Psilocladus costae, Vaz & Silveira & Rosa, 2020

Vaz, Stephanie, Silveira, Luiz Felipe Lima da & Rosa, Simone Policena, 2020, Morphology and life cycle of a new species of Psilocladus Blanchard, 1846 (Coleoptera, Lampyridae, Psilocladinae), the first known bromeliad-inhabiting firefly, Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 60 (24), pp. 1-15 : 3-12

publication ID

https://doi.org/ 10.11606/1807-0205/2020.60.special-issue.24

publication LSID

lsid:zoobank.org:pub:7863784D-C29C-47AC-B52A-317234626D39

persistent identifier

https://treatment.plazi.org/id/6B0087EE-FFD1-FFA4-FE94-FF497627FD50

treatment provided by

Carolina

scientific name

Psilocladus costae
status

sp. nov.

Psilocladus costae View in CoL sp. nov.

( Figs. 3-14 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 View Figure 9 View Figure 10 View Figure 11 View Figure 12 View Figure 13 View Figure 14 )

Type material: HOLOTYPE ♂ ( CLEI): BRAZIL. São Paulo: Campos do Jordão , 22°40′51.3″, 45°35′30.6″, 1464 mm, 02.VII.2017, S. Rosa & Ladenthin leg. PARATYPES. Same locality of holotype, 23.XII.2016, S. Rosa & Ladenthin (3 ♂, CLEI); (collected as larva on 02.VII.2017, adult on 04.XII.2017) , S. Rosa & Ladenthin leg (1 ♂, CLEI) ; 02.XII.2017, Rosa, S & Ladenthin leg (1 ♂, CLEI) ; 08-10. XII.2017, S. Rosa & Ladenthin (3 ♂, MZSP) ; 18-20.I.2018, S. Rosa leg (1 ♂, CLEI) ; 08-13.II.2018, S. Rosa leg (1 ♀, CLEI) .

Additional material examined: BRAZIL. São Paulo: Vale do Rio Pardo , XII.1998, Gounelle, E. (1 ♀, MNHN) ; Campos do Jordão , 22°40′51.3″, 45°35′30.6″, 1,464 m (collect- ed as larva on 05.VII.2018, pupa on 17.XII.2018), S. Rosa leg. (1 pupa, CLEI) ; 27.V.2017, S. Rosa leg. (2 larvae, CLEI) ; 09.XI.2017, S Rosa leg.(1 larva, UNIFEI) ; 04.XII.2017, S.Rosa leg.(1 larva, UNIFEI) ; 22.III.2018, S.Rosa leg. (1 larva, CLEI) ; 25.III.2018, S Rosa leg. (1 larva, 1 larval exuvia, UNIFEI); 05.V.2018, S. Rosa leg. (1 larva, UNIFEI) ; 24.VI.2018, S. Rosa leg. (1 larva, UNIFEI) ; 30.VI.2018, S. Rosa leg. (2 larvae, UNIFEI) ; 16.VII.2018, S. Rosa leg. (2 larvae, CLEI) ; 27.VIII.2018, S. Rosa leg. (1 larva, CLEI) ; 17.IX.2018, S. Rosa leg.(2 larvae, CLEI) ; 08.III.2019, S.Rosa leg. (2 larvae, CLEI) ; 27.X.2019, S. Rosa leg. (1 larva, UNIFEI) .

Adult

jected toward phallobase; parameres symmetric, apically acute; phallobase symmetric, with posterior margin rounded and lateral margins emarginate.

Female: Sternum VII with light organ almost as wide as sternum width, with anterior and posterior margins slightly emarginate.

Color pattern: Frons, antennae and mouthparts dark brown ( Figs. 3 View Figure 3 B-C, 4A-D); pronotum orange ( Figs. 5 View Figure 5 A-E); scutellum light brown ( Fig. 5F View Figure 5 ); elytra black with lateral margins light brown ( Figs. 6 View Figure 6 D-F); pro and mesocoxae entirely orange; trochanter orange; femur, tibia and tarsus dark brown ( Figs. 6 View Figure 6 A-C); sterna II-V dark brown ( Fig. 3C View Figure 3 ), sterna VI-VII with median region translucent ( Fig. 3C View Figure 3 ), sternum VIII brown ( Fig.7A View Figure 7 ) and pygidium dark brown ( Fig.7B View Figure 7 ). Diagnosis ( Figs. 3-9 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 View Figure 9 ): Antennae with 11 antennomeres, biflabellate, covered by dense, upright bristles, males with flabellae twice longer than antennomere body length, basally attached and decreasing in length towards antennal apex. Antennal sockets large, as wide as ⅓ frontal width. Apical maxillary and labial palpomeres securiform. Pronotum semilunar, outlined by deep punctures.

