Astraeus (Depollus) aberrans van de Poll, 1886

Volkovitsh, Mark G. & Bílý, Svatopluk, 2015, Larvae of Australian Buprestidae (Coleoptera). Part 5. Genera Astraeus and Xyroscelis, with notes on larval characters of Australian polycestine taxa, Acta Entomologica Musei Nationalis Pragae 55 (1), pp. 173-202 : 174-178

Astraeus (Depollus) aberrans van de Poll, 1886

( Figs 1–9 , 20 , 28–29 , 44, 53 , 61 , 70 , 77, 85, 114–115)

Material examined. AUSTRALIA: WESTERN AUSTRALIA: Peak Chartes N.P., 8.xi.2001, S. Bílý leg., Eucalyptus sp. (Myrtaceae) , at the base of burned tree, 3 mature specimens (2 in NMPC, 1 in ZIN).

Description. Measurements (1 larva): body length 30.9 mm; width of prothorax 6.2 mm.

Larva of buprestoid type ( Figs 1 , 20 ), morpho-ecological subtype 2 ( VOLKOVITSH 1979, BÍLÝ 1999), prothorax poorly expanded, slightly wider than meso- and metathorax; body creamy-white, sides of thorax with sparse, short whitish setae, sides of abdomen with inconspicuous setae.

Head. Epistome ( Fig. 3 ) strongly transverse, 5.9 times as wide as long; anterior margin deeply emarginate between oval mandibular condyles, with distinct rounded projections laterally; posterior margin bisinuous, distinctly emarginate laterally; latero-posterior corners nearly rectangular, projecting outwards; lateral margins of epistome slightly emarginate; antennal incisions broad, well-defined; 4 epistomal sensilla arranged in two superficial groups of two sensilla situated nearly linearly at midlength, each group consists of one short seta and one campaniform sensillum just above seta; distance between sensilla in each group much less than that between the groups. Clypeus ( Figs 3 , 61 ) strongly transverse, 3.2 times as wide as long, membranous, glabrous.

Labrum ( Figs 3 , 61 ) slightly transverse, 1.2 times as wide as long, anterior margin feebly bisinuous, middle part nearly straight, lateral lobes not developed; lateral sides of labrum widely arcuate, slightly emarginate at base, subparallel; palatine sclerites with well-defined separated branches; medial branches transverse, moderately sclerotised; lateral branches well-sclerotised, strongly expanded at bases; medial sensilla of labrum (t = trichoid, c = campaniform): 1c-2t-3c, distance 1c–3c more than 1c– 2t; 2t relatively short, not reaching anterior margin; antero-lateral sensilla of labrum, external group: (1t, 2c)- 3t + 4t; 1t and 3t relatively short but much longer than 4t, internal group: 1c-(2t, 3t, 4t); labrum dorsally glabrous, ventrally (epipharynx) with large oblique areas of microspinulae along branches of palatine sclerite.

Antennae ( Fig. 7 ) two-segmented, situated in very deep incision between epistome and pleurostome, basal antennomere 1.2 times as long as terminal antennomere; articular membrane glabrous; basal antennomere nearly as long as wide, barrel-shaped, with glabrous anterior margin; terminal antennomere slightly elongate, 1.3 times as long as wide at base, feebly expanded anteriorly, anterior margin with sparse microspinulae; apical cavity of terminal antennomere very shallow, bearing long trichosensilla, nearly 1.5 times as long as antennomere itself, arising from small separate cavity on external wall; sensory appendage elongate, conical, extending beyond anterior margin of cavity; two very short palmate sensilla with jointed bases and two basiconic sensilla of different length.

Mandibles ( Figs 4 , 53 ) triangular, 1.2 times as long as wide, strongly sclerotised at apical half, black, basal half lighter, brown; outer margin with one short seta above condyle; cutting edge with five teeth: apical tooth rather sharp, two internal teeth dorsally and ventrally both arising from common base.

Hypostome. Internal margin of mandibular fossae forms a big tooth-like projection, nearly reaching latero-basal sclerite of cardo ( Fig. 44 ).

