Ancognatha humeralis Burmeister, 1847

Paucar-Cabrera, Aura & Ratcliffe, Brett C., 2018, The Ancognatha Erichson (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini) of Ecuador, with Description of a New Species, The Coleopterists Bulletin 72 (4), pp. 665-687 : 673-675

Ancognatha humeralis Burmeister, 1847 ( Figs. 12–14 , 25a )

Ancognatha humeralis Burmeister 1847: 40 (original combination). Lectotype male at MLUH ( Moore et al. 2018).

Ancognatha longiceps Kirsch 1871: 354 (synonym). Holotype at SMTD (Olaf Jäger, personal communication, July 2018).

Redescription. Length 20.5–27.4 mm; width 9.6–11.3 mm. Color testaceous with piceous or black markings ( Fig. 12 ) as follows: Pronotum with small to large, entire to variably divided vitta on disc; elytra with elongate, black or piceous vitta on humeral umbone and behind scutellum; some specimens (females) with extensive dark stripes from base to near apex; lateral margin testaceous or piceous or black. Femora and tibiae black on bases and apices, tarsi black or brown. Abdominal sternites 1–4 black. Head: Frons rugulopunctate, clypeus moderately rugopunctate; punctures moderate in size and density. Clypeus narrowly parabolic, apex weakly reflexed. Mentum with apex deeply furrowed (about half length of mentum) ( Fig. 2b ). Interocular width equals 3.6 transverse eye diameters. Pronotum: Surface with punctures moderate in size and density. Elytra: Surface with 8 punctate striae. Intervals between striae 1–2, 3–4, 5–6, and 8–lateral margin densely punctate, punctures moderate in size. Epipleuron of female, in ventral view, slightly widened at level of metacoxa to middle of abdominal sternite 2. Pygidium: Surface finely punctate, punctures small, setigerous, moderate in density; setae tawny, short. In lateral view, surface weakly convex in male, nearly flat in female. Legs: Protibia tridentate, teeth subequally spaced ( Fig. 25a ). Venter: Prosternal process moderately long, columnar, apex densely setose, flattened, and with large, raised, round “button” covering most of apex; setae long, tawny. Parameres: Fig. 13 .

Distribution. Ancognatha humeralis occurs in Colombia, Ecuador, and Peru. Endrödi (1966) recorded A. quadripunctata from Mexico and Ecuador (Loja, 2,200 m). We examined the Ecuador specimen listed by Endrödi at the BMNH and believe the specimen is actually A. humeralis and not A. quadripunctata . We believe that A. quadripunctata does not occur in Ecuador, especially since additional specimens from Ecuador have never been collected or seen in collections.

Locality Records ( Fig. 14 ). 202 specimens from BCRC, CMNC, CMNH, DCCC, MECN, NMPC, QCAZ, USNM .

AZUAY (23): Amaluza, Cuenca, General Plaza, ~ Girón (8 km NE), Lentag, Valle Yunguilla. CANAR (1): Shical. CARCHI (22): Los Laureles, San Gabriel Bosque Arrayanes, Tufi~ no (35 km W). COTOPAXI (16): Saguambi, Sigchos, Triunfo Bajo. IMBABURA (8): Otavalo-Apuela. LOJA (85): Argelia (Loja), Estación Agroecológica Zamora Huayco de la Universidad Técnica Particular de Loja, Loja, Loja– Zamora road (km 12), Los Laureles, Paso Lateral (Loja city limits), Parque Nacional Podocarpus, Rocafuerte, San Cayetano Bajo, San Lucas, Saraguro, Uritusinga, Zamora micro-watershed. MORONA SANTIAGO (4): Parroquia Zu~ nac PN Sangay Lingüichaca. NAPO (18): Cosanga, Cosanga (Caba~ nas San Isidro, 2 km NW), Dureno, Estación Biológica Yanayacu, Santa Bárbara. PICHINCHA (9): Aloag–Santo Domingo road, Los Bancos, La Virgen, Los Laureles, Quito, Reserva Calacal´ı El Cedral. SANTO DOMINGO DE LOS TSÁCHILAS (2): Santo Domingo de los Colorados. SUCUMBÍOS (4): El Calvario, La Bonita, Santa Bárbara, via Santa Bárbara–La Bonita (km 23). TUNGURAHUA (1): Chimborazo (7 km NW). ZAMORA CHINCHIPE (8): Estación Cient´ıfica San Francisco, Reserva Tapichalaca, Yanzatza. NO DATA (1).

Temporal Distribution. January (35), February (5), March (8), April (16), May (1), July (3), October (9), November (63), December (1).

Diagnosis. Ancognatha humeralis resembles several species but mostly A. vulgaris . It can be easily distinguished from all congeneric species except A. uncinata and A. vulgaris by the presence of a long furrow at the apex of the mentum that is longer than its base (compare a and b of Fig. 2 ). Ancognatha humeralis , A. uncinata , and A. vulgaris share the long furrow on the mentum, but the male can usually be distinguished by the form of the parameres. Ancognatha humeralis has simple parameres ( Fig. 13 ), while A. uncinata has a hook-like flange at the base of the parameres ( Fig. 34 ), and A. vulgaris has subapical, short teeth ( Fig. 40 ). In the male, the pygidium of A. humeralis has short, sparse setae, while in A. vulgaris the setae are long and dense. Females of A. humeralis and A. vulgaris can be separated by the form of the epipleuron that is slightly expanded in A. humeralis but strongly thickened into an elongate knob in A. vulgari s ( Fig. 39 ).

Natural History. Ancognatha humeralis has been collected at lights at elevations of 1,800–3,120 m.

Figures

Figs. 12–14. Ancognatha humeralis. 9) Habitus; 13) Parameres; 14) Distribution in Ecuador.

Fig. 25. Dorsal view of protibiae of a) Ancognatha humeralis and b) Ancognatha lutea (arrow indicates angulation of inner apical margin).

Fig. 2. Ancognatha species, mentum, ventral view. a) A. atacazo, b) A. vulgaris.

Figs. 32–34. Ancognatha uncinata. 32) Habitus; 33) Parameres; 34) Distribution.

Figs. 38–40. Ancognatha vulgaris. 38) Habitus; 39) Parameres; 40) Distribution in Ecuador.