Pristerophora picipennis (Solier)

Ernesto Cisternas, A. & Roberto Carrillo, Ll., 2012, Descriptions of the Third Instars ofPristerophora picipennis (Solier) andSchizochelus modestusPhilippi (Coleoptera: Scarabaeidae: Melolonthinae: Macrodactylini) from Southern Chile, The Coleopterists Bulletin 66 (2), pp. 131-138 : 132

Pristerophora picipennis (Solier) third instar ( Figs. 1–14 )

The description is based on 34 larvae that were reared from eggs laid by adults that were collected in flight in pastures near Puerto Varas, S41°23′ W73°00′, at 91 m elevation, and were collected from pasture near Osorno, Región de Los Lagos, S40°31′ W73°03′, at 77 m elevation.

Description. C-shaped. Width of head capsule L 1: 0.82 ± 0.01 mm (n = 6); L 2: 1.27 ± 0.05 mm (n = 15) and L 3: 2.01 ± 0.08 mm (n = 34). Ocellus absent. Cranium ( Fig. 1 ): Smooth, shiny, light yellow; frontal suture whitish and bisinuate, forming a sharp angle at joint; epicranial suture 1/3 length of frontal suture; 3–6 dorsoepicranial setae; frontal anterior setae absent, 2 frontal posterior setae; 1 seta adjacent to antennal socket; 4 long setae adjacent and lateral to antennal socket when viewed from front. Antenna ( Fig. 2 ): With 4 antennomeres. Apical antennomere with 1 dorsal sensory spot and 2 ventral sensory spots. Second antennomere 1.6X as long as first antennomere. Third antennomere with elongate process and ventral sensory spot. Clypeus ( Fig. 1 ): Trapezoidal. Surface of preclypeus smooth, lighter in color, without setae. Postclypeus smooth with 2 long exterior setae on each side and 2 clypeal setae. Labrum ( Fig.1 ): Pentagonal, symmetrical, trilobed, rugose, apical lobe with pair of blunt setae; with 2 posterior setae, 4 medial setae, and 2 setae on anterior margin. Epipharynx ( Fig. 3 ): Pentagonal, plegmatia and proplegmatium absent, sclerosed epizygum closely connected to the right zygum, left zygum absent. Corypha with 2 blunt setae. Clithrum present. Acroparia with long, slen- der setae. Haptomerum with 10–12 sensilla and 3–5 heli (mode = 4) in a transverse row. Acanthoparia with 2 thick apical setae and 7–9 sickle-shaped, short setae laterally. Gymnoparia without setae. Chaetoparia with setae. Pternotorma, dexiotorma, and laeotorma well-developed and sclerosed, without apotorma and epitorma. Laeotorma similar in length to dexiotorma. Haptolachus with 2 nesium. Crepis absent. Mandibles ( Figs. 4, 5 ): Asymmetrical. Left cutting region with 3 teeth and right with 2 teeth. Scrobe with 4 basolateral setae. Dorsal carina with 1 seta. Dorso-molar area with small group of short setae close to the molar surface. Right ventral process smaller than the left ventral process. Calyx elongated. Brustia present. Acia well-developed. Stridulatory area absent.Ventral processes with roughness. Maxilla ( Fig. 6 ): Galea and lacinia fused and slightly separated at apex; galea with well-developed uncus; lacinia with 2 unci ( Fig. 7 ). Stridulatory area formed by a row of 8–12 teeth ( Fig. 8 ). Labium ( Figs. 9–10 ): Hypopharyngeal sclerome asymmetrical, strongly developed and sclerosed, left hypopharyngeal lobule with a row of vertical setae and proximal area of the scleroma with a row of horizontal setae. Glossa covered by slender setae and robust setae. Sub-trapezoidal postmentum with 2 slender and long setae. Posterior prementum with 2 setae, anterior prementum with 8 slender setae and 1 short lateral setae close to labial palp. Thorax. Spiracles ( Fig. 11 ): C-shaped; respiratory plate 0.13 mm long, 0.10 mm wide, with 9–12 irregular holes across diameter ( Fig. 12 ). Distance between 2 lobes of respiratory plate equal to dorsoventral diameter of bulla. Pronotum with sclerosed shield, yellow on each side, surrounded by 15–17 setae. Legs ( Fig. 13 ): Gradually increasing in size from prothorax to metathorax. Each tarsungulus affiliated with 2 proximal setae. Metatarsungulus smaller than preceding tarsunguli. Abdomen: Abdominal spiracles on A1–4 and thoracic spiracles of similar size (0.12–0.13 mm), spiracles on A5–7 of equal size (0.09 mm) and smaller than preceding ones, spiracle on A8 conspicuously smaller (0.07 mm). Spiracular area with 3–10 short, medium, and long setae. Dorsum of A1–6 with 3–4 rows of short, acute setae and 1 row of slender, long setae. Raster ( Fig. 14 ): Without palidia. Tegillum with 21–30 hamate setae. Anal openin Y-shaped. Dorsal anal lobe densely covered with short, slender, straight, acute setae. Ventral anal lobe with slender, straight, sharp, short setae. Campus with 2 moderately long setae and 2 lateral slender setae. Barbula with slender setae.

Figures

Figs. 1–8. Pristerophora picipennis, third instar. 1) Head, frontal view; 2) Distal antennomere, a) dorsal, b) ventral, c) lateral view; 3) Epipharynx; 4) Mandibles, ventral view a) left, b) right; 5) Mandibles, dorsal view a) right, b) left; 6) Maxilla, a) dorsal view, b) ventral view; 7) Apex of lacinia and galea showing unci; 8) Maxillary stridulatory area. Scale bar in mm.

Figs. 9–14. Pristerophora picipennis, third instar. 9) Labium, dorsal view; 10) Hypopharynx; 11) Thoracic spiracle; 12) Respiratory plate; 13) Tarsungulus of a) prothoracic leg, b) mesothoracic leg, and c) metathoracic leg; 14) Last abdominal segment with raster, ventral view. Scale bar in mm.