Maxillae ( Figs 5, 6 , 77, 85). Cardo subquadrate, nearly as wide as long, membranous, glabrous; latero-basal sclerite of cardo (Fig. 77) well-defined and sclerotised, bearing two short setae and one campaniform sensillum with enlarged bases. Stipes ( Figs 6 , 85) subquadrate, slightly wider than long; inner sclerite of stipes well-defined, with internal process very short; apical seta of stipes slightly longer than basal palpomere, situated at anterior 1/3 of stipes length between the bases of palpus and mala; lateral seta very short, situated at apex of external part of inner sclerite; external armament composed of small area of sparse, short microspinulae at antero-external corners, anterior margin glabrous, internal armament composed of sparse, short microspinulae laterally, extending mala; additional internal lobe absent. Palpus maxillaris ( Figs 6 , 85): basal palpomere nearly as long as terminal palpomere; basal palpomere trapezoid, slightly transverse, 1.1 times wider than long, completely glabrous, apical seta nearly twice shorter than terminal palpomere; terminal palpomere subcylindrical, weakly narrowed and curved outward apically, 1.4 times as long as wide, with approximately ten short, peg-like apical sensilla, one of them larger than others. Mala ( Figs 6 , 85) slightly elongate, feebly narrowed apically, 1.2 times as long as wide; inner sclerite of mala well-defined and sclerotised, subparallel, slightly longer than wide; external armament of mala composed of one campaniform sensillum, 1 short, peg-like seta, five long robust setae, and short microspinulae apically; mala internally with 3 robust, short setae and dense microspinulae along inner side.

Labium ( Figs 5 , 70 ). Prementum transverse, 1.6 times as wide as long, rounded; anterior margin widely arcuate, deeply emarginate at middle, with broadly rounded corners; lateral sides widely arcuate, strongly converging posteriorly; prementum completely glabrous both dorsally and ventrally; corner sclerites of labium with poorly defined anterior part, apical seta relatively long but not extending anterior margin of prementum; five campaniform sensilla situated below the base of apical setae, three apical (two with long bases) and two basal. Postmentum glabrous, without setae.

Thorax ( Figs 1–2 , 20 , 28–29 ). Slightly expanded, flattened, prothorax 1.2 times wider than mesothorax which is nearly as wide as metathorax and both slightly wider than 1 st abdominal segment; rudiments of legs present ventrally on all thoracic segments. Prothorax transverse, 1.8 times as wide as long; anterior membrane glabrous with sparse short setae and inconspicuous microspinulae medially; lateral sides evenly rounded, with moderately dense, short, whitish setae. Both dorsal and ventral plates poorly defined, unsclerotised, colorless, limited by oblique folds. Pronotal plate ( Figs 1 , 28 ) glabrous, bearing sparse short setae and grainy superficial cuticular sculpture along the groove. Pronotal groove uniramous, widest at apex, gradually narrowed toward base where it is forked; lateral branches short, curved outwards. Prosternal plate ( Figs 2 , 29 ) glabrous, bearing sparse short setae, grainy superficial cuticular sculpture along the groove, and a few concentric rugae. Prosternal groove uniramous, inverted T-shaped, widest at apex, becoming narrower toward base where it shortly triangularly widened forming short, nearly perpendicular branches. Mesothorax ( Figs 1–2 , 28–29 ) transverse, 2.9 times as wide as long and 1.1 times wider than metathorax, with well-defined secondary fold dividing segment into two parts; glabrous, bearing sparse short setae, with hardly visible areas of poorly developed microspinulae laterally; ambulatory pads well-defined dorsally and ventrally, ovale. Metathorax ( Figs 1, 2 , 28, 29 ) transverse, 2.2 times as wide as long and 1.4 times wider than 1 st abdominal segment; lateral sides with sparse short whitish setae; both dorsal and ventral sides of metathorax with distinct, transverse plates covered with microspinulae; dorsally with two large ambulatory pads separated by median depression and bearing inconspicuous cuticular sculpture laterally, ventrally with single, large, transverse, reniform medial pad.

