Oncocephala angulata Gestro, 1885

Calcetas, Orlando A., Staines, Charles L., Adorada, Jessamyn R., Calilung, Venus J., Caoili, Barbara L. & Jamias, Serlie B., 2021, Review of the Genus Oncocephala Agassiz, 1846 (Coleoptera: Chrysomelidae: Cassidinae: Oncocephalini) in the Philippines, The Coleopterists Bulletin 75 (2), pp. 445-458 : 451-453

Oncocephala angulata Gestro, 1885 ( Figs. 11–14 )

Oncocephala angulata Gestro 1885: 172 . Type locality: Indonesia, Sumatra; type depositories (syntypes): MSNG, RBINS.

Oncocephala anulata Gestro (lapsus). Uhmann 1964: 466 (catalog).

Oncocephala bicristata Baly 1888: 659 (not Chapuis) (misattribution). Gestro 1897: 73 (correction).

Oncocephala weisei Gestro 1901: 320 . Type locality: Indonesia, Sumatra; type depository (described from an unknown number of specimens): MSNG. Kimoto 1999: 108 (synonymy).

Oncocephala jeanvoinei Pic 1935: 19 . Type locality: Vietnam, Tonkin, Than-Moi; type depository: MNHN. Kimoto 1999: 108 (synonymy).

Oncocephala weisei yunnanica Chen and Yu in Chen et al. 1962: 137. Type locality: China, Yunnan, Gin-ping ; type depository (holotype): IZCAS.

Oncocephala siamensis yunnanica Chen and Yu in Chen et al. (lapsus). Uhmann 1963: 150 (museum list).

other Asian species of Oncocephala . One specimen of Oncocephala bicristata from MGFT exhibits an asymmetrical character, the exterior apical angle of the elytron on one side is almost 45° while it is an almost 90° angle on the other elytron.

The variation of characters observed within observed specimens of O. bicristata are as follows: the

Redescription (n = 4). Length = 4.2–4.3 mm (apical margin of head to apex of elytron), width = 2.2 mm (middle of elytra). Head, pronotum and elytra dark to pale brown with black tinge; legs pale brown; antennae dark brown with antennomeres 1, 10, and 11 paler than remainder ( Fig. 11 ). Head. Compound eyes conical dorsally, cephalic horn pear-shaped in dorsal aspect, anterior half distinctly narrower than posterior half ( Fig. 12 ), short and boat-shaped in lateral aspect ( Fig. 13 ), each side rounded, but slightly narrower towards anterior margin; cephalic horn formula 4 (2-2-0). Antenna. Almost 2× length of pronotum; antennomere 1 broader apically; antennomere 2 almost straight-sided; antennomere 3 distinctly longer than 4; antennomeres 3–4 broader apically; antennomeres 7–10 quadrate; antennomere 11 short and conical; antennomere 1 without striation, 2–11 with striation, 2–6 broadly striate, 7–11 finely striate. Antennal length 2.5 mm. Pronotum. Subquadrate; anterior margin almost straight medially; lateral protuberance scalene, small, with broad basal margin; lateral margin almost straight posterolaterally; anterior angle obtuse, posterior angle acute; posterior margin concave laterally, rounded medially, entirely broadly carinate; with two conical tubercles subapically; medial longitudinal cavity interrupted medially by callosity; pronotal width 1.2 mm; pronotal length 1.2 mm. Scutellar shield. Anterolateral margin wedge-shaped, lateral margin straight, apically rounded. Elytron. Humeral margin with 2 distinct tubercles; scutellar tubercle minute, humeral tubercle small, slightly higher than elytral tubercle 1 of costa II; lateral margin distinctly broader apically, with pronounced medial sinuation and small, irregularly spaced teeth; exterior apical angle angulate, almost 45°; apical margin wedge-shaped, minute to indistinctly toothed, sutural angle obtuse; striae 10 and 11 with confluent punctures; 8 distinct elytral tubercles; costa II with 4 distinct tubercles: T1 small, equilateral, rounded apically, connected to T2 basally; T2 minute, with broader elevated margin, ridge-like longitudinally, with minute to indistinct tubercles along margin and connected to T3 apically; T3 large, scalene, rounded apically, with short apical margin and connected to T4 basally; T4 minute, ridge-like longitudinally; T2, T3, and T4 coalesced; costa III with 1 distinct tubercle: T1 small, convex; costa IV with 2 distinct tubercles: T1 small, conical; T2 minute, conical; costa V without distinct tubercle; elytral tubercle formula 8 (1-4-1-2-0); elytron width 1.1 mm; elytron length 2.8–3.0 mm. Leg. Femur not rugose or tuberculate ( Figs. 11, 14 ).

Material Examined. Paratype. Indonesia: Sumatra: Dohrn, 1885, Liangagas (4, RBINS) ; Other material. Sri Lanka: Ceylon, Balangoda , 4-ii-1958, G. Frey (1, MGFT) .

Philippine Literature Records. Luzon: Los Baños, Mt. Makiling, Tayalas, Malinao, Cabugao, Kasiguaran, Laguna, Mt. Banaho (Uhmann 1964– 1965); Mindanao: Butuan, Davao ( Gestro 1917); Mindoro: Mt. Calavite (Uhmann 1964–1965).

Distribution. China (Yunnan), India (Andhra Pradesh, Punjab), Indonesia (Java, Sumatra), Malaysia, Myanmar, Philippines (Luzon, Mindanao, Mindoro), Sri Lanka, Thailand, Vietnam.

Host Plants. Orchid ( Orchidaceae ) ( Gestro 1919; Speyer 1954); Solanum melongena L. ( Solanaceae ) ( Hua 2002; Miller 1932); Ipomoea sp. ( Convolvulaceae ) ( Hua 2002); yam ( Dioscoreaceae ) and ginger ( Zingiberaceae ) ( Świętojańska and Kovac 2007).

Remarks. This species can be distinguished from all other Asian species of Oncocephala in this study by the posterior margin of the pronotum being entirely broadly carinate, while it is not carinate medially in other species. Along with O. quadrilobata and Oncocephala siamensis Gestro, 1901 , O. angulata has tubercle 3 of costa II broadly convex laterally. However, it is narrowly convex laterally in O. bicristata .

The variation of characters observed within O. angulata are the following: the exterior apical angle of the elytra is almost uniformly broad in all eight observed specimens, which is similar to O. bicristata in dorsal view, one specimen has a short lateral sinuation near the exterior apical angle of elytra while all other specimens are uniformly sinuate, and the elytral tubercle 3 of costa II is uniformly and distinctly broadly convex laterally.

Figures

Figs. 11–14. Oncocephala angulata. 11) Habitus, dorsal aspect; 12) Cephalic horn, dorsal aspect; 13) Cephalic horn, lateral aspect; 14) Habitus, lateral aspect (paratype from RBINS, courtesy of P. Limbourgh).