Hylamorpha elegans (Burmeister, 1844)

Ernesto Cisternas, A. & Roberto Carrillo, Ll., 2012, Description of the Larvae ofHylamorpha elegans (Burmeister, 1844) andAulacopalpus punctatus (Fairmaire and Germain, 1860) (Coleoptera: Scarabaeidae: Rutelinae: Anoplognathini), The Coleopterists Bulletin 66 (1), pp. 37-44 : 38

Hylamorpha elegans (Burmeister, 1844) , third instar

( Figs. 1–14 )

The description is based on 20 larvae reared from eggs laid by adults and larvae collected in pastures and meadows in Valdivia and surrounding areas, such as the Santa Rosa Experimental Station of the Universidad Austral de Chile, in the Los Rios Region, 39°47′S and 73°14′W, at 21 m elevation.

Description. C-shaped. Width of head capsule L 1 = 1.57 ± 0.08 mm (n = 20); L 2 = 2.62 ± 0.08 mm (n = 20); L 3 = 4.20 ± 0.12 mm (n = 20). Cranium ( Fig. 1 ): Ocellus absent. Surface slightly rugose, shiny, red; frontal suture white and bisinuate, forming a sharp angle at the joint; epicranial suture 1/3 of the length of the frontal suture; 5–6 dorsoepicranial setae and 2 lateral long setae and 3 short setae on each side; 8–10 anterior frontal setae and 9 posterior frontal setae; 1 seta adjacent to antennal socket; 2 setae over precoila; 8–9 long setae adjacent and lateral to antennal socket when viewed from front. Antenna ( Fig. 2 ): Four antennomeres. Apical antennomere with 1 dorsal sensory spot and 2 ven- tral sensory spots. Second antennomere 1.3X as long as antennomere 1. Third antennomere with an elongated process and a ventral sensory spot. Clypeus ( Fig. 1 ): Trapezoidal. Surface of preclypeus smooth, lighter in color, without setae. Postclypeus slightly rugose with 2 exterior setae on each side and 2 clypeal setae. Labrum ( Fig. 1 ): Suboval, asymmetrical; anterior margin irregular, apical lobule with a pair of blunt setae, with 8–10 posterior setae, 6 medial setae, and 6 marginal aoical setae. Epipharynx ( Fig. 3 ): Suboval, without plegmata, proplegmatium absent, epizygum sclerotized and not connected to the zygum. Corypha with 2 blunt setae and 2 slender and straight setae. Clithrum absent. Haptomerum with 3–4 sensilla, a beak-like process, and 8 coarse setae in transverse row. Acanthoparia with 10–12 short, sickle-shaped setae. Gymnoparia without setae. Chaetoparia covered with straight setae. Pternotorma, dexiotorma, and laeotorma well-developed and sclerotized, with epitorma and without apotorma. Dexiothorma 1.3X as long as laeotorma. Haptolachus with 2 nesia, sensory cone, and plate; sensory cone smaller than pterotorma. Crepis absent. Mandibles ( Figs. 4, 5 ): Asymmetrical. Left cutting region with 3 teeth and right with 2 teeth. Scrobe with 7–8 basolateral setae. Dorsal carina with 1 seta. Dorsomolar area with small group of short setae close to molar. Right ventral process smaller than left ventral process. Calyx not elongated. Brustia present. Acia well-developed. Stridulatory area present, suboval with approximately 54–62 transverse ridges. Ventral processes with rough surface. Maxilla ( Fig. 6 ): Galea and lacinia fused; galea with uncus welldeveloped; lacinia with 2 unci fused at the base ( Fig. 7 ). Maxillary stridulatory area formed by row of 9–10 acute, anteriorly directed, recurved teeth and 1 distal, blunt tubercle ( Fig. 8 ). Labium ( Figs. 9, 10 ): Hypopharyngeal sclerome asymmetrical, strongly developed and sclerotized, left lobule of hypopharyngeal with row of horizontally oriented setae, proximal area of scleroma without setae. Glossa covered by slender distal setae and robust posterior robust setae. Postmentum with 2 slender basal slender setae and 2 long apical setae. Basal section of prementum with 2 rows of setae; setae long and moderate in length; anterior section of prementum with 8–10 slender setae and 3 lateral setae close to labial palp. Thoracic spiracles ( Fig. 11 ): C-shaped respiratory plate, 0.35 mm long, 0.25 mm wide, with 20–23 irregular holes across diameter ( Fig. 12 ). Distance between lobes of respiratory plate 1.5X diameter of bulla. Pronotum: With lateral, scalloped scleromata (yellow, irregularly shaped, surrounded by 10–12 setae). Dorsum of prothorax with 3 irregular rows of long, medium-length, and short setae. Legs ( Fig. 13 ): Length of legs increases gradually from prothorax to metathorax. Each tarsungulus with 2 proximal setae. Abdomen: Abdominal spiracles on A2–8 and thoracic spiracles of similar size (0.35–0.37 mm), spiracles on A1 somewhat smaller in size (0.29 mm); spiracular area with 7–12 short, medium-length, and long setae. Dorsal segments A2–6 with 4–6 rows of short setae mixed with long setae. Raster ( Fig. 15 ): Without palidia. Tegillum with 59–71 hamate setae. C-shaped anal opening. Dorsal anal lobules covered distally with small, straight, and cylindrical setae. Ventral anal lobes with slender, straight, medium-length and small setae. Campus with 8 moderately long setae. Barbula not well-defined, with a few long, slender setae.

Figures

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

Figs. 9–14. Hylamorpha elegans, 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, ventral view of raster. Scale bar in mm.

Figs. 15–22. Aulocopalpus punctatus, third instar. 15) Head, frontal view; 16) Distal antennomere, a) ventral view, b) dorsal view, and c) lateral view; 17) Epipharynx; 18) Mandibles, ventral view, a) left and b) right; 19) Mandibles, dorsal view, a) right and b) left; 20) Maxilla, a) dorsal view and b) ventral view; 21) Apex of mala showing unci; 22) Maxillary stridulatory area. Scale bar in mm.