Abdomen ( Figs 1 , 20 ) flattened, segments 1–8 weakly transverse, slightly wider than long; all segments laterally, segments 4–10 dorsally and 6–10 ventrally with microspinulate areas; lateral sides with sparse short whitish setae and poorly defined microspinulae; 1 st abdominal segment trapezoid, narrowed posteriorly, 1.4 times as wide as long and narrower than 2 nd segment; dorsally with large ambulatory pad divided by shallow longitudinal depression, bearing rugulose sculpture; ventrally with large, medial ambulatory pad divided by transverse furrow into two parts, ends of furrow with inconspicuous inner sculpture; mainly glabrous, with sparse short setae; sides covered with microspinulae. Abdominal segments 2–8 slightly transverse, 1.3–1.6 times as wide as long; 9 th abdominal segment slightly transverse, arcuately narrowed posteriorly, 1.4 times as wide as long; 10 th abdominal segment conical, 1.4 times as wide as long, with vertical unsclerotised anal rim.

Spiracles ( Figs 8–9 , 114–115 ). Mesothoracic spiracles ( Figs 9 , 114 ) of buprestoid, cribriform type, reniform, narrow, strongly transverse, 3.3 times as wide as long, situated on sides of anterior part of mesothorax, with cancellate peritreme and numerous, branched trabeculae; spiracles surrounded with poorly defined microspinulae. Abdominal spiracles ( Figs 8 , 115 ) of the same type, renifom, narrow, transverse (that on 1 st abdominal segment 2.7 times as wide as long), situated dorsally in depressions on abdominal segments 1–8, with cancellate peritreme and numerous branched trabeculae; adjacent cuticle glabrous or spiracles surrounded with poorly defined microspinulae.

Proventriculus (Figs 106–107) with complicate inner armament consisting of different elements and moderately developed dorsal and ventral central stripes; nearly globular, with two long, curved gastric caeca at base which are about 1.5 times longer than proventriculus itself; main fields with very dense, robust, singular microteeth situated on tubercles (Fig. 106); their margins with smaller and sparser, reduced teeth and enlarged tubercles, anteriorly with small fine microspinulae situated in rows, posteriorly with very long microspinulae changing to microteeth. Central stripes developed on both sides; dorsally incomplete, not extending apex, at base with long and dense microspinulae (Fig. 107) changing to shorter microspinulae with expanded basal tubercles then, at the middle, to short sparse microteeth, and, anteriorly, to long slender and dense fine setae; ventrally with short posterior area limited with narrow glabrous stripes, bearing long and short microspinulae directed medially and posteriorly and surrounding the field of short inconspicuous microspinulae situated in 2–3 on common bases. Glabrous areas extensive, with long wavy rugosities.

Figures

Figs 1–9. Larva of Astraeus (Depollus) aberrans van de Poll, 1886. 1 – body, dorsal view; 2 – thorax, ventral view; 3 – epistome, anteclypeus and labrum, dorsal view; 4 – right mandible, dorsal view; 5 – labio-maxillary complex, ventral view; 6 – right maxilla, ventral view; 7 – right antenna; 8 – abdominal spiracle I; 9 – mesothoracic spiracle. Drawings S. Bílý.

Figs 20–27. Astraeini, Xyroscelidini, Prospherini, Polycestini, Haplostethini, and Paratrachyini, larval habitus (dorsal view). 20 – Astraeus (Depollus) aberrans van de Poll, 1886 (Australia); 21 – A. (A.) prothoracicus van de Poll, 1889 (Australia); 22 – Xyroscelis crocata Gory & Laporte, 1839 (Australia); 23 – Xyroscelis sp. (Australia); 24 – Blepharum sainvali (Bílý, 2000) (New Caledonia); 25 – Paratrachys (P.) hederae Saunders, 1873 (Japan); 26 – Polycesta (Tularensia)?elata LeConte, 1858 (U.S.A.); 27 – Mastogenius texanus Bellamy, 2002 (U.S.A.). Photo: M. G. Volkovitsh.

