Phaenacantha grimmae, Hartung, 2019

Hartung, Viktor, 2019, New Oriental and Australasian taxa of Colobathristidae (Hemiptera: Heteroptera) in the collection of the State Natural History Museum Stuttgart, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 59 (2), pp. 403-422 : 404-407

Phaenacantha grimmae sp. nov.

( Figs 1–11 , 35–36 , 41–42 , 47 )

Type material. HOLOTYPE: J ( SMNS), collection number SMNS _ HET_00005:“BORNEO: SABAH Crocker / Range N.P., NW Keningau, / 900-1200 m., 18.XI.1996, leg. / D. Grimm [printed in black ink on a yellow paper label]“; specimen mounted on a card, pygophore with genitalia (left paramere separated) dissected and stored in a plastic vial with glycerol attached to the same pin . PARATYPES: 2 JJ ( SMNS) ( Figs 1–5 ), collection numbers SMNS _HET_00006 and SMNS _HET_00007: same collection information (except collection date, 17.XI.1996) and mounting as the holotype, pygophore and genitalia intact; 3 JJ and 3 ♀♀ ( Figs 6–11 , 47 ) (1 J 2 ♀♀ MMBC, 2 JJ 1 ♀ USNM): “ MALAYSIA, Sabah; Borneo / bog nr. km 56, Keningau / Hwy., montane forest / CL 2037 VIII-6 -85 / J. T. & D.A.Polhemus [printed in black ink on a white label, s. insert in Fig. 6–11 ] // loan x gift / J. Polh. 90 [Pavel Štys’ handwriting in black ink on a white label]“; intact specimens mounted on triangles, found among the material left by late Professor Pavel Štys.

Differential diagnosis. Absence of the triangular cell in the wing (a character that occurs within Colobathristidae only in Phaenacatha and Discocentrus Horváth, 1922 ) and absence of a spine on the posterior lobe of the pronotum (that only Discocentrus possess) characterize the species as belonging to the genus Phaenacantha . A singular medial sulcus on the vertex in front of the ocelli places it in the nominotypical subgenus. Within the genus, P. grimmae (together with P. nigrispina described below) belongs to a small group of species (most of them from New Guinea) with a completely black pronotum (the middle lobe + collar – or anterior lobe, as it was seen by HORVÁTH (1904) – are black in almost all other Phaenacantha , whereas the posterior lobe is normally pale brown-yellowish). These are P. ambigua Horváth, 1904 ; P. biroi Horváth, 1904 ; P. consobrina Horváth, 1904 ; P. distincta (Distant, 1901) ; and P. suturalis Horváth, 1904 . Only for P. biroi (the type species of the genus) is there data on the structure of genitalia, provided by GHAURI (1968). Phaenacantha biroi clearly differs from P. grimmae in the structure of hypandrium and parameres, but also in some somatic characters such as colour of femora (black in P. biroi , light brown in P. grimmae ). Differences in other species named above are in the somatic characters: the head is almost completely black in P. grimmae (with only two brown stripes on the vertex each of which start at ocellus and end between the respective antennal tubercle and eye), whereas P. ambigua , P. consobrina , P. distincta and P. suturalis have only two dark stripes and in some cases also the bases of the clypeus and the gula are black; the pleura and sterna of the thorax are all dark in P. grimmae , whereas in the other species the supracoxal lobes, and peritremes of the metathoracic glands or metepimera are pale. Phaenacantha grimmae also differs from P. distincta , P. consobrina and P. ambigua by the dark brown abdomen with a yellowish connexivum (abdomen reddish-testaceous in the other species), the smaller body size (up to 7.5 mm) from P. distincta , P. suturalis and P. ambigua (8–9 mm), the posterior pronotal lobe being only twice as long as the collar + middle lobe (2.5 to 3.0 times as long in P. ambigua , P. consobrina and P. suturalis ), the fourth antennomere being longer than the third in P. grimmae , and shorter than that in P. ambigua , P. consobrina and P. suturalis . Phaenacantha grimmae also differs from P. distincta and P. ambigua by its subvertical scutellar spine (60° oblique in the two species).

Description. Male. Coloration. Head ( Fig. 3 ) overall black, except for two brown or yellowish-brown stripes starting on each side at ocellus and ending between the eye and antennal socket (adjacent parts sometimes dark brown instead of black), and very thin brown semicircular region adjacent to the frontomedial margin of the eye; ocelli red, eyes brown; labium dark brown, with tips of segments I to III paler and tip of the terminal segment black; antennae light brown, with the tip of antennomere III and antennomere IV slightly darker; coxae ( Fig. 4 ) with dark brown basis and yellowish brown tip, trochanter to tarsus yellowish brown, except for darker terminal tarsomere; posterior pronotal lobe dark brown, rest of the thorax greyish black, except yellowish-brown hind margin of scutellum ( Fig. 3 ) and basal two thirds of scutellar spine (tip brown to black) and brown hind dorsal angle of metepimeron; fore supracoxal lobes ( Fig. 4 ) purplish brown, middle supracoxal lobe purplish brown anteriorly and greyish-black posteriorly, hind supracoxal lobes and the rest of the pleura and sternites greyish-black; peritreme of metathoracal gland dark brown; fore wings with yellowish-brown veins (veins in clavus, posterior margin of corium and Cu in the membrane somewhat darker) and very faintly yellowish regions between the veins; claval organ brown; hind wings almost completely transparent except the brown divergence point of R and M; abdomen (except connexiva) mostly dark brown, segments I and II black, tergites III and IV lighter brown and abdominal glands orifices (between segments III/IV, IV/V and V/VI) yellowish; connexiva yellow ( Figs 6–7, 9–10 ) except in segments II and VII concolorous with rest of the segment; pygophore dark brown.

