Dipropus brasilianus (Germar)

Casari, Sônia A. & Biffi, Gabriel, 2012, Immatures of Dicrepidius Eschscholtz, 1829 and Dipropus Germar, 1839 (Elateridae, Elaterinae, Ampedini: Dicrepidiina), Zootaxa 3587, pp. 65-77 : 69-74

Dipropus brasilianus (Germar)

( Figs. 16–37 , 39 , 41 )

Larva redescription. Length: 11.2–26.5mm; width: 1.0–2.2mm.

Elongate, subcylindrical, heavily sclerotized ( Fig. 39 ). General coloration from brownish-yellow to reddishbrown, with head, pronotum, spiracles and abdominal segment IX darker. Integument densely punctured; meso- and metanotum and abdominal segments I–IX with one lateroanterior elongate striate darker area each side (muscular impressions), oblique in relation to lateral margin; striae parallel; striate impressions of meso- and methorax constricted or divided at middle; circular or semi circular muscular impressions forming irregular band near anterior margin ( Fig. 38 ). Ventral surface lighter sclerotized; abdominal segments II–IX bearing, medioanteriorly, transverse irregular band of circular or semicircular muscular impressions, increasing in density to apex direction. Integument densely and coarsely punctured. Pubescence ferrugineous, moderately long and sparse.

Head ( Figs. 18–20 ) flattened, basally slightly narrower than anterior margin of pronotum; lateral margins slightly rounded. Frontal arms ( Fig. 18 ) lyriform, distant at base. Nasale prominent with one trilobed tooth (median lobe longer); paranasal lobes well developed, each with a row with four long setae dorsally and fringe of thin ramified setae ventrally; one long dorsal seta each frontal lobe. Frons ( Figs. 18 , 31 ): 1.2 time wider than long (considering apex and wider width); basal half roundly narrowed; basal half narrow, widened at middle, truncate at extremity, reaching posterior edge of head; punctation umbilicate, moderately coarse and dense, intermingled with punctation simple, fine and sparse. One lateral translucent stemma below each antenna. Each epicranial half with three pairs of long setae near middle: one dorsal, one lateral and one ventral; dorsally with a longitudinal row with three tiny setae near base; ventrally with one long seta near stemma and one longitudinal row of moderately short setae parallel to ventral epicranial ridge. Epipharynx ( Fig. 33 ) densely setous near middle and ramified longer setae under paranasal lobes; one transverse row with six irregular teeth at middle; two moderately long setae near middle and a transverse sclerotized plate at base of central setous area. Mandibles symmetrical ( Fig. 28–30 ), wider near base, with apex sharpened and curved; one well developed retinaculum; lateral margin strongly grooved on basal half to accommodate antenna and with one seta near middle; penicillus elongate, formed by short setae. Antennae ( Figs. 25–27 ) inserted laterally in wide groove at base of mandibles; with antennifer membranous and three antennomeres: basal antennomere elongate with three long dorsal setae near apex and one campaniform laterodorsal sensillum; median antennomere elongate, shorter than basal, bearing two moderately short dorsal setae near apex and one well developed cupuliform membranous sensorium at apex; distal antennomere narrow and elongate, slightly shorter than cupuliform sensorium, width approximately 1/5 of median antennomere width, inserted lateroexternal at apex of median antennomere, adjacent to sensorium, bearing at apex five moderately short setae. Maxilla ( Fig. 32 ): stipes elongate with external margin slightly rounded; four lateroanterior setae, two longer; mala palpiform, two-segmented; basal segment with one campaniform sensillum ventral (near middle) and one dorsal (lateroexternal); distal segment constricted near apex with five long setae near apex and two campaniform sensilla ventrally near base; cardines elongate: median wider, narrowed on distal third and lateral triangular. Palpiger membranous, microsetous; sclerotized area glabrous. Maxilary palp with four palpomeres: first transverse bearing ventrally two setae and seven campaniform sensilla near base; second almost as wide as long, bearing ventrally two campaniform sensilla near base and one laterointernal; third transverse bearing ventrally two setae and one campaniform sensillum near apex and dorsally two setae laterally near apex (one external and one internal); distal elongate, narrower, bearing dorsally one thin and one wide seta and microsensilla at apex. Labium ( Fig. 32 ) narrow, elongate, postmentum connate with stipites, elongate, almost parallel, bearing one pair of long setae near apex and one pair longer at base; prementum pentagonal, punctured, with two long setae below palpi; ligula small, triangular, with two wide setae dorsally. Labial palpi with two palpomeres: basal elongate, bearing ventrally one long seta near apex and one campaniform sensillum near base; distal elongate, narrower, bearing microsensilla at apex. Hypopharynx ( Fig. 34 ) densely setous with weak sclerite at middle; simple setae.

