Euselates cineraceus (Gory & Percheron, 1833)

Vendl, Tomáš, VONDRÁýEK, Dominik, Kubá, VítČzslav & Šípek, Petr, 2014, Immature stages of Taenioderini (Coleoptera: Scarabaeidae: Cetoniinae): a report of hidden morphological diversity, Acta Entomologica Musei Nationalis Pragae 54 (2), pp. 571-604 : 583-592

Euselates cineraceus (Gory & Percheron, 1833)

( Figs 2D ; 3D ; 4D ; 5D ; 6J–L,S ; 8D–F,Q ; 9H,P ; 10D ; 11D ; 12J ; 13C,I )

Material examined. 14 third instar larvae reared from adults reared from ¿eld collected larvae at: MALAY- SIA: PERAK SULTANATE: Cameron Highlands, road between Tapah and Tanah Rata, Batu (= mile 19), 4°22.121ƍN 101°20.012ƍE, 600–660 m a.s.l., 12.iii.2010, P. Šípek leg.

Description of third instar larva. Body ( Fig. 2D ). Length 38.0–49.0 mm, dorsoventral interval of abdominal segments slightly larger than in thoracic segments (the abdominal segment VIII is the thickest). Chaetotaxy sparse, with three distinct types of setae: Short or medium long hair-like setae on dorsal sublobes and the venter of the ultimate segment; long, stiff or slightly flattened setae on legs, ventral part of body and the dorsa of abdominal segments VII and VIII and oblanceolate* long setae on the ultimate abdominal segment; the last two types of setae, dark brown or black, the ¿rst pale brown.

Head capsule ( Fig. 3D ). Maximum width 3.8–4.0 mm, glossy, yellowish or pale brown. Frontal sutures bisinuated. Epicranial insertions of antennal muscles indistinct. Cranial chaetotaxy summarized in Table 1. Anterior and exterior frontal setae with minute single seta or absent.

Antennae ( Figs 3D ; 9H ). Relative length of antennomeres I–IV (an I–IV): an I> an IV> an II> an III), ultimate antennomere with four to eight dorsal and 7–12 ventral sensory spots.

Epipharynx ( Fig. 4D ). Haptomerum: Zygum convex, more or less protruding, with arcuate row of 16–18 stout conical setae and few setae proximad to the row. Sensilla of zygum grouped in single group distad to the row. Acroparia: Lateral lobes of epipharynx with three to ¿ve long setae, medial lobe with eight setae. Acanthoparia with ¿ve to nine setae surrounded by moderately swollen base (or tubercle); the size of the tubercles as well as the setae increasing towards apex of epipharynx.

Chaetoparia: Asymmetric, right side composed of approximately 40–60 setae in three to ¿ve longitudinal rows and medial ¿eld (proximad to plate-shaped sclerite). Left side with approximately 30–40 setae in two to three rows. Both parts of chaetoparia with medial, more or less regular row of prominent long setae. Pedium large. Dexiotorma straight, right pternotorma well developed. Laeotorma absent, left pternotorma well developed.

Haptolachus: Sense cone conical, almost pointed. Plate-like sclerite large, occupying almost the entire area between sense cone and the regular rows on both sides of chaetoparia, however, it can be less distinct in some specimens.

Mandibles ( Figs 6J–L ; 8D–F ; 13I ). Stridulatory area well developed, with approximately 20–25 ridges (ridges in the proximal half less distinct and narrow). Scrobis with three to ¿ve lateral setae. Longitudinal furrow absent. Apical half of mandibles in dorsal aspect with two lateral setae and mediolateral depression (proximad to the base of the third scissorial tooth). Lateral outline of both mandibles without prominent external tooth.

Maxilla ( Figs 5D ; 12J ). Dorsal surface of cardo and labacoparia with four to eight, 15–23 setae respectively. Ventral surface of cardo and labacoparia with two to ¿ve and 5–14 stiff setae respectively. Dorsal surface of stipes with 11–19 slender hair-like setae and one anterolateral stout seta. Maxillary stridulatory apparatus on stipes with more or less regular row of six to eight spine-like stridulatory teeth (in dorsal aspect, Fig. 12J ) and one or two blunt tubercles. Ventral surface of stipes with single proximal and single distal stout seta. Galear portion of mala in dorsal aspect beside large falcate uncus with four to ¿ve large stiff and one to three medium-sized hair-like setae, respectively. Lacinial part of mala with around 13–19 mostly very long and stiff setae. Lacinial apex with two unci (subapical uncus however small and reduced) and with conical, stout setae. Vental surface of mala with two longitudinal rows of two to four (seven) setae; distal setae of the exterior row long and stiff, distal setae of the interior row shorter and stout.

