Trichophallus Ingrisch, 1998

Ingrisch, Sigfrid, 2024, Revision of the genus Trichophallus Ingrisch, 1998 with notes on the genera Secsiva Walker, 1869 and Subrioides C. Willemse, 1966 (Orthoptera: Tettigoniidae: Conocephalinae: Agraeciini), Zootaxa 5442 (1), pp. 1-66 : 7-12

Trichophallus Ingrisch, 1998

Type species: Subria concolor Redtenbacher 1891 , by original designation. Diagnosis: The genus contains medium sized and small, always long-winged species with narrow, elongate tegmina surpassing the abdomen in both sexes. The male phallic complex consists of a pair of sclerites, in few species divided into two pairs of sclerites, and of membranous structures covered with areas of long hairs surrounding or extending these sclerites. The stridulatory file on the underside of the left male tegmen carries densely arranged and usually more than one hundred teeth. The number of teeth and their arrangement differs between species. Females differ from those of other, superficially similar genera by the possession of long, dorsal extensions from both sides of the base of the subgenital plate while the ventral surface of that plate is divided into two plates or narrow lobes varying between species or it is extremely shortened. Very characteristic for the genus is the possession of semi-oval projections from near base of the dorsal margin of the ventral external ovipositor valves provided with hairs along rim.

Discussion: Trichophallus differs from Secsiva by the absence of prosternal spines; by the pronotum which has the humeral sinus little expressed instead of distinct and the auditory swelling is smaller and ovoid instead of very large and rounded, and by more differentiated cerci and the presence of bundles of fine hairs on the titillators or the surrounding membranes.—Females differ from those of Secsiva by the large dorsal expansions from base of the subgenital plate and by the presence of semi-oval lobes arising from the dorsal margin near base of the ventral ovipositor valves, which is obviously a unique character of the genus. Species of Trichophallus are also similar to those of the genus Subrioides C. Willemse, 1966 with which they share the narrow, slender appearance and long narrow tegmina. They differ from that genus by the tegmina that are of similar width over the whole length that is only slightly and gradually narrowing backwards in basal area while in Subrioides they are wider in basal and central area and narrowing in about apical quarter to third. Moreover, both genera differ strikingly by the shape of the male cerci and titillators and by the shape of the female ovipositor that is longer and less strongly curved in Subrioides and missing basal, lateral projections of the ventral ovipositor valves typical for Trichophallus .

Description: Medium sized to small, slender species. Fastigium verticis compressed laterally, conical, shorter than scapus, apex subobtuse or subacute; ventral margin separated by a shallow sinuosity from fastigium frontis. Frons shining, sub-smooth with very few, shallowly impressed dots, slightly depressed at clypeo-frontal suture. Pronotum sub-smooth or with some impressed dots, rather regularly curved from one side to the other, apical area of disc faintly raised, subflat and shouldered; transverse sulcus weak, interrupted in middle, a second transverse sulcus on paranota and angles; anterior margin broadly rounded but slightly concave in middle; posterior margin rounded or almost subtruncate; paranota longer than high, ventral margin very faintly concave or almost straight and little descending posteriorly, ventro-posterior angle rounded; auditory swellings ovoid, well marked; humeral sinus faintly indicated. Fully winged, tegmen long and narrow, surpassing hind knees and often middle of hind tibia. Prosternum unarmed or with two minute tubercles. Meso- and metasternal lobes rounded or rarely mesosternal lobes angular; medial plate with a tubercle or spine at both posterior angles. Mesocoxa with or without a spinule at dorsal-anterior margin, ventral internal projection rather long. All femora with spines on both ventral margins, internal spines of mid femur near base. Knee lobes of fore and of mid femur obtuse or rarely triangular on external side, and obtuse, triangular or spinose on internal side; lobes of hind femur usually bi-spinose, but in small species sometimes uni-spinose and variable within species. Anterior tibia in cross-section quadrangular with dorsal angles rounded.