Prothorax elongate, longer than meso- or metathorax; with one paler impunctate transverse band at anterior and one at posterior margin; each side with an anterior dorsolateral row with four or five setae and one laterobasal row with two setae. Meso- and metathoraces transverse, latter longer; with paler impunctate transverse band at posterior margin; anteriorly with irregular band of circular or semircular muscular impressions; each side with two small lateroanterior elongate striate areas (muscular impressions), oblique in relation to lateral margin; a transverse dorsolateral row with two moderately long setae near middle and one lateroanterior seta. Mesothorax with lateroanterior well developed spiracle ( Fig. 24 ) with one lateral seta; metathorax with lateroanterior semicircular scar with a short lateral setae. Legs (Figs. 21,22, 39) inserted at middline of thorax; increasing in size from anterior to posterior; with fine and long and short and wide setae; coxa elongate, wide and robust, trochanter triangular, femur and tibia elongate, femur wider than tibia; pretarsus elongate, claw-like with two long setae.

Abdominal segments I–VIII with paler impunctate transverse band at base; anteriorly with irregular band of circular or semicircular muscular impressions; each side with one lateroanterior elongate striate area (muscular impression), oblique in relation to lateral margin; striae parallel; one longitudinal lateral carina, starting laterally each striate muscular impression, not reaching posterior margin; each side with posterior row with two setae near middle and a lateroanterior spiracle, smaller than thoracic with lateral seta. Ventrally, segments I–VIII with anterior band of circular or semicircular muscular impressions (segment I not much developed); each side of segments I–VIII with one lateroanterior and one lateroposterior seta. Segment IX ( Fig. 23 ) elongate, rounded with constricted and sharply pointed apex; circular or semicircular impressions at base and one elongate striate area each side; with punctation coarse interspersed with rounded small tubercles, especially dorsally at distal half, giving a rough appearance; tubercles slightly larger or equal punctures; several long dorsal, ventral and lateral setae; circular or semircular impressions ventrally. Segment X ( Figs. 17, 23 ) tubular and ventral.

Pupa description. Length: 15mm; prothorax width: 4mm.

White and glabrous. Head partially visible dorsally ( Figs. 35, 36 ). Pronotum wider than long (excluding fore and hind angles), narrowed at base of fore and hind angles; lateral margins sinuous; hind angles well developed, band-like and slightly outwardly directed, longer than half of mesonotum length; three pairs of sclerotized microspined projections: at fore and hind angles and near median basal area. Mesonotum shorter than metanotum. Abdominal segments I–VI transverse and almost at same size with lateroposterior angles prominent and microspined (except segment I); microspines increasing in density to apex direction; segment VII narrower and longer, transverse with distal margin rounded; segment VIII short, band-like, almost same width that anterior; segment IX transverse, constricted near middle with one sclerotized microspined projection at each hind angle; segments I–VII bearing one spiracle each side, dorsolaterally near anterior margin. Segment X ( Fig. 37 ) venter, partially divided.

Material examined. Brazil. Santa Catarina: Florianópolis, 17.VII.2008; F. Albertoni col., 6 larvae fixed (+ one dissected), one pupa fixed and two larvae reared to adult ( MZSP 10243).

Figures

FIGURES 16 – 24. Dipropus brasilianus, larva: 16, 17, habitus (dorsal, lateral); 18 – 20, head (dorsal, ventral, lateral); 21, 22, mesothoracic leg (anterior, posterior); 23, segments VII – X (ventral); 24, thoracic spiracle. Bars = 0.1 mm except figs. 18 – 20 = 0.5 mm; figs. 21, 22 = 0.2 mm.

FIGURES 25 – 34. Dipropus brasilianus, larva: 25 – 27, antennae (right dorsal, left ventral, left lateral); 28 – 30, mandible (ventral, external, dorsal); 31, frons; 32, maxillolabial complex; 33, epipharynx; 34, hypopharynx. Bars = 0.1 mm except figs. 28 – 32 = 0.2 mm.

FIGURES 35 – 37. Dipropus brasilianus, pupa: 35, 36, habitus (dorsal, lateral); 37, apex of abdomen (ventral). Bars = 0.2 mm except fig. 37 = 0.1 mm.

FIGURES 38, 39. Larva, habitus (lateral): 38, Dicrepidius ramicornis; 39, Dipropus brasilianus. Bars: fig. 38 = 2 mm; fig. 39 = 1 mm.

FIGURES 40, 41. Adult, habitus (dorsal): 40, Dicrepidius ramicornis; 41, Dipropus brasilianus.