Xyloryctes furcatus Burmeister, 1847

Morelli, Enrique & MorÓn, Miguel A., 2003, Descriptions of XYLORYCTES Hope Larvae with a Key to Species Based on the Third Stage Larvae (Coleoptera: Scarabaeidae: Dynastinae), The Coleopterists Bulletin 57 (3), pp. 289-295 : 290

Xyloryctes furcatus Burmeister

Third Instar Larva ( Figs. 1–14 ). This description is based on the exuvium of one third instar larvae from ‘‘ MÉXICO: Hidalgo, Molango, Cañada de Otongo , 1,050 m elevation, 21-XI-1980, F. Cervantes, under leaf litter of pine-oak forest’’ reared to adult stage. Pupal stage at 15-IV-1981. Specimen is deposited at the collection of the Department of Entomology , Instituto de Ecología , A.C. Xalapa, Veracruz, México ( IEXA) .

Description. Maximum width of head capsule: 8.4 mm. Cranium ( Fig. 1 ). Color dark reddish brown. Surface irregularly punctate. Epicranium with 3 dorsoepicranial setae on each side. Clypeus. Rounded, without setae. Labrum. With 2 anterior labral setae, and 2 postero-lateral labral setae on each side. Epipharynx ( Fig. 2 ). Corypha with 4 stout setae. Acanthoparia with 5–6 short setae. Chaetoparia with 23–33 setae on each side. Dexiotorma narrowed toward midline. Laeotorma well-developed, with pternotorma vaguely defined. Haptolachus simple, without sensorial cone. Maxilla ( Figs. 3–4 ). Stridulatory area with row of 9 rounded teeth and a distal, truncate process. Labium ( Fig. 5 ). Dorsal surface with 38 spine-like setae of different length. Hypopharyngeal sclerome asymmetrical with 4–7 setae on each side. Mandibles. Left mandible ( Figs. 8–9, 12 ) with 2 scissorial teeth anterior to scissorial notch and 1 scissorial tooth posterior to notch. Stridulatory area elongate, length 3 times its width. Lateral edge with 5 setae. Molar area bilobed, dorsomolar area with 2 short setae. Brustia consisting of 7 setae Right mandible ( Figs. 10–11, 13 ) with 2 wide, scissorial teeth, stridulatory area slightly smaller than that of left mandible. Lateral edge with 7 setae. Molar area trilobed. Antennae ( Figs. 6–7 ). Surface on last segment with 5 dorsal and 10 ventral sensory spots. Thorax. Prescuta of meso- and metathorax bare. Thoracic spiracles with C-shaped respiratory plate, 0.94 mm high and 0.72 mm wide; distance between the 2 lobes of respiratory plate less than dorsoventral diameter of bulla; plate with 22 holes across diameter at middle, holes suboval. Bulla of all spiracles slightly convex. Abdomen. Spiracles of abdominal segments I–VIII similar in size. Dorsa of abdominal segments I–VII covered with 40– 50 short, spine-like setae and some, scattered, long setae. Dorsa of abdominal segments VIII–IX only with 1 posterior transverse row of 5 slender, long setae. Raster with teges of 25 curved setae. Lower anal lip with 30 short setae and a caudal fringe of 10 long setae. Legs. Tarsal claws each bearing 1 preapical seta on each side ( Fig. 14 ).

Figures

Figs. 1–7. Xyloryctes furcatus, third instar larva. 1) Frontal view of head; 2) epipharynx; 3) right maxilla, dorsal view; 4) apex of right mala showing unci; 5) labium and hypopharyngeal sclerome, dorsal view; 6) apical antennal segment, ventral view; 7) same, dorso-lateral view. Scale lines ¼ 1 mm, except Figures 6–7 ¼ 0.5 mm.

Figs. 8–14. Xyloryctes furcatus, third instar larva. 8) Left mandible, dorsal view; 9) left mandible, ventral view; 10) right mandible, ventral view; 11) right mandible, dorsal view; 12) left mandible, mesad view; 13) right mandible, mesad view; 14) metatarsungulus, lateral view. Scale line ¼ 1 mm.