Elytroleptus humeralis Linsley, 1961

GRZYMALA, TRACI L. & MILLER, KELLY B., 2013, Taxonomic Revision and Phylogenetic Analysis of the Genus Elytroleptus Dugés (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini), Zootaxa 3659 (1), pp. 1-62 : 27-28

Elytroleptus humeralis Linsley, 1961

(Figs. 8, 35)

Elytroleptus humeralis Linsley, 1961b: 14 ; Linsley, 1962b: 11; Chemsak & Linsley, 1965: 197; 1975: 110; 1982: 56; Chemsak et al., 1992: 83; Monné & Giesbert, 1995: 148; Noguera & Chemsak, 1996: 402; Monné, 2005: 604; Monné & Hovore, 2006: 143.

Type locality. Mexico, Chihuahua, Salaices.

Type information. Holotype. Elytroleptus humeralis ( AMNH, ♂) labeled: ‘ Salaices, Chih. Mex. VII-23-47 / D. Rockefeller Exp. Spieth / HOLOTYPE Elytroleptus humeralis Linsley’

Allotype. Elytroleptus humeralis ( AMNH, ♀) labeled: ‘ Mex. VII-23-47 / D. Rockefeller Exp. Spieth / ALLOTYPE Elytroleptus humeralis Linsley’

Diagnosis. This species is distinguished from all other species of Elytroleptus by the following combination of characters: 1) elytral margins subparallel, greatest width <1.5 × humeral angle width, 2) pronotum shining without areas of dense pubescence, 3) pronotal punctation deep and 4) elytron with 4–5 punctures between suture and costa I medially. This species most closely resembles E. divisus and can be separated by the degree of elytral punctation (4–5 punctures between suture and costa I medially instead of 3–4 punctures), the deeply instead of shallowly punctate pronotum, the generally testaceous abdominal sternites instead of black, and antennomere XI weakly appendiculate in males.

Description. Male. TL 5.7–10.2 mm, GW 1.6–3.1 mm. Body elongate, subparallel, dorsoventrally flattened.

Head. HL 0.3–0.8 mm, HW 1.1–1.8 mm, DBE 0.6–1.2 mm, DBA 0.4–0.7 mm. Piceous, except vertex with subquadrate area ferrugineous and anteclypeus, labrum, maxillae, and labium testaceous. Moderately punctate with short, sparse, erect, pale yellow pubescence; gular region glabrous; rugose posterior to lower eye lobe. Antennal tubercles slightly raised, subtriangular, and separated by approximate width of four antennal sockets. Genal apices generally rounded, width greater than ½ × height. Eyes moderately large, finely faceted, lower lobe with about 25 facets at greatest height; integument ventral to lower lobe about 0.4 × eye height; deeply emarginate at antennal insertion, with 3–4 facets at greatest emargination point. Antennae black, extending to approximately 3/5 elytral length, scape and antennomere III, IV, VI, and VII subequal; pedicel slightly less than ½ × scape length; antennomeres V–X decreasing in length, antennomere XI longer than X, subequal to antennomere VIII and weakly appendiculate.

Thorax. PL 1.0– 1.9 mm, PW 1.3–2.1 mm. Pronotum piceous, width slightly greater than length, apical width subequal to basal width, lateral margins slightly angulated, widest medially. Pronotal disc shining, punctate, with short, erect, pale yellow pubescence arising from punctation; punctation on shining areas deep, individual punctures moderate in diameter, majority strongly delimited; oval, more densely punctate areas dorsad of lateral margins absent; pronotal disc slightly convex; sides impressed in dorsal aspect, margin apparently elevated; 2 distinct calli present, 2 moderately raised, submedial, anterior to center. Pro-, meso-, and metasternum dark brown to black, shining, with sparse, erect, pale yellow setae. Scutellum piceous, small, subtriangular, length subequal to width, medially impressed, with short, sparse, black pubescence.

