Hemilepistus ruderalis ( Pallas, 1771 )

Kashani, Ghasem M., 2019, Revision of the terrestrial isopods of the subgenus Hemilepistus (Desertellio) Verhoeff, 1930 (Isopoda: Oniscidea), Zootaxa 4555 (4), pp. 531-547 : 532-535

Hemilepistus ruderalis ( Pallas, 1771)

Figs 1–3

Oniscus ruderalis Pallas, 1771 : 477.81.

Porcellio pallasii Brandt, 1833: 179 .

Hemilepistus ruderalis: Budde-Lund, 1885: 156 .— Borutzky, 1945: 198.

Hemilepistus russonovae Borutzky, 1951: 164 .

Material examined. Southern Russia, leg. Pallas, type of Hemilepistus pallasii , female, 19 mm (MNB 7080);

Azerbaidjan, Apsheron, April 1934, leg. B. H . Russonova, holotype of H. russonovae , male ( ZMMU, Mc-573) ; Azerbaidjan, Apsheron, April 1934, leg. B. H . Russonova, paratypes of H. russonovae , one male and two females ( ZMMU, Mc-573); Tauria (an ancient name for the present Crimean Peninsula), Muspetros, Budde-Lund collection, leg. Charusin, two males ( BMNH 1921.10.18:4133–4134) ; Kazakhstan, Kirghiz steppe, Budde-Lund collection, two males ( BMNH 1921 . 10.18:4135–4136) ; Kazakhstan, Dzhanybek, leg. N . Burnasheva, det. Borutzky, two males and five females ( ZMMU, Mc-699) ; Kazakhstan, Sary-Su River in downstream, 11 July 1948, det. Borutzky 1948, one male and two females ( ZMMU, Mc-572); Western Kazakhstan, Dzhanybek, experimental melon field, 20 April 1951, leg. N . Burnasheva, one male and one female ( ZMMU, Mc-701); Western Kazakhstan, Dzhanybek, under manure and stones, 14 April 1951, leg. N . Burnasheva, 13 females and 10 males ( ZMMU, Mc- 704); Western Kazakhstan, Dzhanybek, under shelters, 11 April 1952, leg. N . Burnasheva, two females ( ZMMU, Mc-697) .

Redescription. Maximum length of both male and female: 20 mm. Color brown in fixative ( Fig. 1A–D ).

Head with well developed quadrangular lateral and shorter median lobes; frons with an incision in middle; vertex thoroughly covered with small rounded tubercles of more or less the same size ( Figs 1A, B ; 2A ). Antenna long equipped with long setae; fifth article of the peduncle to flagellum ratio 1.3:1; flagellum with two articles, proximal article almost two times as long as distal one ( Fig. 2B ).

Pereon tergite I with rounded hind margin, granulated with several rounded tubercles of the same size or two markedly larger tubercles on the median part ( Figs 1A, B ; 2A ). Pereon tergites II and III with a row and few small tubercles, respectively ( Fig. 2A ). Pereon tergites IV–VII smooth.

Pleon smooth, with continuous outline with pereon; telson short, triangular, with concave sides and acute or rounded apex, slightly surpassing uropod protopodites ( Figs 1C, D ; 2C ). Uropod protopodite with conspicuous incision on lateral margin; exopodite 1.5 times as long as telson ( Fig. 2C ).

Pleopod exopodites I–V with monospiracular covered lungs ( Fig. 3B–F ).

Male: Pereopod I merus and carpus with strong spine setae but without brushes of setae ( Fig. 2D ). Pereopod VII ischium with straight ventral margin; merus and carpus equipped with strong spine setae ( Fig. 2E ).

Pleopod endopodite I straight; apex with a short finger-like lobe equipped with a row of setae on inner margin, not surpassing the apex of endopodite ( Fig. 3A ). Pleopod exopodite I with rounded hind margin ( Fig. 3B ). Pleopod exopodites II–V as in Fig. 3C–F .

Remarks. This species is close to H. pavlovskii in the shape of the head with well developed lateral lobes, and vertex with several rounded tubercles of more or less the same size; pereon tergites I–III with rounded tubercles decreasing in numbers posteriorly; male pereopod I merus and carpus without brushes of setae and pereopod VII ischium with straight ventral margin; but differs in having an incision in the middle of the frontal line and in distal part of pleopod endopodite I with a finger-like process at the apex ending at the same level with the summit of endopodite.

Borutzky (1951) described and figured Hemilepistus russonovae from Azerbaijan. He mentioned that this species is similar to H. ruderalis but differs from that in terms of having shorter antennae, different structure of the

lateral lobes of the head and the structure of pleopod endopodite I. However, reexamination of the type material of both species revealed that they belong to the same species. Distribution. Azerbaijan; Crimea; “Caucasus”; Turkmenistan, Kirghizistan, Kazakhstan; Russia.

Figures

FIGURE 1. Hemilepistus ruderalis; A, B: male, BMNH 1921. 10. 18:4133–4134; C: female, MNB 7080, type of Hemilepistus pallasii; D: male, BMNH 1921. 10. 18:4135–4136. A, head and pereon-tergites I–II, dorsal view; B, pleon; C, head and pereontergites 1–3, dorsal view; D, pleon.

FIGURE 2. Hemilepistus ruderalis. A, head and pereon-tergites I–III; B, antenna; C, pleon; D, pereopod I; E, pereopod VII. Scale = 1 mm.

FIGURE 3. Hemilepistus ruderalis. A, pleopod endopodite I; B, pleopod exopodite I; C, pleopod exopodite II; D, pleopod exopodite III; E, pleopod exopodite IV; F, pleopod exopodite V. Scales = 0.5 mm.