Mastogenius texanus, Bellamy, C. L., 2002

Bellamy, C. L., 2002, The Mastogenius Solier, 1849 of North America (Coleoptera: Buprestidae: Polycestinae: Haplostethini), Zootaxa 110, pp. 1-12 : 4-6

Mastogenius texanus , sp. nov.

Figures 4, 5, 6

Description of holotype (habitus Figure 4 ). Small, length 4.2 mm, width 1.7 mm, widest on pronotum slightly anterior to midpoint; body elongate-ovoid, subcylindrical, flattened above and below; coarsely, shallowly punctate, shining black throughout, head and pronotum with faint aeneous reflection, elytra with faint purple reflection; dorsal surface sparsely covered with fine, short, semi­erect white setae, setae on ventral surface recumbent; antennomeres with short, erect setae sparsely, irregularly positioned around entire surface of each. Head with frontovertex entire; eyes of moderate size, with inner margins slightly converging dorsad; clypeal margin narrowly, feebly arcuate; antennal insertions widely separated; antennomere 2, short, globose, 3 shorter than 2, slender, 4­10 elongate triangular, length of each about 2x maximum width; 11 oblong; length of antennae, when laid alongside body, extending to just beyond anterior margin of elytra; left antennomeres 4­11 missing; pronotum with anterior margin very feebly arcuate, posterior margin evenly transverse, lateral contour broadly arcuate, widest just anterior to midpoint; lateral margin entire, sinuate when viewed laterally, supra­lateral margin extending from posterior margin to about anterior 1/6; disc flattened; scutellum triangular, slightly longer than wide, depressed medially; width of elytra at humeri subequal to pronotal width; beyond rounded anterior angle, sides subparallel to about posterior 1/3, then narrowing gradually to separately rounded and subtruncate apices; disc feebly transversely convex, with one small, irregular depression on either side just beyond anterior 1/3 and second smaller depression just before apex; epipleura extending posteriad broadly from anterior margin to opposite metacoxa; prosternum with very feeble bilobed anterior margin; prosternal projection slightly constricted between procoxae, distal margin attenuate; metacoxal plate with posterior margin arcuate, concave; abdominal ventrites with 1 as long as 2+3+4, 2 longer than 3, 3 and 4 subequal, 5 slightly longer than 4, very broadly convex; legs with femora narrowly fusiform, subequal to tibiae; fore­, mesotibiae each with one pair short testaceous apical spines; metatibiae with comb of stout setae on external face; tarsi with ventral pulvilli on tarsomeres 3, 4; pulvillus on 3, very short on distal margin; pulvillus on 4, elongate, distally expanded, extending beyond distal margin; 5 elongate, claws simple; male genitalia ( Figure 6 ) short, testaceous, parameres attenuate distally, median lobe with strong lateral teeth, one on each side, apex triangular, slightly produced.

Variation. The single paratype ( Figure 5 ) differs from the holotype: length 3.8 mm, width 1.3 mm; antennae much shorter, extending only to about posterior margin of pronotum when laid alongside; each triangular antennomere proportionally shorter than in male, length of each about 2x width; coloration differs with dorsal and ventral surfaces black with aeneous reflection, elytra and abdominal ventrites with faint brunneous background, as though teneral.

Specimens examined. Holotype (LACM): USA: TX [Texas] Jeff Davis Co., Davis Mts., Picnic Area, 11.3 mi W Ft. Davis on Hwy 161, elev. 5080', T. C. MacRae/01­176b: em. 10­20.iv.2002, ex. dead branch Quercus [pungens Liebm. var.] vaseyana [(Buckley) C. H. Muller], coll. 24.x.2001; 1 paratype (LACM): [ U.S.A.] Tex[as], [Brewster Co.] Big Bend Nat[ional] P[ar]k, Basin Area, 29.iv.1959, [H.] Howden & [E.] Becker/ Quercus grise a [Liebm.]. The holotype is donated to LACM from TCMC.

Etymology. The specific epithet is for the American state of Texas, where the only two known localities are found.

Remarks. Mastogenius texanus comes closest to M. arizonicus , both being quite slen­ der in proportion and relatively parallel­sided. It differs from M. arizonicus by having the head, pronotum, ventral surface and legs with a slight aeneous reflection and the elytra with a faint purple reflection, while the apex of the median lobe of the aedeagus is more narrowly acuminate. These two species are possibly sister­species from the same ancestral lineage.

The paratype was collected more than 40 years ago and was originally deposited in the CNCI, Ottawa and remained unidentified until I received it from G. H. Nelson. Since this specimen originated in a U.S. National Park, I requested that the specimen be deposited in a U.S. collection, in keeping with the U.S. National Parks Service’s current requirements for conducting research in U.S. National Parks. The recent rearing of a second conspecific specimen by Ted MacRae provided additional information on hosts and distribution and this specimen was chosen as the holotype since it is male. The paratype specimen was damaged during study and is now mounted on a card with the detached abdomen and the left tibia; the entire left middle leg is missing.

Figures

FIGURES 1 - 6. 1 - 3. Mastogenius arizonicus, n. sp. Figure 1, male holotype, dorsal habitus; Figure 2, female allotype, dorsal habitus; Figure 3, male aedeagus, dorsal aspect. 4 - 6. Mastogenius texanus, n. sp. Figure 4, male holotype, dorsal habitus; Figure 5, female allotype, dorsal habitus; Figure 6, male aedeagus, dorsal aspect. Scale bars = 1.0 mm for Figures 1, 2, 4, 5 and 0.5 mm for Figures 3 and 6.