Ybytyramoan Silveira and Mermudes

Silveira, Luiz Felipe Lima Da & Mermudes, José Ricardo M., 2014, Ybytyramoan, a new genus of fireflies (Coleoptera: Lampyridae, Lampyrinae, Photinini) endemic to the Brazilian Atlantic Rainforest, with description of three new species, Zootaxa 3835 (3), pp. 325-337 : 326-328

Ybytyramoan Silveira and Mermudes gen. nov.

( Figs. 1–45 )

Type species. Ybytyramoan praeclarum Silveira and Mermudes sp. nov.

Etymology. From Tupi-Guarani language Ybytyra, mountain; and moan, a corrupted form of muã, firefly ( Bueno 1987). Gender: neutrum.

Diagnosis. Head abruptly depressed at vertex ( Fig. 1 ). Lanterns not fully developed, somewhat rounded or anteriorly rounded, straight posteriad, with posterolateral rounded projections (billycock-shaped), at the middle of the abdominal sterna VI and VII ( Figs. 19 , 29 , 39 ). Abdominal sternum VIII not covered by VII ( Figs. 19 , 29 , 39 ). Aedeagus with dorsobasal excrescences absent; phallus and parameres apically teethed ( Figs. 23–25 , 33–35 , 43–45 ).

Description of the male.

Head. ( Figs. 1–7 , 18 , 28 , 38 , 46 ) Transverse, nearly 2.5x wider than long; completely covered by pronotum, retractable; abruptly depressed at vertex; hypognathous. Cephalic setigerous punctures discreet. Posterior parasagittal indentations poorly-developed, separated by almost 1/3 head width. Eyes large, reaching insertions of mandibles in lateral view; separated from each other in dorsal aspect by about 1/3 head width, separated in ventral aspect almost by about 1/4 head width, higher than vertex, with posterior margins slightly emarginate. Antennal sockets rounded, separated from each other by socket width, inserted anteriad in frons, antennifer conspicuous or indistinct. Antenna densely bristled, with eleven antennomeres equally bristled, flagellum with antennomeres subequal in length, antennomere III 2x longer then pedicel, not reaching 1/2 body length. Frons flat. Frontoclypeus with lateral margins narrow, as long as mandible apical width. Clypeolabral suture distinct, membranous. Labrum transverse, 3x longer than wide, straight or medially indented anteriad, bristles 2x longer than labrum. Mandibles falcate, externally with long setae up to basal 1/4, internally with a dense row of small bristles. Maxillary palp fourarticled; palpomere IV acuminate, IV> III> I = II. Labial palp three-articled, III securiform, longer than the basal two, which are subequal in length. Gula distinct, gular sutures concentric, separated by basal labial width; with two discrete gular pits. Occiput ovoid, narrowing toward bottom, larger at dorsal 1/3. Tentoria slender, internally projected, almost as high as head at vertex.

Thorax. ( Figs. 8–15, 15–16, 18, 25–26, 28, 35–36, 38 , 47 ) Pronotum expanded anteriad, posteriad and laterad; anterior margins rounded or slightly projected, lateral margins parallel, slightly arcuate or divergent posteriad; posterior angle obtuse or slightly acute; disc with a feeble sagittal line medially; as long as wide or slightly wider than long, with setigerous punctures of three kinds: 1. large and deep, outlining pronotal margins; 2. medium-sized at pronotal expansions except by the margins; 3. small at the disc. Hypomeron 1/4 longer than wide. Prosternum straight anteriad, projected posteriad, sparsely bristled all over, bristles very small. Scutellum 2x longer than wide, truncated or rounded posteriad, lateral margins slightly convergent posteriad or subparallel-sided. Elytra with lateral margins divergent posteriad or ellipsoid; rugose, punctures conspicuous at suture and outer margins, lacking conspicuous costae; secondary pubescence present. Mesosternum membranous anteriad, pointed posteriad. Metasternum with anterior portion depressed by the mesocoxae, with an elevated keel medially; discrimen almost as long as 1/2 sternum length; lateral margins enlarging toward lateral-most part of metacoxa, then convergent posteriad; with a pair of parasagittal indentations. Mesosternum/mesanepisternum suture indistinct. Mesanepisternum/mesepimeron conspicuous. Proendosternum divergent laterally. Mesendosternum with two parasagittal projections, irregularly alate. Metendosternum spatulate, projected and acute anteriad, with two lateral laminae, anterior half narrower than posterior. Hind wing membranous, radial cell well developed, bars CuA1 and CuA 3+4 present, RA not fused to C; radial cell almost reaching anterior margin, costal row of setae absent; RP + MP1+2 shorter than CuA1, not reaching distal margin. Alinotum slightly wider than long, lateral margins convergent posteriad, posterior margin beveled. Scutum-prescutal plate well-developed, weakly-sclerotized. Metascutellum glabrous, with incomplete paired ridges medially. Pro and mesocoxae narrowing toward apex. Metacoxa strongly oblique with sparse and small bristles. Tibia with two apical spurs, without rows of setae. Tarsus five-articled; IV short, densely bristled and bilobed, lobes almost reaching V apex. Metatarsomeres I>V>II>III>IV. Claw simple, with basal, rudimentary teeth.