Male: Stridulatory file on underside of left tegmen simple, with dense, narrow teeth. Tenth abdominal tergite to a variable degree prolonged behind. Epiproct variable, often with a pit on dorsal surface. Cerci conical, elongate or short, usually with one internal projection, varying between species. Subgenital plate with converging lateral margins, rounded lateral carinae and lateral areas ascending dorsad; apex excised. Titillators separate or rarely fused; apical part often reduced and thus apex of titillators truncate or obliquely truncate and fused with large membranous bags; internal surface of those apical bags often with a row of long bristles that are distinctly surpassing the end of the bags, external surface with tufts of pale hairs of medium length, but sometimes not conspicuous, ventral-apical angle of apical bags usually granular and weakly sclerotised, often a little projecting; external surface or phallus membranes lateral of apical bags often provided with a weakly sclerotised, granular structure like a cap or a plate. With one pair of narrow, elongate lateral sclerites on dorsal-proximal side of phallus near base of titillators.

Female: Tenth abdominal tergite divided or furrowed and apex excised in middle. Epiproct triangularly rounded, surface depressed. Cerci long-conical, faintly curved, apex acute. Subgenital plate either plate-shaped but deeply divided along mid-length or broadly excised to almost base resulting in two lobes of variable shape and varying length between species; basal-lateral areas greatly projecting dorsad into the intersegmental area between the eight and ninth tergite. In most species, the lateral hind angle of the eighth tergite is excised to provide room for the dorsal, lateral projection of the subgenital plate; in the extreme, all of the lateral areas of the eighth tergite are reduced. Ovipositor falcate, compressed, highest slightly before or behind middle; dorsal margin substraight behind basal curvature; ventral margin regularly curved; apex acute. The dorsal margin of the ventral ovipositor valves is in subbasal area widened to a semi-oval projection bent ventrad and provided with numerous long hairs mainly along rim; in few species only, that area is little expressed. In most species of the genus, this projection is very conspicuous; only in few species it looks like being reduced to a narrow tumescence of the dorsal margin of the ovipositor valve.

Coloration: Uniform between species. Uniformly yellowish-brown, including face; face without black marks. Most individuals with some or all of the following, not very striking patterns that can be variable within species: (0) without marks; (1) antennae with spaced dark rings and scapus and pedicellus with dark spots; (2) tegmina with brown spots, (3) fastigium verticis with a dark spot between lateral ocelli, interrupted in middle; (4) pronotum with a very narrow dark brown medial band split by a light line; (5) anterior tibia with a dark spot below tympana.

Key to known species (females)

1. Main area of subgenital plate in ventral view forming a pair of wide plates........................................2.

- Main area of subgenital plate either consisting of a pair of narrow, elongate lobes, is strongly shortened, or otherwise modified............................................................................................4.

2. Subgenital plate in ventral view rhombic with basal area widening laterally; apical lobes wide, plate shaped with angular apical margin; lobes of both sides meeting or faintly overlapping in midline; in lateral view with basal extensions with parallel margins and angular dorsal end.......................................................... T. solomona ( Willemse, 1966)

- Subgenital plate in ventral view with apical lobes not meeting or overlapping in midline; their apical margins obtuse, rounded...................................................................................................3.

3. Basal area of subgenital plate with a deep but narrow furrow in midline; apical lobes clearly separated at base, then approaching each other and dividing again.............................................................. T. murua ssp. nov.

- Basal area of subgenital plate wide and deeply grooved; apical lobes separated in basal area by a narrow furrow, partly faintly overlapping........................................................................... T. willemsei sp. nov.

4. Subgenital plate in ventral view consisting of a narrow transverse bridge at base that is often furrowed and little prolonged in midline (in museum specimens sometimes collapsed and partly hidden under the preceding sternite); furrowed central area membranous or provided with a fold or with transverse ribs; lateral margins of that bridge prolonged posteriorly into a pair of often curved but always narrow lateral projections that reach or surpass the oval projections of the ventral ovipositor valves.....................................................................................................5.

- Subgenital plate of different shape, not as above............................................................14.

5. Subgenital plate with basal area of ventral lobes rather long, divided by a membranous band along midline; apical projections vertically widened, compressed and rather wide.............................................. T. robustus sp. nov.

- Subgenital plate with apical lobes narrow, laterally widened...................................................6.

