Asydates chumash Mayor and Gimmel

Mayor, Adriean J. & Gimmel, Matthew L., 2019, Revision of the Soft-Winged Flower Beetles of the Genus Asydates Casey, 1895 (Coleoptera: Melyridae: Dasytinae: Listrini), The Coleopterists Bulletin (mo 17) 73, pp. 1-71 : 14-16

publication ID 10.1649/0010-065X-73.mo17.1

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scientific name

Asydates chumash Mayor and Gimmel

new species

4. Asydates chumash Mayor and Gimmel, new species ( Figs. 2C–D View Fig , 7G–H View Fig , 11A–B, 15A–B, 20B, 21D, 25C–D, 28D, 33, 37A, 39)

Type Material. Holotype ♂ deposited in CAS (holotype #19840), labeled “CA: Ventura Co., Los Padres \ Natl. Forest , Hwy. 33, 7.9 mi. N. \of Wheeler Springs; el. 1041m. \ N34°31’53.6”, W119°14’47.1” \ 31 July 2016; A. J. Mayor [white printed label] //Collected beating \ flowers of \ Stephanomeria virgata [white printed label] // HOLOTYPE \ Asydates \ chumash \Mayor and Gimmel 2019 [red printed label]” GoogleMaps . Paratypes: 256 specimens listed in the Material Examined section include the additional label “ PARATYPE \ Asydates \ chumash \Mayor and Gimmel 2019 [yellow printed label]” .

Diagnosis. The elytral fringe with less dense and more widely spaced setae, broad, apically flared aedeagus with a shallow u-shaped notch in dorsal view, and medially denuded female terminal ventrite without pale, whitish setae distinguish A. chumash from other species of Asydates .

Description. Body broad, moderately robust, suboval ( Figs. 2C View Fig , 7G View Fig ), slightly flattened in female ( Figs. 2D View Fig , 7H View Fig ), shiny; microsculpture sparse, inconspicuous on head, pronotum, and elytra. Length 3.0 mm (2.5–3.4 mm, n = 20); width 1.2 mm (0.9–1.3 mm, n = 20). Head, pronotum, and elytra black; elytral apices, elytral epipleura apically, legs, female ventrites, and male terminal ventrite orange; antennomeres darker, reddish brown. Pubescence dense, reclining, pale, golden, rarely whitish; pronotal and elytral fringe long, less dense. Punctation with punctures fine, indistinct on head, pronotum, and elytra. Head: Large, short, typically narrower than pronotum in both sexes, eyes bulging (Fig. 11A–B); male head 1.44 (1.38–1.56, n = 10), female head 1.60 (1.50–1.75, n = 10) times wider than interocular distance. Antennomeres 5–10 weakly serrate; male antennae short, reaching to near middle of pronotum posteriorly, female antennae shorter. Thorax: Pronotum 0.73 (0.67–0.78, n = 20) times as long as wide; widest at middle; lateral edges converging to anterior margin, slightly constricted before anterior margin; anterior and posterior angles obsolete, broadly rounded ( Fig. 15A–B View Fig ). Elytra elongate, broadly oval, elytron 3.84 (3.50–4.22, n = 20) times as long as wide, at humeri slightly wider than pronotum; elytral margins broadly explanate, epipleuron broad to near apex, most pronounced in female; apical margin not broadly rounded, flattened apically, serrate in both sexes, sutural angle slightly produced posteriorly. All tibiae with fine, white setae along external margin; pro- and mesotibiae with short, stout spines sparsely arranged along external margin, inconspicuous in both sexes. Abdomen: Male ventrite 1 with indistinct median patch of white setae. Pygidium unmodified ( Fig. 21D View Fig ), broadly rounded in male, with a shallow median emargination in female. Female ventrite 5 covered with short, sparse, pale setae, denuded medially ( Fig. 20B View Fig ). Median lobe of aedeagus a bowed tube with region beyond dorsal orifice elongate and strongly, sinuately upturned in lateral view ( Fig. 25C View Fig ); in dorsoventral view, with wide, flat, flared apex (slightly narrowed subapically), apex shallowly, inconspicuously emarginate ( Fig. 25D View Fig ); tegmen relatively elongate, with distinct constriction at base of ring ( Fig. 28D View Fig ).