Abdomen. ( Figs. 11–12 , 19–25 , 29–35 , 39–45 ). Spiracles dorsal, laying anteriad in sterna II–VI, and medially in VII–VIII. Tergum I with anterior margin medially projected; spiracle with internal margin indented, connected to a membranous portion of tergum and obliquely, almost longitudinally, attached to thorax; VI–VII with posterolateral lobes acute and poorly-developed. Abdominal sterna VI–VII with a pair of stigmas (similar to those in Photinus Laporte, 1833 ); lanterns rounded, occupying nearly 1/3 or 1/2 sternum area. Abdominal sternum VIII with lateral margins convergent posteriad, posterior margin truncate, not covered by VII. Pygidium almost as long as wide, rounded, posterior margin subtruncate or acuminate. Syntergite subparallel-sided, with posterior margin acuminate, anterior margin truncate or slightly indented; suture between abdominal terga IX and X indistinct; glabrous or bristled posteriad; well-sclerotized except by a central oblong region. Abdominal sternum IX paddleshaped, 3x longer than wide; slightly more than 2x longer than syntergum; bristled at the posterior 1/2; irregularly subtruncate or rounded posteriad, with lateral margins symmetric, abruptly divergent posteriad at the anterior 1/3. Aedeagus: trilobate; phallobase slightly to strongly asymmetric. Parameres symmetric, weakly to strongly projected ventrad, narrowing toward apex, apex rounded, with a pair of apical inner teeth. Phallum enlarging toward apex or with lateral margins sinuous; apex weakly-sclerotized; ventrally opened; slightly or 1/3 longer than paramere; with a pair of teeth apically or subapically, ventrally and dorsally, or laterally; with feeble inner basal projections ventral plate absent.

Immature stages and female unknown.

Biology. Fireflies active from twilight through the first hours of the night, flashing. We have no additional notes on its flash pattern.

Remarks. Ybytyramoan gen nov. is placed in Photinina ( Lampyrinae : Photinini ) as it has lanterns, secondary pubescence and antennae less than 1/2 body length ( Figs. 15–16, 25–26, 35–36 ). For the sake of convenience, we will compare this new genus with other Atlantic Rainforest lampyrid genera. Ybytyramoan gen nov. can be easily distinguished from Ellychnia Blanchard, 1845 and Pyropyga Motschulsky, 1853 , which lack lanterns and have small eyes. Ybytyramoan has lanterns ( Figs. 19 , 29 , 39 ) and much larger eyes (separated from each other in dorsal aspect by about 1/3 head width) ( Figs. 1–6 ), characters shared with the remaining Photinina . Ybytyramoan differs from Robopus Motschulsky, 1853 by the morphology of the lanterns, which are single-spotted and located in abdominal sterna VI and VII in the former, and two-spotted, in the VIII in the latter. Ybytyramoan can also be distinguished from Macrolampis Motschulsky, 1853 by lanterns rounded, occupying nearly 1/3 or 1/2 sternum area ( Figs. 19 , 29 , 39 ), elytra less than 6.5x longer than wide ( Figs. 16 , 26 , 36 ) and presence of aedeagal teeth in phallum and parameres ( Figs. 23–25 , 33–35 , 43–45 ); Macrolampis has full lanterns, elytra more than 6.5x longer than wide and aedeagal teeth absent. Ybytyramoan share with Photinus Laporte, 1833 (mostly), Photinoides McDermott, 1963 and Macrolampis lanterns in abdominal sterna VI and VII, and well-developed eyes. It can be distinguished from Photinus and Photinoides by abdominal segment VIII not retracted under VII ( Figs. 19 , 29 , 39 ), lanterns not fully developed ( Figs. 19 , 29 , 39 ) and aedeagal teeth present ( Figs. 23–25 , 33–35 , 43–45 ). Some Photinus species have lanterns absent, but can be easily distinguished from Ybytyramoan by retracted abdominal sternum VIII in the former.

