Araucariocladus Silveira & Mermudes

Silveira, Luiz Felipe Lima Da & Mermudes, José Ricardo Miras, 2017, A new tropical montane firefly genus and species, active during winter and endemic to the southeastern Atlantic Rainforest (Coleoptera: Lampyridae), Zootaxa 4221 (2), pp. 205-214 : 207-208

Araucariocladus Silveira & Mermudes gen. nov.

Type-species: Araucariocladus hiems Silveira & Mermudes sp. nov., by monotypy.

Diagnosis. Antenna 18-segmented; scape clavate; pedicel almost as long as wide; antennomeres III–XVII biflabellate, long and slender, subequal in length, densely bristled; flabellae symmetrical, long and slender, of increasing length toward middle, then decreasing; subapical flabellae 1/4 longer than apical antennomere. Frontoclypeus with anterior margin strongly rounded. Labrum connected to frontoclypeus by a membranous suture. Labial palp somewhat securiform. Pronotum subtriangular, slightly depressed sagittally, with median, slightly raised paired tubercles; anterior angle rounded, posterior angles acute. Elytra parallel-sided, almost 6x as long as wide. Terga VII and VIII exposed, not covered by elytra. Lanterns absent. Legs with tibiae as long as femur+trochanters, protarsus with tarsomere I at least 1/3 longer than II, meso and metatarsus with tarsomere I at 2x longer than II; tibial spurs absent. Pygidium strongly indented parasagitally, posterior angles produced, at least as long as posterior margin. Aedeagus with parameres entire, glabrous; phallobase symmetric.

Etymology. Araucariocladus derives from Araucaria , the scientific generic name of the Brazilian pine, which has many beautiful branches; and cladus, a greek word for division, referring to its antennal branches. Gender: male.

Morphology. Male. Head ( Figs. 1–13 ) partially covered by pronotum; slightly more than 1/4 wider than long, approximately 1.6x longer and 2x wider than high; lateral margins slightly convergent posteriad. Frons ( Figs. 3, 5- 6 ) strongly prominent, swollen. Antennal sockets reniform ( Fig. 6 ); antennifer process rudimentary. Vertex somewhat plain, with two posterior posterior parasagittal indentations. Frontoclypeus ( Fig. 6 ) strongly curved, projected downwards immediately above mandibles. Labrum ( Fig. 6 ) connected to frontoclypeus by a membranous suture; somewhat rounded, slightly wider than long. Mandibles robust ( Figs. 8-9 ), monotonically arcuate, apex acute, internal tooth absent; external margin sparsely setose in basal 1/2; with a basal wisp of bristles, basally. Maxillary palp 4-segmented ( Fig. 3 ); palpomere IV almost 3x longer than III, fusiform with internal margin covered in minute, dense bristles; cardo well-sclerotized, stipe trapezoidal in ventral view, posterior margins truncate, well-sclerotized, lacinia with dense, minute bristles. Labial palp 3-segmented ( Fig. 6 ), palpomere III securiform; mentum well-sclerotized and bristled, completely divided sagittally; submentum sclerotized and bristled, lateral margins convergent posteriad. Gular sutures ( Fig. 4 ) biconcave, almost indistinct; gular bar straight, 2x as wide as submentum major width. Occiput subcordiform ( Fig. 7 ), as wide as 1/2 posterior width. Tentorium long and slender, almost as high as head high, slightly projected posteriad, projected internally almost on the half of its length, external projection absent. Antenna 18-segmented ( Fig. 10 ), scape clavate, pedicel almost as long as wide, antennomeres III-XVII basally biflabellate, long and slender, subequal in length, densely bristled, flabellae symmetrical, long and slender, of increasing length toward middle, then decreasing, subapical flabellae 1/4 longer than apical antennomere.

Thorax ( Figs. 14–26 ) with pronotum ( Figs. 14–17 ) subtriangular, lateral margins straight in lateral view, slightly wider than long, with a sagittal line slightly depressed, with slightly raised paired tubercles, anterior margin rounded, posterior angles acute, slightly projected posteriad; irregularly, deep punctured, punctures bristled; with a line of distinct deep marginal punctures; disc rectangular, pronotal expansions well-developed, anterior expansion major length almost as long as disc, lateral expansions as wide as 1/3 disc width, posterior expansions bisinuose; almost as wide as basal elytral width. Prosternum ( Figs.2 , 16–17 ) 20x wider than its lesser length; with paired depressions parasagitally. Proendosternite ( Figs.19–20 ) slender, slightly longer than prosternal process smallest width. Mesoscutellum with posterior margin rounded. Elytron ( Fig. 25 ) parallel-sided, almost 6x as long as wide, pubescent, secondary pubescence absent, with four rudimentary costae, plus the marginal one, epipleural projections rudimentary at the humeral angle, with a line of conspicuous punctures all over sutural and lateral margins. Hind wing ( Fig. 25 ) well-developed, subparallel-sided, 2/3 apical radial cell and r4 evanescent, r3 1/2 r4 length, radial cell 4x wider than long, almost reaching anterior margin, costal row of setae inconspicuous; CuA2 and mp-cu crossvein present and aligned; RP + MP1+2 slightly shorter than r4, almost reaching distal margin; J 1/3 AP length. Alinotum ( Fig. 21 ) 1/5 wider than long, lateral margins slightly convergent posteriad, posterior margin straight; prescutum extending up to 1/2 metascutum length; rounded area of scutum weakly sclerotized; scutumprescutal plates weakly-sclerotized, extending ridges almost up to posterior margin; metascutellum glabrous. Mesosternum ( Fig. 22 ) weakly-sclerotized, rounded posteriad; attached to metasternum by a sclerotized, rounded suture. Mesoepimeron ( Fig. 23 ) attached to metasternum by a sclerotized plate. Mesosternum/mesanepisternum suture inconspicuous. Mesanepisternum/mesepimeron ( Fig. 23 ) suture conspicuous. Metasternum ( Fig. 22 ) depressed by the mesocoxae, anterior medial keel prominent up to anterior 1/4; discrimen almost as long as 2/5 sternum length; lateral margins divergent posteriad up to lateral-most part of metacoxa, then convergent posteriad; posterior margin with a pair of parasagittal indentations. Trochantins glabrous. Femur ( Fig. 26 ) as long as tibia in pro and mesolegs; tibia slightly longer than femur in metaleg. Tarsi I>V>II>III>IV; I almost 2x length of II, IV bilobed, dense and finely bristled, lobes as long as 1/ 3 V length.

