 + 8. Postantennal organ 1.7–2.0 as long as neighboring ocelli, with four lobes, the anterior pair slightly larger than posterior one. Accessory boss present, but sometimes hard to observe ( Fig. 14 and Ellis 1976: Figs 9h–k ). Labrum without apical papillae. Labral setae 5, 5, 4, prelabrals 4. Maxillary head as in Fjellberg (1998): Fig. 11d . Lamella 1 broadened at tip, protruding beyond teeth, with two fringes of long cilia. Labial palp as shown in Fjellberg (1999: Fig. 6 ). Outer maxillary lobe with two sublobal hairs.

Tibiotarsi I, II, III with 19, 19, 18 setae, respectively. Apical seta A1 weakly clavate, slightly longer than inner edge of claw. Claws with small inner tooth. Empodial appendage with narrow basal lamella. Ratio empodial appendage/inner edge of claws = 0.5–0.6 ( Fig. 15 and Ellis 1976: Fig. 9c ).

Ventral tube with four setae on each side. Retinaculum with 3 + 3 teeth.

Furca well developed (ratio dens + mucro/inner edge of claw III = 2.7–3.0). Dorsal side of dens with 7 setae and with coarse, uniform granulation. Mucro slightly curved, with globular tip and rather high outer lamella ending just before the apex. Ratio dens/mucro = 2.5–3.2 ( Fig. 16 and Ellis 1976: Figs 9d, f, g ).

Anal spines short (ratio anal spines/inner edge of claws III = 0.3–0.5), slightly curved, on separate papillae of same length as spines ( Ellis 1976: Figs 12a, b ).

Etymology. Named after the type locality, Crete.

Remarks. Ellis (1976) reported the occurrence of a form similar to H. gisini in Crete. H. cf. gisini was found at eleven sites, mainly inland around Iraklion and Rethymno, in anthropogenic habitats (e.g. roads, orchards, meadows) with clay, less often sandy, soil up to 700 m a. s. l. This form differed from H. gisini not only in habitat preferences (the latter occurs in coastal habitats), but also in morphology (the author indicated the length of the empodium as a distinguishing feature). Ellis did not decide to describe H. cf. gisini as a new species because he did not have the opportunity to study the type material of H. gisini . After redescription of this species and examination of H. cf. gisini specimens from the collections of Ellis (NBCN) and DIBEC it became clear that they are morphologically distinct. As a consequence, this last form has been recognized as a species new to science – H. cretensis sp. nov. The differences between them, as well as other species of the H. manubrialis group sensu Babenko et al. (1994) that have a retinaculum with 3 + 3 teeth and a maxillary head of the H. vernalis type ( Fjellberg 1984), i.e. H. breviempodialis , H. tianshanica and H. ubsunurensis are presented in Tab. 1 .

Figures

FIGURES 12–16. H. cretensis sp. nov.: 12, tegumental granulation and chaetotaxy of Abd. V; 13, chaetotaxy of Ant. III–IV; 14, postantennal organ and ocelli; 15, claw III with empodial appendage; 16, dens and mucro. Abbreviations in text. Scale bar 0.01 mm.

FIGURES 5–11. H. gisini: 5, chaetotaxy of Ant. III–IV; 6, postantennal organ and ocelli; 7, claw III with empodial appendage; 8, dens and mucro; 9, mucro, lateral view; 10, mucro, lateral view (variant); 11, mucro, lateral view (variant). Abbreviations in text. Scale bar 0.01 mm.