Wings. EL 4.4–7.5 mm. Elytron with basal 1/5 testaceous, apical 4/5 black, extending obliquely to meet suture, margin irregular. About 4.5 × PL, width at humeral angles, subequal to PW. Elytron subparallel, greatest width <1.5 × width at humeral angle. Elytron with 3 distinct costae; from suture, costa I arising from anterior margin and extending to 3/5 elytral length, costa II arising from anterior margin and extending to 4/5 elytral length, costa III arising from humeral angle and extending to 3/5 elytral length; elytron with distinct, deep punctation, 4–5 punctures medially between suture and costa I, becoming slightly shallower apically, subequal basally; elytron with short, suberect, pale yellow pubescence, one seta per puncture, overlying testaceous and black areas, outer elytral margins with pubescence more dense. Metathoracic wing completely darkly tinted.

Abdominal Sternites. Testaceous, shining, sparsely punctate with sparse, short, suberect, testaceous pubescence. Legs. Piceous except apices of femurs testaceous. Femora and tibia finely, shallowly punctate; femora with short, erect, pale yellow pubescence, tibia with short, erect black pubescence; tarsi moderately clothed with short, appressed, black pubescence. Genitalia. Not examined for this species.

Female. TL 8.1–11.5 mm, GW 2.6–3.3 mm, HL 0.5–0.8 mm, HW 1.3–1.6 mm, DBE 0.8–1.0 mm, DBA 0.5– 0.7 mm, PL 1.2–2.0 mm, PW 1.7–2.2 mm, EL 6.4–8.7 mm. As male, except antennae only reaching to 3/10 elytral length; antennomeres V–XI less strongly serrate; antennomere XI less strongly appendiculate; appearance of pronotal calli much reduced.

Intraspecific variation. Many specimens with pronota ferrugineous, pronotal calli strongly to only slightly apparent; basal area of scutellum testaceous; elytral integument testaceous only at humeral angles.

Phylogenetic relationship. This species is recovered as sister to the clade composed of E. divisus , E. pallidus , E. similis , E. apicalis , E. grandis , E. ignitus , E. limpianus , E. rufipennis , E. nigripennis , and E. quadricostatus supported by the character of the integument below the lower eye lobe in lateral view greater than 0.3× height of the lower eye lobe (Character 1). Other equally parsimonious trees place this species as sister to the clade composed of E. luteus , E. scabricollis , E. divisus , E. similis , E. pallidus , E. ignitus , E. apicalis , E. grandis , E. limpianus , E. rufipennis , E. nigripennis , E. quadricostatus supported by pronotal lateral margins slightly to moderately angulate (Character 5) and the elytral basal setae more erect compared to the apical setae (Character 19) ( Figs. 31 , 32 ).

Distribution. Central Mexico (Chihuahua) ( Fig. 35 ).

Natural history. Flight period July.

Material examined: MEXICO, Chihuahua: Camargo , 1 ♂, 13.vii.1947, Spieth ( AMNH) ; 1 ♀, 13.vii.1947, Gertsch ( AMNH) ; 2 ♂, 13–15.vii.1947, Cazier ( AMNH) ; Salaices, 4 ♀, 9 ♂, 23.vii.1947, Spieth ( AMNH) ; 2 ♀, 2 ♂, 23.vii.1947, Spieth ( EMEC) ; 1 ♀, 23.vii.1947, Spieth ( BMNH) .

Figures

FIGURE 31. Three of six most parsimonious trees retrieved from phylogenetic analysis of Elytroleptus (L = 59, CI = 50, RI = 75). Numbers above branches are characters and numbers below branches are character states. Characters are optimized for

FIGURE 32. Strict consensus for six most parsimonious cladograms resulting from cladistic analysis of Elytroleptus. Numbers above branches are Bremer support values.

FIGURE 35. Distribution map for Elytroleptus grandis, Elytroleptus humeralis, and Elytroleptus ignitus.