Euconnus (Euconnus) pyriformis Jałoszyński 2025, stat. rev.
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Euconnus
Euconnus pyriformis

description: Euconnus (Euconnus) pyriformis (Nietner), stat. rev.
(Figs 28, 51–52)
Scydmaenus pyriformis Nietner, 1856: 552.
Euconnus (Microscydmus) pyriformis (Nietner), Csiki, 1919: 56. Note: Microscydmus by all other authors is treated as separate genus, which implies the combination Microscydmus pyriformis.
Type material. Lectotype (here designated): ♂, three labels: “ Ceylon / Nietner..s” (white, printed and handwritten, text in black frame], QR code label with collection number 8192, and newly added “ EUCONNUS / (s. str.) / pyriformis (Nietner, 1856) / LECTOTYPUS / P. Jałoszyński, 2025 ” (MIZ). Paralectotypes (4 exx.): 2 ♂♂, 2 ♀♀, one male with original Locality label and collection number 8193, remaining specimens with white printed copies of Locality labels and identification labels with “PARALECTOTYPE” (MIZ).
Revised diagnosis. Vertex not bulging posterodorsad and with sparse, barely discernible bristles; eyes moderately large, in lateral view slightly shorter than tempora; antennal clubs trimerous, infuscate, stout, antennomeres 9 and 10 each distinctly transverse; pronotum widest near base, with one lateral pair of antebasal pits connected by shallow transverse groove, and with short but distinct sublateral carinae; protibia of male distinctly curved inwards at apex; aedeagus in ventral view broadest in sub-basal region, with dorsal and ventral apical plates abruptly demarcated laterally from basal capsular portion of median lobe, dorsal plate in lateral view indistinctly recurved; endophallus with symmetrical set of poorly defined subapical structures; parameres not reaching apex of median lobe.
Redescription. Body of male (Fig. 28) moderately slender, strongly convex, moderately dark brown, antennal clubs distinctly infuscate; setae distinctly lighter than cuticle; BL 1.13–1.15 mm.
Head broadest across eyes, HL 0.23 mm, HW 0.25 mm; frontal and anterior vertexal regions confluent, weakly convex, vertexal region not bulging posterodorsad; supraantennal tubercles barely marked; eyes moderately large, in lateral view slightly shorter than tempora. Punctures on frons and vertex fine and inconspicuous; setae sparse, short and weakly suberect; tempora and vertex with dense and long bristles directed posteriorly. Antennae slender, with sharply delimited trimerous clubs, AnL 0.45–0.48 mm; antennomere 1–2 each strongly elongate, 3 and 4 each about as long as broad, 5 slightly elongate, 6 and 7 each about as long as broad, 8 weakly transverse, 9 and 10 each distinctly transverse, 11 indistinctly broader than 10, much shorter than 9–10 combined, about 1.6 times as long as broad.
Pronotum subtrapezoidal, broadest near base; PL 0.28 mm, PW 0.25 mm; anterior margin arcuate, anterior corners poorly marked, obtuse-angled and blunt; lateral margins weakly rounded; posterior corners obtuse-angled and blunt; posterior margin straight; base with two small round lateral pits connected by shallow transverse groove slightly deepened at middle, and with distinct but short sublateral carinae. Punctures on pronotal disc similar to those on frons and vertex, inconspicuous; setae moderately long, moderately dense and suberect, lateral margins with dense and long bristles.
Elytra together oval, broadest slightly anterior to middle; EL 0.63–0.65 mm, EW 0.45–0.50 mm, EI 1.25–1.39; humeral calli distinctly elevated, basal impressions shallow but distinct; elytral apices separately rounded. Punctures and setae similar to those on median region of pronotal disc.
Legs moderately long, slender, protibiae with apices distinctly curved inwards.
Aedeagus (Figs 51–52) moderately stout;AeL 0.20 mm; median lobe in ventral view approximately drop-shaped, broadest in sub-basal region, narrowing distally and in subapical region abruptly narrowed so that subtriangular apical area is sharply delimited from basal capsule; ventral plate short and subtrapezoidal, dorsal plate much longer and with subtriangular apex; in lateral view dorsal plate indistinctly recurved; endophallus symmetrical, with poorly defined subapical sclerites; parameres in ventral view slender, weakly curved and their apices not reaching apex of median lobe, each with two long apical setae.
