Pyrodes nitidus (Fabricius, 1787)

Casari, Sônia A. & Nascimento, Francisco E. De L., 2019, Immature stages of American Prioninae Latreille, 1802: descriptions and phylogenetic considerations in Cerambycidae Latreille, 1802 (Coleoptera), Zootaxa 4568 (1), pp. 113-138 : 120-127

Pyrodes nitidus (Fabricius, 1787)

( Figs. 18–50 )

Description of larva. Length: 40–70 mm. Body ( Figs. 31–36 , 41–45 ) soft, yellowish-white, subcylindrical, slightly dorsoventrally depressed. Head yellowish, with mouth frame and mandibles black, and reddish-brown to ferruginous on anterior half; mouthparts membranous, partially light brown; palpi and antennae strongly sclerotized. Legs yellowish, densely setose. Thorax and abdomen with more or less retractile ambulatory ampullae. Pubescence yellowish, sparse and of varied sizes, denser on prothorax.

Head ( Figs. 18, 19 , 32, 33 ) moderately convex, deeply retracted into prothorax, longer than wide, widest behind middle; posterior margin notched at middle forming two rounded lobes; mouthframe strongly sclerotized and rugose. Median frontal endocarina long, not reaching epistomal margin. Epistomal margin projecting above anteclypeal base, with additional carina above epistoma; upper boundary feebly carinate, sinuous and lower boundary projecting in an acutely pointed lobe on each side above clypeus; three pairs of epistomal setae; postcondylar area concave. Head capsule with three long setae near postcondylar area and four on pleurostoma; short setae concentrated anteriorly, on each side of endocarina, and four small setae forming one inclined row on each side. Five stemmata at each side ( Fig. 23 ): three protuberant subcontiguous below antenna placed on raised area, and two small, separated, below previous. Tentorial cross-arm dividing foramen into an anterior and a posterior portion ( Fig. 19 ). Hypostomal line elongate, reaching foramen. Gular lines very weak, short and arched. Antennae ( Figs. 24, 25 ) short, extensible, strongly sclerotized with antennifer membranous and two elongate antennomeres: basal antennomere with four long setae near apex and six small pores with internal channel dorsally; distal antennomere obliquely truncate apically, ventrally with two lateral campaniform sensillae; apex with one elliptical, flat sensorium, four campaniform sensillae and seven setae (two long). Clypeus ( Figs. 18, 20 ) bandshaped, trapezoidal and membranous. Labrum ( Fig. 20 ) subelliptical and narrowed basally, soft, convex and continuous ventrally; surface sclerotized on basal half; wide and long setae more concentrated on distal third; each seta inserted into a sclerotized patch; basal half with small pores with internal channel. Epipharynx ( Fig. 21 ) densely covered with setae directed to middle; basal region narrow with short setae; one sclerite on each side on basal half (tormae). Mandibles ( Figs. 37–40 ) about 1.2 longer than wide, strongly sclerotized, distal margin declivous, gouge-like; apical internal half with two inclined irregular keels; a wide subapical dorsal tooth; external margin with a transverse, semicircular depression near middle and irregularly striate on distal half, irregularly rugose and with sparse yellowish setae on basal half. Maxillolabial complex ( Figs. 19 , 27, 29 ) partially membranous; submentum, maxillary articulating areas and cardines fused, forming basal part; maxillary articulating areas with long and short setae. Distal maxilla: stipes with brown, inclined, transversal band near base, bearing long setae, more concentrated near margins; mala wide with rounded apex, bearing inclined sclerotized band near base and numerous long setae dorsal and ventrally. Palpifer membranous with sclerotized ventral basal band, and numerous long setae, dorsal and ventrally; ventrally bearing a pointed well-developed lateroanterior membranous lobe (dorsolateral process of maxillary palpiger). Maxillary palpi trimerous; palpomeres sclerotized except distal band; basal palpomere transverse with numerous long setae near apex, dorsal and ventrally; median palpomere elongate, dorsally ( Fig. 30 ) with small pores with internal channel, and ventrally with one distal stout seta each side and two lateral small pores, each with internal channel; distal palpomere elongate, wider near base, dorsally with five pores each with internal channel: three near base and two lateral; apex with numerous pegshaped sensillae. Distal labium ( Fig. 27 ): mentum wider than long with lateral margins rounded; numerous long setae laterally; median basal region with about five pairs of long setae and many short and very wide setae; mentum fused to submentum, membranous with sclerotized lateral rounded band, bearing many lateral moderately long setae on anterior 2/3; each side with 5–6 long setae near middle and many wide and short setae; barely sclerotized band at base, with two long and some short and very wide setae, five campaniform sensillae on each side, on membranous area. Prelabium with basal sclerotized band reaching palpiger; 6–7 long setae on palpiger; numerous wide setae distributed on entire area, except basal region; setae longer and more concentrated toward apex. Labial palpi dimerous and very sclerotized; palpomeres elongate; palpomere basal with three small pores, each with internal channel; palpomere distal with peg-shaped sensilla at apex. Hypopharynx ( Fig. 29 ) covered by stout setae, directed to middle; setae wider and with rounded apex near anterior margin.

Prothorax ( Figs. 31–33 ) longer than meso- and metathorax together. Pronotum convex dorsally and flattened ventrally; prominent anterior and posteriorly, and slightly transversely grooved after anterior fifth; anterior fifth with transverse yellowish band and pubescence long and dense; remaining areas sculptured and setose; median frontal line (mfl) incomplete. Ventrally, prothorax sculptured and with two yellow patches each side: one larger on episternum and one smaller near coxosternum; pubescence short and dense. Meso- and metathorax almost same size, with pubescence fine and short, more concentrated laterally; mesothorax with latero anterior large elliptical spiracle ( Fig. 22 ). Leg ( Figs. 26 , 32 ): short, inserted ventrolaterally on thorax; strongly sclerotized and 4- segmented: coxa short and wide with about five long setae and four campaniform sensillae; femur robust, wider than long, with numerous long setae near distal margin; tibiotarsus elongate with numerous long setae; pretarsus elongate, glabrous and tuberculate.

