Aechmutes subandinus, Clarke, 2012

Clarke, Robin O. S., 2012, Bolivian Rhinotragini V: New Species Of Erythroplatys White, 1855, Rhinotragus Germar, 1824, Ornistomus Thomson, 1864, And Aechmutes Bates, 1867 (Coleoptera, Cerambycidae), Papéis Avulsos de Zoologia 52 (5), pp. 55-79 : 74-78

Aechmutes subandinus sp. nov.

Figs. 7A, 7B

Holotype male: 11.15 mm. Deposited at MNKM.

Diagnosis: Aechmutes subandinus is readily separated from Aechmutes boliviensis , by the single, black fascia occupying midline of pronotum (in A. boliviensis the pronotum has three black fasciae, one situated at the base of the midline, the other pair laterally placed). Structural differences between the two species are small; but, as described in the text, the slightly wider interocular space, narrow base of the fourth antennomere, and more cylindrical abdomen will separate the two species.

Aechmutes subandinus is separated from A. armatus by the following differences of colour distribution: lateral margins of black fascia on pronotum subparallel, the apical margin not much wider than basal margin (in A. armatus this fascia is wine glassshaped: narrow at base, and strongly widened towards apex); distance between central and apical black fasciae of elytra greater than width of apical fascia (in A. armatus the distance between these fasciae is distinctly less than width of apical fascia); and in females of A. subandinus the central black fascia is absent (in A. armatus not so).

Aechmutes subandinus is readily separated from Aechmutes lycoides Bates, 1867 by the following: midline of pronotum occupied by broad, black fascia ( A. lycoides has paired fasciae at sides of pronotum); metafemoral clave almost entirely black, including apex (in A. lycoides the clave is yellow at apex); male abdomen slightly tapering from base to apex (in the only specimen of A. lycoides in the MZUSP collection the abdomen is strongly constricted between urosternites II and III).

Description of holotype: colour opaque; dull; black and yellow. Head yellow, the following black: apex of mandible; palpomeres; vertex with pair of parallel fasciae behind antennal tubercles; rectangular fasciae on each side of neck; and antennae (segments VIII-XI yellow at base). Prothorax yellow, the following black: on pronotum broad fascia, narrowing from apex to base, occupying all of midline; and to each side of prothorax, running from front to hind margin, a broad fascia shared by sides of pronotum and sides of prosternum. Mesothorax black (including scutellum), the following yellow: mesosternal process; and, adjacent to base of latter, at centre of mesosternum, narrow, rectangular fascia. Elytra yellow; on each elytron the following black: long, lobate fascia, running from base of scutellum towards middle of elytron, situated between humero-apical costa and suture; strongly scalloped fascia occupying apical quarter of elytron. Metathorax almost entirely black; only metasternal process yellow. Abdomen black; except centre of urosternite I with yellow quadrate fascia. Legs black, the following yellow: coxae; most of sides and underside of profemora; and apical half of metafemoral peduncle.

General pubescence: dorsad almost glabrous. Sides and basal depression of pronotum with short, dense, recumbent, golden coloured pubescence. Similar (but pale yellow pubescence) on underside; most noticeable on centre of prosternum, base and midline of metasternum, and latero-posterior margins of urosternites I-IV. Surface ornamentation: dorsad almost entirely covered by contiguous, alveolate punctures; smaller and more uniform on head and pronotum; larger, and semi-alveolate (and somewhat asperate) on elytra (except pre-apical yellow fascia with small, non-alveolate punctures). Mentum-submentum with large punctures anteriorly, posteriorly almost impunctate; the surface transversely carinate. Centre of prosternum strongly shagreened, with large, well-defined, rectangular patch of dense punctures (the latter small and semi-alveolate). Mesosternum reticulate and densely covered by very small, setiferous punctures; mixed with larger punctures towards sides and on mesepimera. Midline of metasternum densely and finely punctured; followed by smooth area with large, separated punctures; these becoming confluent and alveolate towards sides, and on metepisternum. Abdomen very shining, with reduced reticulation; punctures at centre of urosternite I similar to those of metasternum; small, shallow and sparse at centre of II-V, denser, and somewhat bevelled laterally.

