Coleolissus monstrosipenis, Kataev, 2022

Kataev, Boris M., 2022, Notes on carabid beetles of the genera Coleolissus and Siopelus (Coleoptera: Carabidae: Harpalini), with description of four new species with unusual aedeagi from India and China, Zootaxa 5168 (3), pp. 285-305 : 296-301

Coleolissus monstrosipenis sp. n.

( Figs. 31–45 )

Type material. Holotype: male, India occ., Maharashtra st., Wai env., 70 km S of Pune, 3–6.X.2005, F. & L. Kantner leg. ( SMNS).

Paratypes: 4 males, 7 females, same data as holotype ( SMNS, ZIN) ; 1 male, 2 females, India occ., Maharashtra state, Mulshi env., 40 km W of Pune, 7–11.X.2005, F. Kantner leg. ( SMNS) ; 1 male, 2 females, India occ., Maharashtra st., Bhushi Dam env., 4 km S of Lonavala, 500 m, 12–15.X.2005, F. & L. Kantner leg. ( SMNS) .

Description (5 males and 5 females measured). Body elongate, comparatively large for the genus, length 10.6– 12.4 mm, width 4.0– 4.9 mm. Habitus as in Figs. 31, 33 .

Body dark brown to black, shiny and iridescent on dorsal side, with labrum, base of mandibles and very narrow lateral margins of pronotum reddish brown; ventral side in most specimens reddish black; palps, antennae and legs yellowish brown; tibiae, tarsi, apical palpomeres and antennomeres 3–11 very slightly infuscate.

Head medium-sized (HWmax/PWmax 0.63–0.67, HWmin/PWmax 0.51–0.56), very finely punctate dorsally. Eyes large, moderately convex (HWmax/HWmin 1.18–1.28), separated ventrally from buccal fissure by distance approximately equal to width of antennomere 1 apically. Genae glabrous. Tempora short, oblique, gently sloping to neck. Labrum somewhat flat, very shallowly and widely concave anteriorly. Clypeus very slightly convex, very shallowly emarginated along anterior margin, with one setigerous pore at each outer angle and with very fine and short longitudinal wrinkles adjacent medially to each pore. Fronto-clypeal suture fine, superficial, almost straight. Frontal foveae very small and shallow, almost punctiform, without prolongation on clypeus. Fronto-ocular furrows very fine, vaguely reaching supraorbital furrows. Frons with more or less distinct, very small and shallow medial depression. Supraorbital furrows very narrow, touching upper margin of eyes. Supraorbital setigerous pores small, situated markedly before level of posterior margin of eyes and removed from supraorbital furrows by distance equal to width of antennomere 2 basally. Mentum separated from submentum by complete transverse suture, with a prominent acutangular median tooth; epilobes markedly widened apically; submentum with one pair of long lateral setae. Ligular sclerite almost parallel-sided, almost truncate at apex, with one pair of ventroapical setae. Paraglossae glabrous, comparatively narrow, slightly projecting beyond ligular sclerite and markedly separated from it apically. Basal labial palpomere not carinate; penultimate labial palpomere slightly longer than apical one. Mandibles moderately elongate, evenly curved apically, with oblique wrinkles in apical half dorsally; left mandible acute, at most only slightly blunted at tip. Dorsal microsculpture highly obliterated, not forming distinct meshes. Antennae slender, surpassing pronotal basal edge by approximately two and a half apical antennomeres, pubescent from apical 0.7 antennomere 3, with antennomeres 4–8 about three times as long as wide and basal antennomere slightly longer than antennomere 3.

Pronotum only slightly wider than long (PWmax/PL 1.03–1.15), widest in the middle or just before it, slightly more strongly narrowed apically than basally (PWmax/PWmin-ap 1.41–1.55, PWmax/PWmin-bas 1.29–1.39), with one lateral seta inserted slightly before the middle. Sides evenly rounded along entire length; lateral bead complete, very narrow throughout. Apical margin moderately emarginated, almost straight medially, very narrowly bordered along entire length. Apical angles protruding anteriorly, narrowly rounded at apex. Basal margin almost straight in middle portion, slightly rounded laterally, bordered along entire length, slightly longer than apical margin (PWmin-bas/PWmin-ap 1.03–1.15) and slightly shorter than base of elytra between humeral angles; basal edge without fringe of short setae. Basal angles widely rounded. Disc convex. Lateral depressions beginning from apical angles as grooves, markedly widened from lateral setae and fused basally with basal foveae forming deep oblique laterobasal depressions isolated from each other by undepressed area. Median line fine, superficial, rather long, almost reaching apical margin and basal margins. Anterior transverse depression very shallow. Punctation distinct and dense, restricted to lateral furrows and laterobasal depressions. Microsculpture highly obliterated, not forming distinct meshes.