6. Ovipositor prolonged, not dorso-ventrally widened around mid-length but of equal width in that area. Subgenital plate with a medial furrow; lateral lobes elongate, narrow, reaching to about end of lobes of ovipositor valves...... T. elongatus sp. nov.

- Ovipositor not prolonged, with distinct dorsal-ventral widening around mid-length.................................7.

7. Ventral surface of subgenital plate elongate, entire, with a medial furrow, at end divided into a pair of moderately long lobes with obtuse end. Basal-lateral lobes of ventral ovipositor valves rather long, ovoid. Ovipositor around mid-length of about the same dorsal-ventral width as near base.................................................... T. forcipatus sp. nov.

- Ventral surface of subgenital plate only in basal area entire, afterwards divided into a pair of elongate lateral lobes. Ovipositor in most other species of the genus with a dorsal-ventral widening. Basal-lateral extension of the ventral ovipositor valves semi-oval, not prolonged....................................................................................8.

8. Subgenital plate in basal area with surface concave and provided with two parallel, stiffened, transverse ribs in anterior area..................................................................................... T. augustus sp. nov.

- Subgenital plate in basal area with surface not markedly concave nor with a pair of transverse ribs but in basal-central area provided with a furrow and on both margins prolonged into elongate narrow projections.............................9.

9. Subgenital plate with basal lateral extensions moderately wide, projecting dorsal-laterally; with bilobate hind margin; the apical lobes narrow, curved, not very long, reaching about middle of lateral lobes of ventral ovipositor valves.................................................................................................. T. gracilis ( Karny, 1907) .

- Subgenital plate of different shape, not as above............................................................10.

10. Subgenital plate with narrow and elongate lateral lobes reaching or surpassing end of the basal-dorsal extensions of the ventral ovipositor valves; basal-lateral extensions elongate and vaulted in preserved specimens.............. T. capillatus sp. nov.

- Subgenital plate of different shape, not as above............................................................11.

11. Subgenital plate from dorsal, apical margin with a short projecting lobe; apical lobes rather wide, sinusoidally curved when at rest; basal extensions curved in mid-length and provided in apical half with a furrow................ T. punctatus sp. nov.

- Subgenital plate of different shape, not as above............................................................12.

12. Subgenital plate with basal area stout, box-shaped, with distinct but rounded angles laterally and with a transverse fold in subbasal area that is ending shortly after into a wavy apical margin while the compressed, narrow, lateral prolongations reach to about end of the projections of the ventral ovipositor valves............................ T. uniformis Willemse, 1966

- Subgenital plate of different shape, not as above............................................................13.

13. Subgenital plate in ventral view angular with rather broad rims, subdivided in midline of basal margin by a narrow membranous line....................................................................... T. concolor Redtenbacher, 1891

- Subgenital plate with prolonged, dorso-ventrally compressed and little widened apical area that has the internal margin convex and with sharp rim, the external margin concave, and the end pointed............................... T. umboi sp. nov.

14. Subgenital plate in ventral view with transverse basal area shortened but apical lobes prolonged and with alternating wider and narrower areas, widest around mid-length; internal margin wavy...............................................15.

- Subgenital plate of different shape, not as above............................................................16.

15. Subgenital plate in ventral view with transverse basal margin sinuate, depressed in middle and there provided with a rod shaped process; apical lobes narrow at base, internal surface widening toward about mid-length then narrowing again toward little incurved, narrow conical tip............................................................... T. hamatus sp. nov.

- Subgenital plate in ventral view with transverse basal area shortened and straight, on both sides with a short compressed process with parallel margins that ends into a step after which the internal margin of the apical projection is widened and convex but becomes afterward concave while the external margin of the process is convex throughout; the lobes end into little incurved, subacute tips.......................................................................... T. furcatus sp. nov.

16. Subgenital plate with central lobes shortened but little widened thus touching each other in midline but hardly surpassing or as long as basal extensions of subgenital plate, and with end just reaching but not surpassing dorsal lobes of ventral ovipositor valves.............................................................................................17.

- Subgenital plate more strongly modified..................................................................18.

17. Subgenital plate with central lobes shortened but little widened thus touching each other in midline, about as long as or little surpassing the basal extensions of the subgenital plate, and with its end just reaching but not surpassing dorsal lobes of ventral ovipositor valves........................................................................ T. lobatus sp. nov.