Structure: length of forebody and abdomen (5.00 mm) subequal. Head with eyes (1.45 mm) distinctly narrower than pronotum. Rostrum moderately wide (0.70 mm) and long (0.50 mm); sides parallel; slightly shorter than length of inferior lobes (0.65 mm). Labrum wide, ca. twice as wide as long; front margin slightly excavate; sides rounded and explanate; one large setiferous puncture to each side, two groups of 4-5 smaller ones between them. Apex of clypeus slightly narrower than apex of labrum; separated from frons by shallow declivity. Adjacent surface of frons irregular (with depressed and prominent areas). Eyes large and convex; distal margin of inferior lobe lying on gena, proximal margin moderately oblique. Inferior lobes of eyes moderately close; width of one lobe 3.82 times interocular space (0.17 mm); the latter almost planar, prominent at sides, with relatively deep, V-shaped depression (wide enough to accommodate two rows of punctures to either side of narrow frontal suture). Width of one superior lobe of eye about half interocular space (0.40 mm). Antennal tubercles with rounded, slightly prominent apices; the distance between them slightly wider than maximum width of scape (0.40 mm). Antennae short, just reaching apex of urosternite I; basal segments moderately robust, apical ones distinctly less so. Underside of antennal segments I-VI densely setose; antennomeres III-VII incrementally wider; V serrate; VI and VII moderately strongly serrate; VIII-X incrementally narrower and less serrate; XI not serrate, slightly longer than X, with relatively short apical cone. Scape strongly pyriform (viewed laterally), moderately long (0.75 mm), and densely punctured (these confluent, large and deep). Pedicel short (0.25 mm) with rounded sides. Antennomere III cylindrical, short, but slightly longer (0.80 mm) than scape and IV (0.60 mm); V (0.75 mm); VI (0.70 mm); VII (0.65 mm); VIII (0.60 mm); IX (0.55 mm); X (0.50 mm); XI (0.55 mm). Prothorax subtrapezoidal; slightly longer than wide (1.80 mm), widest well behind middle (at this point sides slightly rounded to front margin, straighter and subparallel to basal margin); apical margin (1.20 mm) distinctly narrower than basal margin (1.70 mm). Surface of pronotum weakly convex, slightly irregular, on basal third, with one, rather weak, but large callus to either side of midline; apical and basal constrictions weak; but the latter deep and narrow, and furnished with large fovea towards each side; basal angles square. Prosternum depressed across apical fifth, moderately inclined to prosternal process; base of latter ca. seven times narrower (0.10 mm) than width of procoxal cavity; apex inclined upwards, large, trapezoidal, with weak, slightly raised borders. Procoxal cavities closed at sides and behind; procoxae slightly more prominent than mesocoxae. Mesosternal declivity deep and abrupt. Mesosternal process with broad, raised sides; moderately wide (0.30 mm), about half width of mesocoxal cavity; apex bilobed (the lobes separated by relatively small notch). Mesocoxal cavity narrowly open to mesepimeron; the latter not broad, but distinctly narrowed towards middle. Scutellum small, elongate, subrectangular; narrowly depressed at midline. Elytra hiding meso- and metasterna; for basal half moderately narrowed and subparallel (flattened between humero-apical costae and suture, only moderately steeply inclined to sides); towards apex moderately flared (slightly depressed between humero-apical costae and suture, weakly inclined to sides). Humero-apical costae elevated for middle half, absent from apical fifth. Border of epipleura, narrow, from above visible from mid-humerus to apex. Elytra 3.4 longer than width of humeri (2.25 mm); spatula-shaped; suture not completely straight (with slight dehiscence from well behind level of humeri to apex); laterally distinctly curved outwards from middle to near apex; maximum width (3.35 mm) at apical fifth. Humeri slightly rounded, not prominent, nor projecting. Apices of elytra divergent; apical margin oblique (sutural margin the longest); hardly bisinuate; both suture and lateral borders prolonged into short spine. Metathorax with posterior margin distinctly oblique. Metasternum not much broader than prothorax; convex (but most of midline occupied by relatively deep, oval depression); and planar with mesocoxae; metasternal suture almost entire, deep posteriorly, not quite reaching metasternal process. Metepisternum moderately large; subrectangular; weakly tapering towards acuminate apex. Abdomen strongly convex; only slightly tapering from base to apex. Urosternites II-IV transverse with slightly rounded, subparallel sides. V long (for a male), ca. as long as IV; trapezoidal (but transversely constricted before apex); surface slightly convex (not flattened, nor depressed); apex strongly excavate, each side prolonged into sharp tooth. Abdominal process triangular; almost planar with rest of abdomen; and abruptly acuminate. Legs moderately robust and long; length of front, middle and hind legs in the ratio 1.0:1.4:1.8. Pro- and mesofemora strongly pedunculate-clavate (claves flattened laterally); profemoral peduncle very short; mesofemoral peduncle flattened at sides, relatively long (ca. half length of clave). Metafemora relatively short (3.80 mm); weakly pedunculate-clavate; clave longer than peduncle, almost cylindrical, apices prolonged into short spines (lateral one longer); with spine, reaching apical third of urosternite IV. Protibia thickly clothed with short, rigid, yellowish pubescence mesally; apex obliquely excised laterally. Metatibia distinctly shorter (3.20 mm) than metafemora; cylindrical; bisinuate; hardly widening to apex; clothed with moderately sparse, short setae, but otherwise unspecialised. Pro- and mesotarsi rather robust (the tarsomeres subequal in length, short and wide). Metatarsomere I cylindrical; slightly shorter than length of II + III (0.65 mm); II (0.35 mm) weakly trapeziform, III moderately bifid.