Green (1956) identified processes on the parameres of some Photinus species. Zaragoza (1995, 2007) referred to it as dorsobasal excrescences, which he considered so useful to distinguish between species that he proposed the subgenus Paraphotinus to accommodate the species lacking it ( Zaragoza 1995). Zaragoza (2007) also pointed out that at least some Ellychnia species share this feature with Photinus , which could, thus, be a more ancestral feature of the group. Ybytyramoan gen. nov. lacks this feature, but in the absence of a phylogeny – and given the complexity of neotropical lampyrid taxonomy, – we prefer not to infer the affinities of this new genus.

Figures

FIGURES 1 – 7. Ybytyramoan praeclarum sp. nov. head. 1, frontal. 2, ventral. 3, dorsal. 4, lateral. 5, posterior. 6, occipital. 7 tentoria detail, frontal. Scale bar 1 – 7 = 1,0 mm.

FIGURES 8 – 12. Ybytyramoan praeclarum sp. nov. 8 – 10 prothorax. 8, pronotum, dorsal. 9 - prothorax, posterior. Note the proendosternite. 10, prosternum, ventral. 11 – 12, allinotum. 11, dorsal. 12, lateral. Scale bar 8 – 12 = 1,0 mm.

FIGURES 13 – 15. Ybytyramoan praeclarum sp. nov. 13, wing. 14, mesoendosternite. 15, metaendosternite. Scale bars 13: 2 mm, 14 – 15 = 0,5 mm.

FIGURES 16 – 25. Ybytyramoan praeclarum sp. nov. 16 – 17, habitus 16, dorsal. 17, ventral. 18, pronotum, dorsal. 19, abdomen, ventral. Note the lanterns shape. 20, pygidium, dorsal. 21, abdominal sternum VIII, ventral. 22, syntergite, dorsal, abdominal sternum IX, ventral. 23 – 25 aedeagus. 23, dorsal. 24, ventral. 25, lateral. Scale bars 16 – 19 = 1,0 mm, 20 – 25 = 0,5 mm.

FIGURES 26 – 35. Ybytyramoan diasi sp. nov. 26 – 27, habitus 26, dorsal. 27, ventral. 28, pronotum, dorsal. 29, abdomen, ventral. Note the lanterns shape. 30, pygidium, dorsal. 31, abdominal sternum VIII, ventral. 32, syntergite, dorsal, abdominal sternum IX, ventral. 33 – 35 aedeagus. 33, dorsal. 34, ventral. 35, lateral. Scale bars 26 – 29 = 1,0 mm, 30 – 35 = 0,5 mm.

FIGURES 36 – 45. Ybytyramoan monteirorum sp. nov. 36 – 37, habitus 36, dorsal. 37, ventral. 38, pronotum, dorsal. 39, abdomen, ventral. Note the lanterns shape. 40, pygidium, dorsal. 41, abdominal sternum VIII, ventral. 42, syntergite, dorsal, abdominal sternum IX, ventral. 43 – 45 aedeagus. 43, dorsal. 44, ventral. 45, lateral. Scale bars 36 – 39 = 1,0 mm, 40 – 45 = 0,5 mm.

FIGURES 46 - 47. 46. Ybytyramoan diasi sp. nov., head, frontal view. White arrows: antennifer processes, black arrow: medial indentation of labral anterior margin. 47. Ybytyramoan praeclarum sp. nov., thorax, ventral. Black arrow: metasternal keel. Scale bars 46 = 0. 5 mm, 47 = 1 mm.