Hypogastrura ellisi Skarzynski & Kahrarian

Skarzynski, Dariusz, Kahrarian, Morteza, Piwnik, Agata & Zawisza, Marlena, 2017, Description of Hypogastruraellisi sp. n. with notes on H. tethyca Ellis and the trybomi group (Collembola, Hypogastruridae), ZooKeys 719, pp. 45-57 : 45

Hypogastrura ellisi Skarzynski & Kahrarian sp. n. Figs 1-3, 4-8, 9-10

Type material.

Holotype: female on slide, litter in oak forest, Zagros Mountains, Dalab mountain (33°34'N, 47°31'E / 1700 m a.s.l.), Kohdasht County, Lorestan Province, Iran, 4.XII.2013, leg. M. Kahrarian. Paratypes: 4 females, 1 male, same data as holotype; 1 female, 1 male, litter in oak forest, Zagros Mountains, Sorkhdom mountain (33°34'N, 47°32'E / 1650 m a.s.l.), Kohdasht County, Lorestan Province, Iran, 14.XI.2013, leg. M. Kahrarian; 2 females, 1 male, litter in oak forest, Zagros Mountains, near Patogh ghaut (34°25'N, 46°00'E / 1030 m a.s.l.), Sarpol-e-zahab County, Kermanshah Province, Iran, 9.II.2014, leg. M. Kahrarian; 1 male, oak forest, Zagros Mountains, near Shabankareh village (34°52'N, 46°30'E / 1600 m a.s.l.), Paveh County, Kermanshah Province, Iran, 20.I.2014, leg. M. Kahrarian. Holotype and 7 paratypes deposited at the Department of Agronomy, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran and 4 paratypes deposited in the collection of the Institute of Environmental Biology, University of Wrocław, Poland.

Other material.

Greece, Lesbos, leg. Ellis (deposited at the Naturalis Biodiversity Center, Netherland): 22 females, 6 males (21038-21054, 21056-21059, 21062-21064, 21066-21068), Antissa, 30.X.1973, 973240; 18 females, 23 males (21060, 21078-21117), Antissa, 30.X.1973, 973243; 1 male (21061), Antissa, 30.X.1973, 973244; 1 male (21037), Gavathas, 31.X.1973, 973247.

Etymology.

Dedicated to Dr. Willem N. Ellis, an excellent specialist in Collembola .

Diagnosis.

Habitus typical of genus. Ant. IV with three lateral and one dorsal long thin and curved blunt sensilla (sometimes 1-2 more in dorsal group, longer and less curved). Postantennal organ equal to, or slightly larger than, nearest ocellus. Labrum with distinct apical papillae. Tibiotarsi with one clavate tenent hair. Empodial lamellae broad. Ventral tube with 4 + 4 setae. Retinaculum with 4 + 4 teeth. Dens with fine, uniform granulation and seven setae. Mucro with comparatively high outer lamella. Anal spines small, situated on low basal papillae.

Description.

Body length 1.1-1.6 mm. Habitus typical of the genus. Color in alcohol pale brown dorsally and yellowish ventrally, eye-patches dark. Granulation fine and uniform, 12-20 granules between setae p1 on Abd. V.

Chaetotaxy of head typical of the genus, with complete set of v-setae (Fig. 1). Setae slightly differentiated in length, especially on last abdominal segments, smooth and rather thick and stiff. Body sensilla (s) about 2-3 times longer than ordinary setae, fine and smooth. Dorsal chaetotaxy of Th. I–III and Abd. III–VI as in Figs 1-3. Th. I with 3 + 3 setae. Th. II with setae m2 absent, m3 present or absent and m4, m6 present. Th. III with setae m2 and m3 absent and setae m4 and m6 present. Abd. IV with setae p3 present, p7 absent and increased number of m-setae. On Abd. V setae p2 present and m-setae absent. Subcoxae I, II, III with 1, 3, 3 setae respectively. Microsensillum on Th. II present.

