Gyascutus planicosta 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 : 2257-2266

Gyascutus (s. str.) planicosta planicosta (LeConte) , stat. nov.

(®gures 1, 15, 27, 33, 47) Chalcophora planicosta LeConte, 1858a: 66 . Gyascutus planicosta LeConte, 1860 (1859) : 189, pl. 12, ®gure 1; Horn, 1868: 134; Saunders,

1871: 22; Horn, 1883: 287; Waterhouse, 1889: 171; Duges, 1891: 2; Kerremans, 1892: 55;

FIGS 24±26 (line5 1 mm). Protibiae: (24) G. (s. str.) paragranulatus , holotype male; (25) G. (s. str.) granulatus , holotype male; (26) G. (s. str.) westcotti , holotype female.

FIGS 27±32 (line5 1.5 mm for 27, 29, 30, 31b, 32a; 1.0 mm for 28, 31a, 32b). Last visible abdominal sterna: (27) G. (s. str.) p. planicosta , (a) male, (b) female; (28) G. (s. str.) westcotti , holotype female; (29) G. (s. str.) paragranulatus , male; (30) G. (s. str.) fulgida , (a) male, (b) female; (31) G. (s. str.) carolinensis , (a) male, (b) female; (32) G. (s. str.) granulatus , (a) male, (b) female.

Townsend, 1892: 38; 1895: 42; Wickham, 1896: 162; Cockerell, 1898: 151; Fall, 1901: 115;

Wickham, 1905: 167; Fall & Cockerell, 1907: 179; Casey, 1909: 61; Woodworth, 1913:

196; Obenberger 1926: 160; Chamberlin, 1926: 205; Blackwelder, 1944: 310.

Hippomelas planicosta Kerremans, 1903: 65 ; 1908: 314; Leng, 1920: 179; Van Dyke, 1942:

110; Cazier, 1951: 55 (part); Barr, 1970: 4; Alcock, 1976: 343; Linsley & Ross, 1977: 276.

Gyascutus obliteratus Van Dyke, 1902: 173 ; Kunze, 1904: 243; Waterhouse, 1889: 171. Gyascutus snowi Casey, 1909: 62 ; Obenberger, 1926: 160; Chamberlin, 1926: 205. Hippomelas snowi Leng, 1920: 179 . Gyascutus pimalicus Casey, 1909: 63 ; Obenberger, 1926: 160; Chamberlin, 1926: 205. Hippomelas pimalicus Leng, 1920: 179 . Gyascutus W delis Casey, 1909: 65; Obenberger, 1926: 160. Hippomelas cribriceps Leng, 1920: 179 . Hippomelas pistorius Leng, 1920: 179 . Hippomelas acutangulus Leng, 1920: 179 . Hippomelas amplus Leng, 1920: 179 . Hippomelas aerata Leng, 1920: 179 . Hippomelas egregius Leng, 1920: 179 . Gyascutus cribriceps Chamberlin, 1926: 205 . Gyascutus pistorius Chamberlin, 1926: 205 . Gyascutus acutangulus Chamberlin, 1926: 205 . Gyascutus amplus Chamberlin, 1926: 205 . Gyascutus aerata Chamberlin, 1926: 205 . Gyascutus egregius Chamberlin, 1926: 205 .

Redescription, lectotype female. Width of head between eyes 1.4 Ö width of eye when viewed from above; front surface densely ®nely punctate, with numerous small, irregular, raised areas except on vertex and in depression above clypeus; punctate areas densely clothed with moderately short, semi-recumbent, whitish, hair-like setae; supra-antenna l ridge prominent; clypeus largely impunctate, margin shallowly emarginate; antennae reaching posterior third of pronotum when laid alongside, serrate from antennomere 4, 4±10 ¯attened, elongate triangular becoming progressively shorter apicalward, 11 with notch at outer angle (®gure 15).

