Chlaeniini Brullé, 1834

Guéorguiev, Borislav & Will, Kipling, 2025, A new genus and tribal placement for Ceneus speculiferus Fairmaire, 1879, comments on Grundmannius Basilewsky, 1965, Mirachlaenius Facchini, 2011 and Stenoodes Basilewsky, 1953, and a key to the Oriental and Australasian genera of Chlaeniina Brullé, 1834 (Coleoptera, Carabidae), Zoosystema 47 (15), pp. 231-259 : 234-235

Tribe Chlaeniini Brullé, 1834

(see below, key to the adults of subtribes of Chlaeniini Brullé, 1834)

NOTES ON TRIBAL CHARACTERIZATION OF CHLAENIINI

Regarding delimitation of Chlaeniini , a tentative diagnosis was recently given by Guéorguiev (2014: 89). That included common traits for the Carabidae Conchifera (sensu Jeannel 1949b) as well as distinguishing tribal features.

However, in the course of the current study, we established three features of tribal significance (Guéorguiev ibid.), namely 1) the elytron with internal plica; 2) metepisternum laterally coadunate with elytral epipleuron; and 3) stria 7 distinct to apex, not uniformly present in all representatives of the tribe. These character states are only useful as supplemental traits given the context and restrictions provided below.

1) As stated by Jeannel (1949a) and verified herein the crossed elytral epipleuron is present in Chlaeniina (except for Grundmannius ) and absent in Callistina .

2) The coadunate metepisternum and elytral epipleuron is a feature to consider with some caution. Based on a comprehensive study of the morphology of carabid taxa from different tribes and on an earlier statement of Habu (1956), Bousquet (1996: 449) stated that “I have found this feature in all species of oodines and panagaeines studied and in some species of Chlaeniini . Likely the character state has been secondarily lost in several chlaeniine lineages”. Ober & Maddison (2008) investigated the phylogenetic relationships among the harpalinae tribes using data from two nuclear loci and found that in most trees, oodines, chlaenines, panagaeines, and the genus Dercylus Laporte, 1832 form a clade. Given the Ober & Maddison investigations and pygidial gland defensive secretion data, Bousquet (2012: 53) then stipulated anew, now with improved evidential support, that the complex of Panagaeini – Chlaeniini – Oodini “possibly constitute a clade since the adults (except in some chlaeniines) have the metepisterna coadunate with the elytral epipleura, a synapomorphic condition that has probably been secondarily lost in some chlaeniine lineages”. However, no study has explored the distribution and extent of this character across all relevant taxa. What is known shows it is absent in representatives of the two callistine genera, Callistus and Callistomimus (see Terada & Wu 2018: 5, fig. 3H). Among the taxa from Chlaeniina we studied, the appearance of the character varies. In some species the coadunation is obvious (Chlaeniellus Reitter, 1908, Chlaeniostenus Kuntzen, 1919), in others – less noticeable (Amblygenius La Ferté-Sénectère, 1851 and some Pleroticus Péringuey, 1896), and it is ambiguous or appears to be lacking in some (Callistoides, some Stenochlaenius Reitter, 1908). To avoid incorrectly scoring this state care must be taken to note the condition of the specimen. If present, the state can be seen when both the sternal and elytral structures are in close proximity to each other. It is the case when the elytra are closely retracted and the lateral margin of the anterior part of the metepisternum forms a more or less distinct protrusion that covers the paired site on the medial margin of the elytral epipleuron. If the lateral margin of the metepisternum does not cover the medial margin of the elytral epipleuron then the state of the character can be difficult to ascertain though it is present. Compare the Figure 3A, B and Figure 12 : the first two figures show “unnatural” states or artifacts of preservation where the metepisternum does not reach the epipleuron though both structures lie on the same level ( Fig. 3A ) or are concealed under the epipleuron ( Fig. 3B ). In Figure 12 the “natural” condition is shown - the metepisternum is tightly retracted on epipleuron.

3) In most chlaeniine genera, stria 7 is well-marked along the whole elytron length, including near the apex. However, Callistus lunatus and some species of Holosoma have stria 7 obliterated apically. In Hololeius ceylanicus stria 7 is usually hardly distinguishable in basal three fourths and well-perceptible on apical one fourth only.

KEY TO THE ADULTS OF SUBTRIBES OF CHLAENIINI BRULLÉ, 1834

1. Galea of maxilla two-segmented ( Figs 2B ; 11B ). Tips of ultimate maxillary and labial palpomeres slightly rounded, truncate or widened (cf. Habu 1987: 7, figs 4-13). Pronotum with or without posterolateral setiferous puncture. Elytral epipleuron straight throughout or crossed (i.e., plica present) near apex ........................................... 2

— Galea of maxilla one-segmented (cf. Andrewes 1921: 233, fig. 12a; Jeannel 1942: 978). Tips of ultimate maxillary and labial palpomeres acuminate (cf. Habu 1987: 7, fig. 3). Pronotum without posterolateral setiferous puncture. Elytral epipleuron straight throughout (i.e., plica absent) ........... subtribe Callistina Laporte, 1834

2. Pronotum with posterolateral setiferous puncture. Lateral edge of elytral epipleuron bare. Elytral epipleuron crossed near apex. Metacoxa with only anterolateral seta ................................................................................ ....................................... subtribe Chlaeniina Brullé, 1834 (all genera save Grundmannius Basilewsky, 1965 )

— Pronotum without setiferous puncture. Lateral edge of elytral epipleuron spiniferous ( Fig. 11A ). Elytral epipleuron straight throughout. Metacoxa with two lateral setae ............. subtribe Chlaeniina (genus Grundmannius ).

Figures

FIG. 3. — Lapitachlaenius speculiferus (Fairmaire, 1879) n. comb., male specimen: A, left metepisternum. Arrows mark a depression on medial margin of elytral epipleuron that usually is covered by a lateral protrusion of metepisternum – edge of the protrusion is marked by a continuous red line; B, right metepisternum. Arrow points to the sublateral longitudinal sulcus of metepisternum. Scale bars: 0.5 mm.

FIG. 12. — Grundmannius dispar (Péringuey, 1896), female specimen, right metepisternum.The black arrow indicates the coadunation of metepisternum with elytral epipleuron. Scale bar: 1 mm.

FIG. 2. — Lapitachlaenius speculiferus (Fairmaire, 1879) n. comb., female specimen, mouthparts: A, right mandible, dorsal view; B, right maxilla, ventral view; C, glossal sclerite,dorsal view. Abbreviations:car, cardo;dls, dorsal lobe of stipes;g1, galeomere 1; g2, galeomere 2; gsc, glossal sclerite;it, incisor tooth; lc, lacinia;lgs, lateral glossal seta;mgs, medial glossal seta;lp2, labial palpomere 2;mp1-4, maxillary palpomeres 1-4; mt, molar tooth;pgl, paraglossa;pog, posterior occlusal groove; pmt, premolar tooth; rr, retinaculum ridge; tr, terebral ridge; tt, terebral tooth; vls, ventral lobe of stipes. Scale bars: A, C, 0.2 mm; B, 0.5 mm.

FIG. 11. — Grundmannius dispar (Péringuey, 1896), female specimen (A, B), male specimen (C, D): A, dorsal view; B, head, ventral view; C, right anterior coxal cavity. The black arrows indicate positions of two foramina; D, right protarsomeres 1-5 (claw absent), ventral view. Scale bars: A, 2 mm; B, C, 1 mm; D, 0.5 mm.