Macraspis morio Burmeister, 1844

Begha, Bruno Piotrovski & Santos, Mateus Henrique, 2020, Description of the third instar larva and pupa of Macraspis morio Burmeister, 1844 (Coleoptera: Scarabaeidae: Rutelinae) from Southern Brazil, Papéis Avulsos de Zoologia 60, pp. 1-6 : 2-5

Macraspis morio Burmeister, 1844

Description of third larval instar

( Figs. 2-7 )

Body length: 10 cm, width: 4.5 cm; with yellowish white color, covered with brownish setae ( Fig. 2A ). Cranium

( Fig. 3 ) with vertex reddish-brown or light yellowish-brown; frons, clypeus, and labrum reddish-brown; mandibles dark reddish-brown. Surface of vertex nearly smooth, posterior area of frons sparsely punctate, anterior area of frons densely punctate. Stemmata (STM) present. Epicranial suture present. Each side of head with 4 dorsoepicranial setae (DES), 3 posteroepicranial setae (PES); 5-8 externoepicranial setae (EES), 2-3 anteroepicranial setae (AES), 6 posterofrontal setae (PFS), 1 externofrontal seta (EFS), 1 long anterofrontal angle seta (AAS); and 3-4 anterofrontal setae. Clypeus subtrapezoidal, each side with 2 externoclypeal setae (ECS), anteroclypeal setae absent. Antenna ( Fig. 3 ) with four antennomeres, as long as mandibles. Antennomeres II and III subequal in length, IV shorter than III and with 7 dorsal sensorial spots (SPT) and 4-5 ventral sensorial spots. Epipharynx ( Fig. 4A ) with haptomerum moderately raised and with 23-26 spine-like setae, heli absent, epizygum indistinct. Acroparia with 9-11 stout setae. Left acanthoparia with 4 stout setae and right acanthoparia with 3 stout setae. Plegmata absent. Gymnoparia wide. Both sides of the chaetoparia with 15-17 inner stout setae and 13-15 outer thinner, smaller setae. Dexiotorma elongate. Laeotorma elongate and with pternotorma wide and rounded. Haptolachus with slightly sclerotized sensorial cone, sclerotized plate indistinct. Edges of the epipharynx well-sclerotized, with a darker brownish color. Labrum ( Fig. 4B ) subtrapezoid; with 4 preapical tubercles; each side with 8-11 anterolabral bristle-like setae (ALS); 3 laterolabral setae (LLS); 1 mediolabral seta on each side (MLS); and 5 posterolabral setae (PLS). Left mandible ( Figs. 5A, D ) with incisor bearing 3 teeth (S1-S3), the second teeth with a blunt apex, not as sharp as the other incisors, apex blunt. Stridulatory area elongated and bearing 51 fine striae (STA). Molar (MLR) with 3 lobes (dorsal view). Calx (CLX) prominent, rectangular. Acia absent. Brustia (BTA) with 9-11 setae. Outer margin with 7 setae. Right mandible ( Figs. 5B, C ): incisor with 2 teeth (S1-S2). Stridulatory area with a slim-oval shape and bearing 44 fine striae, one ventral seta comb (VST). Brustia with 8-11 setae (BTA). Outer margin with 7 setae. Maxilla ( Fig. 6 ) with galea and lacinia fused (forming the mala) (MLA). Galea (GLA) with a row of 7 stout setae in an inner row, apex with 1 large uncus (UNC) ( Fig. 6A ); lacinia with 1 small and blunt uncus; stipe with stridulatory area bearing 7 acute teeth. Maxillary palpus with 4 segments. Labium ( Fig. 6 ) with prementum (PRM) with 6 medium setae between palps (LPL); mentum (MNT) with 2 setae on each side; submentum (SBM) with 6 setae on each side. Palps with 2 palpomeres. Hypopharynx ( Fig. 6A ) with hypopharyngeal sclerome (HSC) strongly asymmetrical, right side with raised tooth-like process. Right lateral lobe with 6 thin setae; left lateral lobe with about 15 mixed long and short setae. Ligula (LGL) with 22-25 long setae and 15-17 inner spine-like setae. Legs ( Fig. 2B ): metathoracic legs (MTL) larger than prothoracic (PRL) and mesothoracic legs (MSL). Pro- and mesopretarsus (TRS) slightly asymmetrical, short, and with 2 setae; metapretarsus reduced and with 2 setae. Thorax ( Fig. 2A ) with dorsal area sparsely setose. Spiracle in the mesothorax with a reniform, in “reversed-C” shape respiratory plate. Subequal in size to the VIII abdominal spiracle. Abdomen ( Fig. 2A ) with 8 spiracles along the lateral of the abdomen, with reniform respiratory plates, similar to each other. I-VI abdominal spiracles subequal in size, VII-VIII slightly larger. Raster ( Fig. 7 ) with each palidia (PLD) bearing 15-19 setae;septula (SPT) well defined with irregular margins. Palidia and septula are placed mainly on the ventral anal lobe (VAL), with a short part on the venter of last abdominal segment. Anal slit (AST) curved. Each side of tegillar area with more than 90 spine-like setae, with 30 preseptular setae.

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.

Figures

Figure 2. Macraspis morio Burmeister, 1844; third instar larva. (A) Lateral view; (B) right legs; inner view. PRL= protibiotarsus; MSL = mesotibiotarsus; MTL = metatibiotarsus;TRS = pretarsus.Scale = 1 mm.

Figure 3. Macraspis morio Burmeister, 1844; third-instar larva, head, frontal view. AAS = anterofrontal angle setae; AES = anteroepicranial setae; ALS = anterolabral setae; DES = dorsoepicranial setae; ECS = externoclypeal setae; EES = externoepicranial setae; EFS = externofronal setae; LLS = laterolabral setae; MLS = mediolabralsetae;PES =posteroepicranial setae;PFS = posterofrontalsetae;PLS =posterolabral setae;SPT =dorsal sensorial spots;STM =stemma.Scale= 1 mm.

Figure 4. Macraspis morio Burmeister,1844; third instar larva. (A) labrum, dorsal view; (B) epipharynx, ventral view. ACP = acroparia; ALS = anterolabral setae; CTP = chaetoparia; DXT = dexiotorma; GMP= gymnoparia; HTL = haptolachus; HTM = haptomerum; LAP = left acanthoparia; LLS = laterolabral setae; LTM = laeotorma;MLS = mediolabral seta;PLS = posterolabral setae;PTM = pterotorma;RAP = right acanthoparia.Scale = 1 mm.

Figure 5. Macraspis morio Burmeister, 1844; third instar larva. (A) left mandible, ventral view; (B) right mandible, ventral view; (C) right mandible, dorsal view; (D) left mandible,dorsal view.BTA = brustia;CLX = calx;MLR = molar lobe;S1-S3 = incisor teeth;STA = stridulatory area;VSC = ventral setal comb.Scale = 1 mm.

Figure 6. Macraspis morio Burmeister,1844;third instarlarva, maxilla and labium.(A) dorsal view;(B) ventral view.GLA= galea;HSC = hypopharyngeal sclerome; LGL= ligula;LPL= labial palpi;MLA = mala;MNT = mentum;PRM = prementum;SBM= submentum;UNC= uncus.Scale = 1 mm.

Figure 7. Macraspis morio Burmeister, 1844; third instar larva. Raster, rear view.AST = anal slit; PLD= palidia; VAL = ventral anal lobe; SPT = septula (ingrey);Scale = 1 mm.