- Subgenital plate with main, ventral area very short and lobes subfused in mid-length, its convex apical margin not reaching end of basal, lateral extensions. Ovipositor only faintly widened around mid-length..................... T. reductus sp. nov.

18. Subgenital plate in ventral view short with straight and parallel lateral margins that are prolonged into a pair of long and narrow apical projections with apical margin of plate angularly excised in between; apical lateral projections in ventral view narrow, in lateral view elongate triangular, tip rounded..................................................... T. aru sp. nov.

- Subgenital plate with both halves separated from each other by a membranous zone along midline....................18.

19. Apical area of subgenital plate and basal extensions auricular, with rounded margins and for a great part attached to each other; apical area vaulted-triangular with obtuse end......................................... T. borneensis Ingrisch, 1998

- Apical area of subgenital plate and basal extensions angularly arranged to each other with substraight margins................................................................................................ T. armatus sp. nov.

Key to species (males)

1. Tenth abdominal tergite with a pair of long apical extensions forming a deep incision in between......................2.

- Tenth abdominal tergite without long extensions, only moderately emarginated from apical margin....................6.

2. Cercus with a process from inner surface arising between mid-length and apical third of cercus.......................3.

- Cercus with internal process arising near end of cercus........................................................4.

3. Cercus moderately curved near base; internal process arises little behind mid-length of cercus and curved ventrad. Stridulatory file with teeth less densely arranged; with about 110 teeth. Titillators with a fold at about beginning of apical third............................................................................................. T. willemsei sp. nov.

- Cercus rather straight near base; internal process arises before beginning of apical third of cercus, less curved ventrad. Stridulatory file with teeth narrow and very densely arranged; with about 150 teeth. Titillators regularly curved from base to tip.................................................................................... T. murua sp. nov.

4. Internal process of cercus narrow conical, arising shortly before end of cercus. Smaller species. Stridulatory file with about 103 teeth distinctly spaced throughout......................................................... T. apicatus sp. nov.

- Internal process of cercus triangular with converging margins..................................................5.

5. Internal process of cercus dorso-ventrally compressed; apical area of cercus thin. Stridulatory file with teeth on underside of left tegmen less densely arranged, with about 108–110 teeth)........................... T. salomona pilorota ssp. nov.

- Large species. Internal process of cercus swollen; apical area of cercus rounded (not very thin). Stridulatory file on underside of left tegmen with about 120–130 teeth that stand in apical area very dense....... T. salomona salomona ( Willemse, 1966)

6. Cerci with two internal projections.......................................................................7.

- Cerci with only one internal projection...................................................................10.

7. Cercus with a bell-shaped internal projection carrying a spine at tip and with a stylus shaped projection from end of ventral margin............................................................................... T. augustus sp. nov.

- Cercus of different shape...............................................................................8.

8. Cercus with two projections from end of cercus: the dorsal projection stylus shaped, elongate and the ventral projection curved with converging margins; both with a spinule at tip........................................... T. armatus sp. nov.

- Cercus of different shape, not as above....................................................................9.

9. Cercus with two short conical projections with a spinule at tip, from behind mid-lengh and at end of cercus................................................................................................. T. borneensis sp. nov.

- Cercus curved at end and provided with a thin lamella from last curvature to nearly base; also provided with a short spine at beginning of wide area of lamella and a second conical spine at end of curvature................... T. forcipatus sp. nov.

10. Cerci long and substraight, rounded, near end of basal third with a rounded internal projection with a short spine at tip and base lamelarily widened along cercus stem; apical area of cercus obviously membranous and little curved in specimen at hand. Titillators with sclerotised area in about basal half long, thin and curved, around mid-length with a short triangular widening, followed by a long membranous, band-shaped area that only at end carries a short, narrow sclerotisation..................................................................................................... T. mollipes sp. nov.

- Cerci and titillators of different shape....................................................................11.

11. Cercus with an internal projection at base, in shape triangular with a spine at tip................ T. gracilis ( Karny, 1907)

- Cercus with internal projection inserted around mid-length or closer to end of cercus...............................12.