Abdomen: segments I-VI decreasing in width to apex direction; segment VII wider than VI; segments VII–IX decreasing in width to apex direction; segment X reduced, apical and trilobed; segments I–VII, each with one retractile ambulatory ampulla dorsal and one ventral; each ampulla divided by a transverse furrow; segments VII– IX with epipleural tubercles; segments I–VIII, each with one elliptical spiracle on each side, smaller than thoracic; spiracles of segment I larger than thoracic.

Redescription of pupa ( Figs. 46–48 ). Length: 50 mm. Coloration yellowish-cream (darkened after fixation). Head partially visible from above, glabrous; mouthparts glabrous. Antennae slightly curved beneath, almost reaching metaventrite.

Pronotum wider than long, glabrous, grooved longitudinally-medially and laterally; lateral grooves deeper and rounded, continuous with lateral margins of head; lateral margins rounded and prominent on anterior 2/3, forming a small tubercle backwardly directed. Mesonotum grooved transversely near apex; scutellum very prominent almost reaching anterior third of metanotum. Elytra and wings surpassing ventrite I.

Abdomen glabrous; segments band-like, increasing in width from I–III and decreasing from IV to apex; segments III–IV, widest; segment VIII long, narrow and triangular; segment IX with a pair of divergent urogomphi; segment X ventral and trilobed; gin traps on abdominal tergum of segments II–III, III–IV, IV–V and V–VI; posterior plate of each gin-trap not dentate or crenulate along front margin. Functional spiracles laterally on tergites I–VI; VII–VIII closed and probably non-functional.

Material examined. Brazil. São Paulo: Salesópolis, (Estação Biológica de Boracéia) [Boracéia, 23°39'15"S, 45°53'22"W], 23.III.1994, Ide & Campaner cols ( MZSP8787 ); idem, (“ Castelinho ”, in rotten trunk), 17- 19.XI.2017, exp. MZSP leg., 1 larva fixed and 1 larva reared to adult (larval exuviae fixed) (MZSP); São Paulo (Parque Estadual da Cantareira), 30.XI.1992, Exc. PG-UNESP col. ( MZSP8665 ); idem, 12.III.1993, Exc. MZUSP col. (8672); idem, 20.X.1994, Exc. MZUSP col. ( MZSP8681 ) .

Remarks. Based on the description of Hileolaspis auratus and the examined material of Pyrodes nitidus , the larvae of Mallaspini are characterized by having: epistomal margin projected above clypeal base and additional carina above epistoma; upper boundary rather feebly carinate ( Hileolaspis auratus ) and sinuous ( Pyrodes nitidus ); lower boundary not projected above clypeus ( Hileolaspis auratus ) or projected laterally in a prominent triangular process ( Pyrodes nitidus ); five pairs of stemmata (three subcontiguous) on each side; antennae with two antennomeres; second antennomere obliquely truncate; legs 4-segmented; presence of dorsolateral process of maxillary palpiger ( P. nitidus ); thorax and abdomen with retractile ambulatory ampullae glabrous, not tuberculate; spiracles with peritreme oval; anus trilobate.

The pupa of Pyrodes nitidus is the only one known for the tribe Mallaspini .

Figures

FIGURES 18‒26. Pyrodes nitidus (Fabricius, 1878). Larva: 18, 19, head (dorsal, ventral); 20, clypeus and labrum; 21, epipharynx; 22, spiracle thoracic; 23, head capsule with stemmata (lateroanterior); 24, 25, antenna (apex ventral, dorsal); 26, leg (prothoracic). Bars = 1 mm, except figures 20, 25, 26 = 0.5 mm and fig. 24 = 0.1 mm. crd: dorsomedian cranial duplicature; mfl: median frontal line.

FIGURES 27‒30. Pyrodes nitidus (Fabricius, 1878). Larva: 27, 29, maxillolabial complex (ventral, dorsal); 30, two last maxillary palpi (ventral, dorsal). Bars = 1 mm, except figures 28, 30 = 0.1 mm.

FIGURES 31‒36. Pyrodes nitidus (Fabricius, 1878). Larva: 31‒33, head and thorax (dorsal, lateral, ventral); 34-36, habitus (dorsal, lateral, ventral). al: alar lobe; cxl: coxal lobe; epl: epipleuron; epld: epipleural disc; epm: epimeron; epst: episternum; lfur: lateral pronotal furrow; lpst: lateropresternum; pasc: parascutum; pl: pleuron (fused episternum and epimeron); pll: pleural lobe; pn: pronotum; pon: postnotum; (fused mesothoracic prescutum and anteromedial portion of scutum-I); psc: prescutum; sc: scutum; scl: scutellum; scpl: scutal plate (of dorsal abdominal ampulla); sli: sublateral pronotal impression; spa: spiracular area.

FIGURES 37‒45. Pyrodes nitidus (Fabricius, 1878). Larva: 37‒40, mandible (external, dorsal, ventral, internal); 41‒43, middle of abdomen (dorsal, ventral, latera); 44, 45, Apex of abdomen (dorsal, ventral).

FIGURES 46‒50. Pyrodes nitidus (Fabricius, 1878). Pupa: 46, head, pro-and mesonotum; 47, 49, apex of abdomen (dorsal, ventral); 48, gin-traps. Adult: 50, habitus (dorsal).