Hypopharyngeal sclerome ( Fig. 5D ). Four to ¿ve tegumentary expansions (phoba-like processes) present on the left lateral lobe of hypopharynx, tegumentary expansions on right medial portion of scleroma present.

Ligula ( Figs 5D ; 13C ). Dorsal surface with two lateral groups of nine hair-like setae, two paramedial setae at the apical margin and central group of setae and sensilla. This group is composed of two paramedial rows of three stout and conical setae, and transverse, basomedial row with four conical and four to six campaniform setae.

Thorax ( Figs 2D ; 6S ; 8Q ; 9P ). Prothoracic sclerite with seven to ten setae on the anteroventral margin and another two setae in the posterio-dorsal area. Each sublobe of prothorax dorsally with one row of mostly medium-long or long setae interspersed with few short setae. Thoracic spiracle ( Fig. 6S ) 0.7 × 0.4 mm (height × width), bullar opening narrow, arms of respiratory plate almost concealed. Respiratory plate with approximately 20–40 holes across diameter. Venter of each thoracic segment with four to six prominent dark setae (usually one pair of long and several medium-long or short setae present). Similar setae also on coxa. Pretarsus ( Fig. 8Q ) conical with falcate tip and two apical setae.

Abdomen ( Figs 2D ; 10D ; 11D ). Each dorsal sublobe of abdominal segments I–VIII with one row of mostly medium long setae, however, short and long setae also present. Dorsum of abdominal segment VII–VIII, as well as venter, and spiracular and pleural areas of all abdominal segments with several prominent dark stiff setae. Spiracles on abdominal segments I–V elliptical, similar to thoracic spiracle, abdominal spiracles on segments VI–VIII almost circular.

Raster ( Figs 10D ; 11D ). Palidium monostichous (however with few pali scattered around the main row), approximately 25 pali arranged in single elongate U-shaped row. Septula opened posteriorly, about three times longer than broad. Tegilla fused, with numerous short, stout, apically recurved setae, ventral and dorsal anal lip with dense rows of similar setae. The ultimate abdominal segment with sparse but prominent dark oblanceoate setae.

Euselates laoticus Mikši ü, 1974 ( Figs 2E ; 3E ; 4E ; 5E ; 6M–O,T ; 8G–I,R ; 9I,Q ; 10E ; 11E ; 12F,K,N ; 13J )

Material examined. 2 third instar larvae reared from eggs laid by adults collected in: LAOS: HOUA PHAN PROVINCE: 20°13ƍ09–19ƎN 103°59ƍ54Ǝ–104°00ƍ03ƎE, Mount Phou Pane, 1480–1510 m a.s.l., 1.–16.vi.2009, V. KubáĖ leg.

Description of third instar larva. Body ( Fig. 2E ). Length 27.0–34.0 mm, dorsoventral interval of body segments gradually increasing toward the penultimate segment; penultimate and ultimate segment distinctly thicker than the previous segments. Chaetotaxy more or less sparse, however with numerous long or extremely long setae, giving the larva ‘hairy appearance’, the longest setae present on the ultimate abdominal segment.

Head capsule ( Fig. 3E ). Width 2.9 (n = 1), brow with pale spots, clypeus and labrum yellow. Frontal sutures bisinuated. Epicranial insertions of antennal muscles visible as pale depressions. Cranial chaetotaxy summarized in Table 1. Anterior and exterior frontal setae with minute single seta.

Antennae ( Figs 3E ; 9I ). Relative length of antennomeres I–IV (an I–IV): an I> an IV> an II> an III), ultimate antennomere with eight dorsal and nine ventral sensory spots (n = 1).