Male: Sternum VI with light organ as long as ¾ sternum length and as wide as ½ sternum width. Sternum VII with light organ as long as ⅔ sternum length and as wide as sternum width. Sternum VIII with posterior margin slightly emarginate; syntergite robust, slightly longer than sternum IX with anterior margin emarginate; phallus with dorsal and ventral plates; dorsal plate basally fused to parameres, slightly smaller than parameres, struts pro- Head ( Figs. 3-4 View Figure 3 View Figure 4 ) entirely covered by pronotum ( Figs. 3 View Figure 3 A-C); almost 2× wider than tall ( Fig. 4D View Figure 4 ); lateral margins slightly convergent posteriad ( Figs. 4B, E, F View Figure 4 ). Frons slightly emarginate ( Fig. 4D View Figure 4 ). Antennal sockets reniform, ½ as wide as frons ( Figs. 4A, C, D View Figure 4 ); vertex convex ( Figs. 4 View Figure 4 E-F). Antennae with 11 antennomeres, covered by dense, upright bristles, scape robust apically, pedicel almost as long as wide, antennomeres III-X biflabellate, cylindrical, decreasing in length, apical antennomere as long as scape ( Fig. 4G View Figure 4 ). Frontoclypeus slightly curved ( Figs. 4A, D View Figure 4 ). Labrum connected to frontoclypeus by membrane ( Fig. 4D View Figure 4 ). Mandibles stout basally, acute apically, with a basal fringe of bristles ( Figs. 4A, D View Figure 4 ). Maxillae with cardo well-sclerotized; stipites rounded.Palpi 4-segmented: I short, trapezoidal with angles acute in relation to II, II rectangular 2× longer than III, III rounded, IV securiform, 1.5× longer than II and 2× wider than II narrowing towards apex. Labium with palpi 3-segmented, palpomeres I and II rectangular, slightly enlarged towards apex;III triangular and elongated,2× longer than II. Gular sutures almost indistinct ( Fig. 4B View Figure 4 ).

Thorax ( Figs. 5-6 View Figure 5 View Figure 6 ). Pronotum semilunar, anterior margin rounded, lateral margins divergent, posterior margin with central region slightly projected posteriad and medially emarginate, posterior angles rounded, regularly punctured, punctures small and bristled ( Figs. 5 View Figure 5 A-D). Hypomeron 2× longer than tall ( Fig. 5E View Figure 5 ). Prosternum slightly constricted medially ( Fig. 5B View Figure 5 ). Elytra ellipsoid, 4× longer than wide at greatest width, secondary pubescence absent ( Figs. 6 View Figure 6 D-F). Hind wing well-developed, posterior margin sinuose, 2× longer than wide, r4 almost 3× longer than r3, radial cell 3× wider than long, almost reaching anterior margin; CuA2 cross vein absent; MP3 + 4 Y-shaped and basally connected with Cu; RP + MP1 + 2 of three fourths r4 length, almost reaching distal margin; AA3 parallel with CuP + AA3; CuA truncate in the origin ( Fig. 6G View Figure 6 ). Alinotum slightly wider than long, lateral margins slightly convergent posteriad, posterior margin straight; prescutum extending slightly less than half metascutum length; rounded area of scutum weakly sclerotized, scutum-prescutal plates sclerotized, extending ridges almost up to posterior margin; metascutellum glabrous. Mesosternum weakly sclerotized, acute medially, attached to metasternum by a suture, almost as wide as mesosternum. Mesepimeron attached to metasternum by membrane. Mesosternum/mesanepisternum suture inconspicuous. Mesanepisternum/mesepimeron suture conspicuous. Metasternum oblique and strongly depressed by mesocoxae, anterior medial keel prominent up to anterior third, discrimen distinct, lateral margins divergent posteriad up to lateral-most part of metacoxae, then convergent posteriad, posterior margin bisinuose ( Figs. 5 View Figure 5 F-I). Femur slightly shorter than tibia ( Figs. 6 View Figure 6 A-C). Tarsomere I 2× longer than II, II slightly longer than III, III subequal in length to IV, IV bilobed, lobes reaching half V length ( Figs. 6 View Figure 6 A-C).

