Isthmiade mariahelenae, Clarke, 2013

Clarke, Robin O. S., 2013, Bolivian Rhinotragini Vii: Provisional Report Of Higher Altitude Species (Coleoptera, Cerambycidae) With Descriptions Of New Taxa, Papéis Avulsos de Zoologia 53 (28), pp. 373-406 : 373-406

Isthmiade mariahelenae sp. nov.

Figs. 2A, 2B , 12A

Holotype male: 15.6 mm. Deposited at MNKM.

Diagnosis: Isthmiade mariahelenae sp. nov. is very similar in appearance to Isthmiade ichneumoniformis Bates, 1870 (see Clarke, 2009: Figs. 3A, 3B ), but on examination, with marked differences as follows: colour distribution (mandibles entirely black, pronotum only black at anterior margin, scutellum yellow, underside almost entirely orange-red, legs entirely dark coloured); pubescence (patches of recumbent pubescence white); and structure, the most important being: rostrum longer, female interocular not carinate, elytra more than three times longer than width of humeri (and, when seen from directly above, hardly hide sides of sterna), prosternum strongly declivous across middle, apex of prosternal process trapeziform, metasternum strongly tumid (leaving metacoxae well below its level), male abdomen apiform (widened towards apex) and urosternite V differentiated (with deep, horseshoe-shaped depression), female abdomen with urosternites much widened ( III almost 1.5 width of I) and urosternite V only weakly elongate, legs comparatively more slender (peduncles longer and femora not as abrupt, nor as robust).

However similar the two species, the tegmen of the aedeagus of I. mariahelenae ( Fig. 12A ) and I. ichneumoniformis ( Fig. 12B ) are unexpectedly, and strikingly, different: in I. mariahelenae robust and compact; lateral lobes wide and proximate, and slightly twisted; apices slightly expanded, and apical margin rounded, and the only area bearing rather few, fine setae; and basal piece relatively short (in I. ichneumoniformis tegmen is composed of two setose, elongate, narrow, diverging, acuminate lateral lobes, these not at all robust, nor compact, nor twisted, and the basal piece long. Median lobes of the two species show few differences.

Comment: The extraordinary differences described between the tegmen of these two, strikingly similar species, mandates serious introspection regarding the importance of genital structure as a tool for determining species’ relationships. That the median lobes of the two species are so similar in structure, only adds to the difficulty of explaining the apparent anomaly. The author has examined the genitalia of more than 100 species of Rhinotragini without finding anything similar. Before attempting any interpretation of this example, and any declaration suggesting it be one of natures’ anomalies, it would seem prudent to further the examination of genitalia among Neotropical Cerambycidae .

Description of holotype: The following opaque black: head (including mandibles and antennal segments I-IV) and front margin of prothorax; the following opaque chestnut: rest of antenna, centre of prosternum, apical third of elytra, and legs (except mesocoxae paler); the following translucent orange-red: rest of prothorax, meso- and metasterna, and urosternites I-IV; the following translucent yellow: mouthparts, post coxal process, mesepimeron, scutellum, basal two-thirds of elytra (disc almost vitreous), and urosternite IV. Abdominal process whitish in colour. Pre-apical band on wings ochraceous-yellow.

General pubescence: Head almost glabrous, genae and frons with sparse, very short, recumbent pubescence; submentum and gula with group of short setae at each side. Scutellum completely clothed with, and sides of pronotum (adjacent to procoxae) with moderately small patch of, glistening white recumbent hairs; rest of pronotum glabrous. Prothorax anterior to prosternal process and apical half of metasternum somewhat sparsely hirsute, mesepimeron and base of metasternum clothed with glistening white, recumbent pubescence; metepisternum and sides of abdomen almost glabrous (urosternites I-III with sparse, long hairs towards midline), IV with additional scattered, recumbent hairs, the latter becoming dense on V; tergites with short golden coloured pubescence; pleurites of all abdominal segments adorned with farinose, golden coloured pubescence.

Surface ornamentation: Punctures non-alveolate. Labrum with single large, setaceous punctures to each side, and two groups of very small punctures to each side of midline; clypeus impunctate; frons with mix of large and small punctures, smaller and contiguous towards sides, interocular impunctate; vertex inconspicuously carinate, with single row of well separated punctures between antennal tubercles, these extending around inner and hind margins of superior lobes in two irregular rows, leaving vertex partly impunctate; mentum-submentum inconspicuously, transversely carinate, with irregular lines of large and small punctures, gula impunctate; prosternum anterior to prosternal process with irregular, sparse, large and small punctures, interstices micro-punctate; pronotum almost impunctate, sides with few scattered punctures, and below white pubescence somewhat more densely punctured (representing the sexual puncturation); disc of elytra with shallow, irregular, sparse, small punctures, basal half with single row of deeper, small punctures adjacent to sutural border, towards sides punctures denser, and larger on humero-apical costa; mesosternum micropunctate at centre smooth towards sides; metathorax similar, metasternum with small, dense, somewhat beveled punctures adjacent to midline; abdomen almost impunctate, micropunctate where pubescent, dense on urosternite V.