Epipharynx ( Figs 4E ; 12F ). Haptomerum: Zygum convex, more or less protruding, with arcuate row of approximately 14 stout conical setae and few setae proximad to the row. Sensilla of zygum grouped in single group on more or less prominent cone. Acroparia: Lateral lobes of epipharynx with four to ¿ve long setae, medial lobe with eight setae. Acanthoparia with ¿ve to six setae surrounded by moderately swollen base (or tubercle); the size of the tubercles as well as the setae increasing towards apex of epipharynx.

Chaetoparia: Asymmetric, right side composed of approximately 45 setae in irregular longitudinal rows and medial ¿eld (proximad to plate-shaped sclerite). Left side with approximately 30 setae in three irregular rows. Pedium large. Dexiotorma straight, right pternotorma absent (only slightly indicated). Laeotorma strongly reduced, however present, left pternotorma well developed.

Haptolachus: Sense cone low, cob-like. Plate-like sclerite reduced.

Mandibles ( Figs 6M–O ; 8G–I ; 13J ). Stridulatory area well developed, with approximately 20–25 ridges. Scrobis with two to ¿ve lateral setae. Longitudinal furrow absent. Apical half of mandibles in dorsal aspect with two lateral setae and mediolateral depression (proximad to the base of the third scissorial tooth). Lateral outline of both mandibles without prominent external tooth.

Maxilla ( Figs 5E ; 12K ). Dorsal surface of cardo and labacoparia with four to six and 10 setae, respectively. Dorsal surface of stipes with 13–14 slender hair-like setae and one anterolateral stout seta. Maxillary stridulatory apparatus on stipes with four to ¿ve spinelike stridulatory teeth (in dorsal aspect, Fig. 12K ) and two blunt tubercles. Galear portion of mala in dorsal aspect beside large falcate uncus with ¿ve large stiff and three to four medium-sized hair-like setae, respectively. Lacinial part of mala with around 15 mostly long and stiff setae. Lacinial apex with two unci (subapical uncus however small and reduced) and with conical, stout setae.

Hypopharyngeal sclerome ( Figs 5E ; 12N ). Four to ¿ve tegumentary expansions (phoba-like processes) present on the left lateral lobe of hypopharynx, tegumentary expansions on right medial portion of scleroma absent.

Ligula ( Fig. 5E ). Dorsal surface with two lateral groups of nine hair-like setae, two paramedial setae at the apical margin and central group of setae and sensilla. This group is composed of two paramedial rows of three stout and conical setae, and transverse, basomedial row with three to conical and six campaniform setae.

Thorax ( Figs 2E ; 6T ; 8R ; 9Q ). Prothoracic sclerite with anterior row of approximately 20 hair-like setae and posterior row of four to ¿ve setae. Each sublobe of prothorax dorsally with one row of mostly medium-long or long setae interspersed with few short setae. Thoracic spiracle ( Fig. 6T ) 0.6 × 0.3 mm (height × width), bullar opening broad, distance between the arms of respiratory plate equals the widest diameter of respiratory plate. Respiratory plate with approximately 15 holes across diameter. Venter of each thoracic segment with row of numerous long hair-like setae. Pretarsus ( Fig. 8R ) cylindrical with small falcate tip and two apical setae.

Abdomen ( Figs 2E ; 10E ; 11E ). Each dorsal sublobe of abdominal segments I–VIII with one or two rows short and long hair-like setae. Setae of ventral and lateral parts of body extremely long. Spiracles on abdominal segments I–VII similar to the thoracic spiracle in shape and size, spiracle of abdominal segment distinctly smaller.

Raster ( Figs 10E ; 11E ). Palidium monostichous (however with few scattered pali around the main row), approximately 20–25 pali arranged in single U-shaped row. Septula opened posteriorly, about two times longer than broad. Tegilla fused, with approximately 15 hamate setae. Hamate setae also present on the ventral anal lip. The ultimate abdominal segment with numerous extremely long hair-like setae especially on sides.

Figures

Fig. 2. Third instar larvae of Taenioderini.A–H – habitus.A – Chalcothea neglecta. B – Coilodera diardi. C –C. penicillata. D – Euselates cineraceus. E – E. laoticus. F – Meroloba suturalis. G – Plectrone tristis.H – Taeniodera sp. Figures not to scale.

