Isthmiade zamalloae, S., 2009

Clarke 1, Robin O. S., 2009, Bolivian Rhinotragini II: ISTHMIADE Thomson, 1864 (Coleoptera, Cerambycidae), with two new species Robin O. S. Clarke, Papéis Avulsos de Zoologia 49 (44), pp. 577-591 : 582-584

Isthmiade zamalloae sp. nov.

( Figs. 2A, 2B )

Holotype: Male. Total length 17.1 mm. Deposited at MNKM.

Diagnosis. I. zamalloae sp. nov. is immediately recognizable in both sexes by short metatarsomere I, dusky round fascia of profemora, wings almost entirely translucent.

General colour: mostly translucent orange-yellow. Head mostly black (including underside of rostrum), including tip of mandibles, scape, pedicel and base of antennomere III, rest of antennomeres brown; mouthparts, labrum, clypeus, genae (above and below), and upper side of rostrum orange-yellow. Prothorax: front border of pronotum, most of prosternum (including sides and hind edge of coxal cavities, and tip of coxal process) black; rest of pronotum and prosternal process orange-yellow. Mesothorax (including scutellum and elytra) and metathorax orange to orange-yellow, sides of elytra from behind humeri to apical third slightly dusky. Abdomen orange-yellow (including abdominal process), urosternites IV and V and last two tergites fuscous. Legs mostly orange-yellow, the following chestnut or dusky: front of procoxa and most of metacoxa, trochanter and base of peduncle of meso- and metafemora, profemora with round spot on clave, dorsad of protibia; obscure, broad facia at middle of mesofemoral clave; metafemoral clave with broad band around middle, apical half of metatibia. Tarsi of middle and hind leg pale chestnut, onychia darker. Wings almost entirely translucent.

General pubescence: reduced and more uniform, yellow, hirsute hairs shorter and less dense, patches of glistening, recumbent pubescence almost absent. Head almost glabrous; short scattered hairs on genae and line of denser hairs adjacent to apex of inferior lobes; submentum and gula glabrous with group of 2-3 long setae to each side. Front of prothorax and disc of pronotum glabrous; a rectangular patch of dense, unruly, short and long hairs in front of prosternal process, sides of pronotum with oblique, large patch of short, very dense hair. Scutellum with uniform, fine, recumbent pubescence. Mesosternum with fine sparse hair at centre, denser on mesepimeron; and coxae with long recumbent hair. Basal half of metasternum and inner front corner of metepisternum with dense, recumbent, glistening pubescence; apical half of metasternum with sparse, long, erect hair. Abdomen almost glabrous, urosternites IV and V with sparse rows of long, erect hair.

Surface ornamentation: labrum with two compact group of five small punctures at base; genae almost impunctate; clypeus impunctate, adjacent depression of frons with irregular fine punctures; group of shallow punctures adjacent to front of inferior lobes and line of 5-6 punctures adjacent to inner side of lobes; upper part of frons with single row of irregular punctures to each side of frontal suture, these passing around inner margins of superior lobes in two rows of confluent punctures, leaving vertex, including postorbital area, impunctate; submentum with four rows of arced carina separated by rows of large, semi-confluent punctures. Prothorax with rectangular patch of somewhat rugose and reticulate punctures in front of prosternal process; base of prosternal process with large punctures, apex with uniform small punctures; sides of pronotum with large, oblique, flat patch of rugose punctures (representing the sexual puncturation) spreading to disc of pronotum, two groups of 7-9 large punctures to either side of central callus and two groups of 6 just behind central callus. Mesothorax (x40) densely punctured at centre of mesosternum and entirely on mesosternal process; mesepimeron and mesepisternum smooth and shining; scutellum densely micro-punctate; elytra almost impunctate, with small group of asperate punctures on humeri and irregular line of small, confluent punctures on epipleura. Metasternum moderately densely punctured except at sides; outer front corner of metepisternum with small group of small dense punctures, rest smooth and shining. Abdominal urosternites I-III almost impunctate, IV and V with a few scattered punctures throughout, centre of V reticulate.

Structure: Head. Rostrum short, frons separated from clypeus by shallow, transverse declivity; lengths of gena/ inferior lobe 0.7/1.0 mm; inferior lobes very convex, widest behind antennal tubercles, not at all contiguous, interocular distance/width of lobe 0.25/ 1.10 mm; interocular space delimited by well marked, elevated borders and deep frontal suture, and terminating in raised, ogivoid area on apex of frons (where it is further delimited by contrasting colour (interocular black, frons orange); superior lobes proximate, interocular distance/width of lobe 0.5/ 0.25 mm. Frontal suture deep and relatively wide to hind margins of superior lobes (where it is wide enough to be furnished with a single line of small punctures). Submentum slightly depressed, separated from gula by transverse depression. Antenna slender, reaching middle of urosternite III; scape (1.1 mm) almost three times longer than pedicel (which is slightly elongate), two-thirds length of antennomere III (1.5 mm); antennomere IV (0.9 mm), V as long as three, VI subequal (1.4 mm), remaining antennomeres gradually shortening to X (0.9 mm), X1 slightly longer (1.0 mm).

Thorax. Prothorax longer (2.5 mm) than width of front and hind margins (both 2.2 mm), deeply constricted at base and apex, basal depression externally delimited by deep fovea; basal angles right-angled (when viewed from above); sides strongly rounded, widest (2.4 mm) just in front of middle. Disc of pronotum with five, somewhat ill-defined, low calli: central one elongate; anterior pair small and round; posterior pair ovate. Prosternal process almost flat, base narrow (about 1/10 width of coxal cavity) and moderately short; apical triangle elongate, relatively small, sides elevated around central depression.