12. Cercus with basal half rounded, in apical half compressed, narrowing toward end that carries a minute spine at tip; internal projection slightly curved, with spine-like end...................................... T. uniformis ( Willemse, 1966)

- Cercus of different shape, not as above...................................................................13.

13. Cercus short, stout and curved, at end terminating into a compressed, about semi-oval projection with a spinule at tip. Titillators rectangular with the apical branch carrying a bunch of hairs and is at end folded into a parallel branch of the same size that is moveable against the main branch.......................................................... T. lobatus sp. nov.

- Cerci of different shape, longer and not so strongly curved; titillators of different shape, not angular...................14.

14. Last abdominal tergite terminating into a pair of roughly triangular projections with obtuse tips. Male cerci with apical area swollen spatulate-triangular, slightly curved with obtuse tip; known from Amboina and Buru.................................................................................................... T. concolor Redtenbacher, 1891

- Last abdominal tergite and cerci of different shape..........................................................15.

15. Titillators with two pairs of main sclerites plus a pair of less conspicuous lateral sclerites...........................16.

- Titillators with one pair of main sclerites plus a pair of less conspicuous lateral sclerites............................20.

16. Cerci elongate, narrow, regularly curved from base to obtuse tip and carrying in subapical area from internal margin a short, acute spine. Titillators with apical sclerites connected to basal sclerites by membrane and moveable against basal sclerites; the apical sclerites each carry a lateral membranous bursa with setose margin and divide at end into a larger sickle-shaped and a shorter obtuse lobe. Cerci curved, narrow, in subapical area with a tiny, acute process..............................17.

- Different combination of characters. Sclerites of titillators fully separated from each other..........................18.

17. Cerci narrow, regularly curved to narrow, subobtuse tip, in subapical area from internal margin with a tiny, acute spine. Epiproct with a medium long apical process........................................................ T. hamatus sp. nov.

- Epiproct strongly prolonged into a narrow apical projection. Cerci in subapical area with a larger, compressed, triangular, internal process with acute tip. Apical area of titillators separated from basal area by a narrow membranous zone............................................................................................... T. tabubil sp. nov.

18. Cerci with substraight trunk, incurved apical area with approaching margins and obtuse tip, and a narrow, styliform projection arising from the curvature. Titillators simple but covered by complex sheaths in form of two pairs of membranous bursae....................................................................................... T. furcatus sp. nov.

- Different combination of characters, not as above...........................................................19.

19. Male cerci elongate, straight in basal half, then slightly curved and little narrowing toward obtuse tip; from proximal surface of end of cercus provided with a long, narrow, and straight projection with little curved, acute tip. Titillators fused in about basal halve, then separated and slightly sinuate and with re-curved, acute end; from subbasal area of apical halve and connected by a narrow membranous area provided with compressed and strongly curved projections that afterward become narrow and rounded and at tip spinose............................................................... T. spinosus sp. nov.

20. Male cerci rather narrow with converging margins and a short triangular, sub-apical internal projection. Titillators at base wide, narrowing to narrow tip; from backside with another pair of sclerites with wide base, long and narrow central area, and curved and widened apical area..................................................................... T. aru sp. nov.

- Male cerci of different shape, not as above................................................................21.

21. Cerci rather long and narrow, little curved and before end divided into a short, compressed dorsal lobe with truncate tip and a narrowed ventral lobe with acute tip. Titillators long and narrow and in apical area embraced and replaced by membranous structures that carry long hairs along margin................................................ T. elongatus sp. nov.

- Cerci roundish, rather short and stout, slightly curved behind base, otherwise almost straight, apex obtuse. Titillators separate, basal area strongly sclerotised, elongate, band-shaped with internal surface little concave, curved behind mid-length, at end obliquely truncate but somewhat irregular; apical area hyaline, sub-membranous with granular surface, and obviously movable against basal area; at end little swollen with granular rim and somewhat expanded dorsad-proximad; from membranous areas covering apical areas of titillators with a pair of large, hyaline, and faintly stiffened discs that carry at convex apical rim a row of long bristles largely surpassing apices of titillators......................................... T. capillatus sp. nov.

Description of species