Female. Externally similar to male except for straight protibiae. BL 1.10–1.13 mm; HL 0.23 mm, HW 0.25 mm, AnL 0.43 mm; PL 0.28 mm, PW 0.26–0.28 mm; EL 0.60–0.63 mm, EW 0.48–0.50 mm, EI 1.20–1.32.
Distribution. Sri Lanka, near Colombo.
Remarks. The type series of E. pyriformis consists of five specimens, of which three and two were mounted on two separate cards and pins. Nietner (1856) stated that he collected them “in the sweeping net on the lawns of my garden about sunset.” Three of these specimens are males, and females seem to be conspecific with them. The male that (after remounting on a separate card and pin) bears the historical locality label and the collection number 8192 is here designated as the lectotype.
Because of the trimerous club, Euconnus pyriformis (and E. graminicola treated in previous paragraphs) would have been placed in the subgenus Psomophus Casey, 1897 at the time when Franz has been working on his Sri Lankan monograph. Psomophus is now merged with Euconnus s. str. (see Jałoszyński (2017) for morphology of the type species of Psomophus, and Jałoszyński (2022b) for arguments supporting the synonymy). Species with trimerous antennal clubs, male protibiae bent mesad in apical regions and aedeagi similar to those illustrated here for E. pyriformis and E. graminicola belong in the Euconnus callidus group. They are difficult to identify, because both the external morphology and aedeagi are highly similar and only subtle differences exist to distinguish species. In Franz (1982) one species of this group is recorded from Sri Lanka (as a member of the subgenus Spanioconnus Ganglbauer, 1899, merged with Psomophus in Franz (1985b)), and surprisingly identified as Euconnus intrusus (Schaum, 1844).
Euconnus pyriformis is involved in a synonymy with E. intrusus, which requires clarification. Franz (1982) placed Scydmaenus brunnipennis Motschulsky, 1858: 30 as a junior synonym of E. intrusus (as “ brunneipennis ”, which is an unjustified emendation of brunnipennis in Csiki (1919): 57). Because earlier Csiki (1919): 56 placed S. brunnipennis as a junior synonym of E. pyriformis (Nietner), the Franz’s synonymy of S. brunnipennis (further treated as Euconnus) with E. intrusus automatically made E. pyriformis a junior synonym of E. intrusus (because Franz did not remove S. brunnipennis from synonymy with E. pyriformis). Euconnus intrusus is broadly distributed in Europe (Schülke & Smetana 2015), while E. brunnipennis was described based on material from Sri Lanka. Unfortunately, Franz (1982) illustrated the aedeagus of the type specimen of E. brunnipennis only in lateral view. This illustration is not sufficient to verify whether the European specimens of E. intrusus are identical with E. brunnipennis, and no evidence was provided that other specimens from Sri Lanka that Franz had examined were conspecific with E. brunnipennis. Motschulsky most likely described E. brunnipennis based on specimens obtained from Nietner, because in the introduction to his work, he stated that “M. Nietner me gratifia d’un grand nombre de petites espèces”, that is, “Mr. Nietner gifted me with a large number of small species.”
The aedeagus of E. pyriformis (and that of E. graminicola) is very similar to that of European specimens of E. intrusus examined during the present study, but in ventral view they clearly differ. Moreover, European specimens of E. intrusus also externally differ from the Sri Lankan E. graminicola and E. pyriformis. Even though the aedeagi of E. graminicola and E. pyriformis are almost identical, these two species clearly differ from each other in external features. It is possible that one of the Nietner’s species with trimerous antennal clubs (E. graminicola or E. pyriformis) is identical with E. brunnipennis, but they are not identical with European specimens of E. intrusus. It was not possible to examine the type material of E. brunnipennis preserved in Moscow, so the relation of E. brunnipennis with E. graminicola and E. pyriformis remains unsolved. However, it seems highly unlikely that the Sri Lankan E. brunnipennis is identical with the European E. intrusus. Scydmaenus brunnipennis (as Euconnus (s. str.) brunnipennis (Motschulsky, 1863)) and E. pyriformis are here reinstated as valid names of separate species, pending further study.
Euconnus pyriformis has the aedeagus almost identical with that of E. graminicola, only the apical region in lateral view is less recurved (Fig. 52). However, externally these species clearly differ in several characters listed in Remarks for E. graminicola.
description: Published as part of Jałoszyński, Paweł, 2025, John Nietner collection of Sri Lankan Scydmaeninae (Coleoptera, Staphylinidae), pp. 79-109 in Zootaxa 5633 (1) on pages 98-100, DOI: 10.11646/zootaxa.5633.1.4, http://zenodo.org/record/15372835