Structure: Forebody (6.55 mm) 0.71 length of abdomen (9.25 mm). Head with eyes (1.90 mm) slightly narrower than prothorax. Frons separated from clypeus by strong, transverse declivity; frontal suture represented by deep V-shaped depression extending to hind margin of antennal tubercles. Rostrum widest (1.35 mm) at base, 1.8 wider than long (0.75 mm); sides slightly constricted at middle. Labrum small and projecting, transverse, rectangular (three times wider than broad), apical half slightly declivous. Inferior lobes of eyes subcontiguous, interocular distance (0.20 mm) 4.5 width of lobe (0.90 mm); very convex laterally; below level of interocular medially; distal margin lying on frons, proximal margin oblique. Superior lobes with 11-12 ommatidia, relatively proximate; interocular distance (0.50 mm) twice width of lobe (0.25 mm). Area of submentum depressed with evanescent, arced carinas; not separated from gula by distinct declivity. Antennae slender, somewhat short, reaching apical third of urosternite III; VI-X with short, but acute, serrations; scape (0.85 mm) more than four times longer than pedicel, two-thirds length of antennomere III (1.30 mm); IV (1.00 mm); V (1.35 mm), slightly longer than VI (1.30 mm); remaining antennomeres gradually shortening to X (1.00 mm); X1 slightly longer (1.05 mm). Prothorax about 1.1 longer (2.15 mm) than wide (2.00 mm); sides deeply constricted at base and apex, middle third occupied by large, rounded callus; width of front and hind margins equal (1.80 mm). Pronotal disc with five prominent calli; those to either side of centre subcircular; median callus elongate and narrowed posteriorly; posterior pair with secondary, smaller callus laterally, and slightly behind each one. Prosternum abruptly declivous across apical third; basal two-thirds strongly inclined to base of prosternal process. The latter rather long, and almost flat; about 12 times narrower than width of coxal cavity; apex trapezoidal, sides hardly raised, declivous across apical third. Postcoxal process relatively broad (0.25 mm), closing posterior coxal cavities. Mesosternum deeply and abruptly declivous; mesosternal process moderately broad at base (0.25 mm), about one third width of coxal cavity; apex weakly cordiform with well elevated sides. Scutellum moderately large, rather narrow, subtrapezoidal, sides slightly sinuate, apex truncate. Elytral surface adjacent to scutellum narrowly raised and concolourous with basal two-thirds of elytra. Elytra elongate (7.60 mm), 3.30 width of humeri (2.30 mm), reaching base of urosternite III; narrowed from humerus to apex; dehiscent for apical half; humero-apical costa weak (absent from humeri, and weakest at middle, only slightly salient towards apex, absent from extreme apex); apical margin slightly thickened and obliquely truncate. Metasternum tumid (more so behind); more prominent than mesocoxae; and much more prominent than metacoxae; sides rounded from base to middle of apex; longitudinal suture long, occupying apical four-fifths, not deeply impressed behind. Abdomen moderately robust and elongate; subparallel (broadest at middle of urosternite III and IV), urosternite I longest (2.65 mm), cylindrical, and constricted at middle; II (1.85 mm), slightly trapezoidal, narrowest at base, sides almost straight; III (1.65 mm) subquadrate; IV transverse (1.40 mm). Urosternite V (0.90 mm) trapezoidal; with strong horseshoe-shaped depression from near base to apex (sides of depression raised and extended posteriorly, almost “winged”); apical margin rounded, but slightly sinuate at each side. Abdominal process long and narrow; base vertical; apex recurved and horizontal to abdomen (and deeply inserted between metacoxae). Legs long and moderately robust, ratio of length from front to hind leg 1.0:1.4:2.5. Front leg (5.85 mm): peduncles very short; clave fusiform, moderately robust and abrupt, sides only moderately flattened; tibia straight, sides subparallel (narrow at extreme base, gradually widening to apex), apex weakly excised laterally. Middle leg (7.95 mm): femora slightly bisinuate; peduncle flattened (about half length of clave); clave fusiform (and sinuate at apex), moderately abrupt, flattened laterally, slightly less so mesally; tibia straight, slightly flattened, gradually widening from middle to apex, and rather abruptly widened at extreme apex. Hind leg (14.70 mm): femora more cylindrical, peduncle straight and cylindrical (about half length of clave); clave not well demarcated from peduncle (but more so when viewed laterally, appearing narrowly fusiform), apex reaching basal third of urosternite IV; tibia cylindrical, bisinuate (when viewed laterally, straight from directly behind), slightly shorter (5.65 mm) than metafemora, gradually thickened to apex, rather finely setose, and without specialised pubescence. Pro- and mesotarsi similar; tarsomeres rather narrow (I moderately elongate, II slightly elongate and trapezoidal, III wide and moderately strongly bilobed). Metatarsus also narrow (but more robust); hardly setose; metatarsomere I cylindrical and curved, about 1.3 longer (1.40 mm) than II + III (1.10 mm); II cylindrical (with narrow base); III small, narrow, and deeply bilobed; onychium moderately long and robust.