Fig. 3. Third instar larvae of Taenioderini. A–H – cranium. A – Chalcothea neglecta. B – Coilodera diardi. C –C. penicillata. D – Euselates cineraceus. E – E. laoticus. F – Meroloba suturalis. G – Plectrone tristis. H – Taeniodera sp. Scale bars: Figs 3A–H = 1mm.

Fig. 4. Third instar larvae of Taenioderini. A–H – epipharynx. A – Chalcothea neglecta. B – Coilodera diardi. C – C. penicillata. D – Euselates cineraceus. E – E. laoticus. F – Meroloba suturalis. G – Plectrone tristis. H – Taeniodera sp. Scale bars = 1 mm.

Fig. 5. Third instar larvae of Taenioderini. A–H – maxillo-labial complex.A – Chalcothea neglecta. B – Coilodera diardi. C – C. penicillata. D – Euselates cineraceus. E – E. laoticus. F – Meroloba suturalis. G – Plectrone tristis. H – Taeniodera sp. Scale bars = 1 mm.

Fig. 6. Third instar larvae of Taenioderini.A–O – left mandible (dorsal, medial and ventral aspect), P–T – thoracic spiracle. A–C,P – Chalcothea neglecta. D–F,Q – Coilodera diardi. G–I,R – C. penicillata. J–L,S – Euselates cineraceus. M–O,T – E. laoticus. Scale bars: Figs A–O = 1mm; Figs P–T = 0.5 mm.

Fig. 8. Third instar larvae of Taenioderini.A–O – right mandible (ventral, medial and dorsal aspect), P–T – pretarsus. A–C,P – Coilodera penicillata. D–F,Q – Euselates cineraceus. G–I,R – E. laoticus. J–L,S – Meroloba suturalis. M–O,T – Plectrone tristis. Scale bars: Figs A–P,T = 1 mm; Figs Q–S = 0.5 mm.

Fig. 9. Third instar larvae of Taenioderini.A–C – right mandible (ventral, medial and dorsal aspect), D – pretarsus, E–L– antenna (dorsal and ventral aspect), M–T – metathoracic leg: A–D – Taeniodera sp. E,M – Chalcothea neglecta. F,N – Coilodera diardi. G,O – C. penicillata. H,P – Euselates cineraceus. I,Q – E. laoticus. J,R – Meroloba suturalis. K,S – Plectrone tristis. L, T – Taeniodera sp. Scale bars = 1 mm.

Fig. 10. Third instar larvae of Taenioderini. A–H – ultimate abdominal segment, ventral aspect. A – Chalcothea ne- glecta. B – Coilodera diardi. C – C. penicillata. D – Eusela- tes cineraceus. E – E. laoticus. F – Meroloba suturalis. G – Plectrone tristis. H – Taenio- dera sp. Scale bars = 1 mm.

Fig. 11. Third instar larvae of Taenioderini. A–H – ultima- te abdominal segment, lateral aspect: A – Chalcothea neglecta. B – Coilodera diardi. C – C. peni- cillata. D – Euselates cineraceus. E – E. laoticus. F – Meroloba suturalis. G – Plectrone tristis. H – Taeniodera sp. Scale bars = 1 mm.

Fig. 12. Third instar larvae of Taenioderini, SEM images.A–C – epipharynx:A – Chalcothea neglecta. B – Coilodera diardi. C– Taeniodera sp. D–F – sense cone (haptolachus, epipharynx): D – Chalcothea neglecta. E – Coilodera diardi. F– Euselates laoticus. G–M – maxillar stridulatory teeth: G – Chalcothea neglecta. H – Coilodera diardi. I – C. penicillata. J – E. cineraceus. K – E. laoticus. L – Meroloba suturalis.M – Taeniodera sp. N,O – hypopharyngeal scleroma: N – E. laoticus. O – Meroloba suturalis.

Fig. 13. Third instar larvae of Taenioderini, SEM images. A–E – ligula: A – Chalcothea neglecta. B– Coilodera diardi, C – Euselates cineraceus. D – Meroloba suturalis. E – Taeniodera sp. F–L – mandibular stridulatory area: F – Chalcothea neglecta. G – Coilodera diardi. H – C. penicillata. I – E. cineraceus. J – E. laoticus. K – Meroloba suturalis. L – Taeniodera sp.