Figs 28–43. Astraeini, Xyroscelidini, Prospherini, Polycestini, Haplostethini, and Paratrachyini, thoracic and basal abdominal segments (dorsal and ventral views).28, 29 – Astraeus (Depollus) aberrans van de Poll, 1886; 30, 31 – A. (A.) prothoracicus van de Poll, 1889; 32, 33 – Xyroscelis crocata Gory & Laporte, 1839; 34, 35 – Xyroscelis sp.; 36, 37 – Blepharum sainvali (Bílý, 2000); 38, 39 – Polycesta (Tularensia)?elata LeConte, 1858; 40, 41 – Mastogenius texanus Bellamy, 2002; 42, 43 – Paratrachys (P.) hederae Saunders, 1873. Photo: M. G. Volkovitsh.

Figs 44–60.Astraeini, Xyroscelidini, Prospherini, Polycestini, Haplostethini, and Paratrachyini, hypostome, epistome (details), antennae, and mandibles. 44 – Astraeus (Depollus) aberrans van de Poll, 1886, tooth-like projection of hypostome (arrow); 45 – Xyroscelis sp., lateral projection of epistome (arrow). 46–52 – antennae: 46 – Prospheres aurantiopicta Laporte & Gory, 1837; 47 – A. (A.) prothoracicus van de Poll, 1889; 48 – Xyroscelis crocata Gory & Laporte, 1839; 49 – Xyroscelis sp.; 50 – Strigoptera bimaculata (Linnaeus, 1758); 51 – Mastogenius texanus Bellamy, 2002; 52 – Paratrachys (P.) hederae Saunders, 1873. 53–60 – mandibles (left): 53 – Astraeus (D.) aberrans; 54 – A. (A.) prothoracicus; 55 – Xyroscelis crocata; 56 – Xyroscelis sp.; 57 – Prospheres aurantiopicta; 58 – Strigoptera bimaculata; 59 – Mastogenius texanus; 60 – Paratrachys (P.) hederae. Photo: M. G. Volkovitsh.

Figs 61–68. Astraeini, Xyroscelidini, Prospherini, Polycestini, Haplostethini, and Paratrachyini, labrum dorsally: 61 – Astraeus (Depollus) aberrans van de Poll, 1886; 62 – A. (A.) prothoracicus van de Poll, 1889; 63 – Strigoptera bimaculata (Linnaeus, 1758) (arrows show campaniform sensilla); 64 – Xyroscelis crocata Gory & Laporte, 1839; 65 – Xyroscelis sp.; 66 – Prospheres aurantiopicta Laporte & Gory, 1837; 67 – Mastogenius texanus Bellamy, 2002; 68 – Paratrachys (P.) hederae Saunders, 1873.

Figs 69–76. Astraeini, Xyroscelidini, Prospherini, Polycestini, Haplostethini, and Paratrachyini, labium ventrally: 69 – Prospheres aurantiopicta Laporte & Gory, 1837; 70 – Astraeus (D.) aberrans van de Poll, 1886; 71 – A. (A.) prothoracicus van de Poll, 1889; 72 – Strigoptera bimaculata (Linnaeus, 1758) (arrows show campaniform sensilla); 73 – Xyroscelis crocata Gory & Laporte, 1839; 74 – Xyroscelis sp.; 75 – Paratrachys (P.) hederae Saunders, 1873; 76 – Mastogenius texanus Bellamy, 2002. Photo: M. G. Volkovitsh.

Figs 114–129. Astraeini, Xyroscelidini, Prospherini, Polycestini, Haplostethini, and Paratrachyini, mesothoracic (114, 116, 118, 120, 122, 124, 126, 128) and abdominal (115, 117, 119, 121, 123, 125, 127, 129) spiracles: 114, 115 – Astraeus (Depollus) aberrans van de Poll, 1886; 116, 117 – A. (A.) prothoracicus van de Poll, 1889; 118, 119 – Xyroscelis crocata Gory & Laporte, 1839; 120, 121 – Xyroscelis sp.; 122, 123 – Prospheres aurantiopicta Laporte & Gory, 1837; 124, 125 – Strigoptera bimaculata (Linnaeus, 1758); 126, 127 – Mastogenius texanus Bellamy, 2002; 128, 129 – Paratrachys (P.) hederae Saunders, 1873. Photo M. G. Volkovitsh.