Abdomen ( Fig. 2 ) with sterna II–IX visible. Spiracles dorsal ( Fig. 27 ), at almost half sterna length. Tergum I with anterior margin membranous and medially emarginate, laterotergite membranous, polygonal in shape, with scarse bristles; spiracle obliquely attached to thorax, more vertically. Abdominal terga II–VII ( Fig. 27 ) of approximately right angles posteriad, rounded, posterior margins straight. Rudimentary sternum VIII ( Fig. 30 ) larval lanterns absent. Syntergite (T9+10) ( Fig. 28 ) slightly longer than wide, less than half sternum IX length, rounded posteriad, straight anteriad, median suture indistinct, symmetric, with sparse bristles. Abdominal sternite IX ( Fig. 29 ) symmetric, setose in posterior 1/2, posterior margin rounded. Aedeagus ( Figs.31–33 ) with phallobase symmetric, divided medially by a conspicuous suture; parameres symmetric, internally sinuose, apically rounded, entire, and rather membranous, turned inwards apically, slightly longer than phallus; phallus subparallel-sided, ventrally concave, weakly sclerotized.

Females and immature stages unknown.

Remarks. Araucariocladus has biflabellate antenna ( Fig. 10 ), strongly arcuate mandibles (“normal mandibles”, Figs.8–9 ), and dorsally-oriented abdominal spiracle ( Fig. 27 ), which justifies its placement in Amydetinae . The new genus also has long and diffuse flabellae, and has no lanterns as well, typical features of the Psilocladina sensu McDermott (1964) (besides some Psilocladus species, which have lanterns).

The new genus is unique among the Psilocladina sensu McDermott (1964) by the combination of characteristics given in the Diagnosis section, particularly the possession of an antenna with 18 antennomeres. Araucariocladus shares with Psilocladus Blanchard the biflabellate antennae, with flabellae long and slender, but the latter has a rather oval outline, generally 11 antenommeres, pronotum rounded, elytra never as narrow as 6x as long as wide, and an asymmetrical phallobase (as pointed in Jeng et al. 2006). Araucariocladus can be easily distinguished from Ethra Laporte by its biflabellate antenna (uniflabellate in Ethra ), and Scissicauda McDermott (uniflabellate or compressed and serrate in Scissicauda ). It differs from Pollaclasis Newman by the subparellelsided elytra (epipleura basally inflexed in Pollaclasis ). Lastly, Araucariocladus differs from Photoctus McDermott by terga with posterior angles right (projected posteriad in Photoctus ).

Figures

FIGURES 1 – 2. Araucariocladus hiems sp. nov.: 1, male dorsal habitus; 2, ventral. Scale bar: 2.0 mm (1 – 2).

FIGURES 3 – 13 Araucariocladus hiems sp. nov.: 4 – 7, male head overview, 3, dorsal; 4, ventral; 5, lateral; 6, frontal; 7, posterior; 8 – 9, mandible; 10, antenna; 11 – 13, frontal tentoria, detail, 11, frontal; 12, lateral; 13, dorsal. Scale bar: 0.5 mm (3 – 9), 2.0 mm (10), 0.5 mm (11 – 13).

FIGURES 14 – 20 Araucariocladus hiems sp. nov., prothorax: 14, pronotum dorsal; 15, ventral; 16, frontal; 17, posterior; 18, lateral; 19, prosternum dorsal, 20, ventral. Scale bar: 0.5 mm (14 – 20).

FIGURES 21 – 26 Araucariocladus hiems sp. nov., pterothorax and associated structures: 21, dorsal; 22, ventral; 23, lateral; 24, elytron ventral; 25, left wing; 26 pro, meso and metalegs (top-down). Scale bar: 1.0 mm (21 – 23), 2.0 mm (24 – 26).

FIGURES 27 – 33 Araucariocladus hiems sp. nov., male abdomen: 27, terga I – VI dorsal; 28, syntergite, dorsal; 29, sternum IX, ventral; 30, sternum VIII and pygidium, ventral; 31 – 33 aedeagus, 31, dorsal, 32, lateral, 33, ventral. Scale bar: 1.0 mm (27), 0.5 mm (28 – 30), 0.2 mm (31 – 33).