Aetheomorpha prosvirovi Romantsov & Bezděk, 2025

Aetheomorpha prosvirovi Romantsov & Bezděk , sp. nov.

( Figs 1, 3, 5 View FIGURES 1–6 , 20 View FIGURES 20–24 )

Type locality. Thailand, Chiang Mai Prov., 100 km N from Chaing Mai, Chiang Dao Hill Resort , 19°33'28.9"N, 99°04'33.3"E GoogleMaps .

Type specimens. Holotype: ♂ ( ZIN), “ Thailand, Chiang Mai Prov., / 100 km N from Chaing Mai, Chiang / Dao Hill Resort , h= 494 m, / 19°33'28.9"N, 99°04'33.3"E / 10. VI. 2017, A. S. Prosvirov leg. [w, p]” GoogleMaps . Paratypes: 1 ♀ ( PRCS), same data as in holotype, but “ 17.VI.2017 ” GoogleMaps ; 1 ♀ ( PRCS), “ Thailand, Chiang Mai Prov. 100 / km N from Chaing Mai, Chiang / Dao Hill Resort evn. h= 550 m, at light / 19°33'30.31"N, 99° 4'38.69"E / 10. VI. 2017, A. S. Prosvirov [w, p]” GoogleMaps ; 1 ♂ 1 ♀ ( ♂ PRCS, ♀ JBCB), “ Thailand, Chiang Mai Prov. 100 / km N from Chaing Mai, Chiang / Dao Hill Resort. 19°33'30.31"N, / 99° 4'38.69"E, h= 550 m., at light / 17.VI. 2017, A. S. Prosvirov [w, p]” GoogleMaps ; 1 ♀ ( ZIN), “ Laos / Vientiane [w, p] // Coll. R. I. Sc. N. B. / Laos [y, p]”. The type specimens are provided with one additional printed red label: “ Holotypus [or Paratypus] / Aetheomorpha prosvirovi / Romantsov & Bezděk, sp. n. / det Romantsov & Bezděk, 2025 ” .

Description. Measurements. Males: 4.2–4.9 mm ( holotype 4.9 mm), females: 4.3–4.9 mm. Body elongate. Head brown with area along inner edges of eyes connecting to vertex black, palpi light brown, apices of mandibles black. Pronotum light brown with four black spots in transverse row at basal third. Scutellum black with brownish small spot on apex. Elytra light brown, each elytron with black pattern consisting of five black spots (humeral spot, spot at basal part between scutellum and humerus obliquely connected with humeral one, spot in middle near lateral margin, spot at two thirds near suture, and last on apex) and black suture, lateral and apical margins; variable lateral black stripe connecting with humeral spot as well as with third and apical spots. Underside brown, prosternum with black elongate spot on each side, mesosternum and metasternum in middle and partly laterally black, abdomen including pygidium brown. Antennae brown, antennomeres V–VIII brownish ventrally and laterally, dorsally darkened, IX–XI black. Legs brown with femora (except bases) and tarsi black.

Male ( holotype, Fig. 1 View FIGURES 1–6 ). Head large, impunctate, 1.42 times narrower than pronotum. Frontoclypeus with slightly rugose clypeal part, anterior margin with wide incision in middle and with triangular anterior angles. Frons very slightly convex with small groove in middle, surface near eyes covered by fine microsculpture and adpressed silver setae. Frontal tubercles absent. Eyes rather large, slightly bean-shaped with small notch on inner margin, 1.4 times as long as wide. Interocular space twice as wide as transverse diameter of eye and 1.7 times narrower than head with eyes. Vertex slightly convex, lustrous and impunctate. Antennae short and robust, about 3.8 times shorter than body, just extending to posterior third of pronotum. Antennomere I large, stout; II short, almost round; III shortest; antennomere IV inverse trapezoid; V–X strongly serrate, XI elongate with triangular apex. Antennomeres I–IV lustrous with sparse, short, erected setae on edges, V–XI dull with slightly rugose surface covered with short adpressed setae and with longer erected setae on edges. Length ratio of antennomeres I–XI as 9: 4: 3: 4: 5: 4.5: 4.5: 4: 4: 4.5: 7, width ratio as 6.5: 4.5: 4: 5: 8: 8: 7: 6: 5.5: 4: 3.

Pronotum convex, transverse, 2.13 as wide as long, about as wide as elytra on base, widest in middle. Anterior margin slightly convex in middle, lateral margins evenly rounded, posterior margin almost straight near lateral angles, in middle of pronotal base distinctly protruded opposite scutellum. Surface lustrous, sparsely covered with very small punctures (visible only at 20x magnification) and with denser microscopic punctures in interstices between them. Anterior angles rectangular with rounded tip, posterior ones almost imperceptible, widely rounded. Anterior angles bearing setigerous pore with rather long, curved pale seta. Anterior margin bordered only near angles then unbordered; posterior margin thinly bordered and lateral margins widely bordered. Scutellum triangular with sharply rounded apex, about 1.7 times as wide as long; surface covered with fine punctures, scutellar apex very weakly elevated upon level of elytra.

