Gyascutus (s. str.) dianae (Helfer) Nelson, 2000

Nelson, G. H., 2000, A revision of the subtribe Hippomelanina, part II: Gyascutus (Gyascutus) LeConte (Coleoptera: Buprestidae), Journal of Natural History 34 (12), pp. 2251-2292 : 2283-2284

10. Gyascutus (s. str.) dianae (Helfer) , comb. nov.

(®gures 12, 38, 43, 49)

Hippomelas dianae Helfer, 1954: 117 .

Hippomelas (Gyascutus) dianae Barr, 1970: 4 ; Linsley and Ross, 1977: 274.

Diagnosis. Colour brassy-green to greenish copper; males average 15.6 mm long, females 15.9 mm; width between eyes 1.6 Ö width of eye in dorsal view; antennae reaching to or beyond posterior angles of pronotum when laid alongside in male, to middle in female; pronotum widest at posterior margin; pronotal disc ®nely densely punctate with numerous weakly elevated smooth areas; elytra with faintly indicated costae; male genitalia moderately broadly lanceolate (®gure 38).

Redescription, holotype male. Head width between eyes 1.6 Ö width of eye in dorsal view; front ¯attened, densely ®nely seto-punctate along medial margin of eyes, pubescence of long, semi-erect, white, hair-like setae, rest of front a mixture of punctures and smooth raised areas; clypeal margin shallowly, triangularly emarginate; antennae reaching elytral humeri when laid alongside, serrate from antennomeres 4±10, each elongate triangular and progressively shorter from 4±10, 11 with distinct notch at outer angle.

Pronotal width 1.6 Ö length, ¯aired and widest at posterior margin; lateral margins carinate in posterior half, subparallel to middle, then arcuately converging to narrowest at anterior margin that has feeble arcuate median lobe; posterior margin with distinct, broad, emarginate median lobe; disc moderately convex, somewhat ¯attened posteriorly, transversely impressed behind anterior margin, and more deeply along posterior margin midway to lateral margin; surface moderately, densely punctate with numerous mildly elevated smooth areas becoming more broken-up laterally, punctate areas with short, semi-recumbent, white setae. Scutellum small, rounded with disc glabrous, impunctate and depressed.

Elytra as wide as pronotum at base; lateral margins converging from behind base to arcuately emarginate, distinctly bidentate apices, margins serrate on apical fourth; disc with ®ve faintly indicated costae, surface a mixture of punctures and weakly raised smooth areas with transverse strigae toward base; clothed by short, semi-recumbent, white setae.

Ventrally, ®nely densely punctate laterally, less dense medially, punctate areas clothed by short, semi-recumbent, white, hair-like setae; prosternal anterior margin without lobes, disc with coarse punctures, process smooth with midline row of punctures, and setose sulcus along lateral margin; metasternum with midline sulcus; protrochanter with weak tooth; protibia slender, weakly arcuate with few small teeth along inner margin toward apex; mesotibia slender, weakly arcuate; metatibia slen- der, straight; metatarsomere 1 longer than 2 1 3, longer than 5; last visible abdominal sternum triangular with weak submarginal crest, apex emarginate with broad rectangular lobe and dentate posterolateral angles (®gure 31a). Length, 12.3 mm; width, 4.4 mm.

Male genitalia (®gure 38).

Redescription, allotype female. DiOEers from male as follows: more robust; antennae shorter, reaching middle of pronotum when laid alongside, antennomeres of serrate part shorter more triangular; pro- and mesotibia less arcuate, protibia without teeth; apex of last visible abdominal sternum roundly truncate (®gure 31b). Length, 16.5 mm; width, 6.3 mm.

Type locality: California, Riverside Co., Whitewater .

Type material. The holotype lof Hippomelas dianae Helfer (CASC) is labelled as follows: Whitewater Riverside Co. Calif. VII-9-1950 (p)/ Ephedra (p)/P. D. Hurd Collector (p)/(red label) HOLOTYPE Hippomelas dianae Helfer 1953 (h)/ California Academy of Sciences Type No. (p) 8112 (h).

Variation. The 410 male, 339 female and 552 non-sexed specimens examined revealed the usually uniform brassy-green colour is sometimes uniform brassy or the pronotum brassy and the rest brassy-green. In occasional specimens the usually acute posterior pronotal angles are rectangular. The males vary from 10.5 to 20.0 mm long (mean 5 15.6 mm, n 5 50) and 3.6±7.4 mm wide (mean5 6.0 mm, n 5 50); females from 8.4 to 20.4 mm long (mean 5 15.9 mm, n 5 50) and 3.0± 8.1 mm wide (mean 5 6.1 mm, n 5 50).

Distribution (®gure 49). Found in low desert areas as follows: USA, Arizona Ð Maricopa Co., Arlington; Mesa; Phoenix. Mohave Co., Parker. Yuma Co., Ligurta; 29 km SE Parker; San Luis. California ÐImperial Co., Algodones Dunes; Brock Research Station; 64.5 km E El Centro; Glamis; Gordon’s Well; 35.5±40 km E Holtville; Mt. Springs; Ogilvy; Red Hill Marina and Campground; Salton Sea; Seeley; Winterhaven. Inyo Co., Panamint Valley Sand Dunes; Saline Valley Dunes. Kern Co., Red Rock Canyon. Riverside Co., P. L. Boyd Desert Research Center; Box Canyon E of Mecca; Cahuilla Lake; Cathedral City; Coachella; Desert Hot Springs; Dead Indian Canyon; Dos Palmas; Indian Wells; Magnesia Canyon; Oasis; Palm Desert; Palm Springs; Palm Springs Station; 25.5 km S Vidal; Whitewater. San Bernardino Co., Cronise Lake; Kelso Dunes; Palm Valley; Yucca Valley. San Diego Co., Borrego Springs; Collins Valley; Rancho de Anza. Nevada ÐClark Co., Las Vegas; N Las Vegas. Mexico, Baja California Norte Ð 16±19.1 km N LaVentana; 93±108 km S Mexicali; 112 km N San Felipe. Sonora: Bahia San Jorge.

Biology. Some biological information on this species is recorded in Linsley and Ross (1977). It has been reared from the following: Allenrolfea occidentalis (Wats.) Kuntze , Dalea emoryi Gray and Datura discolor Benth. Adults have been collected from the following: Acacia greggii Gray (Linsley and Ross, 1977) , Beloperone californica Benth. , Croton wigginsii Wheeler , Ephedra californica Wats. , E. trifurca Torr. (Linsley and Ross, 1977) (®gure 43), E. viridis Cov. , Eriogonum deserticola Wats. , Larrea tridentata (Sesse & Moc. ex DC.) Cov. (Linsley and Ross, 1977) and Parkinsonia aculeata L. Adults have been collected from early May to early September.

Comparisons. It is most similar to G. carolinensis Horn and is compared to it under that species.