Etymology. The species name honors the Native American Chumash people who historically inhabited the southern Coast Ranges of California, including the Santa Ynez Mountains where A. chumash was first collected by the authors. The name is treated as a noun in apposition.

Host Plant Associations. Adults of A. chumash have been collected from the flowers of plants in the families Asteraceae [ Ericameria sp. (1), Lepidospartum squamatum (4), Stephanomeria cichoriacea (8) ( Fig. 33A–B View Fig ), S. exigua coronaria (17), S. pauciflora (33), S. virgata (156), and Stephanomeria sp. (5)] and Polygonaceae [ Eriogonum fasciculatum (1), E. inflatum (1), and E. nudum (26)].

Seasonal Distribution. 6 July – 15 October ( Fig. 39 View Fig ).

Geographic Distribution. Coast ranges from Kern County south to Griffith Park in the Santa Monica Mountains of Los Angeles County , California ( Fig. 37A View Fig ).

Material Examined. Records reported here are based on the examination of 257 specimens. USA: CALIFORNIA: Kern County: Los Padres National Forest, Mount Pinos , 34.8222°, -119.0868°, 3 August 2008, M. S. Caterino (paratypes, 1♂, 1♀, SBMNH) ; Los Angeles County: Benedict Canyon [34.10°, -118.44°], 16 August 1967, leg. E. Giesbert (paratype, 1♀, LACM) ; same except 12 October 1967 (paratype, 1♂, LACM) ; Brentwood S. [anta] M.[onica] Mts. , 10 August 1964, L. Woodley (paratype, 1♂, UCRC) ; along Franklin Canyon Drive , 34.11088°, -118.41602°, 240 m, 9 August 2017, ex Stephanomeria pauciflora, M. & L. Gimmel, ML225 (paratypes, 2♂♂, 4♀♀, SBMNH) ; Griffith Park, Innsdale Trail , 34.13030°, -118.32244°, 320 m, 26 August 2017, ex Stephanomeria pauciflora, M. & L. Gimmel, ML249 (paratypes, 1♂, 4♀♀, SBMNH) ; Santa Barbara County: East Camino Cielo at Romero Canyon , 34.47592°, -119.59600°, 940 m, 5 September 2016, ex Stephanomeria cichoriacea, M. & L. Gimmel, ML111 (paratypes, 3♂♂, 5♀♀, SBMNH) ; Ventura County: Cuyama River on Hwy. 33, elev. 991 m, N34°46’11.2”, W119°25’18.9”, 1 August 2017, A. J. Mayor, collected beating flowers of Stephanomeria pauciflora (paratypes, 7♂♂, 15♀♀, UCRC) GoogleMaps ; Los Padres N[ational] F[orest], Hwy. 33 N. of Wheeler Springs , 34°31’N, 119°16’W, on flower of Stephanomeria sp., 10 Sept. 1999, leg. J. Dilley & D. Bishop (paratypes, 1♂, 1♀, LACM) ; Highway 33 and Rose Valley Road, 34.53445°, -119.23870°, 1,065 m, ex Stephanomeria , 28 August 2015, leg. M. & L. Gimmel & P. Jump (paratype, 1♂, SBMNH) ; Hwy. 33, 4.5 mi. N of Wheeler Springs, 34.52808°, -119.27085°, 780 m, 12 August 2016, ex Eriogonum fasciculatum, M. & L. Gimmel, ML108 (paratype, 1♀, SBMNH) ; Hwy. 33, 10 mi. N of Wheeler Springs, 34.55397, -119.24290, 1050m, 12 August 2016, ex Lepidospartum squamatum, M. & L. Gimmel, ML110 (paratypes, 3♂♂, 1♀, SBMNH) GoogleMaps ; CA-33, 1 mi S of Wheeler Springs , 34.49987°, -119.30118°, 395 m, 15 October 2016, ex Stephanomeria virgata, M. & L. Gimmel, ML115a (paratypes, 3♂♂, 7♀♀, SBMNH) ; Los Padres Natl. Forest, Hwy. 33, 7.9 mi. N. of Wheeler Springs , el. 1,041 m, N34°31’53.6”, W119°14’47.1”, 31 July 2016, A. J. Mayor, collected beating flowers of Stephanomeria virgata (holotype ♂, CAS, paratypes, 29♂♂, 20♀♀, UCRC, 1♂, 1♀, SBMNH) GoogleMaps ; same except Hwy. 33, 10.6 mi. N. of Wheeler Springs , el. 1057 m, N34°33’12.0”, W119°14’30.8” (paratypes, 33♂♂, 29♀♀, UCRC, 1♂, 1♀, SBMNH) GoogleMaps ; same except Rose Valley Rd., E. of Ojai Valley Gun Club, 1,036 m, N34°32’52.4”, W119°10’51.0”, 31 July 2016, A. J. Mayor, collected beating flowers of Stephanomeria virgata (paratypes, 1♂, 5♀♀, UCRC) GoogleMaps ; Rose Valley Road above Gun Club , 34.54755°, -119.18098°, 1,050 m, 12 August 2016, ex Stephanomeria virgata, M. & L. Gimmel, ML109 (paratypes, 9♂♂, 15♀♀, SBMNH) ; Middle Lion Campground , 34.54977°, -119.16680°, 970 m, ex Ericameria , 28 August 2015, leg. M. & L. Gimmel & P. Jump (paratype, 1♂, SBMNH) ; CA-33 at Cherry Creek Road, 34.60641°, -119.35722°, 1,270 m, 21 July 2017, ex Stephanomeria , M. & L. Gimmel, ML214 (paratypes, 2♂♂, 1♀, SBMNH) ; N. of Pine Mountain Summit, on Hwy 33, elev. 1,501 m, N34°39’26.7”, W119°22’54.7”, 1 August 2017, A. J. Mayor, collected beating flowers of Eriogonum nudum (paratypes, 19♂♂, 7♀♀, UCRC) GoogleMaps ; same except collected beating flowers of Stephanomeria exigua coronaria (paratypes, 5♂♂, 4♀♀, UCRC, 4♂♂, 4♀♀) .

