Ontherus sulcator Fabricius, 1775

González-Vainer, Patricia, Cantil, Liliana F. & Morelli, Enrique, 1775, Ontherus sulcatorFabricius, 1775 (Coleoptera: Scarabaeidae: Scarabaeinae): Descriptions of the Third Instar and Pupa, The Coleopterists Bulletin 1775 (2), pp. 355-360 : 355-360

Ontherus sulcator Fabricius, 1775 third instar

( Figs. 1 – 15 )

Description. Body: Length 28 mm; maximum width of the abdomen 8 mm ( Fig. 1 ); color white. Cranium: Maximum width of head capsule 6 mm. Surface smooth. Epicranial suture distinct, with apical end extending beyond frontal suture ( Fig. 2 ). Each side of epicranium with 4 small dorsoepicranial setae, 3 of them grouped next to frontal suture. Frons on each side with 1 anterior frontal seta, 1 angular anterior frontal seta, and 4 elongated lateral setae, 1 of them next to antennal base. One pair of anterior clypeal setae; postclypeal surface with 2 setae on each side. Labrum: Wide, asymmetric with 1 broad, central lobe and with rounded lateral edges ( Fig. 3 ); 4 short setae on the apex; 4 lateral setae and 2 central setae on each side. Epipharynx: Asymmetrical, wider than long, with rounded margins and apical margin with slight central depression ( Fig. 4 ); corypha simple; acroparia with 6 short setae, 3 long setae. and 1 external seta; epizygum absent; pedium bearing setae in right apical corner; acanthoparia with 3 aligned setae on underneath margin and 2 distal setae; gymnoparia wide, right

2) Head, frontal view.

chaetoparia with 6 – 8 short setae in a group, left chaetoparia with 6 – 8 short setae aligned; plegmatia and proplegmatia absent; laeotorma and dexiotorma long and thin; haptolachus complete; epitorma conspicuous, anterior and posterior epitorma arrowhead-shaped, pterotorma absent; dexiophoba with 12 – 14 microsetae aligned; protophoba rounded, with 28 – 30 microseate aligned; laeophoba similar to dexiophoba. Antenna: Short, 4-segmented with intersegmental edges indefinite ( Fig. 5 ); antennomeres 1 – 2 subequal, 3 shorter than others, with 1 sensorial conical projection, 4 elongate. Mandibles: Asymmetric, strongly sclerotized. Right mandible ( Figs. 6 – 8 ) with 2 scissorial blunt teeth (S 1, S 2), S 2 short, separated from S 1 by a scissorial notch; molar area strongly and irregulary lobed, with 2 teeth; scrobe with 1 elongate seta, 1 median seta well-developed, and brustia with 2 short setae; ventral surface with a well-marked stridulatory area with a row of short setae (18 – 20). Left mandible ( Figs. 9 – 11 ) with 3 scissorial teeth, S 3 smallest; ventral stridulatory area shorter than that of right mandible, with 8 – 12 setae; scrobe with 1 seta; brustia with a row of tight setae. Maxilla: Galea and lacinia separated ( Figs. 12, 13 ); galea with apical uncus surrounded by 6 – 8 thick apical setae; uncus of lacinia with 2 basal teeth and inner edge of lacinia with 6 – 7 short setae. Maxillary palp 4-segmented, palpomeres 2 – 3 subequal, 4 conical with small sensorial area. Stridulatory area with 8 short teeth ( Fig. 12 ). Labium-hypopharynx: Hypopharyngeal with quadrangular glossa ( Fig. 14 ); central lobe of glossa with 8 – 10 aligned setae, lateral lobes with 6 – 8 elongate setae; 20 – 30 microsensillae skirting sclerome; 2 oncyli asymmetrical, strongly sclerotized; a row of elongate, silky setae on each side. Thorax: Whitish; segments with 2 lateral setae. Prothoracic shield with 5 setae on each side. Prothoracic spiracle 0.26 mm long, 0.24 mm wide;

14) Hypopharynx, dorsal view; 15) Raster. Pupa: 16) Dorsal view; 17) Lateral view; 18) Ventral view.

respiratory plate C-shaped, with concave margin directed ventrally, arms not constricted; plate with 12 holes across diameter at middle, holes with irregular edges. Legs with terminal papillae; prothoracic legs slightly shorter than meso- and metathoracic legs. Abdomen: Segment I: prescutum with 2 – 4 small setae; scutum with 6 – 8 long setae; pleural lobe with 1 short seta on each side. Segment II: prescutum glabrous; scutum with 7 – 8 elongate setae, scutellum with 8 – 10 elongate, separated setae. Segment III: prescutum with 28 – 30 short setae; scutellum with 20 – 22 short setae. Segments IV – VI with chaetotaxia similar to segment III. Segments VII – IX with 8 – 10 elongate setae. Segment X without dorsal setae. Raster ( Fig. 15 ) distinct, with a broad, median patch of short setae arranged in 2 loose fields.

Figures

Figs. 1–2. Ontherus sulcator, third instar. 1) Habitus;

Figs. 3–11. Ontherus sulcator, third instar. 3) Labrum; 4) Epipharynx; 5) Antenna; 6) Right mandible, ventral view; 7) Right mandible, frontal view; 8) Right mandible, dorsal view; 9) Left mandible, dorsal view; 10) Left mandible, frontal view; 11) Left mandible, ventral view.

Figs. 12–18. Ontherus sulcator. Third instar: 12) Left maxilla, dorsal view; 13) Left maxilla, ventral view;