Male variation: Colour differences are few; most of prosternum (but not post-coxal process) and all coxae may be black; legs may be almost black; elytral epipleur from behind humeri may be dusky.

Description of female ( Fig. 2B ): Example size 19.50 mm. Colour differences limited to the following: mouthparts may be darker; centre of mesosternum, metasternum adjacent to mesocoxal cavities, apical half of urosternite V dusky (and in largest female all urosternites clouded dusky); and legs black. Surface pubescence (and its corresponding puncturation, is sparser or absent, dense patches of white pubescence absent, except on mesepimera.

Structure: Rostrum almost parallel sided, about 1.8 wider than long (0.90 mm), equal to length of inferior lobe. Labrum larger, 2.5 wider than broad. Inferior lobes of eyes smaller and less convex than in male; proximal margin reaching sides of genae, posterior margin more oblique; well separated, the distance between them equal to width of one lobe (0.75 mm); interocular demarcated by raised sides (these extending onto frons beyond front margin of lobes); bisected by moderately deep and wide frontal suture, each half depressed to midline, with short, comma-shaped sulcus anteriorly (containing group of 2-3 small punctures), and irregular group of small contiguous punctures posteriorly. Superior lobes of eyes with 11-12 ommatidia, relatively proximate, interocular distance (0.50 mm) twice width of one lobe. Area of mentum-submentum lacking carinas. Antennae as male, but reach middle of urosternite III. Prothorax very similar to that of male, but almost quadrate (1.04 longer than wide); central callus distinctly more prominent than others on disc; and prosternal process slightly arced and wider (base about 0.2 width of coxal cavity). Mesosternal process wider than male, about half as broad as coxal cavity, and without elevated sides. Scutellum as male, but apex slightly emarginate. Elytra 3.0 longer than width of humeri, reaching apex of urosternite II; more strongly dehiscent than in male (leaving apices much wider apart, the tips of latter with slightly inwardly projecting lobes). Abdomen vespiform; very robust (almost twice as wide as that of male); urosternites II-IV much wider than I ( III the widest, almost 1.5 wider than I), and more rounded at sides; V triangular, with apical margin moderately acuminate, but otherwise undifferentiated; abdominal process as in male, but slightly broader. Legs very similar to male; ratio length front, middle and hind leg the same (but front leg somewhat shorter than in male); metatarsomere I 1.3 longer than II + III.

Measurements (mm): 8 males / 5 females: total length 15.35-18.7/18.25-21.05; length of pronotum 2.25-2.45/2.35-2.70; width of pronotum 1.85-2.05/2.15-2.50; length of elytra 7.10-8.25/7.60-10.00; width at humeri 2.20-2.50/2.60-3.15.

Type material: Holotype male, BOLIVIA, Santa Cruz, Provincia Florida, Floripondio (east), 18°08’S / 63°44’W, 1914 m, on/flying to flowers of “Sotillo”, 27.XI.2009, Clarke & Zamalloa col. ( MNKM).

Paratypes with nearly same data as holotype : 3 males, 1 female, 26. XI .2009 ( RCSZ) ; 1 male, 27. XI .2009 ( MNRJ) ; 2 males, 29. XI .2009 ( RCSZ, ACMT) .

Paratypes with same locality as holotype, but different host flower: On /flying to flowers of “ Sagüintillo ”, 1 male, 1 female, 29. XI .209, Clarke & Zamalloa col. ( MZUSP); 1 male, 1 female, 29. XI .209, Clarke & Zamalloa col. ( MCNZ).

Paratype with slightly different locality from holotype, and different host flower: Floripondio (west), 18°08’S / 63°45’W, 1893 m, on/flying to flowers of “Lloque colorado”, 1 female, 02. XI .2009, Clarke & Zamalloa col. ( RCSZ) .

Comment: “Lloque colorado” is also known by the local name “Garapatillo” (tick-like), which refers to the appearance of the seeds of this shrub.

Etymology: This new species is dedicated to Dr. Maria Helena Galileo ( MCNZ) in recognition of her huge contribution cataloguing the Neotropical Cerambycidae .

Figures

FIGURES 1‑3: 1, Acyphoderes amboroensis sp. nov.: A = male holotype. 2, Isthmiade mariahelenae sp. nov.: A = male holotype, B = female paratype. 3, Chrysaethe lazzoi sp. nov.: A = male holotype, B = female paratype, C = male paratype (colour variety).

FIGURES 7‑12: 7, Ecliptoides pseudovicinus sp. nov.: A = male holotype, B = female paratype. 8, Stenopseustes lingafelteri sp. nov.: A = male holotype. 9, Tomopterchasia sullivanorum sp. nov.: A = male holotype. 10, Tomopterchasia cuneiformis (Fisher, 1952) comb. nov., A = female. 11, Tegmen of aedeagus: A = Ephippiotragus wappesi sp. nov., B = Ephippiotragus thomasi sp. nov., C = Amborotragus vestigiepimeron sp. nov. 12, Tegmen of aedeagus: A = Isthmiade mariahelenae sp. nov., B = Isthmiade ichneumoniformis Bates, 1870.