Vestiture and texture. Head (except the two symmetrical depressions posterolaterally of ocelli), pronotal collar and middle lobe as well as the propleura, prosternum and abdomen covered with short adherring silvery setae ( Figs 3–4 ), relatively sparse on head and dense on the forementioned parts of prothorax (sometimes at least partly obliterated on the middle lobe of the pronotum). Pronotum punctate; punctures on posterior lobe of pronotum larger than on middle lobe and each with a short seta, but regions between punctures glabrous and shiny. Punctation and vestiture of scutellum similar to that of pronotum. Meso- and metapleura and -sterna as densely punctate as posterior pronotal lobe with little vestiture, but not shiny due to mycoid microsculpture typical for evaporatoria covering thoracic region. Legs ( Figs 4–5 ) with short adhering light-coloured setae easily visible on dark background but merging with it on yellowish tibiae; tibiae also with some slender short spines. Setae on antennae slightly darker and mostly very short. Wing veins with short, sparse, light setae. Pilosity overall on pygophore short ( Figs 35–36 , 41 ).

Structure. Head ( Figs 3–4 ) with a median sulcus starting anteriad ocelli and reaching middle of vertex. Sulcus with a slim row of setae anteromedially not reaching posterior end of sulcus. Two other depressions on the head starting in front of ocelli and extending posterolaterad, symmetrical on each side, with hind margin sinuate and building a sharp edge and anterolateral slope being very smooth ( Fig. 3 ). Ridges on the head not pronounced, only a tripartite elevation just behind antennal socket recognizable, median area of vertex convex. Eyes substylate.Angle between gula and clypeus sharp, gula oblique ( Fig. 4 ). Labium almost reaching middle coxae. Antennae thin, longer than body ( Figs 1–2 ), most segments (especially I and IV) slightly to moderately curved. Foremost part of pronotum ( Fig. 3 ) forming a collar, the lowest and the thinnest part of pronotum. Middle lobe with convex lateral outline, broader than collar; posterior lobe with a weakly convex lateral outline, broader than the middle lobe. Middle and posterior lobe in the same plane, separated only by a shallow transverse impression; this plane’s degree of ascension not steep. Hind third of posterior pronotal lobe sloped posteriad, building an obtuse angle with the rest of the pronotum. Hind margin of pronotum weakly bisinuate, concolorous with the rest of the pronotum. Scutellar spine subequal in length to posterior pronotal lobe ( Fig. 4 ), slightly inclined anteriad (the angle to the plane of meso- and metanotum 90–100°), slightly curved posteriad. Legs as long as or longer than body, hind legs the longest; femora slightly bent. Fore femora with slightly curved spine subterminally ( Fig. 5 ). Fore tibia thickened on tip, semicircularly incised medially and with a comb of setae. Fore and hind wings well developed (all specimens regardless of sex macropterous), but much shorter than abdomen ( Fig. 6 ), often not reaching hind margin of tergite V (last abdominal gland opening thus visible even with wings in repose), but sometimes almost reaching hind margin of tergite VI. Abdomen slimmest around segment II and thickest at segment V. Most abdominal segments clearly separate, only ventral border between segments IV and V indistinct, but dorsal border more distinctive; all segment borders smooth and not elevated. Lateral segment outlines straight or slightly and broadly convex at most ( Fig. 1 ). Hind border of segment VII in lateral outline straight ( Figs 7, 10 ). Segments VIII and IX (pygophore) sunken into segment VII, whereas small part of segment VIII still visible in lateral view ( Fig. 7 ). Pygophore with hypandrium ( Figs 35–36 , 41 ) broadly elevated and expanded terminally, not building parandria; posterior margin of hypandrium broadly rounded, not angulate. Paramere ( Fig. 42 ) oblong, of complicated relief, terminating in a process directed posteriad.