Abdomen ( Fig. 7 View Figure 7 ): Seven visible sterna (II-VIII) ( Fig. 3C View Figure 3 ), lateral margins convergent posteriad,spiracles dorsal (i.e. dorsally reflexed margins of sternite) ( Fig. 3B View Figure 3 ); sternum VIII 3× wider than long, posterior margin emarginate ( Fig. 7A View Figure 7 ); pygidium sclerotized, anterior margin indented, lateral margins rounded and posterior margin with two parassagital sinuosities, lateral angles poorly developed ( Fig. 7B View Figure 7 ); syntergite subtriangular, subdivided and with anterior margin emarginate ( Fig. 7C View Figure 7 ); sternum IX with posterior margin convergent posteriad, posterior margin rounded, with a spine in central region of the anterior margin ( Fig. 7D View Figure 7 ). Aedeagus ( Figs. 7 View Figure 7 E-G): Phallobase symmetrical, with a distinct longitudinal line ( Figs. 7E, G View Figure 7 ); parameres symmetrical, connected basally by a thin bridge, apically acute, apical ½ membranous, internal margin sinuose ( Figs. 7 View Figure 7 E-G); phallus with struts almost straight, extending basally slightly beyond parameres; ventral plate coriaceous, dorsal plate flat, apically acute, strongly sclerotized ( Fig. 7G View Figure 7 ).

Female ( Figs. 8 View Figure 8 , 9 View Figure 9 ): Eye almost ⅔ as wide as frons in frontal view ( Figs. 8B View Figure 8 , 9 View Figure 9 A-E); antennae with short flabellae which are slightly longer than core antennomere ( Fig.9F View Figure 9 ); pronotum 2× wider than long ( Fig. 8A View Figure 8 ); sternum VI with subrectangular light organ ( Fig. 8B View Figure 8 ) almost as wide as sternum width; sternum VII lacking light organ ( Fig. 8B View Figure 8 ); sternum VIII with lateral margins converging posteriad and posterior margin with central region emarginate ( Fig. 9G View Figure 9 ); pygidium with lateral margins convergent and posterior margin rounded ( Fig. 9H View Figure 9 ). Genitalia: ovipositor with baculus sclerotized, coxites membranous, styli (pointed) apically sclerotized and bristled outwards at the lateral edges ( Figs. 9 View Figure 9 I-J).

Immature stages

Mature larva ( Figs. 10-12 View Figure 10 View Figure 11 View Figure 12 ). Description: Body ( Figs. 10 View Figure 10 A-C) 15-22 mm long, oblong (pronotum semio-

val, widest at metathorax and gradually decreasing in width posteriorly from abdominal segment III), dorsoventrally flattened. Head dark brown, antennae, palpi and mandibles lighter ( Figs. 11 View Figure 11 A-C); dorsal surface of body brown, with yellow spot on anterior ⅔ of lateral margins of thorax and abdominal terga I-VI ( Fig. 10A View Figure 10 ); terga VII-VIII with lateral vitreous spots ( Fig. 11F View Figure 11 ). Tegument densely covered with short, very fine, grayish pubescence ( Fig. 10B View Figure 10 ).

Head ( Figs. 10 View Figure 10 B-C, 11A-C, 12A): As long as wide, almost entirely retractable into prothorax ( Figs. 10 View Figure 10 B-C); dorsal surface with long, fine and sparse setae on anterior and lateral regions, one stemma with convex lens laterally at base of antennifer; antennifer membranous and glabrous,as long as basal antennomere ( Figs.12A,E View Figure 12 ). Frontal arms V-shaped, well impressed at posterior half, weakly impressed at anterior half, almost reaching base of antennifer ( Fig. 12A View Figure 12 ); epicranial stem very short; clypeolabrum fused to frons, partly membranous, lateral part darkly sclerotized and bilobate, median part translucent, with dark fusiform plate at middle; fusiform plate with anteri- or part fused to cranium, forming acute tooth; posterior part fused to epipharynx and visible through translucent cuticle ( Figs. 11A View Figure 11 , 12C,D View Figure 12 ). Antennae ( Figs. 11A, C View Figure 11 , 12E View Figure 12 ) elongate, with three antennomeres, antennomere I partially sclerotized, sparsely setose, setae on membranous region very short; antennomere II 1.1× as long as I, fully sclerotized, sparsely setose, laterally flattened, apex ventrally with elliptical, flattened sensorium; antennomere III attached dorsally to antennomere II, digitiform, 0.2× as long as antennomere II, with few fine setae subapically, one very short spiniform projection at apex. Epipharynx ( Fig. 12C View Figure 12 ) with cross-shaped sclerite and two triangular striate plates; plates with anterior margin densely covered with fine setae and two orifices at lateral margins; hypopharynx ( Fig. 12D View Figure 12 ) with anterior lobe triangular, densely setose; posterior part sclerotized, glabrous, with elongate concave projection. Mandibles ( Fig. 12F View Figure 12 ) symmetrical, falcate, with a channel opening near apex, with ventral tuft of fine setae near channel opening; lateral margin at base covered with fine long setae; mesal margin at base with very short setae; row of sparse setae along channel dorsally; retinaculum well developed, forming a large and acute tooth; mesal membranous extension densely setose. Maxillolabial complex ( Fig. 12B View Figure 12 ) separated from ventral head capsule by broad membrane; maxillae with cardo narrow, elongate, 0.5× as long as stripes, subparallel-sided; stipites elongate, with short membranous area on anterior margin, few fine setae irregularly distributed and a stout seta near base of galea; palpus 4-segmented, tapering toward apex with sparse fine setae and a stout seta on anterolateral margin of palpomere I; galea 2-articulated: basal palpomere triangular, as wide as long; apical palpomere digitiform, 5× longer than wide, with one stout long seta apically and few shorter setae subapically; lacinia consisting of densely pubescent structure connected to dorsomesal stipital edge; labium ( Fig. 12B View Figure 12 ): prementum densely covered with moderately long setae, emarginated between palpi; palpus 2-articulated, apical palpomere as long as the basal one, strongly tapered apicad, with slot sensorium on outer side; mentum with anterior ⅓ membranous; posterior ⅔ sclerotized with pair of long setae at midlength; submentum and gula membranous. Post-occipital region as long as head, glabrous, with 3 elongate weakly sclerotized areas contiguous to anterior prothoracic collar.