Pronotal width 1.6 Ö length, widest at posterior margin; lateral margins expanded at posterior margin, then subparallel to middle and roundly converging to narrowest at anterior margin that is slightly emarginate and feebly lobed at middle; posterolateral angles acute; posterior margin with broad truncated median lobe; disc moderately convex, transversely depressed behind anterior margin and slightly ¯attened posteriorly; surface densely, ®nely punctate, with broad median smooth raised area reaching anterior third and other smooth, irregular, raised areas laterally. Scutellum small, transversely rounded, glabrous, disc with two large punctures.

Elytra at base slightly wider than pronotum; lateral margins subparallel to near middle, then converging to bidentate emarginate apices, slightly serrate near apices; disc moderately convex with irregular bluish black costae as follows: scutellar costa in basal sixth joining sutural costa, two discal costae, and one near lateral margin; costae separated by greenish brassy, ®nely punctate intervals; punctate areas densely clothed by short, greyish white, hair-like setae, especially dense along base.

Ventrally, lateral areas of thoracic sterna and anterior areas of abdominal sterna densely, ®nely punctate and clothed by short, semi-recumbent, greyish white hair-like setae; medially on thoracic sterna and posteriorly on abdominal sterna glabrous and sparsely punctate; prosternum transversely sulcate just behind anterior margin and with median oval depression just anterior to procoxal cavities; mesosternum broadly divided; metasternum with deep median sulcus; metacoxa moderately expanded medially; protrochanter with sharp tooth; pro- and mesotibia feebly arcuate, metatibia straight, all without teeth but with two slender, apical spurs; metatarsu s with tarsomere 1 as long as 2 1 3, and longer than 5; length ratio of metatibia to metatarsus 1.3:1.0; last visible abdominal sternum elongate triangular, apex sinuately truncate with posterolatera l angles toothed (®gure 27b). Length, 26.3 mm; width, 9.3 mm.

Homotype male. Similar to female but diOEers as follows: less robust, more cuneate; antennae longer, reaching posterior angles of pronotum, each antennomere more elongate and more parallel-sided (®gure 15); protibia with 5 small teeth on inner margin; mesotibia with several smaller teeth along inner margin; metatarsi longer, length ratio of metatibia to metatarsus 1.1:1.0; last visible abdominal sternum more broadly triangular (®gure 27a). Length, 24.0 mm; width, 9 mm.

Male genitalia (®gure 33).

Redescribed from a specimen collected on Larrea tridentata at California, San Diego Co., Borrego Springs , 25 August 1990, GHNC .

Type locality:`San Diego trip’.

Type material. The lectotype m of Chalcophora planicosta LeConte (MCZC) is labelled as follows: Grey disc/(red label) Type (p) 2642 (h)/ Gyascutus planicosta LeC. (h)/(red label) LECTOTYPE Chalcophora planicosta LeConte det. G. H. Nelson`95’ (h). Another female, apparently part of the type series of C. planicosta , is labelled as follows: Grey disc/planicosta 2 (h)/J. L. LeConte Collection (p)/(yellow label) PARALECTOTYP E Chalcophora planicosta LeConte det. G. H. Nelson`96’ (h). The holotype lof Gyascutus snowi Casey (USNM) is labelled as follows: Bill Wms. Fork Ariz. Aug. F. H. Snow (p)/ l(h)/Casey bequest 1925 (p)/(red label) TYPE USNM (p) 35708 (h) snowi Csy. (h). The holotype m of Gyascutus pimalicus Casey (USNM) is labelled as follows: Casey bequest 1925 (p)/(red label) NEO (h) TYPE USNM (p) 35712 (h) pimalicus Csy. (h) [paper indicates type locality as Arizona]. The lectotype lof Gyascutus W delis Casey (USNM) (designated in Bellamy and Nelson, 1990 (1989): 294) is labelled as follows: Ari (p)/ l(p)/ l(h)/Casey bequest 1925 (p)/(red label) TYPE USNM (p) 35716 (h)/®delis Csy. (h)/ LECTOTYPE (p) Gyascutus ®delis lCsy. (h) by (p) G. H. Nelson`87’ (h). Two other males are labelled as paralectotypes.

