Description of the third instar larva and pupa of Macraspis morio Burmeister, 1844 (Coleoptera: Scarabaeidae: Rutelinae) from Southern Brazil

The third instar larva and pupa of Macraspis morio Burmeister, 1844 (Rutelinae: Rutelini: Anticheirina), collected in Paraná, Brazil, is described and illustrations and comments are given. The larva differs from other Macraspis larvae by the head with 6 posterofrontal setae and mandibles with a blunt second left incisor tooth. The pupa is similar to that of M. festiva Burmeister, 1844. Key-Words. Immature; Chaetotaxy; Neotropical; Taxonomy; White grub.

Third-instar larva of Macraspis species is diagnosed by left mandible with incisor bearing three teeth, antennomere IV with four or more dorsal sensorial spots, and metapretarsus reduced and weakly sclerotized relative to propretarsus and mesopretarsus (Jameson & Morón, 2001). The pupa is very simililar to those of other Rutelinae: adecticous, exarate, with reddish-brown body and well-developed meso-metaventrite process (Costa et al., 1988). Immature stages of Macraspis as well as other Rutelinae are usually found in rotten, humid wood or soil, feeding on decaying plant matter (Morón & Paucar-Cabrera, 2003;Marshall, 2018).
Macraspis immatures are scarcely known. Until now, within the catalogued species only eight of them have their larva and pupa described (Medeiros et al., 2019;Albertoni et al., 2014). The objective of the present paper is to describe the immature stages of Macraspis morio Burmeister, 1844. We present illustrations and propose an update to the identification key of Medeiros et al. (2019) to include the larva of M. morio.

MATERIAL AND METHODS
The larvae were collected at the municipality of Carambeí, Paraná state (PR), Brazil (24°55′30″S, 50°04′51″W), inside rotten wood. A reared adult ( Fig. 1) was sent to the Museu de Zoologia de São Paulo (MZSP) and was identified by Carlos Campaner. The larva was killed in hot water and preserved in alcohol 70%. The adult was killed by being put in a freezer and later pinned. The specimens are housed in the Laboratório de Genética e Evolução of the Universidade Estadual de Ponta Grossa.
Photographs were taken with a Leica MC170 HD camera attached to a Leica M205 C stereomicroscope and processed using the Leica Application Suite (LAS) software 4.8.0. The photographs were edited using the software Adobe Photoshop. Illustrations were made using the software Adobe Illustrator based on the photographs.
The terminology used follows Böving (1936) and is in accordance with Carvalho et al. (2019) and Medeiros et al. (2019).
Remarks: when compared to other species of the genus, the larva of M. morio can be distinguished by the following combination of characters: 6 posterofrontal setae, second incisor of the left mandible with a blunt apex, maxilla with 7 stridulatory teeth.  Description of female pupa (Fig. 8) Body lenght: 13 cm; width: 7.1 cm; shape oval, reddish-brown. Body surface glabrous, except at apex of the abdomen, that is covered by many small hairs. Meso-and metaventrite with an anterior keel-like projection.

Updated identification key for third instar larvae of
Head ventrally directed, slightly visible from above; clypeus inflated, triangular; clypeofrontal suture sinuate; labrum, mandibles, maxillae, and palpi discernible, tubercle-like, antennal thecae rounded. Thorax with pronotum convex, margins curved. Posterior margin of mesonotum posteriorly expanded, the medial portion almost reaching the posterior margin of metanotum. Posterior margin of metanotum expanded medially, posterior projection covering the middle of the first abdominal tergite. Elytral and hind wing thecae curved ventrally around the body; elytral thecae extending to second abdominal segment; hind wing thecae extending to third abdominal segment, covering the metafemur in ventral view; legs with tarsomeres distinct. Abdomen with tergites II-VI with 4 pairs of gin traps between II-III, III-IV, IV-V, and V-VI; tergite IX with posterior area bearing dense, minute, reddish-brown setae. Spiracles of abdominal segment I hidden under posterior border of the hind wing thecae; spiracles II-IV visible, larger and darker, apparently functional with peritreme, spiracles V-VII closed and without peritreme. Urogomphi absent, tergite IX lateroventrally folded; fold posterior area rounded.
Remarks: when compared to pupae of other Rutelini, Macraspis can be identified by the long thoracic ventrite process that is extended between anterior legs, whilst other species, alike Chlorota and Lagochile, have the thoracic ventrite not prominent between anterior legs (Costa et al., 1988;Albertoni et al., 2014). When compared to other members of its genus, M. morio is very similar to M. festiva, with the fold in the abdominal tergite IX reddish brown with short setae and a frontoclypeal suture somewhat straight and medially indistinct (Bento et al., 2018).