Thorax( Fig. 10 View Figure 10 ): tip of posterior angles of terga with long stout seta; pronotum semielliptical 1.3-1.6× wider than long, with posterior margin slightly emarginate, prosternum weakly sclerotized with short endocarinate rod between procoxae; anterior prothoracic collar membranous dorsally,strongly sclerotized on anterior ⅔ ventrally; sclerotized region finely punctate/setose. Mesonotum as long as metanotum, both transverse with anterior angles rounded, posterior angles straight; mesonotum 3-3.3× wider than long; metanotum 3.3-3.6× wider than long; mesepisternum with a functional biforous spiracle on anterior corner; ventral surface of meso- and metathorax membranous medially, with sclerotized regions on pleurae laterally to coxae. Legs ( Fig. 11D View Figure 11 ): coxa conical, strongly projected ventrad, partly strongly sclerotized, with fine long setae; trochanter with a few short stout setae; femur with sparse, evenly distributed spiniform setae and few short stout setae, and one long stout seta ventrally; tibiotarsus densely covered with spiniform setae; pretarsus with one seta on each side at base.

Abdomen ( Figs. 10 View Figure 10 , 11 View Figure 11 E-F): Gradually narrowed posteriorly from segment III; terga I-VIII with well impressed sagittal ecdisial line, anterior angles rounded, posterior angles acute and strongly projected posteriad with stout long seta at tip; terga I-VI transversal, subequal in length; tergum I about 4.3× wider than long, VI 3.7× wider than long; tergum VIII 1.5× wider than VII, with posterior margin broadly emarginate; tergum IX as long as wide, lateral margins subparallel, posterior angles weakly projected with tuft of foliaceus setae at tip, posterior margin slightly rounded. Sternites I-IX sclerotized, with two pairs of parasagittal very short stout setae (at midlength and posterior margin) and long stout seta at posterior angles; sternites VI-VIII with additional pair of stout seta near lateral margins; stout setae increasing in length from sternites I-IX; laterotergites I-VIII 0.6-0.8× as large as respective sternites, sclerotized, posterior corners projected, with 2 prominences; anterior prominence with biforous spiracle, posterior prominence with a stout long seta; sternite VIII with pair of light organ on anterior corners. Segment X ( Figs. 10 View Figure 10 B-C) attached under segment IX, tergum broadly conate or fused to sternum IX; sternum glabrous, most part sclerotized, except by subapical membranous transverse area; pygopod present.

Pupa ( Fig. 13 View Figure 13 ): Total length ca. 7.0 mm, adecticous, exarate, white. Pronotum semicircular, anterior and lateral margins densely setose, setae long and stout. Dorsal surface with short setae. Posterior margin with posteri- or angles rounded, projected posteriad, median region straight. Mesothorax with a pair of reniform spiracles on posterior half of pleurite. Metanotum 1.1× as long as mesonotum, with a pair of long setae on posterior third. Abdominal terga I-VIII transverse, with posterior angles acute, strongly projected posteriad; lateral margins densely setose; setae long stout; tergite IX subquadrate with posterior angles weakly projected, with tuft of stout setae.Pair of light organ on sterna VI and VII ( Fig. 14B View Figure 14 ), inconspicuous in alcohol-preserved specimen. Abdominal spiracles located ventrally on posterior angles of pleurae on segments I-VIII.

