Scissicauda McDermott, 1964

Silveira, Luiz Felipe Lima Da, Mermudes, Jose Ricardo M. & Bocakova, Milada, 2016, Systematic review of the firefly genus Scissicauda (Coleoptera, Lampyridae, Amydetinae) from Brazil, ZooKeys 558, pp. 55-75 : 57-62

Taxon classification Animalia Coleoptera Lampyridae

Scissicauda McDermott, 1964

Scissicauda McDermott, 1964: 10, 39; 1966: 87.

Schistura Olivier, 1911:51 (nec Schistura McClevelland, 1838 Actinopterygii).

Aethra Laporte, 1833 (partim). Olivier in Wytsman 1907: 16; Blackwelder 1944: 353.

Lychnuris Motschulsky, 1853 (partim). McDermott 1966 (quid pro quo).

Schistura Olivier, 1911: 51; McDermott 1964: 10, 39.

Type species.

Lucidota disjuncta Olivier, 1896, by monotypy.

Diagnosis.

Antenna 11-segmented, compressed, filliform to flabellate, uniramose (while biramose in Psilocladus and Pollaclasis ), with dense, upright bristles, rami atmost twice longer than antennomere body, attached basally (distally in Ethra ). Antennal sockets large, two thirds of frontal width, close-set, reniform, antennifer process distinct. Occiput as wide as one third head width. Apical maxillary palpomere lanceolate. Apical labial palpomere securiform. Pronotum semilunate, with a marginal row of gross, deep punctures. Abdominal terga with posterior angles progressively produced and acute. Tibial spurs present. Tarsomere I 2 × longer than II, II 2 × longer than III, III of subequal length as IV. Tarsomere IV bilobed, lobes reaching two thirds of length of tarsomere V. Male sternum IX retracted under VIII. Aedeagus with phallus consisting of a dorsal plate basally fused to parameres, symmetric, projected dorsolaterally toward apex; ventral plate with lateral margins sinuose, weakly sclerotized; parameres symmetric, apically rounded, with a ventrobasal process rudimentary or extended beyond phallus.

Redescription.

Head (Figs 1-15, 44-45, 53-54, 59) entirely covered by pronotum (Figs 1, 2, 42, 51, 67); almost 2 × as wide as long, slightly longer than high (Figs 4-7); lateral margins slightly convergent posteriad (Fig. 4). Frons slightly prominent dorsally, swollen (Fig. 6). Antennal sockets reniform, of two thirds frons width; antennifer process conspicuous (Fig. 7). Vertex somewhat convex, with two posterior parasagittal indentations (Fig. 4). Antenna 11-segmented, scape constricted basally, pedicel almost as long as wide and constricted medially, antennomeres III–X serrate to flabellate (males of Scissicauda disjuncta ), compressed, subequal in length, with dense, upright bristles, lamellae long and slender, subequal in length, apical antennomere slightly longer than subapical one (Figs 10, 42, 54, 68). Frontoclypeus slightly curved (Fig. 7). Labrum connected to frontoclypeus by a membranous suture; 2 × as wide as long, anterior margin evanescent (Fig. 4). Mandibles long and slender, monotonically arcuate, apex acute, internal tooth absent, external margin sparsely setose in basal ½, with a basal wisp of bristles up to half its length (Figs 14, 15). Maxilla with cardo well-sclerotized; stipe oblong in ventral view, posterior margins truncate, well-sclerotized, palpi 4-segmented; palpomere III triangular; IV lanceolate, with internal margin covered with minute, dense bristles, almost 3 × longer than III (Fig. 7). Labium with mentum well-sclerotized and bristled, completely divided sagittally; submentum sclerotized and bristled, subcordiform, elongate; palpi 3-segmented, palpomere III securiform (Fig. 5). Gular sutures almost indistinct; gular bar transverse, 2 × as wide as submentum minimal width. Occiput piriform, as wide as one third posterior width (Fig. 9). Tentorium long and slender, almost as high as half head high, projected internally almost on the half of its length, strongly curved backwards (Figs 11-13).