Mesothorax abruptly declivous before mesosternal process, the latter broad at base (1/4 length of coxal cavity), apex cordiform without elevated sides, the whole process somewhat deformed by coarse puncturation. Scutellum trapezoidal, sides of apex elevated, apical border notched. Elytra only moderately elongate (2.3 times width of humeri), reaching basal third of urosternite II; strongly dehiscent and sharply acuminate; humero-apical costa weak just behind humeri, otherwise entire and salient to apex, giving elytron distinct convex appearance for apical two-thirds.

Metasternum broad (entire sides of mesosternum visible from above) and moderately strongly convex (planar with pro- and mesocoxae); longitudinal suture deeply impressed, occupying apical two-thirds.

Legs robust, front leg less so; procoxae very salient, distinctly more so than mesocoxae (as in I. planifrons , but no other Bolivian species); profemur short (2.5 mm), peduncle short, clave not strongly tumid, fusiform; mesofemur longer (3.0 mm), peduncle moderately long (0.9 mm), clave wide vertically, widest at middle, attenuate to apex; metafemur (6.1 mm) with short, robust peduncle (1.5 mm) and long tumid clave, the latter widest at middle, apex reaching middle of urosternite III. Tarsi moderately robust, protarsus less so; protarsomeres I and II subequal, III longer; mesotarsomere I subcylindrical equal to II in length, both shorter than III; metatarsomere I cylindrical, shorter (0.9 mm) than II + III. II (0.6 mm) and III (0.5 mm), III not strongly bifid.

Abdomen. Elongate and subparallel, widest at apex of urosternite III. Urosternite I longest (2.5 mm), trapezoidal and constricted at middle; II (1.8 mm), quadrate, sides parallel; III (1.7 mm) transverse, sides subparallel; IV (1.6 mm) trapezoidal, sides rounded; V (1.1 mm) trapezoidal, centre of apex slightly depressed, apical margin with rounded protuberance at middle; abdominal process long and broad, sides elevated, same colour as urosternite I.

Variation: Colour differences unremarkable: procoxal process entirely yellow; sides of elytral (and sometimes epipleuron) may be blackish for middle third; wings slightly duskier (but still much less than other Bolivian species); antennae may reach apex of urosternite III; urosternites IV and V almost black. Punctures more numerous on disc of pronotum (up to 12/group).

Female: Colour distribution of the single female specimen shows no significant difference from males (including the characteristic dusky fascia on profemoral clave) except procoxal process entirely orange-yellow and abdomen fuscous.

Sexual dimorphism: interocular space almost three times wider than male (1.3 mm) and slightly narrower than width of inferior lobe (1.5 mm), moderately deeply incised by frontal suture, between this and lateral border one complete carina (and associated sulcus) and one short, comma-shaped sulcus at base, with a few scattered, large punctures towards antennal tubercles, otherwise almost impunctate; antennae long, reaching apex of urosternite III; prosternal process with very short base and larger apex; mesosternal process almost impunctate; prothorax weakly constricted at base, pronotum more elongate and sides much less rounded than male, disc more tumid (and consequently calli more distinct), sides glabrous, impunctate anteriorly (except for group of 12 large punctures at extreme sides), posteriorly punctures much sparser; elytra 2.4 times width of humeri, reaching basal third of urosternite II, less parallel-sided, and dehiscence stronger; metasternum less convex and slightly less salient than pro- and mesocoxae; abdomen fusiform, widest at middle, urosternite V long (1.5 mm), conical (apex moderately pointed) and convex; hind leg less robust, peduncle longer and clave less thickened; metatarsomere I short as in male.

Measurements (mm): 4 males / 1 female respectively: total length 14.6-17.4/15.0; length of pronotum 2.2-2.7/2.6; width of pronotum 2.2-2.6/1.9; length of elytra 5.5-6.2/5.5; width of humeri 2.3-2.6/2.2.

Type material: Holotype male, BOLIVIA, Santa Cruz: Hotel Flora & Fauna, 5 km SSE of Buena Vista , 17°29’96”S/ 63°39’13”W, 430 m, 26.IV.2006, R. Clarke & S. Zamalloa col., on flower of “Bejuco hoja lanuda” ( MNKM) . Paratypes with same data as holotype : 1 female 6. V .2005 ( RCSZ) , 1 male 25. IV .2006 ( MNRJ) , 1 male 20. IV . 2008 ( MZSP) . Paratype with other host flower, same locality: 1 male 25.XII.2005, on flowers of “Sapaimosi” ( RCSZ) .

Discussion: In some ways this species seems to have reversed sexual dimorphism, the male habitus looks more like that of a female (larger, heavier and broader), the female the reverse; male antennae are shorter than female’s and male metasternum more convex than female’s.

Etymology: This species is dedicated to my wife, Sonia Zamalloa Herrera, persistent cerambycid hunter.

Figures

FIGURAS 1‑5: Bolivian species of Isthmiade Thomson, 1864. 1. Isthmiade laevicollis Tippmann, 1953, 1A female 1B male; 2. Isthmiade zamalloae sp. nov., 2A male holotype, 2B female; 3. Isthmiade ichneumoniformis Bates, 1870, 3A male, 3B female; 4. Isthmiade martinsi sp. nov., 4A male holotype; 5. Isthmiade planifrons Zajciw, 1972, 5A male, 5B female.