Rhopalus parumpunctatus Schilling, 1829

Gapon, D. A., 2018, An instance of intergeneric copulation in the family Rhopalidae (Heteroptera): structure, functioning and congruence of the genitalia in two different species from the standpoint of the lock-and-key hypothesis, Zoosystematica Rossica (Zoosyst. Rossica) 28 (1), pp. 3-18 : 5-11

Rhopalus parumpunctatus Schilling, 1829

( Figs 1 , 7–9 , 12 ; Figs 13–16 as electronic supplementary material)

Material examined. Russia: Tver’ Prov. [?], Meledikha Settlm. , 16.VII.1912 (S. Rodionoff), 1 female; Moscow Prov., Zaraysk Distr. , Gremyachevo Settlm . (L. Bianki), 1 female; Ryazan’ Prov., Ryazan’ Distr., Sten’kino Settlm. , 14.VII.1913 (L. Bianki), 1 male; Nizhniy Novgorod Prov., Arzamas Distr., Staraya Pustyn’ , 11.VIII.1939 (Kiritshenko), 1 male, 1 female; Voronezh Rrov.: Voronezh env. , 9.VIII.1929 (I. Gudim), 1 male; Kalacheevskiy Distr., Kalach , 24–25. VII.1937 (Lukjanovitsh), 1 male; Ternovska Distr., Saval’skoe lesnichestvo [forestry], 3,25. V.1954 (Stark), 1 male, 1 female; “ Kubanskaya Prov., Maykopskiy okrug, Mogilki ”, 9.VII.1911 (Bogdanov-Katjkov), 1 female; Krasnoyarsk Terr., Kuragino Distr., Mazharka [Settlm.], 19.VI.1925 (Serebrennikov), 2 males; Irkutsk Prov., Irkutsk, 9.VI.1912 (S. Rodionoff), 1 female.

Aedeagus. Phallobase ( Figs 2 , 7 ) with relatively narrow basal plates and short arms forming small acute-angled protrusion at posterior-dorsal margin, connected with rather short dorsal connectives. Capitate processes rather small, oval, with very short stalk. In medial part of phallobase, anterio-dorsal margin of its basal plates with two contiguous, rather large triangular protrusions with rounded apices and medial to them with two narrow sclerotised processes splitting at apex and connected with anterior ends of hyaline bands. Transversal bridge wide and short. Ventral (anterior) processes of phallobase not developed, and ventral connectives joining directly to margin of basal plates. Pump of erection fluid rather small, membranous, rounded sac.

Theca ( Figs 2 , 6–9 ) uniformly cylindrical, relatively short and wide, about 1.3 times as long as wide. Walls of theca as a whole weakly sclerotised; large part of dorsal wall in its basal half convex, rounded at distal margin, more strongly sclerotised and covered with sculpture of smallest transverse ridges; ventral wall with two wide and somewhat more sclerotised areas percurrent almost from base of theca but not reaching its apical margin, with rounded distal ends. Extreme base of theca membranous at its dorsal and lateral sides, forming rounded, large but weakly convex lateral tubercles at sides, and capable of being swelled.

Conjunctiva (Figs 6, 9) rather short, having convex dorsal wall and bearing a pair of large membranous dorso-lateral lobes. Each lobe with cone-shaped apex, membranous tubercle on posterior wall and elongated sclerite on posterior-ventral wall; sclerite reaching apex of lobe and protruding by its ventral margin beyond wall of lobe as sharp ridge; proximal end of sclerite connecting with prominent small conical and sclerotised tubercle. Membranous tubercles on posterior walls of lobes asymmetrical: left tubercle smoother. Both tubercles in Rh. parumpunctatus slightly longer than those in C. hyoscyami, and right tubercle is directed dorso-laterally, while left tubercle is directed posteriad (Fig. 6). In C. hyoscyami, apex of each lobe at inner side with large rectangular membranous protrusion (Fig 9); lobes in Rh. parumpunctatus smooth at inner sides.

Ejaculatory reservoir (Figs 2–9) in its posterior part weakly sclerotised and having shape of rather large, flattened dorso-ventrally cone with truncated apex directed posteriad. Anterior-ventral margin of this cone continued as wide, thickened and strongly sclerotised plate curved at ventral side. Anterior wall of reservoir is represented by two wide and convex sclerotised plates. These plates movably connecting with anterior lateral angles of reservoir and with lateral part of its deflexed ventral plate, and also connecting to each other and to dorsal and ventral posterior margins of reservoir through membrane. Outer parts of these plates continuing into long rod-shaped articular sclerites slightly curving ventrally and diverging by their apices. Wall of endosome inter-growing with posterior margins and apices of articular sclerites and also with both anterior dorsal and deflexed ventral margins of ejaculatory reservoir along their entire length; line of this intergrowth separating conjunctiva and vesica. Posterior ends of two narrow hyaline bands connecting to anterior ventral deflexed margin of reservoir at some distance from each other. Dorsal wall of reservoir near posterior margin with rounded, weakly sclerotised area having in middle narrow, highly sclerotised strip, which splitting and reinforcing place where ductus seminis attaching to ejaculatory reservoir. Ductus ejaculatorius originating from posterior wall of reservoir.