Thorax (Figs 16-29, 46, 55, 56, 70). Pronotum semilunar, posterior angles acute; disc subquadrate in dorsal view, notably convex, regularly punctured, punctures small and bristled; with a line of distinct deep marginal punctures; pronotal expansions well-developed, anterior expansion maximal length almost half as long as disc, posterior expansions straight; slightly wider than humeral distance (Figs 16, 46, 55, 70). Hypomeron longer than high (Figs 18, 56). Prosternum 4 × as wide as its major length; slightly constricted parasagitally (Fig. 17). Proendosternite clavate, slightly longer than prosternal process minimal width (Fig. 20). Mesoscutellum with posterior margin rounded (Fig. 21). Elytra ellipsoid, almost 5 × as long as wide, pubescent, secondary pubescence absent, with a line of conspicuous punctures all over sutural and lateral margins (Fig. 25).

Hind wing well-developed, posterior margin sinuose, 2 × as long as wide, r3 almost as long as r4, radial cell 2 × wider than long, almost reaching anterior margin, costal row of setae inconspicuous (Fig. 26); CuA2 crossvein absent, mp-cu crossvein present; RP + MP1+2 of three fourths r4 length, almost reaching distal margin, J indistinct (Fig. 26). Allinotum slightly wider than long, lateral margins slightly convergent posteriad, posterior margin straight; prescutum extending slightly less than half metascutum length (Fig. 21); 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 (Fig. 22). Mesoepimeron attached to metasternum by membrane (Fig. 22). Mesosternum/mesanepisternum suture inconspicuous (Fig. 22). Mesanepisternum /mesepimeron suture conspicuous (Fig. 22). Metasternum oblique and strongly depressed by mesocoxae, anterior medial keel prominent up to anterior one third, discrimen indistinct, lateral margins divergent posteriad up to lateral-most part of metacoxa, then convergent posteriad posterior margin bisinuose (Fig. 22). Femur slightly shorter than tibia (Fig. 28). Tibial spurs present (Fig. 28). Tarsomere I 2 × longer than II, II 2 × longer than III, III subequal in length to IV, IV bilobed, lobes reaching two thirds V length (Fig. 29). Mesendosternum with two parasagittal projections directed outwards, irregularly alate (Fig. 26). Metendosternum spatulate, 2 × longer than wide, median projection acute anteriad, with two lateral laminae (Fig. 27).

Abdomen (Figs 21, 23, 30-41, 47-50). Tergum I with anterior margin membranous (Fig. 21), laterotergite membranous, polygonal in shape, with sparse bristles (Fig. 23); spiracle obliquely attached to thorax, more vertically (Fig. 21). Terga II–VII with posterior angles progressively produced and acute posteriad, posterior margins progressively bisinuose (Fig. 30). Sterna II–VIII visible (Fig. 31). Spiracles dorsal, at almost half sterna lenghts (Fig. 30). Sternum VIII with larval lanterns elongate (Figs 33-58).

Male. Syntergite consisting of paired lateral plates convergent posteriad (putatively tergite IX or paraproct), median transversal suture absent (Figs 34, 35, 61, 62). Sternum IX asymmetric, posterior margin acute. Aedeagus with phallus consisting of a dorsal plate basally fused to parameres, symmetric, medially grooved, projected dorsolaterally toward apex (Figs 36-38, 41, 63, 64); ventral plate with lateral margins sinuose, weakly sclerotized; parameres symmetric, apically rounded, with a ventrobasal process rudimentary or projected and extended beyond phallus (Figs 40, 65, 66).

Female. Sternum VIII as long as wide, spiculum ventrale long and slender, three fourths sternum length (Fig. 47). Internal genitalia with a large and somewhat rounded spermatophore-digesting gland anteriad to the common oviduct (Fig. 50). Valvifers free, twisted basally, 3 × coxite length; coxites medially fused, coxital baculi well-developed, sclerotized, divergent basally; styli minute, sclerotized; proctiger indistinct (Fig. 49).

Remarks.

Concerning the etymology for the generic name, McDermott (1964) did not refer explicitly to the meaning of Scissicauda , neither did Olivier (1911) for Schistura . Scissi is putatively derived from the English word scissor, which in turns refer to the old French cisoires and the Latin caedo, caesus; and cauda, a Latin word for the pygydium (Brown, 1956) (see Figs 30, 32). Scissicauda is of a feminine gender.

Key to species (both sexes)