Female. Similar to male in coloration, vestiture, sculpture and structure. Differences in abdominal structure, with abdomen broadest at segment IV and not V as in male, maximal abdominal width also being slightly higher in female.Abdominal segment borders all clear, even between sternites IV and V; smooth except those between segments IV–V, V–VI and VI–VII slightly bulging ( Fig. 9 ). Outlines of abdominal segments similar to male except segment IV clearly convex, segment V concave and segment VI bisinuate (all straight in male). Sternite VII broadly incised medially ( Fig. 47 ). Valvula I long and broad, dark brown, but with paler median margins ( Fig. 10 ). Valvula I indistinct in unprepared specimen. Valvifer II long and slim, uniformly brown as tergite IX. Other parts of genital apparatus sunken deep into segment VII, dark coloured and indistinct in intact specimen ( Fig. 11 ).

Measurements. Body length JJ 6.60–7.10 mm, ♀♀ 7.40–7.70 mm; head width (= max. body width) JJ 1.23–1.37 mm, ♀♀ 1.30–1.34 mm. Total antennae length JJ 9.01–10.37 mm (average segment ratios, I to IV: 1.00- 1.45-1.72-2.15), ♀♀ 9.42–9.69 mm (average segment ratios, I to IV: 1.00-1.49-1.77-2.02). Ratio antenna: body 1.36–1.47 in JJ, 1.26–1.27 in ♀♀. Labium length JJ 1.40–1.60 mm, ♀♀ 1.55–1.63 mm. Distance between ocelli JJ 0.07–0.08 mm, ♀♀ 0.06–0.10 mm, between ocellus and eye JJ 0.26–0.30 mm, ♀♀ 0.29–0.32 mm, ratio in JJ3.50–4.21, in ♀♀ 2.95–4.92. Length of collar+middle lobe of pronotum JJ 0.50–0.52 mm, ♀♀ 0.48–0.54 mm; length of posterior pronotal lobe JJ 0.77–0.97 mm, ♀♀ 0.90–1.05 mm, ratio of the two measurements 1.54–1.94 in JJ and 1.67–2.10 in ♀♀. Scutellar spine length JJ 0.84–1.08 mm, ♀♀ 0.86–0.96 mm; ratio to length of posterior pronotal lobe 0.92–1.20 in JJ and 0.90–1.07 in ♀♀. Measurements of the hind tarsus (segments I / II / III, respectively): JJ 0.90–1.16 / 0.19–0.24 / 0.27–0.32 mm, ♀♀ 1.04–1.07 / 0.20–0.22 / 0.30–0.33 mm, total length of the hind tarsus JJ 1.39–1.70 mm, ♀♀ 1.57–1.62 mm. Maximum width of abdomen JJ 0.87–0.95 mm, ♀♀ 1.20–1.23 mm, minimum width JJ 0.60–0.65 mm, ♀♀ 0.65–0.71 mm, ratio 1.38–1.57 in JJ and 1.72–1.85 in ♀♀.

Etymology. The species is named after Dorothee Grimm (then SMNS), who first collected it in Borneo.

Distribution. Malaysia (Sabah).

Figures

Figs 1–5. Phaenacantha grimmae sp. nov., paratype. 1 – habitus, dorsal view. 2 – habitus, lateral view. 3 – head and thorax, dorsal view. 4 – head and thorax, lateral view. 5 – right fore femur with the spine. Insert – specimen label. Abbreviations: col = pronotal collar, mp = middle lobe of the pronotum, pp = posterior lobe of the pronotum.

Figs 6–11. Phaenacantha grimmae sp. nov., paratypes, abdomen with terminalia in situ. 6–8 – paratype male, 9–11 – paratype female. 6, 9 – dorsal view. 7, 10 – lateral view. 8, 11 – caudal view. Abdominal segments are indicated with Roman numbers. Insert – labels of the female paratype. Male paratype illustrated is the same as in Figs 1–5.Abbreviations:ag = dorsoabdominal gland, hyp = hypandrium, pyg = pygophore, t = tergite, val = valvula, vf = valvifer.

Figs 35–40. Male genitalia of the new Phaenacantha species. 35, 37, 39 – pygophore in left lateral view, with the left paramere detached to make the hypandrium better visible. 36, 38, 40 – pygophore with intact parameres in dorsal view. 35–36 – P. grimmae sp. nov., holotype. 37–38 – P. nigrispina sp. nov., holotype. 39–40 – P. paveli sp. nov., holotype. Abbreviations: hyp = hypandrium, p = paramere, par = parandrium, pyg = pygophore.

Figs 41–46. Male genitalia of the new Phaenacantha species. 41, 43, 45 – pygophore in caudal view, parameres intact. 42, 44, 46 – outer surface of the left paramere. 41–42 – P. grimmae sp. nov.; 43–44 – P. nigrispina sp. nov.; 45–46 – P. paveli sp. nov. Abbreviations: hyp = hypandrium, p = paramere, par = parandrium, pyg = pygophore.

Figs 47–48. Female abdomen tip in new Phaenacantha species, ventrolateral (oblique) view; note the deep broad semicircular median incision of the 7th sternite in 47. 47 – P. grimmae sp. nov. 48 – P. nigrispina sp. nov. Abdominal segments are indicated with Roman numbers.