Variation in males: the single male paratype shows one significant difference of colour distribution: the central black fascia on each elytron is slightly broader at base; and extended to epipleuron by the addition of a narrow longitudinal patch (the latter partially separated from the proximal part of the fascia by a deep indentation anteriorly).

Description of female ( Fig. 7B ): in both female paratypes colour distribution is little different from the male; except for the following: in one female the central, black fascia on the pronotum is deeply bifid apically; in both female paratypes the elytra of both females are entirely yellow as far as the apical, black fascia; and in one the anterior margin of the latter is not scalloped.

Structure: most structural differences limited to sexually dimorphic ones usual in species of this tribe. Rostrum longer (0.60 mm) than length of inferior lobes (0.50 mm). Eyes smaller, but equally convex; width of one inferior lobe 1.5 times interocular space (0.40 mm). Frontal suture represented by two fine, contiguous striae; and closely and confusedly punctured throughout. Antennae slightly more robust than male, but of equal length. Prothorax quadrate, more trapezoidal (i.e. sides straighter) than in male, with maximum width close to base of pronotum. Underside appears to be very similar to that of males, but abdomen wider, and sides of urosternites straighter. Urosternite V constricted well before apex, apical margin slightly sinuate, and each side extended to form small, blunt tooth. Abdominal process less acuminate at apex, and planar with rest of abdomen. Legs slightly shorter than in male (but almost same ratio); apex of metafemora just passing base of urosternite IV; and basal metatarsomere 0.92 length of II + III.

Measurements (mm): 1 male / 1 female: total length 11.15/12.25; length of pronotum 1.85/1.80; width of pronotum 1.80/1.80; length of elytra 7.60/7.70; width at humeri 2.25/2.30.

Type material: Holotype male, BOLIVIA, Santa Cruz, Estancia Caraparicito , 19°48’76”S/63°39’67”W, 1070 m, 6 km W Caraparicito, on/flying to flowers of Croton sp. A , 03.I.2008, Clarke & Zamalloa col. ( MNKM).

Paratypes: Chuquisaca, Incahuasi , 1600 m, E. Muyupampa, XII.1984, L.E.Peña col., 1 male and 1 female ( MZUSP), and 1 female ( RCSZ) .

Discussion: Comparison between A. armatus and the other species of the genus had to be made using a photograph of the holotype available on the internet. Unfortunately, Gounelle was not sure which sex his specimen represented, he thought it might be a female, and the photograph of it does not provide the information to clarify its sex. However, comparison with males and females of the two Bolivian species indicate it to be a female, because the eyes do appear to be slightly further apart than males, and the antennae more crassate as in other females.

In the MZUSP collection there are three specimens from southern Bolivia, identified by Dr. Martins as A. armatus ; these have been treated as paratypes of A. subandinus as shown above. Apart from the distinct differences of colour distribution set out in the diagnosis, the radical difference between the two ecosystems from which they come ( A. armatus from Amazonian forest, A. subandinus from Chaco Forest) present cogent arguments for recognising the two species.

Etymology: in this case A. subandinus implies the lower section of the Andes, where the specimens were collected.

Figures

FIGURES 5‑7: 5, Ornistomus simulatrix sp. nov.: A male holotype, B female paratype. 6, Aechmutes boliviensis sp. nov.: A male holotype, B female paratype. 7, Aechmutes subandinus sp. nov.: A male holotype, B female paratype.