Elytra convex, elongate, slightly wider than pronotum (EL/EW 1.55–1.66, EL/PL 2.39–2.61, EW/PWmax 1.11–1.19), widest before the apical third; sides slightly rounded, with very weak sinuation before the middle; subapical sinuation distinct, but very shallow. Humerus rounded, without denticle at apex. Sutural angle blunted or narrowly rounded at tip, not extended posteriorly. Basal edge slightly arched, forming a very obtuse angle with lateral margin. Striae crenulate, impressed along entire length, reaching anteriorly basal elytral edge, with granulate microsculpture on bottom of striae in their apical portion. Intervals glabrous, convex, strongly narrowed apically, sparsely micropunctate. Parascutellar (abbreviate) striole long, with a large setigerous pore basally isolated from basal elytral edge. Interval 3 with a series of 9–13 small discal setigerous pores adjoining stria 2 along entire length; intervals 5 and 7 without discal pores. Marginal umbilicate series without distinct gap at middle, consisting of 23–31 setigerous pores. Lateral groove narrow and flat, slightly widened apically. Microsculpture highly obliterated, at most with indistinct transverse lines on intervals, with obliterate isodiametric meshes in lateral groove. Wings fully developed.

Ventral side of thorax smooth or micropunctate, glabrous, except for sparse very fine short setae on prosternum anteriorly. Metepisternum markedly longer than wide, strongly narrowed posteriorly.

Metacoxa with two obligatory setigerous pores, without additional pores and setae. Profemur with deep longitudinal excavation on inner side. Metafemur ventrally with two long setae at posterior margin and with two or three very short setae at anterior margin. Protibia on dorsal side without longitudinal sulcus, on outer margin preapically with two stouter and one thiner spines in male and with three comparatively stout spines in female. Tarsi with very fine and short setae dorsally. In male, protarsomeres 1–4 and mesotarsomeres 2–4 markedly widened, with biseriate adhesive scales ventrally; mesotarsomere 1 weakly widened, with scales only apically, slightly shorter (in female, slightly longer) than mesotarsomeres 2 and 3 combined. Metatarsus ( Figs. 32, 34 ) slender, in male slightly longer, in female slightly shorter than HWmax, with metatarsomeres 2–4 very short, markedly widened distally; metatarsomere 1 elongate, weakly widened distally, longer than metatarsomeres 2–4 combined. Tarsomere 5 in most specimens with three pairs of ventro-lateral setae.

Abdominal sternites glabrous, smooth or micropunctate; apex of last visible sternite (VII) in male subtruncate, with one pair of marginal setae, in female rounded, with two pairs of setae; these setae not distant from margin.

Female genitalia ( Figs. 35, 36 ). Laterotergite asymmetrical, longer than wide, with four (occasionally five) thick setae apically. Gonosubcoxite shorter than laterotergite, widened posteriorly, with a preapical thick seta on outer margin. Gonocoxite short, strongly curved, about two times as long as gonosubcoxite, with a tiny spine (short thick seta) on ventral edge of outer side. Vagina membraneous, no specific features observed.

Aedeagus ( Figs. 37–45 ) with comparatively large parameres ( Figs. 39, 40 ), moderately large basal bulb and highly modified, hypertrophic apical portion. Median lobe of aedeagus ( Figs. 37, 38 ) narrow basally, slightly arcuate in lateral view; apical portion greatly enlarged laterally, irregular-shaped. Apical orifice divided into two isolated portions: proximal portion very vast, beginning from basal bulb on left side and going along dorsal and right side of median lobe up to its modified apical portion; four of five examined males having probably constantly everted elongate saccule “ a ” of internal sac ( Figs. 37, 38 ) at distal margin of membranous area; this saccule absent in one of the examined males ( Fig. 41 ); distal portion small, oval, situated on dorsal side just at apex of median lobe. Internal sac without sclerotic elements, everting mostly through distal portion of apical orifice; in everted condition ( Figs. 41–45 ), small, with two apical lobes and with two narrow saccules “ b ” ( Fig. 45 ) on the right side prebasally.

Etymology. The specific name is a Latin noun at apposition, referring to the monstrous form of the median lobe of the aedeagus.

