Diplocheila (Diplocheila) walterrossii, Allegro & Giachino, 2021

Allegro, Gianni & Giachino, Pier Mauro, 2021, The genus Diplocheila Brulle, 1834 in Cambodia, with descriptions of two new species (Coleoptera, Carabidae, Licinini), ZooKeys 1044, pp. 427-448: 427

publication ID


publication LSID


persistent identifier


taxon LSID


treatment provided by

ZooKeys by Pensoft

scientific name

Diplocheila (Diplocheila) walterrossii

sp. nov.

Diplocheila (Diplocheila) walterrossii   sp. nov. Figures 4 View Figure 4 , 10 View Figures 6–11 , 16 View Figures 12–17 , 19 View Figures 18–19 , 22 View Figures 20–25 , 29 View Figures 26–32 , 33 View Figure 33

Type locality.

Cambodia, Siem Reap Province, N Siem Reap City, 13°26'29"N, 103°52'25"E.

Material examined.

Holotype: ♂, Cambodia, Siem Reap Province, N Siem Reap City , 13°26'29"N, 103°52'25"E, light trap, 13.XI.2018, W. Rossi and V. Kong leg. (CGi). GoogleMaps  

Paratypes: (7 ♂♂ and 3 ♀♀); 2 ♂♂, same data as HT   ; 2 ♂♂ Cambodia, Kampong Chhnang Province, Khom Domnatpopol, Tonle Sap Lake , 12°14'14"N, 104°41'15"E, light trap, 21.V.2018, Rossi, Bernardi and Kong leg. GoogleMaps   ; 1 ♂ 1 ♀, Cambodia, Kampong Chhnang, banks of Tonle Sap Lake , light trap, 17.V.2019, W. Rossi and V. Kong leg.   ; 1 ♂, Cambodia, Kampong Chhnang, Rolea B’ier District, Toulkrolanh Village , 12°13'31"N, 104°39'50"E, light trap, 7.XI.2018, W. Rossi and V. Kong leg. GoogleMaps   ; 2 ♀♀, Cambodia, Banteay Meanchey Province, near Sisophon, Campus of the Mean Chey University , light trap, 22.X-23.XI.2019, P. Bun and W. Rossi leg.   ; 1 ♂, Cambodia, Khsam , Kampong Chhnang, 12°16'47"N, 104°39'28.6"E, light trap, 29.XI-3.XII.2019, W. Rossi and V. Kong leg. GoogleMaps   (CAl, CCa, CGi, BMNH, MCSNG).


A medium-sized (ABL: 15-18 mm) Diplocheila   of the Diplocheila polita   group in the subgenus Diplocheila Diplocheila   (sensu Ball 1959). Among the species of this group having a sexsetose labrum, it is easily distinguished from D. erwini   sp. nov. by the larger body size (15-18 mm vs 12-14 mm), from D. laevigata   and D. laevigotoides   by the more transverse pronotum (PW/PL = 1.38 vs 1.28-1.32), from D. indus   by the hind angles of pronotum not protruding (externally protruding in D. indus   ) and from all these species by the morphology of the aedeagus.


Habitus: ABL: 15-18 mm (HT ♂ 15.6 mm). Body parallel-sided, moderately shiny, black with antennae and palpi piceous-brown (Fig. 4 View Figure 4 ).

Head: almost quadrangular, robust, glabrous except for the supraorbital setae. Eyes markedly convex; a single supraorbital seta on each side. Dorsum with microsculpture not evident, only with scattered punctures visible at >100 × magnification; frontal impressions short and superficial. Labrum symmetrically and deeply (LR = 0.72) emarginate, with six setigerous punctures on anterior margin (4 medial equidistant + 2 lateral on lobes). Clypeus trapezoid, distinctly concave anteriorly, with 1 seta at each anterolateral corner. Antennae moderately long, densely pubescent from segment 4, with terminal two articles surpassing base of pronotum; segments elongate, the second one short, as long as a half of first. Mandibles elongate, broad, approximately similar to one another (the left with apical cutting edge more concave), with scrobe well-defined and glabrous and apex blunt; terebral tooth triangular and prominent. Labial and maxillary palps fusiform, with apices narrowly truncate.

