Agrilus argythamniae Hespenheide and Westcott

Hespenheide, Henry A., Westcott, Richard L. & Bellamy, Charles L., 2011, Agrilus Curtis (Coleoptera: Buprestidae) of the Baja California peninsula, México, Zootaxa 2805, pp. 36-56 : 40

Agrilus argythamniae Hespenheide and Westcott , New Species

(Figs. 5–7)

Description. Holotype male: robust, proportionately broad and somewhat flattened, in cross-section flattened above, convex below, 3.40 mm long, 0.95 mm wide; black throughout with golden reflections, except green on front of head and reddish-bronzy on elytra; setae short, recumbent, and inconspicuous throughout, denser in vague narrow short sutural stripes before middle of elytra and in broader area on apical 1/4, somewhat denser on upper 1/ 2 of posterior coxae, posterior 1/2 of epimeron, somewhat denser and semierect on prosternal process and along midline of anterior portion of metasternum, setae longer and hair-like on posterior margin of abdominal ventrite 5.

Head with front somewhat convex with vague shallow depression along midline and narrow transverse depression above antennal insertions, surface weakly rugose; epistoma shallowly concave between antennal insertions with fine transverse carina, width 1/3 of distance between inner margins of eyes, shallowly emarginate below; eyes oval; antennae compact, serrate from antennomere 5, antennomere 5 rounded-triangular.

Pronotum slightly narrower than elytra at posterior margin, with sides shallowly expanded outward nearly to apex where they are broader than elytra at humeri, then narrowing slightly; marginal and submarginal carinae somewhat widely separated at apices then converging and joining before base when viewed from side; from above anterior margin slightly produced as broadly, shallowly rounded lobe; basal margin undulate, shallowly emarginate at middle of each elytron, transverse before scutellum; disk broadly, shallowly convex, with indistinct medial depression on anterior 1/2 beyond middle and stronger depressions along lateral margins; prehumeral carinae absent; surface finely concentrically rugose. Scutellum narrowly pentagonal with strong raised transverse ridge.

Elytra with lateral margins nearly parallel to basal 1/3, then widening slightly to beyond middle then narrowing to apices, apices broadly, separately rounded, minutely toothed; disk shallowly convex in cross section, each elytron with small, shallow oval depression at base, narrow, shallow setose sutural depression before middle; surface imbricate.

Prosternum with sides of prosternal process parallel between coxae, apex rounded; prosternal lobe emarginate at middle. Metacoxae with posterior margin regularly concave, upper exterior angles obtuse. Abdomen with no indication of suture between ventrites 1 and 2, regularly convex, dorsal portions of ventrites1–5 narrow, equal in width, not significantly more setose than lateral portions. Mesotibia with short acute tooth on inner angle at apex; metataromere 1 equal in length to next three combined, tarsal claws similar on all legs, cleft with shorter inner tooth. Genitalia as in Figure 7.

Allotype female: as male except pronotum dark greenish blue, 4.20 mm long, 1.25 mm wide; front of head golden coppery; setae on prosternum and anterior portion of metasternum sparse and inconspicuous; mesotibiae without short acute tooth on inner angle at apex.

Type material. Holotype: México: Baja California Sur, Sa. Victoria, trail: La Burrera-La Laguna, 800–875 m, 28.VIII.1977, R.L. Westcott, Swept or beaten from Argythamnia sp., euphorbiaceous shrub ( CAS). Allotype: same data as holotype ( CAS). Paratypes: same data as holotype (6M, 4F, RLWE), Sa. Victoria, trail: La Burrera- La Laguna, canyon stream, 800 m, 2.IX.1977, R.L. Westcott, Swept or beaten from Argythamnia sp., euphorbiaceous shrub (15M, 6F, RLWE), Sa. Victoria, trail: La Burrera-La Laguna, ridge, 1375–1465 m, 2.IX.1977, R.L. Westcott, Swept or beaten from Argythamnia sp., euphorbiaceous shrub (8M, 3F, RLWE) 1.5 mi W San Pedro, 13.IX.1977, B.K. Dozier (M, FSCA), 4.1 km NW La Huerta, 2402/11010 (DryCpThrnFrst), 640 m, B&S [beating and sweeping], VIII-9/10 -78, E. L. Sleeper (F, CAS). Paratypes also to be deposited in BMNH, CHAH, CLBC, SGWC, USNM, WFBM.

Host. Specimens were collected on a shrubby species of Argythamnia in the Euphorbiaceae .

Etymology. This species is named for the adult and presumed larval host.

Discussion. The color dimorphism in this species is surprisingly similar to that in Agrilus barri , above, with males being more or less uniformly coppery above and females with bluish pronota and coppery elytra. The more complex pattern of setae on the elytra of A. argythamniae is similar to that of other species that are putative mimics of ants ( Hespenheide 1986). Males in the type series measure 3.00–4.00 mm long (mean = 3.41 mm, n = 31 specimens), and females measure 3.10–4.50 mm long (mean = 3.83 mm, n = 15 specimens).