Remarks. Asydates chumash is most closely related to A. rufiventris and A. tongva. The broad, moderately robust body, suboval and slightly flattened in the female, with the elytral epipleura broad and planate to near the apical margin in both sexes, the serrate elytral apex, and the median lobe of the aedeagus (in dorsoventral view) with a broad, elongate, flattened tip are characteristic of all three. Except for subtle differences in size, sculpturing, punctation, and the setal fringe of the elytra, all structures other than the male genitalia and the distribution of setae on the female terminal ventrite are similar in the three species. The primary difference is in the structure of the male genitalia, in particular the shape of the median lobe beyond the dorsal orifice. In A. rufiventris, the median lobe has the lateral margins strongly convergent before the narrow, flared, distinctly emarginate apex ( Fig. 25B View Fig ). In A. chumash, the median lobe has the lateral margins slightly convergent before the wide, flared, slightly emarginate apex ( Fig. 25D View Fig ). In A. tongva, the median lobe has the lateral margins inconspicuously convergent before the wide, straight, not flared, indistinctly emarginate apex ( Fig. 25F View Fig ).

A more subtle difference, but helpful for separating females, is in the distribution of setae on female ventrite 5. In A. rufiventris, female ventrite 5 is sparsely, evenly covered with white setae. In A. chumash and A. tongva, female ventrite 5 is denuded in the median third. In A. chumash, female ventrite 5 is more narrowly denuded medially. This character can be easily observed under high magnification in point-mounted specimens.

Distribution is another clue to identity. So far, the three species have proven to be allopatric — despite intensive fieldwork, none have been collected from the same locality ( Fig. 37A View Fig ). However, A. chumash and A. rufiventris will likely occur in close approximation in the southern Tehachapi Mountains and western San Gabriel Mountains. It is not known which, if any, species in this “flat-tip” complex occur in the Sierra Pelona Mountains and surrounding smaller mountain systems, which lie between the known ranges of the latter two species. Finally, A. tongva is the only “flat-tip” species known to occur in the Lytle Creek drainage of the San Gabriel Mountains, although A. rufiventris is known from Camp Baldy in Icehouse Canyon, a separate drainage only a few miles west of Lytle Creek.


California Academy of Sciences


Santa Barbara Museum of Natural History


Natural History Museum of Los Angeles County


University of California, Riverside