Thorax: pronotum smooth, with very faint isodiametric microsculpture evident at >200 × magnification and with scattered punctures, transverse (PW/PL = 1.38), widest just above middle (Fig. 10 View Figures 6–11 ). Disk moderately convex. Sides moderately rounded in anterior half, delicately sinuate backwards. Hind angles rounded obtuse, with a postero-lateral seta. Posterior margin rectilinear between basal impressions, which are linear and markedly impressed; anterior margin with front angles nearly obsolete. A single lateral seta on each side at anterior third. Lateral bead continuous, separated from the discal area by a narrow groove, only scarcely dilated before hind angles. Medial longitudinal impression fine, nearly reaching anterior and posterior margins; anterior transversal impression absent.

Elytra: moderately long (EL/EW = 1.65), parallel-sided, slightly convex and flattened on disk, widest at middle, with rounded shoulders and sides delicately sinuate before apex. Surface moderately shiny; microsculpture evident only at high magnification (>100 ×), consisting of fine, slightly transverse meshes. Epipleura without any distinct external plicae ("uncrossed epipleura"). Intervals moderately convex, smooth; striae deeply impressed on the whole length, delicately punctate. Parascutellar stria present; scutellar setigerous pore present at base of stria 1, just before conjunction with stria 2. Basal margin complete. Discal setigerous punctures absent; umbilicate series of setigerous punctures continuous, but punctures more widely spaced at middle. Hind wings fully developed.

Ventral surface (thorax and abdomen): prosternum and proepisterna glabrous and impunctate (only with very fine punctures). Metepisterna twice as long as their width at anterior side; metepimera narrow, nearly rectangular. Prosternal intercoxal process parallel-sided with blunt apex, delicately bordered. Abdominal ventrites IV-VI shiny but shagreened at sides, glabrous except one pair of subapical central setae; males with 2, females with 4 setae at apex of ventrite VII.

Legs: moderately slender. Posterior face of femora with 1 seta in profemora, 2 setae in mesofemora and metafemora. Metatrochanters glabrous and as long as one-third of metafemora. Protibial antennal cleaning organ well developed, with 2 clip setae. Protibiae robust, with 6 or 7 outer apical spines; mesotibiae with a group of setae at middle of inner face; metatibiae longitudinally furrowed at inner face. Dorsal face of tarsomeres smooth. Protarsomeres 1-3 of males moderately dilated, slightly asymmetrical; meso- and metatarsomeres not dilated in both sexes; tarsomere 5 ventrally glabrous, dorsally with 2 apical setae; claws smooth.

Male genitalia: median lobe of aedeagus short and moderately swollen before apex in lateral view (Fig. 22 View Figures 20–25 ); apical lamella very short and apically rounded in dorsal view (Fig. 29 View Figures 26–32 ), apex thick and very slightly bent downwards in lateral view. Ostium long, in dorsal position. Right paramere elongate and subtruncate at apex; left paramere conchoid.


This species is named after its collector, Walter Rossi, a world-renowned specialist in entomoparasitic fungi, as a token of our esteem and as a sign of gratitude for the gift to the authors of the specimens of the new species.

Distribution and ecology.

Geographical distribution   : this species is recorded from Central and North-Western Cambodia (Fig. 33 View Figure 33 ). Life habits: the specimens of the type series were collected by light trapping. No other data are available.


Diplocheila walterrossii   sp. nov. belongs to the D. polita   group (sensu Ball 1959), as it shares the characters distinguishing this group and, at first sight, is very similar in external morphology to D. laevigata   . Nevertheless, at a deeper examination its aedeagus (Figs 22 View Figures 20–25 , 29 View Figures 26–32 ) reveals evident morphological differences and is easy distinguished from that of D. laevigata   (Figs 20 View Figures 20–25 , 26 View Figures 26–32 , 27 View Figures 26–32 ), as well as from that of D. erwini   sp. nov. (Figs 23 View Figures 20–25 , 30 View Figures 26–32 ), both species sympatric and syntopic with D. walterrossii   sp. nov. in Cambodia. Moreover, the new species shows a character almost unique in this group, as far as we know, that is the less enlarged male fore tarsi 1-3. For these reasons, D. walterrossii   sp. nov. could represent a rather isolated species in the D. polita   group, and its closest relatives remain uncertain.