Ant. IV with simple apical vesicle, subapical organite (or), microsensillum (ms), three lateral and one dorsal long thin and curved blunt sensilla (sometimes 1-2 more in dorsal group, longer and less curved, marked with an asterisk in Fig. 4) and 5-10 short pointed setae in ventral file (Fig. 5). Ant. III-organ with two long (outer) and two short (inner) sensilla (Fig. 4). Microsensillum on Ant. III present. Ant. I with seven setae (seta p’ absent).

Ocelli 8 + 8. Postantennal organ equal to, or slightly larger than, neighboring ocellus, with four subequal lobes. Accessory boss present (Fig. 6). Labrum with six distinct apical papillae (four large and two smaller, Figs 9-10). Labral setae 5, 5, 4, prelabrals 4. Maxillary head of the H. tullbergi type ( Fjellberg 1984) and labium as in Fjellberg (1999: fig. 6). Outer lobe of maxilla with two sublobal hairs.

Tibiotarsi I, II, III with 19, 19, 18 setae respectively. Apical seta A1 long and clavate. Claws with small inner tooth. Empodial appendage with broad basal lamella and apical filament reaching slightly beyond inner tooth of unguis (Fig. 7).

Ventral tube with four setae on each side. Retinaculum with 4 + 4 teeth.

Furca well developed (ratio dens + mucro/inner edge of claws III 2.4-2.7). Dorsal side of dens with fine, uniform granulation and seven setae. Mucro with relatively high outer lamella. Ratio dens/mucro 2.0-2.3 (Fig. 8).

Anal spines small, situated on low basal papillae (Fig. 3), ratio anal spine/basal papilla 0.7-1.1, ratio anal spine + basal papilla/inner edge of claws III 0.5-0.6.

Remarks.

It is difficult to find a right place for H. ellisi sp. n. within the genus. This species does not key to any of the groups in Skarżyński (2009). However, having weakly differentiated blunt Ant. IV sensilla, one tenent hair on the tibiotarsi, broad empodial lamellae, dens without tooth-like granules and ventro-apical swelling and a mucro without a distinct subapical tooth, it can be compared with some representatives of the trybomi or monticola groups as well as H. aterrima Yosii, 1972, which has an isolated position within the genus.

Undoubtedly, H. ellisi sp. n. is the most similar to H. tethyca , considered as a member of the trybomi group. Most noticeably they differ in the shape of labral apical papillae ( H. ellisi sp. n. - convex, strong, well visible, Figs 9-10; H. tethyca - flat, delicate, hardly visible, Figs 11-13). Apart from this H. ellisi sp. n. lacks setae m2 on Th. II (present in H. tethyca ) and possesses smaller anal spines (the ratio of anal spine + basal papilla/inner edge of claws III 0.5-0.6 in H. ellisi sp. n. vs 0.75-1.1 in H. tethyca ), 5-10 short pointed setae in the ventral file on Ant. IV (Fig. 5) ( H. tethyca - approx. ten short and stiff sensilla, truncate at apex, Fig. 14), and a mucro with a relatively high outer lamella (both inner and outer lamellae are low in H. tethyca ).

Both species have similar general ranges of distribution ( H. ellisi sp. n.: Iran, Greece - Lesbos; H. tethyca : Greece - Crete, Lesbos and Azerbaijan), but on a local scale they co-occur only in Lesbos. In Ellis’s material from this island, numerous H. ellisi sp. n. from two localities and rare H. tethyca individuals from five sites were found. Nevertheless, they were isolated spatially. Unfortunately, due to incomplete collecting data, we do not know whether these populations differ in habitat preferences.

The new species is easy to distinguish from the members of the monticola group by the absence of m-setae on Abd. V (vs present) and the size of the postantennal organ, which is equal to, or slightly larger than, the neighboring ocellus (vs 1.5-2 times larger than ocellus). H. aterrima can also be easily separated from H. ellisi sp. n. due to tridentate retinaculum (vs quadridentate), minute anal spines, slightly larger than surrounding granules (vs large, the ratio of anal spine + basal papilla/inner edge of claws III 0.5-0.6 in H. ellisi sp. n.), the presence of setae m2 on Th. II, and the absence of setae m6 on Th. II–III.