Elytra subcylindrical, 1.27 times as long as wide. Basal margin bordered only near shoulders, lateral margin widely bordered in anterior two third and thinly bordered in posterior third. Elytral surface covered with confused punctures in basal part but arranged in more or less distinct rows in middle and lateral parts. Punctures at basal third rather large, then gradually diminishing and disappearing in apical slope. Epipleura glabrous, basally moderately wide, then gradually narrowed, disappearing in apical third of elytra. In lateral view, lateral margin of elytra distinctly lobed below shoulders. Pygidium slightly exposed with rounded apex.

Legs robust. All tibiae almost straight, noticeably widened towards apex. Tarsi short. Protarsomere I enlarged, slightly wider than III. Length ratio of protarsomeres I–III and V as 10: 8: 10: 15; width ratio of protarsomeres I–III as 10: 8: 9. Mesotarsomere I almost as wide as III; metatarsomere I narrower than III. Claws simple.

Aedeagus ( Fig. 3 View FIGURES 1–6 ) rather short and wide with triangular apex. Underside with wide and low ridge medially and ridges at lateral margins, area between ridges rather deeply depressed. In lateral view apex strongly bent ventrally. Length of aedeagus 1.25 mm, width 0.4 mm.

Females. Tarsi are narrower than in males. Pygidium with rounded apex, without any notches ( Fig. 5 View FIGURES 1–6 ). Spermatheca U-shaped with sharp apex ( Fig. 20 View FIGURES 20–24 ).

Variability. One male and two females have tibiae completely black. Female from Laos has posterior part of head with more developed black pattern (frons and vertex black with transverse brown spot in middle), pygidium with spot near apex black and blurred blackish strokes on each sides of abdominal ventrites.

Differential diagnosis. This new species belongs to a group of species from Indochina and India characterized by a pronotum with four black spots and elytra with black suture, lateral margins, and four black spots. This group includes Aetheomorpha weigeli Medvedev, 2010 , A. bilobata Wang & Zhou, 2012 from China ( Yunnan), A. quatuordecimpunctata (Jacoby, 1895) from South India, and possibly also A. decemnotata (Jacoby, 1892) , which is distributed across China ( Yunnan), Myanmar, Vietnam, Laos and Thailand.

With its large head and triangular apex of the aedeagus, Aetheomorpha prosvirovi sp. nov. is most similar to A. weigeli . These two species can be distinguished as follows. Aetheomorpha prosvirovi sp. nov. ( Fig. 1 View FIGURES 1–6 ): body smaller ( 4.2–4.9 mm); black pattern on head more developed; spots on pronotum larger, intermediate ones not connected; third spot on elytra usually connecting with lateral black edging; middle antennomeres more transverse (antennomeres V–VIII 1.5–1.8 times as wide as long); underside of aedeagus with a low, wide longitudinal ridge, in lateral view apex strongly bent ventrally; female pygidium not incised at the apex. Distribution: Norhern Thailand ( Chiang Mai), Laos ( Vientiane).

Aetheomorpha weigeli ( Fig. 2 View FIGURES 1–6 ): body larger ( 5.1–5.9 mm); black pattern on head less developed; spots on pronotum smaller, intermediate two sometimes connected, forming a large oblong spot; third spot on elytra not connected to the lateral black edge; middle antennomeres less transverse (antennomeres V–VIII approximately as wide as long); underside of aedeagus with a high, sharp ridge medially, in lateral view apex slightly bent ventrally ( Fig. 4 View FIGURES 1–6 ); female pygidium slightly incised at the apex ( Fig. 6 View FIGURES 1–6 ); spermathecal with basal and apical parts almost parallel ( Fig. 21 View FIGURES 20–24 ). Distribution: China ( Yunnan), Northern Thailand ( Mae Hong Son).

Aetheomorpha bilobata can be easily distinguished from other species in this group by its smaller head and slightly elongated, broad, and feebly bilobed apex of aedeagus. Some specimens of A. decemnotata have four obscure spots on the pronotum, but this species differs in shape of aedeagus with a narrower apex and an underside without ridge. Aetheomorpha quatuordecimpunctata (Jacoby, 1895) from South India can be distinguished by its strongly transverse middle antennomeres, completely black head, and elytra lacking black lateral margins and a black suture. Its aedeagus has a narrower triangular apex, and the underside is evenly convex without any depression or ridge. In lateral view, the apex of the aedeagus is only very slightly bent ventrally.

Etymology. The new species is named in honor of A.S. Prosvirov, a specialist in Elateridae , who collected the majority of the type series.

Distribution. Thailand, Laos.