Triplax sulphuricollis Reitter, 1887

Thorn, Simon, Kazerani, Farzaneh, Farashiani, Mohammad Ebrahim & Morinière, Jérôme, 2022, Triplax sulphuricollis Reitter, 1887 from the Hyrcanian forests of Iran recognized as a valid species by morphology and barcoding (Coleoptera: Erotylidae), Zootaxa 5196 (3), pp. 443-450 : 445-447

Triplax sulphuricollis Reitter, 1887 , new status

( Figs. 2c–f )

T. collaris var. sulphuricollis Reitter 1887: 8 . Type Locality: “ Lenkoran ” [= Lankaran, Azerbaijan].

T. collaris sulphuricollis: Jacobson 1915: 934 .

T. sulphuricollis (as synonym of T. collaris ): Węgrzynowicz 2007: 543.

Specimens examined: Type material: Triplax collaris var. sulphuricollis : 1, Lenkoran, col Reitter ( HNHM), Holotypus; 7, Lenkoran, col Reitter ( HNHM) , Paratypus. Non-type material: IRAN: 1, Mazandaran, Kelârdascht , 36.54584°, 51.0791°, 01.05.2018, (male), leg. S. Thorn ( ZSM) ; 56, Gilan, West of Asalem , 37.670861°, 48.752667°, 25.04.2018, leg. S. Thorn ( ZSM, NBG, STC) ; 3, Gilan, Shafarud , 37.474146°, 48.820231°, 25.04.2018 leg. S. Thorn ( STC) ; 15, Part Kola , 36.139060°, 53.408954°,01.08– 31.08.2015, leg. H. Barimani ( ZSM, NBG, STC) ; 11, Sika , 36.35762°, 53.54408°, 13.05.2017, leg. J. Müller ( ZSM, NBG, STC) ; 19, Kelardascht , 36.54528°, 51.08021°, 11.05.2017, leg. J. Müller; 23 , Mazandaran, Sika , 36.35641°, 53.53896°, 28.04.2018, leg. S. Thorn ( ZSM, NBG, STC) ; 37, Gilan, 37.55827°, 49.09062°, 08.05.2017, leg. J. Müller ( ZSM, NBG, STC) ; 12, Chalandar , 36.542249°, 51.645507°, 30.06.2014, leg. S. Thorn ( STC) .

Diagnosis: Body compact, oval, egg-shaped, elytra black, pronotum orange-yellow. Terminal maxillary palpomere hatchet-shaped. Pronotal basal margin with weak marginal bead. Antennal club orange-yellow. Linear punctation on elytra in depressed rows. Last 1–4 abdominal ventrites without significant orange-yellow pigmentation ( Fig. 2d ).

Triplax collaris has a brown to black antennal club, no or only shallow elytral striae, and the last 1–4 abdominal ventrites with significant orange-yellow pigmentation ( Figs. 2a–b ).

Redescription: Total length 2.3–4.9 mm; width (at broadest point of elytra) 1.9–2.4 mm. Body ( Figs. 2c–d ) compact, oval, egg-shaped, male and female general appearance similar. Elytra and head uniformly black with moderate metallic luster, pronotum and legs orange-yellow. Head, pronotum, and scutellar shield with shallow punctation. Head with triangular form and irregular punctation dorsally.

Antennae orange-yellow with club composed of 3 antennomeres, expanded, orange-yellow. All antennomeres filiform, longer than wide, third antennomere elongated, 1.5–2 times length of fourth antennomere. Antennal club sometimes with distinct pigmentation but never brown to black. Terminal maxillary palpomere hatchet-shaped.

Pronotum with lateral marginal bead, anterior edge with slight margin. Claws with lighter pigmentation than tarsi.

Elytral length 1.4–3.1 mm, basal margin of elytra crenulate, forming a distinct ridge. Punctation on elytra arranged into distinct elytral striae, punctation between those striae in a vague alternating double row. Elytral striae becoming more indistinct laterally. Abdomen black ( Fig. 2d ).

Male aedeagal tegmen sclerotized, triangular, laterally compressed; lateral margins gradually converging posteriorly; apically with 2 elongate, bar-shaped parameres. Parameres dorsoventrally compressed, apically with setae. Aedeagus with median lobe laterally compressed, sclerotized, in lateral view strongly curved, apex tapering to rounded point ( Fig. 2e ). Female genitalia with gonocoxites triangular, gradually narrowing posteriorly; apices of gonocoxites laterally with concave impression and setae. Gonostylus inserted at the apex of the concave impression of the gonocoxite, with several short setae at apex ( Fig. 2f ).

Natural history and distribution. The Hyrcanian region is a humid mountainous zone in northern Iran and southern Azerbaijan that extends from around 20 m in the southern coastal plain of the Caspian Sea to 2500 m a.s.l. on the northern slopes of the Alborz Mountains ( Fig. 3 ). The mean annual temperature ranges between 9 and 15 °C, and annual precipitation ranges between 400 and 1100 mm, whereas the western Hyrcanian region has higher amounts of precipitation ( Gholizadeh et al. 2019). The mountains in this region are covered by deciduous forests dominated by Oriental beech, Fagus orientalis Lipsky (Fagaceae) , between 700 and 1500 m a.s.l. ( Sagheb-Talebi 2002). Triplax sulphuricollis occurs regularly on oyster mushrooms ( Pleurotus spp. ; Pleurotaceae ) found on F. orientalis .

Key to species

The following key will distinguish T. sulphuricollis from T. collaris :

1. Antennal club dark, brown to black or no more than the last antennomere reddish in the outer half ( Figs. 2a–b ); rows of elytral punctation not or only in shallow linear elytral striae; last 1–4 abdominal ventrites with significant orange-yellow pigmentation ( Fig. 2b ). Europe, Caucasus, Urals.................................................... T. collaris (Schaller, 1783)

- Antenna club of the same orange-yellow color as all other antennomeres ( Figs. 2c–d ); linear punctation on elytra in depressed rows; last 1–4 abdominal ventrites without significant orange-yellow pigmentation ( Fig. 2d ). Azerbaijan and Hyrcanian Forest in northern Iran................................................................ T. sulphuricollis Reitter, 1887

Figures

FIGURE 2. (a) Dorsal view and (b) ventral view of Triplax collaris (Schaller, 1783) (Austria, Neusiedler See, 05.05.1989, leg. Dries, col H. Bussler) (c) Dorsal view of male Triplax sulphuricollis (Iran, Chalandar, 36.94225°, 51.64551°, 30.06.2014, leg. S. Thorn) with characteristic orange-yellow antennal club and linear punctation in depressed rows on elytra, (d) ventral view, (e) male genitalia and (f) female genitalia.

FIGURE 3. Localities of sampled specimens of Triplax collaris (Schaller, 1783) and T. sulphuricollis Reitter, 1887 examined in this study. The Hyrcanian forest in northern Iran and Azerbaijan is depicted by a dark green line.