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.