Vesica (Figs 6, 9) consisting of two parts strongly differing in their structure. Basal part of vesica as more or less large membranous sac curved to the left. Right wall of basal part of vesica distal to its base forming large navicular lobe with pointed apex, convex sclerotised outer and concave membranous inner walls. Similar, but much smaller lobe lying at left wall of basal part of vesica near its base. At dorsal wall of basal part of vesica near place where endosomal wall adhering to anterior margin of ejaculatory reservoir, apical part of vesica originating. It looking like narrow, long tube straight or curved to the left at base and twisted spirally in remaining part. For most of its length, this tube possesses a membranous wall closely adjoining the strongly sclerotised wall of ductus ejaculatorius located inside; only the outer portion of membranous wall capable of swelling. Secondary gonopore lying at apical part of vesica terminally. In Rh. parumpunctatus , spiral part forming one small and one significantly larger turn oriented clockwise in rest and lying anticlockwise in completely inflated aedeagus (see the section ‘Functional morphology of the genitalia’ below); remaining distal section curving slightly outward, straight behind bend and curved slightly ventrally before extreme apex; secondary gonopore small ( Figs 2–6 ). In C. hyoscyami , spiral part with two small and one significantly larger turn, oriented clockwise, at rest and when in completely inflated condition of aedeagus; secondary gonopore large, due to spoon-like expanding walls of vesica ( Figs 7–9 ).

Terminalia of females ( Figs 10–12 ), as in all rhopalids, drawn into abdomen and covered by ventrite VII. Gonocoxites VIII, being the largest genital plates, transverse, with slightly elongated and rounded posterior-inner angle and more elongated, pointed and curved dorsally anteriorinner angle; inner margin between them convex. Gonapophyses I slightly shorter than the latter; their inner parts, located between gonocoxites VIII and visible from outside, longitudinally oval, convex and sclerotised, attached by anterior end to anterior inner angle of gonocoxites VIII; located under gonocoxites VIII, their outer parts and apices lamellar; apices directed posteriad, pointed and sclerotised. Inner margins of gonapophyses I connected to each other by wide membrane reinforcedinmiddlebylargesclerotisedincomplete ring opened at dorsal side; parts of membrane on sides of incomplete ring long, forming a deep fold, concave in the dorsal direction. Dorsal wall of each gonopophysis I along its outer margin reinforced with narrow thin sclerotised band, anterior end of which arcuate curved and fused with lamellar process of laterotergite IX (part of gonangulum), and posterior end significantly short of reaching apex of gonapophysis.

Laterotergites IX rather large, transverse, close to rhomboid in shape; their inner angle short, wide and rounded; outer angle long, strongly elongated and directed laterally and anteriad. Outer-anterior margin of each laterotergite thickened at dorsal side; anterior angle continuing anteriad as sclerotised, dorso-ventrally flattened process almost reaching under gonocoxites VIII to its concave anterior margin. Outer angle, thickening of outer-anterior margin, and lamellar process of each laterotergite IX together entering into composition of gonangulum. Outer-posterior margins of laterotergites IX fused with margins of rather long tergite of corresponding segment. Laterotergites VIII rather small, transverse, with widely rounded internal angle, overlying outer parts of laterotergites VIII and bearing spiracles; their outer margins connecting to margins of tergite VIII without suture in anterior part.

Reduced gonocoxite IX lying along anteriorinner margin of laterotergite IX and having the appearance of a rod-shaped sclerite slightly widened in middle of length; reaching apex of lamellar process of laterotergite IX and lying dorsally to it. Gonocoxite IX rigidly connecting with anterior margin of laterotergite IX and its lamellar process, but not completely fused with them. Gonapophyses II as longitudinal, rather wide membranous swellings located diagonally under gonapophyses I, their posterior ends converging and contiguous, and anterior ends widely diverging. Posterior ends of gonapophyses II forming small convex sclerites visible from outside at rest. Middle of each gonopophysis II with thin sclerotised band, anterior end of which arcuately curving and is fused with anterior end of gonocoxite IX. Part of gonapophysis inside this band, membranous, lamellar, with convex margin; part outside band with form of weakly sclerotised plate curved dorsally and posteriad at anterior end, where it forms a sclerotised area on ventral wall of gynatrial sac; this area by its outer margin is fused with process of gonocoxite IX, and its inner margin forming a rather short and wide sclerotised band directed medially and posteriad.

Proctiger as wide elliptical sclerotised tube somewhat flattened dorso-ventrally, with dorsal wall longer than ventral one, and sclerotised valve inside with lips-shaped flaps. All visible from outside parts of terminalia covered with dense, rather long setae.