Comparison. Having elongate, almost parallel-sided elytra, Coleolissus monstrosipenis is somewhat similar in appearance to the members of the genus Oxycentrus Chaudoir, 1854 , for example, to O. fulgens Ito, 1997 from Vietnam.The new species is treated as belonging to Coleolissus since it possesses the following characters typical for this genus: frontal foveae without prolongation on clypeus, parascutellar striole long, interval 3 with a row of 9–13 setigerous pores, and protibia with two preapical spines on outer margin (see Kataev, 2021). Within Coleolissus , C. monstrosipenis sp. n. is similar to C. iridipennis Ito, 1999 from Laos in having elongate body with widely rounded basal pronotal angles, but well differs from it in having metatarsomeres 2–4 very short and markedly widened distally, apex of last visible abdominal sternite (VII) in male with one pair of marginal setae and median lobe of aedeagus strongly modified. In metatarsus with shortened tarsomeres 2–4, the new species is distinguished from all other congeners, which have all these tarsomeres slenderer, with combined length greater than metatarsomere 1. The new species can be additionally distinguished from C. inessae Kataev, 2021 , which is also described from the Western Ghats and also has elongate body and only one pair of setae on last abdominal sternite of male, in greater size (body length 10.6–12.4 mm versus 7.8 mm) and pronotum markedly depressed laterobasally and with more widely rounded sides and basal angles.

Distribution. The type series has been collected in Western India, the state of Maharashtra, on the western margin of the Deccan Plateau at the eastern slopes of the Western Ghats at altitudes of about 500 m.

Remarks. The very unusual shape of the median lobe of the aedeagus in this new species is far beyond the known variability of genital structures not only in Harpalini but also in other ground beetles, and at first glance gives the impression of an individual anomaly; however, since all males examined have such genitalia, there is no doubt that this unusual structure is a constant feature of the species. Particular attention should be given to the similarity of the modified apical portion of the median lobe of C. monstrosipenis sp. n. with inverted internal sac to the apical portion of the median lobe of many carabids with fully everted internal sac. In everted condition, the internal sac of carabids looks as an apical extension of the sclerified median lobe ( Deuve, 2021). The shape and sclerotic armature of the fully everted internal sac are very variable in different species and are considered the most reliable morphological basis both for distinguishing similar species and for grouping species into natural units. The special investigations indicate that the internal sac of carabids is the real copulatory organ that not only forms spermatophore, but also transfers it to the vagina of the female during mating ( Jeannel, 1955); it acts as an intromittent apparatus and its features apparently correspond as a counterpart with the vagina of the same species ( Ishikawa, 1978, 1987; Sasabe et al., 2010). During genital coupling, males mould the spermatophore within the vagina using the everted internal sac. Strong adhesion of spermatophore to a particular site of the vagina seems to be unique for each species ( Takami, 2002). Although these investigations were carried out on the Carabus species, their results are apparently suitable for other carabids. It is possible that the modified apical portion of the aedeagus of C. monstrosipenis sp. n. took over some of the mechanical functions of the internal sac, which is quite small in this species ( Figs. 41–45 ). Small internal sac everting in two places of the median lobe (before the modified apical portion and at its apex) counts in favor of this assumption. The genetic base of such converting is obscure and needs special study. The members of Harpalini demonstrate several cases of definite modifications of the aedeagus as a result of probably hormonal imbalance during the embryonic development ( Kataev, 1995; Kataev & Wrase, 2019). It has been suggested that in the case of the genetic determination of such modifications, the aberrant specimens under certain conditions can be considered as material for speciation ( Tichomirova, 1979, 1991) and give rise to species with sharply different, including monstrous, genitalia ( Kataev & Wrase, 2019). Among ground beetles, strong modifications of the male genitalia are quite rare, but in some other beetle families, for example in Catopidae , Leiodidae and Pselaphidae , they seem to be more common ( Jeannel, 1955). The discovery among representatives of the genus Coleolissus of several species with an unusual structure of the aedeagus suggests that this genus has a genetic predisposition to such genital transformations.

Figures

FIGURES 31–34. Coleolissus monstrosipenis sp. n. (31, 32, male holotype; 33, 34, female paratype). 31, 33, habitus; 32, 34, right metatarsus. Scale bars = 1.0 mm (A: 31, 33; B: 32, 34).

FIGURES 35–40. Coleolissus monstrosipenis sp. n. (35, 36, female paratype; 37, 40, male holotype). 35, laterotergite, gonosubcoxite, and gonocoxite; 36, gonocoxite; 37, 38, median lobe of aedeagus; 39, left paramere; 40, right paramere. Ventral (35), left lateral (36, 37, 40), dorsal (38) and right lateral (39) views. a, saccule of internal sac. Scale bars: A = 0.5 mm (35, 36), B = 1.0 mm (37–40).

FIGURES 41–45. Coleolissus monstrosipenis sp. n. (paratype), median lobe of aedeagus with everted internal sac. Laterodorsal (41, 42), latero-caudal (43), lateral (44) and caudal (45) views. b, saccules of internal sac. Scale bars = 1.0 mm.