Variation. The 927 males and 794 females examined exhibited a large degree of variation. The typical pattern in the nominate subspecies is rather striking, with the smooth raised areas of the pronotum large and prominent and the elytra with prominent blue-black costae. In some specimens of these same populations, however, the elytral costae are entirely absent but they still show the typical bluish colour. Some are more brassy-green but this is not common. The males vary from 15.5±27.0 mm long (mean5 22.5 mm, n 5 50) and 5.0± 10.5 mm wide (mean 5 8.4 mm, n 5 50); females from 14.0±29.0 mm long (mean5 24.7 mm, n 5 50) and 5.0 ± 11.5 mm wide (mean 5 9.6 mm, n 5 50).

Distribution. Figure 47 shows this subspecies occupies the south-western part of the species range, primarily the sonoran desert with extensions into the southern Mojave Desert. It has been found in the USA as follows: Arizona ÐCochise Co., St. David. Gila Co.: Globe; San Carlos. Mohave Co.: Mohave Valley. Maricopa Co.: Avondale; Buckeye; Goodyear; Higley; Papago Park; Phoenix; Tempe. Pima Co.: Ajo; San Xavier Mission; 24 km S Three Points. Pinal Co.: 17 km SE Casa Grande; Florence. Yavapai Co., Camp Verde. Yuma Co.: Adair Park; Cibola; Ehrenberg; Gila Bend; Johnsonburg; Mohawk Valley; 8 km S Parker; San Luis; Welton. California ÐImperial Co.: Andrade; Bard; Calipatria; El Centro; Fish Springs; Harper’s Well; Holtville; La Puerta; Mt. Springs; Niland; Palo Verde; Salton Shores; Westmorland. Riverside Co.: Blythe; Coachella; Indian Wells; Indio; LaQuinta; Mecca; Painted Canyon; Palm Desert; Palm Springs; Thermal; Thousand Palms; Whitewater. San Bernardino Co.,: Amboy Crater; 24 km W Baker; Barstow; Cronise; Daggett; Needles. San Diego Co.: Borrego Springs; Collins Valley; Jacumba; La Puerta; Scissor’s Crossing; Sentonel Canyon. Nevada ÐClark Co.: Las Vegas; Overton. In Mexico as follows. Baja California Norte Ð 11 km N Bahia San Luis Gonzaga; El Mayor, 70 km S Mexicali; 19 km N. La Ventana; Mexicali; 1 km N Rancho El Progresso; 6.6 km N Rio Hardy Fish Camp; San Felipe; San Matias Pass; 28.3 km E Valle de Trinidad. Sonora Ð 3.3 km N El Doctor.

Biology. Observations on courtship and mating in Hippomelas planicosta were presented by Alcock (1976), and much information on the biology of this species was recorded by Linsley and Ross (1977) under Hippomelas planicosta and H. obliterata . With the revised view of those names, some of those records may need to be reapplied. Gyascutus p. planicosta (LeConte) has been cut or reared from the following: Atriplex canescens (Pursh) Nutt. , A. hymenelytra (Torr.) Wats. , A. lentiformis (Torr.) Wats. , A. torreyi (Wats.) Wats. , Encelia farinosa Gray ex Torr. , Suaeda torreyana Wats. Adults have also been collected on the following plants, some of which may prove to be larval hosts: Acacia greggii Gray , Allenrolfea occidentalis (Wats.) Kunze , Cercidium X oridum Benth., C. microphyllum (Torr.) Rose & Johnston (recorded in Kunze, 1904), Dalea spinosa Gray , Larrea tridentata (Sesse & Moc. ex DC.) Cov., Medicago sativa L. (alfalfa), Pluchea sericea (Nutt.) Cov. , Prosopis glandulosa torreyana (L. Benson) M. C. Jtn. , P. pubescens Benth. , Tamarix gallica L. Adults have been collected from early June to late September.

Figures

FIG. 47. Known geographic distribution of Gyascutus (s. str.) planicosta planicosta (black circles); G. (s. str.) p. obliteratus (black triangles); G. (s. str.) p. cribriceps (black squares).