Gynatrial sac large ( Figs 11 , 12 ). Its posterior part posteriorly resembling a wide and rather long semicircular fold with a convex dorsal wall and a flat ventral one. Transverse ring sclerites lying on ventral wall of this fold with thin edging; relatively small in Rh. parumpunctatus ( Fig. 11 )and relatively larger in C. hyoscyami ( Fig. 12 ). Anterior to this fold, between anterior ends of laterotergites IX, gynatrial sac widening and forming a pair of lateral pouches with convex dorsal walls; ventrally these pouches reinforced with bends of weakly sclerotised lamellar parts of gonapophyses II, described above.

Anterior part of gynatrial sac wide, its anterior angles sharply elongated, set apart, rather short and wide in Rh. parumpunctatus ( Fig. 11 ) and narrow, long and having connivent bases in C. hyoscyami ( Fig. 11 ). Gynatrial cone lying closer to base of common oviduct, large and consisting of two parts. Its basal part lying in inclined position, more or less close to transverse plane, subconical in shape, flattened dorso-ventrally, with broad base and directed to the right apex. Anterior wall of basal part of cone as triangular protrusion continuing anteriad and reaching base of common oviduct. In Rh. parumpunctatus , dorsal wall of basal part of gynatrial cone at some distance from its base with broad and deep semicircular fold ( Fig. 11 ); basal part of cone in C. hyoscyami without such a fold, but with triangular prominence at left side and furthermore with shallow fold on anterior-right wall. Internal surface of dorsal wall of basal part of cone bearing narrow, arcuately curved groove with thickened margins forming shallow folds; one end of this groove reaching mouth of common oviduct, and other end going into apical part of gynatrial cone. In Rh. parumpunctatus , radius of curvature and relative length of this groove larger than in C. hyoscyami . Apical part of gynatrial cone tubular and extending from apex of basal part. In Rh. parumpunctatus , proximal half of this part rather narrow and continuing the curvature of groove on dorsal wall of basal part of cone; distal half wider, also arcuately curved, but located in longitudinal plane almost perpendicular to longitudinal plane of proximal half and ventrally to transverse plane of the latter ( Fig. 11 ). In C. hyoscyami , apical part of gynatrial cone with appearance of simple, short, rather wide tube ( Fig. 12 ).

Slightly sclerotised spermathecal duct attached terminally to apical part of gynatrial cone, uniformly wide and very long, forming 5–6 turns of small radius basally and of larger radius distally, with part of turns oriented clockwise and part against. Distal turns of duct embracing base of large, slightly sclerotised spermathecal capsule, with ellipsoid shape.

Figures

Fig. 1. Copulation of Corizus hyoscyami (male) and Rhopalus parumpunctatus (female), Novgorod Province. Photograph by E.Yu. Kirtsideli.

Figs 7–9. Aedeagus of Corizus hyoscy- ami, sequential stages of inflation. 7, most initial stage; 8, intermediate stage; 9, final stage of complete inflation. Wet (7, 8) and dry (9)preparations in ventral (7) and dorsal (8, 9) views. a.p.v, apical part of vesica; ar.s, articular sclerite; d-l.l, dorso-lateral lobes of conjunctiva; ej.r, ejaculatory reservoir; l.l.v, left lobe of basal part of vesica; r.l.v, right lobe of basal part of vesica; s.gp, secondary gonopore. Scale bar: 0.14 mm.

Fig. 12. Female internal ectodermal genitalia in Corizus hyoscyami. b.g.c, basal part of gynatrial cone; a.g.c, apical part of gynatrial cone; l.p.g, lateral pouches of gynatrial sac. The basal part of gynatrial cone is shown in more or less dorso-ventral plane. Scale bar: 0.14 mm.

Figs 2, 3. Aedeagus of Rhopalus parumpunctatus. 2, at rest; 3, at very beginning of inflation. Wet preparations in dorsal view. a.p.v, apical part of vesica; ar.s, articular sclerite; d-l.l, dorso-lateral lobes of conjunctiva; ej.r, ejaculatory reservoir; l.l.v, left lobe of basal part of vesica; r.l.v, right lobe of basal part of vesica; s.gp, secondary gonopore. Scale bar: 0.14 mm.

Fig. 6. Completely inflated aedeagus ofRhopalus parumpunctatus. Dry preparation in dorsal view. Scale bar: 0.14 mm

Figs 10, 11. Female terminalia in Rhopalus parumpunctatus. 10, external terminalia, ventral view; 11, internal ectodermal genitalia, dorsal view. b.g.c, basal part of gynatrial cone; a.g.c, apical part of gynatrial cone; gon, gonangulum; gp.I, gonapophysis I; f.d.w, fold on dorsal wall of basal part of gynatrial cone; gp.II, gonapophysis II; gx.VIII, gonocoxite VIII; gx.IX, gonocoxite IX; l.p.g, lateral pouches of gynatrial sac; lt.VIII, laterotergite VIII; lt.IX, laterotergite IX; prg, proctiger; sp.d, spermathecal duct. At fig. 10, the genital plates are shown somewhat driven apart and the inner margins of laterotergites IX are shown slightly turned ventrally; at fig. 11, the basal part of gynatrial cone is shown in more or less dorso-ventral plane. Scale bar: 0.14 mm.