Xyroscelis crocata Gory & Laporte, 1839

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 : 181-184

Xyroscelis crocata Gory & Laporte, 1839

( Figs 10–19 , 22 , 32–33 , 48, 55 , 64 , 73 , 79, 87, 95–96, 99, 109, 118–119)

Material examined. AUSTRALIA: WESTERN AUSTRALIA: Perth, xi.2001, S. Bílý leg., Macrozamia sp. (Zamiaceae) , 15 specimens, different instars (10 in NMPC, 5 in ZIN).

Description. Measurements: body length 8.0–12.7 mm; width of prothorax 1.9–2.5 mm.

Larva of the buprestoid type ( Figs 10 , 22 ), morpho-ecological subtype 2 ( VOLKOVITSH 1979), prothorax poorly expanded, slightly wider than meso- and metathorax; body creamy-white, body sides with relatively long and dense whitish setae.

Head. Epistome ( Fig. 12 ) strongly transverse, 4.0 times as wide as long; anterior margin shallowly emarginate between nearly globular mandibular condyles, with distinct long angular projections laterally ( Fig. 45 ); posterior margin distinctly bisinuous; latero-posterior corners widely rounded, not projecting outwards; lateral margins of epistome slightly emarginate; antennal incisions deep, well-defined; four epistomal sensilla arranged in two superficial groups of two sensilla situated trapezoidally, each group consists of one campaniform sensillum anteriorly and one short seta posteriorly; distance between sensillum and seta in each group is about half distance between sensilla. Clypeus ( Figs 12 , 64 ) moderately transverse, 1.9 times as wide as long, membranous, glabrous.

Labrum ( Figs 12, 16 , 64 ) 1.1 times as wide as long, anterior margin widely arcuate, nearly straigt medially, lateral lobes not developed; lateral sides of labrum feebly arcuate, slightly diverging posteriorly; palatine sclerites well-defined and sclerotised, medial and lateral branches merging apically and basally forming ring-like structure, medial branches transverse, stronger sclerotised medially; medial sensilla of labrum (t = trichoid, c = campaniform): 1c-2t-3c, situated at subequal distances, 2t relatively short, not reaching anterior margin; antero-lateral sensilla of labrum, external group: (1t, 2c)-3t- 4t; 1t and 3t distinctly longer than 4t, internal group: 1c+(2t, 3t, 4t); labrum dorsally ( Figs 12 , 64 ) with narrow stripe of long microsetae along entire anterior margin, ventrally (epipharynx) ( Fig. 16 ) with two longitudinal areas of dense microspinulae arising from tubercles.

Antennae ( Figs 17 , 48 ) two-segmented, situated in deep incision of epistome, basal antennomere 1.3 times as long as terminal antennomere; articular membrane glabrous; basal antennomere 1.1 times as long as wide, barrel-shaped, with well-defined inner sclerite and with fringe of dense microspinulae along anterior margin; terminal antennomere subcylindrical, elongate, 1.6 times as long as wide at base, distinctly expanded apically, anterior margin with long dense microspinulae; apical cavity of terminal antennomere very shallow, bearing long trichosensilla, nearly 1.5 times as long as antennomere itself; sensory appendage strongly elongate, extending beyond anterior margin of cavity; two very short poorly visible palmate sensilla and one or two poorly visible basiconic sensilla.

Mandibles ( Figs 13 , 55 ) triangular, flat, 1.3 times as long as wide, strongly sclerotised at apical half, black, basal half lighter, yellowish-brown; outer margin without seta above condyle; cutting edge with five teeth: three blunt apical teeth and two internal small, obtuse teeth dorsally.

Hypostome poorly sclerotised, yellowish, bearing a few setae and campaniform sensilla; stemmata present, small, in form of white spots ouward mandibular fossae.

Maxillae ( Figs 14–15 , 79, 87). Cardo ( Figs 14 , 79) elongate, slightly narrowing apically, membranous, glabrous; latero-basal sclerite of cardo (Fig. 79) poorly defined and sclerotised, irregular in shape, bearing two moderately long setae and one campaniform sensillum just beneath external seta. Stipes ( Figs 15 , 87) nearly as wide as long; inner sclerite of stipes well-defined and sclerotised with short and broad internal process; apical seta of stipes nearly as long as palpus, situated at anterior margin of stipes between the bases of palpus and mala; lateral seta very short, situated beneath external side of basal palpomere; external armament composed of fringe of sparse microspinulae along anterior margin, internal armament composed of area of sparse short microspinulae extending mala; additional internal lobe absent. Palpus maxillaris ( Figs 14–15 , 87): basal palpomere 1.5 times as long as terminal palpomere; basal palpomere trapezoid, slightly elongate, 1.2 times longer than wide, with fringe of microspinulae along antero-lateral margin internally; apical seta nearly as long as terminal palpomere; terminal palpomere subcylindrical, distinctly narrowed apically, 1.3 times as long as wide, with approximately ten, short, peg-like apical sensilla. Mala ( Figs 15 , 87) weakly expanded apically, 1.2 times as long as wide; inner sclerite of mala well-defined and sclerotised, subquadrate; external armament of mala composed of one campaniform sensillum, two short, peg-like setae, and four long, robust setae apically; mala internally with four long, robust setae and dense microspinulae along inner side.