Remarks: Psilocladus costae sp. nov. is the first Psilocladinae species to have their immature stages de- scribed. The larva of this species is more similar to those of Photurinae species: Photuris fulvipes Curtis ( Rosa,2007) and an unidentified species of Bicellonycha Motschulsky (Costa et al., 1988) . Those species share the oblong body (with semioval pronotum, widest at metathorax and gradually decreasing in width from abdominal segment III) ( Fig. 10A View Figure 10 ), head with frontal arms well impressed posteriorly and divergent anteriad (V- or U-shaped), clypeolabrum with a median tooth darkly sclerotized, sensorium on second antennomere flattened ( Figs. 11A View Figure 11 , 12A, E View Figure 12 ), pretarsus with one basal seta on each side, and presence of localized stout setae on thorax and abdomen ( Fig.11E View Figure 11 ). They differ in the density and distributional pattern of the stout setae on thoracic and abdominal segments. Stout setae are sparser in Psilocladus costae sp. nov. and in Photuris femoralis , but in P. costae sp. nov. they are shorter and absent on median part of thoracic and abdominal terga. Larvae of P.costae sp. nov. also differ from both P. femoralis and Bycellonycha sp. larvae by having mandible sparsely setose and abruptly curved on apical half ( Fig. 12F View Figure 12 ), hypopharynx with single anterior lobe and posterior part elongate ( Fig. 12D View Figure 12 ), vitreous spots on terga VII and VIII, and tergite IX somewhat quadrate ( Fig. 11F View Figure 11 ) (in Photurinae larvae, mandible is densely setose and gradually curved, the hypopharynx is bilobed with posterior part short, vitreous spots are absent, and the tergite IX is semioval). The pupa of P. costae sp. nov. is also more similar to the pupae of the photurine species than to pupae of other Neotropical species belonging to the genera Aspisoma Laporte , Lucio Laporte , Cratomorphus Motschulsky and Pyractonema Olivier. Photurinae and P. costae sp. nov. pupae share the presence of dense, long and stout setae on pronotal margins and posteri- or angles of abdominal terga ( Fig. 13 View Figure 13 ). Psilocladus costae sp. nov. pupa differs by having photophores on abdominal segments VI and VII ( Fig. 14B View Figure 14 ), whereas photurine pupae have only one pair of photophores on segment VIII.

Etymology: The specific epithet is in honor to Professor Dr. Cleide Costa who dedicated many studies to immature beetles, especially Elateroidea. Singular genitive, feminine.

Field and laboratory observations: We collected 49 larvae inside fallen epiphytic bromeliads. Few larvae were collected outside of bromeliads during the night when they were localized by their very bright bioluminescence ( Fig. 14A View Figure 14 ). Those larvae were identified by comparison with the bromeliad larvae. Of the 61 fallen bromeliads investigated, 26 had larvae of Psilocladus costae sp. nov., the majority of which found in the innermost leaves of the bromeliad rosette. The number of larvae inside each bromeliad ranged from one to five, but in most of them (n = 16) we found only one larva. They were found inside bromeliads throughout the year (22 larvae from April to August and 21 larvae from September to March), whilst active glowing larvae outside of bromeliads were found in the beginning of the rainy season (six larvae in October and November). At night larvae were found by their intense glow near bromeliad tanks, above leaf blades ( Fig. 14A View Figure 14 ) and on trunks and branches near bromeliads fixed on trees. Larvae emit green light, easily seen from above through the vitreous spots on tergum VIII when the larvae are stretched, as well as through vitreous spots on tergum VII, that covers the VIII when larvae shrink. In the lab, larvae preyed on termites and scirtid larvae. Mortality was very high and only two firefly larvae molted into pupa and adult, therefore we could not determine the number of larval instars. Larval length ranged from 9 to 22 mm and the larvae which molted into pupa and adult were ca. 15 mm long, therefore we infer that mature larva may be 15-22 mm long. A few larvae possibly died due to acari infestation, but the causes of overall mortality were not known. Adults were observed on wet and dark nights in December and January. They flew at about 10 meters height whilst glowing green continuously, rarely below 5 meters, yet 10 specimens could be collected on the grass and on leaf blades of bromeliads fixed lower on the trees. The flying adults concentrated in areas with higher density of canopy bromeliads ( Figs. 1B, C View Figure 1 ).

MZSP

Sao Paulo, Museu de Zoologia da Universidade de Sao Paulo

MNHN

Museum National d'Histoire Naturelle

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Lampyridae

Genus

Psilocladus

Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF