Georissus (Neogeorissus) trifossulatus Motschulsky, 1843

Fikáček, Martin & Falamarzi, Shahram, 2010, Georissus persicus sp. nov. from Iran, with notes on the West-Palaearctic species of the G. laesicollis group (Coleoptera: Georissidae), Acta Entomologica Musei Nationalis Pragae 50 (1), pp. 107-116 : 111-115

Georissus (Neogeorissus) trifossulatus Motschulsky, 1843

( Figs. 2–3 , 6 , 9–10, 12 )

Georissus trifossulatus Motschulsky, 1843: 658 .

Georissus trifossulatus: ERICHSON (1847: 504 , synonymized with G. laesicollis ), REITTER (1901: 66, specific rank confirmed), ALFIERI (1976: 110, faunistic record from Egypt), HANSEN (1999: 49, catalogue).

Type locality. ‘Sur le bord du fl. Alasan à Matany en Géorgie’ [= Georgia, Matani, at the margin of the Alazani river, ca. 42°05′N 45°13′E].

Type material. LECTOTYPE (hereby designated): J ( ZMUM), ‘Matany // Georissus / tri fossulatus / mihi / Matany (Alasan) // 1752 ’. PARALECTOTYPES: 2 JJ, 7 spec. ( ZMUM), same label data as lectotype [all specimens originally mounted on a single piece of transparent plastic].

Redescription. Body widely oval, weakly convex. Length 1.20–1.40 mm (lectotype 1.40 mm); width of pronotum 0.60–0.70 mm (lectotype 0.65 mm); maximum width of elytra 0.75–0.90 mm (lectotype 0.90 mm). Coloration dark reddish, anterior portion of pronotum slightly paler than rest of the body, head dark reddish.

Head. Clypeus smooth, with a line of low granules along anterior margin and sparsely scattered granules on disc. Sublateral longitudinal ridge arising at lateral portion of clypeus and reaching midlength of frons, posteriorly connected to submedian pair of elongate bulges by an arc of sparsely arranged granules; submedian bulges divergent anteriad, not reaching anterior margin of frons.

Pronotum 1.6× as broad as long, with maximum width at posterior third; lateral margin with large curved protrusion on each side. Anterior portion slightly convex, with shallow median longitudinal groove; anterolateral portions with sparse granulation more or less arranged in irregular longitudinal series. Median portion with deep rhomboidal depression surrounded by irregular series of granules; depression slightly longer than wide. Posterolaterally on each side of central depression with oval depression surrounded by the densely arranged granules. Lateral portions of pronotum above the lateral protrusions with a small sparsely granulated bulge on each side.

Elytra combined 1.1× as long as wide, base of elytra ca. as wide as maximum width of pronotum. Humeral bulge distinct, sparsely granulate. Even and odd intervals elevated to same height, all intervals more or less uniformly elevate, bearing only indistinctly prominent rounded granules. Lateral ridges on each elytron highly elevate, consisting of distinct granules. Elytral punctures indistinct.

Abdomen with lateral margins of ventrites 1 and 2 strongly narrowing posteriad. Ventrite 1 bearing sparse scattered granules on the whole surface; sublateral teeth on posterior margin developed, large. Ventrite 2 depressed anteriorly, posteriorly bearing small teeth facing those on ventrite 1.

Aedeagus medium large, 0.30–0.37 mm long (0.37 mm in lectotype). Parameres slightly longer than (1.15× as long as) phallobase, their basal portions combined distinctly narrower than anterior portion of phallobase; paramere straight at very base, widening apicad, wide and strongly convex laterally in apical portion. Length of median lobe slightly shorter than (0.80× as long as) length of paramere; apical portion triangular, narrow, widest at posterior 0.4 of total length; basal struts short, shorter than apical triangular portion of median lobe. Phallobase ca. 2.0× longer than wide, slightly widening posteriad; posterior portion with large basal foramen.

Variation. Except for the body measurements and size of the aedeagus, the type specimens of G. trifossulatus vary slightly in the depth of the median pronotal depression (very distinct and rather deep in the lectotype, slightly less distinctly developed in some of the paralectotypes) and in the general body shape (widely oval in the lectotype, slightly more elongate in some of the paralectotypes). Morphology of the aedeagus is rather uniform in all dissected specimens, with the different proportions of the phallobase (see Figs. 2–3 ) caused by its variable torsion in respect to parameres. Arrangement of the submedian bulges of frons is constant in all specimens examined for this character.

Comments on the taxonomic status. The species was described as distinct from G. laesicollis on the basis of the differences in pronotal sculpture ( MOTSCHULSKY 1843: 661). Based on the examination of the specimens from Georgia deposited in his collection, ERICHSON (1847) synonymized the species with G. laesicollis a few years later. REITTER (1901) removed G. trifossulatus from synonymy with G. laesicollis on the basis of a specimen collected in Uzbekistan (Bukhara). Reexamination of this specimen (deposited in HNHM) showed that it differs from both G. laesicollis and G. trifossulatus in many characters (body larger, anterior portion of pronotum widely pale, lateral portion of pronotum with one large and multiple small protrusions, abdominal ventrite 1 without tubercles on posterior margin, aedeagus clearly different from G. laesicollis and G. trifossulatus ) and seems to be similar to the Himalayan species G. bipartitus Champion, 1923 and G. instabilis Champion, 1923 based on its external morphology. REITTER’ s (1901) confirmation of the specific rank of G. trifossulatus was therefore based on the misidentified specimen.

Based on the examination of the type material of G. trifossulatus , we can confirm that this taxon is extremely similar to the European G. laesicollis . We compared the types of G. trifossulatus with non-type specimens of G. laesicollis from Austria (‘ Carinthia, lgt. Reitter’), Bosnia Herzegovina (‘ Herzegowina, lgt. Th. v. Wanka’) and northeastern Turkey (‘Trapezund [= Trabzon], 4. IV. 1917, lgt. Dr. W. Eicher’), all deposited in NMPC. Both species agree in all details of the superficial sculpture of the head, pronotum and elytra, but seem to differ in the body proportions (body elongate oval in G. laesicollis specimens, widely oval in G. trifossulatus types) and in the depth of the elytral striae (deeply grooved in G. trifossulatus types, striae shallower in G. laesicollis specimens). Aedeagus morphology of both species is very similar, with the phallobase slightly shorter than the paramares, wider than the combined width of the paramere bases and the parameres narrow basally but widening apicad; both species, however, slightly differ in the size of the genitalia (0.37–0.42 mm in G. laesicollis specimens, 0.32–0.37 mm in G. trifossulatus types) and in the general proportions (aedeagus of G. trifossulatus ( Figs. 2–3 ) is more subtile and narrower than that of G. laesicollis ( Fig. 4 ) even in specimens with the same length of the aedeagi).

Based on the specimens examined for this study, we are not able to decide whether G. trifossulatus is a distinct species or if it falls into the variability of G. laesicollis , and we therefore refrain from its synonymization. The situation with the G. laesicollis complex seems to be rather complicated based on our initial study done for this paper – there seem to be more ‘morphotypes’ of G. laesicollis even in European material examined, and a small sample of material examined from Kazakhstan (deposited in HNHM) also contains specimens slightly differing from both G. laesicollis and G. trifossulatus in the morphology of the aedeagus, but otherwise corresponding with these species in external morphology. Moreover, the types of G. laesicollis have to be reexamined in detail to understand the real meaning of this name.

Figures

Figs. 1–4.Aedeagophores of Georissus species. 1 – G. persicus sp.nov., holotype; 2–3 – G. trifossulatus Motschulsky, 1843 (2 – lectotype; 3 – paralectotype); 4 – G. laesicollis Germar, 1831, non-type specimen from Bosnia Herzegovina.

Figs. 5–6. Head of Georissus species, dorsal view. 5 – G. persicus sp. nov.; 6 – G. trifossulatus Motschulsky, 1843. Scale bar: 0.1 mm.

Figs. 7–12.Type specimens of Georissus species.7–8, 11 – G. persicus sp. nov., holotype; 9–10, 12 – G. trifossulatus Motschulsky, 1843, lectotype. 7–10 – habitus (7, 9 – dorsal view; 8, 10 – lateral view); 11–12 – abdominal ventrites. Scale bars: 0. 5 mm (habitus), 0.1 mm (abdomen).