Labium ( Figs 14 , 73 ). Prementum slightly transverse, 1.3 times as wide as long, rounded; anterior margin widely arcuate, weakly emarginate at middle, with broadly rounded corners; lateral sides widely arcuate; prementum dorsally (hypopharynx) with two large microspinulate areas laterally, ventrally with densely microspinulate W-shaped area along entire anterior margin, posterior tips of this area reaching the level of bases of apical setae of corner sclerites ( Fig. 73 ); corner sclerites of labium with poorly sclerotised anterior part, apical setae relatively short, far not extending anterior margin of prementum; five campaniform sensilla situated below base of apical setae: three apical and two basal. Postmentum with two short setae.

Thorax ( Figs 10–11 , 32–33 , 95–96, 99). Slightly expanded, flattened, prothorax 1.1–1.2 times wider than mesothorax which is as wide as metathorax and both slightly wider than 1 st abdominal segment; rudiments of legs poorly defined ventrally on all thoracic segments. Prothorax transverse, 1.6–2.1 times as wide as long; anterior membrane with densely microspinulate and glabrous areas and rather dense long setae; lateral sides evenly rounded with sparse, relatively long, whitish setae. Both dorsal and ventral plates poorly defined, unsclerotised, covered with dense colorless microteeth. Pronotal plate ( Figs 10 , 95) nearly entirely covered with microteeth (Fig. 99) but with glabrous areas surrounding anterior part of groove and postero-lateral corners. Pronotal groove (Fig. 95) uniramous, poorly defined and sclerotised, yellowish-brown at anterior half, widest at apex, gradually narrowing toward base, looking double apically due to light median stripe, slightly expanded basally. Prosternal plate ( Figs 11 , 96) covered with dense microteeth and narrow glabrous areas along groove and large areas at postero-lateral corners. Prosternal groove (Fig. 96) uniramous, well-defined and sclerotised, particularly at base and apex, brownish, inverted T-shaped, subparallel, at base abruptly forked forming perpendicular, curved, rather long, slightly sclerotised, basal branches. Mesothorax ( Figs 10–11 , 32–33 ) transverse, 2.3–2.9 times as wide as long and 1.0–1.1 times wider than metathorax; with well-defined secondary fold dividing segment into two parts; nearly glabrous, covered with isolated, short setae; with hardly visible areas of poorly developed microspinulae laterally, ambulatory pads poorly developed both dorsally and ventrally, ovale, occasionally divided by median depression. Metathorax ( Figs 10–11 , 32–33 ) transverse, 2.1–2.3 times as wide as long and 1.4–1.5 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 microteeth; dorsally and ventrally with poorly defined, transversely oval ambulatory pads occasionally divided by median depression.

Abdomen ( Figs 10 , 22 ) flattened; segments 1–8 transverse, slightly wider than long, sides arcuate, dorsally and ventrally bearing central and lateral microspinulate areas; lateral sides with sparse, short, whitish setae and well-defined microspinulae; 1 st abdominal segment transverse, 1.5–2.0 times as wide as long and slightly narrower than 2 nd segment; dorsally with cordate ambulatory pad. Abdominal segments 2–8 transverse, 1.2–1.9 times as wide as long; 9 th abdominal segment transverse, arcuately narrowed posteriorly, 1.9–2.6 times as wide as long; dorsally and ventrally with narrow, zigzag-shaped microspinulate band interrupted medially on ventral side; 10 th abdominal segment conical, slightly transverse, 1.4–2.0 times as wide as long, dorsally with inconspicuous microspinulate area, ventrally glabrous; apex with vertical unsclerotised anal rim.

Spiracles ( Figs 18–19 , 118–119 ). Mesothoracic spiracles ( Figs 18 , 118 ) of buprestoid, cribriform type, renifom, transverse, 1.6 times as wide as long, situated on sides of anterior part of mesothorax, with cancellate peritreme bearing parallel slots, without inner trabeculae; spiracles surrounded with microspinulae.Abdominal spiracles ( Figs 19 , 119 ) of the same type, renifom, narrow, weakly transverse (that on the 1 st abdominal segment 1.3 times as wide as long), with a few parallel slots, situated dorsally in depressions on abdominal segments 1–8, surrounded with microspinulae.

Proventriculus with complicated inner armament consisting of different elements and moderately developed dorsal and ventral central stripes; large, cordiform, with two long curved gastric caeca at base which are about twice longer than proventriculus itself. Main fields formed by moderately dense, mainly isolated microteeth situated on tubercles (Fig. 109), with longitudinal stripe of longer and smaller teeth laterally; their margins with smaller and sparser, reduced teeth, anteriorly and posteriorly changing to fine microspinulae and setae. Central stripes well-developed on both sides, not extending the apices, at base with long and dense setae changing to shorter microspinulae situated in groups of 2–3 on common scale-like bases. Glabrous areas narrow, separated by central stripes.

Figures

Figs 10–19. Larva of Xyroscelis crocata Gory & Laporte, 1839. 10 – body, dorsal view; 11 – thorax, ventral view; 12 – epistome, anteclypeus and labrum, dorsal view; 13 – right mandible, ventral view; 14 – labio-maxillary complex, ventral view; 15 – right maxilla, ventral view; 16 – labrum, ventral view (epipharynx); 17 – right antenna; 18 – mesothoracic spiracle; 19 – abdominal spiracle I. 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.