Xenorhipis bajacalifornica Westcott

Westcott, Richard L., 2008, A new species of Xenorhipis LeConte and of Mastogenius Solier from Mexico, with a discussion of Chrysobothris ichthyomorpha Thomson and its allies and notes on other Mexican and Central American Buprestidae (Coleoptera), Zootaxa 1929, pp. 47-68 : 48-49

Xenorhipis bajacalifornica Westcott , new species

( Figs. 1, 2 , 15, 16 )

Holotype male. As in Fig. 1 , 4.2 mm long, 1.27 mm wide; head black with bronze reflection, mostly on upper half, antennae pale brown; pronotum black with strong coppery bronze reflection; elytra coppery brown apically and in humeral region, narrowly blue along basal margin, blue to purplish to coppery brown medially on basal half, and with cream-colored median fascia reaching to lateral margins; beneath brown, except black on middle of metasternum; black laterally on propleurae; forecoxae testaceous anteriorly, legs shining brown.

Head evenly convex with a very fine black median groove on vertex extending short distance onto front; strongly densely and coarsely areolate-reticulate; antennal flabellar processes beginning on second antennomere, first process 3/5 as long as second, which is 3/4 as long as third, remaining processes slightly longer than third and about equal in length; last maxillary palpomere cylindrical, truncate apically. Pronotum broadly, evenly convex, 1.4 X wider than long, slightly narrower at apex, lateral margins weak to obsolete anteriorly, well defined posteriorly and with a slight basal rounding on either side; anterior margin with a broad prominent lobe at middle; posterior margin transverse, slightly sinuate towards sides; disk with a small deep puncture at base in front of scutellum; surface coarsely irregularly granulate-reticulate, with indistinct (at 80X) short sparse white setae on lateral thirds. Scutellum irregularly transverse-ovoid, narrowly lobed behind, deeply foveate-depressed on middle, partly hidden under anteriomedial sutural elytral angles; surface microreticulate. Elytra extending to opposite about anterior 1/4 of second abdominal ventrite, slightly wider than pronotum, rather parallel-sided, slightly narrower at base; lateral margins serrulate on apical half, broadly rounded at apex; surface distinctly, narrowly and transversely depressed along base, broadly shallowly depressed behind middle on pale fascia, and with punctures fine and deep but denser basally on middle, where they appear asperate, and with indistinct (at 80X) very short sparse white setae. Beneath with surface microreticulate, overlain with coarse shallow reticulations on prothorax, remainder of thorax finely deeply punctured except for mesopleurae and anterior middle portion of metasternum, surface of abdominal ventrites sculptured with irregularly transverse ridges; setae white, distinct, much longer than on dorsal surface; prosternum with anterior margin broadly, very shallowly lobed on middle; metasternal sensory pit extending for basal 3/4 of sclerite, containing fine long light golden setae; metacoxal plates narrowed externally to 1/2 internal width, lateral margin truncate; last ventrite broadly, semicircularly emarginate, lateroapical portions finely asperate. Aedeagus as in Figs. 15 & 16 .

Allotype. As in Fig. 2 , 3.95 mm long, 1.27 mm wide, differs from male as follows: head, pronotum and narrowly along base of elytra black with strong deep blue reflection, remainder of basal portion of elytra in front of pale fascia black with slight bluish to purplish reflection, apical portion dark brown; beneath black with slight dark blue reflection, except abdomen yellowish brown. Head with surface sculpture less sharply reticulate, antennae not flabellate, slightly serrate beginning with fifth antennomere. Pronotum more broadly, shallowly convex, lateral margins broadly rounded, lateral margins sharp and well defined on basal half, not present on apical half; surface less sharply and more confusedly reticulate, the reticulations not evidently granulate, yet microsculptured within. Scutellum transversely oval, broadly and shallowly depressed.

Elytra extending to about apical 1/3 of third ventrite. Beneath much smoother and with much finer and shorter setae, sparsely granulate on hind portion of metasternum, notably on hind coxal plates which are more or less triangular, and much narrower at sides; abdomen vaguely, irregularly punctate and without ridges, last ventrite truncate and with a dense brush of long golden setae, lateroapical portions smooth.

Material examined. Holotype ( CSCA) labeled “ MEXICO, Baja Calif. Sur [BCS], Los Barriles, IV-27- 29-1979, Malaise trap, 8 AM-6 PM/M. Wasbauer collector”; allotype ( RLWE); BCS, wash 11 mi NW Cabo San Lucas, 17-23-IV-85, R. L. Westcott; 4 male paratypes, all from BCS as follows: same data as allotype; 7.5 km N El Triunfo, 18-IV-81, D. S. Verity coll. ( DSVC); 6.5 mi S, 1 mi E El Pescadero, 21-VII-77; arroyo 0.4 mi N, 0.6 mi E Migriño, 18-21-IV-85, R. L. Westcott ( RLWE).

Variation. The four male paratypes range from 3.50–4.20 mm in length. On two of them the blue color on the pronotum is restricted to the basal margin, and it is scarcely evident on one. The elytral fasciae vary from 1.5 X wide as long to 0.67 X wide as long, that of the largest paratype closely matching the holotype, while the smaller specimens have the fasciae more quadrate, not projecting forward.

Distribution. This species is known only from the Cape Region of Baja California Sur, Mexico.

Biology. The specimens I collected in 1985 were taken by beating shrubs and trees, likely acacia or mesquite growing in the thornscrub vegetation near the coast.

Comparison and discussion. Xenorhipis bajacalifornica is somewhat enigmatic in its placement to genus. As currently recognized ( Bellamy and Nelson, 2002), the genus is distinguished from Hesperorhipis by a single key character: “posterior coxal plates scarcely narrowed laterally” vs. “posterior coxal plates triangular, hind margin strongly oblique” in the latter genus. This was adapted from Fall (1930), who discussed other characters that he thought distinguished the two genera. In X. bajacalifornica the posterior coxal plates are more triangular, yet they are not acute laterally as in some species of Hesperorhipis . Described species of Xenorhipis that I have seen have the plates more or less transverse, though this is variable, sometimes even between the sexes. The elytra in the male of Hesperorhipis usually do not attain even the second ventrite, though they may reach the third ventrite on some specimens of H. albofasciata Fall ; while in described species of Xenorhipis the elytra of males cover from the third ventrite ( X. osburni Knull ) to almost the entire abdomen. In X. bajacalifornica the elytra of males reach just beyond the first ventrite. Fall (1930) used the length of the basal segment of the hind tarsus as a distinguishing character, but I do not find it useful. Truly puzzling is why he stated, in the same paper, that Hesperorhipis lacks the metasternal excavation (= sensory pit), as his description of H. albofasciata was from a single male. Based on my admittedly limited study, I conclude that the only consistent distinguishing character is the male antenna, on which the flabellar processes begin with the second antennomere in Xenorhipis , the third antennomere in Hesperorhipis . In Nelson’s (1968) key to males, X. bajacalifornica reaches a dead-end at couplet 2. In my opinion it is as much, perhaps more, related to species of Hesperorhipis as it is to any species of Xenorhipis that I have seen.

Figures

FIGURES 1 – 2. Xenorhipis bajacalifornica. 1, holotype; 2, allotype.

FIGURES 11 – 16, Aedeagus of Chrysobothris and Xenorhipis. 11, Chrysobothris chiriquita; 12, C. ichthyomorpha; 13, C. thomsoni, Colombia; 14, same, Trinidad; 15, Xenorhipis bajacalifornica, dorsal; 16, same, ventral.