Scea, WALKER, 1854

Miller, James S, 2009, Generic Revision Of The Dioptinae (Lepidoptera: Noctuoidea: Notodontidae) Part 2: Josiini, Bulletin of the American Museum of Natural History 2009 (321), pp. 675-1022 : 831-842

publication ID	https://doi.org/ 10.1206/321.1-1
persistent identifier	https://treatment.plazi.org/id/03FF87E0-FF29-9EE6-BF47-1341FDB84EBD
treatment provided by	Felipe
scientific name	Scea
status

Treatment

SCEA WALKER, 1854 View in CoL

Figures 304 View Fig , 346–353 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig ; plates 33–35, 39Q

Scea Walker, 1854: 293 View in CoL . Type species: Josia auriflamma Geyer, [1827] View in CoL (in Hübner, 1806 – 1838) 2: pl. 186 (by monotypy).

Thirmida Walker, 1854: 466 View in CoL . Type species: Thirmida dimidiata Walker, 1854 View in CoL (by monotypy). New synonymy.

Cyanotricha Prout, 1918: 426 View in CoL . Type species: Sangala necyria Felder and Rogenhofer, 1875 (by original designation). New synonymy.

DIAGNOSIS: Scea contains beautiful moths (pls. 33–35). Details of their morphology, such as eye size and head-scaling arrangements, vary across species, but wings in the genus exhibit a general theme. Usually, the FW shows a large, orange-yellow area in the basal two-thirds, the outer third being dark gray to bluish gray. In some taxa, the orange is restricted to the basal fourth. Within the orange-yellow region, the FW veins are lined with black to varying degrees, although this area is uniformly orange in a few species (e.g., S. erasa and S. bryki ; pl. 35). The HW is usually uniformly dark gray to bluish gray, or less frequently, shows orange areas at its base. Many species exhibit blue iridescence on the wings and body. Some, such as Scea necyria and S. bellona (pl. 35), are almost completely covered with iridescent, royal-blue to violet scales. Genitalia in Scea are relatively uniform (figs. 347–353), but provide numerous synapomorphies supporting monophyly of the genus.

This characterization notwithstanding, caution must be exercised in assigning a particular dioptine species to Scea ; extremely similar wing patterns occur in another, smaller josiine genus— Notascea , gen. nov. For example, compare the wings of Scea auriflamma (pl. 34) and Notascea obliquaria (pl. 31). Superficially at least, they are indistinguishable. The two species, sympatric throughout their ranges, are invariably confused in collections. Members of the two genera can be separated by the following traits: Males of Notascea posses a small fovea, located at the anterolateral angle of the FW DC (figs. 331E). The scales within this fovea are short and rounded (fig. 332C– F). The FW of Scea , on the other hand, is unmodified (figs. 332A, 332B, 346H). In females, the antennal shaft of Scea is narrow with parallel sides, whereas in Notascea the antennal shaft is wider near the middle, and tapered toward the apex. Differences in genitalia (e.g., compare figs. 335, 347) pro- Hering, exhibit wing patterns remarkably vide indisputable characters for separating similar to those of Scea (see also Watson the two genera. and Goodger, 1986; pl. 3, figs. 49, 50). In

Several arctiid genera in the Pericopinae , another arctiid subfamily—the Lithosiinae— such as Episcea Warren (pl. 34) and Scearctia members of Euryptidia , such as E. basivitta (pl. 35), could be confused with certain Scea species. However, Arctiids can be separated from Dioptinae by a host of morphological characters, such as their quadrifid FW venation (see Kitching and Rawlins, 1999; Fibiger and Lafontaine, 2005). In addition, the metathorax in arctiids bears a tymbal organ, or striated band ( Forbes and Franclemont, 1957), and the first abdominal segment is characterized by a large countertympanal hood ( Richards, 1932), not present in notodontids ( Miller, 1991).

REDESCRIPTION: Male. FW length 5 14.0–25.0 mm. Head (fig. 346A–G): Labial palpus relatively long, thin, curving upward to middle of front, in some species porrect; palpus either closely scaled ( S. auriflamma ), or loosely scaled, with a long ventral fringe of hairlike scales on Lp1 and Lp2 ( S. necyria , S. discinota ); Lp1 moderately long, curved upward; Lp2 roughly equal in length to Lp1, sometimes much shorter; Lp3 usually elongate, sometimes with an acute apical tuft (e.g., S. discinota ), rarely short ( S. necyria ); scales of front pointing ventromedially, rarely ( S. auriflamma ) pointing horizontally; frontal scales in some species elongate, forming a loose tuft between antennal bases; eye size variable, ranging from large, rounded and bulging outward ( S. auriflamma ), to relatively small ( S. dimidiata ) with a wide postgena and a wide scaleless gena; vertex with elongate, forward-pointing scales; antenna bipectinate, rami long, terminal 8–12 annulations simple.

Thorax: Pleuron often covered with elongate, hairlike scales; epiphysis long and narrow, extending to apex of tibia or beyond; tegula two-thirds as long as mesoscutum, distal portion narrow, with a strong transverse sulcus below, ventral process acute; metathoracic tympanum kettledrum shaped, region below and behind tympanal opening scaleless; tympanal membrane large, enclosed, oriented horizontally.

Forewing (figs. 332A, 332B, 346H; pls. 33– 35): Broad, outer margin rounded; vein Rs 1 arising from radial sector below veins Rs 2 – Rs 4; Rs 2 –Rs 4 in the pattern [2+3]+4; M 1 arising from DC approximate to (or touching) base of radial sector, M 1 sometimes stalked for a short distance with base of radial sector; DC much longer than one-half FW length; veins M 3 and CuA 1 long stalked; ground color dark gray, gray with blue iridescence, or brilliant iridescent blue; basal portion of wing invariably with some form of orange, yellow-orange or reddish orange pattern; pattern either small and restricted to basal fourth (e.g., S. necyria ), or occupying majority of wing surface, extending from base to at least two-thirds out.

Hind wing (fig. 346H; pls. 33–35): Broad, rounded, sometimes slightly elongate; M 3 and CuA 1 long stalked; pattern most frequently uniformly dark gray, iridescent blue gray, or iridescent blue, occasionally with orange or orange-yellow markings.

Abdomen: Moderately long to extremely long; apex acute; color usually steely gray with blue iridescence, occasionally ( S. necyria ) deep iridescent purplish blue.

Terminalia (figs. 347A–C, E; 348A–D; 349A, B, D, E; 350A–D; 351A–D; 352A–D; 353A–C, E): Tg8 gradually narrowing posteriorly, anterior margin concave at midline, with short, wide lateral apodemes, posterior margin with a U-shaped mesal excavation; St8 larger and wider than Tg8, anterior margin with a wide, broad mesal apodeme, posterior margin with a U-shaped or horseshoe-shaped mesal apodeme, variable in size; socii/uncus complex narrowly attached to tegumen; uncus long and thin, slightly wider near apex, curving gradually downward; socii extremely thin, shorter than uncus; tegumen moderately wide, slightly shorter than vinculum, inner margins approximate in upper two-thirds; vinculum taller and wider than tegumen; saccus wide, extended upward a short distance, barely covering valva bases; valva large, mostly membranous; BO large, occupying two-thirds of valva or more; region between BO and apex membranous, with transverse striations bearing fine, hairlike androconia; costa sclerotized, narrow, parallel-sided, usually expanded near apex, sometimes forming a blunt distal process (e.g., S. auriflamma ); aedeagus wide, bulbous, base rounded; apex of aedeagus gradually narrowing to form an acute ventral point; vesica longer than aedeagus, ranging from bulbous (e.g., S. auriflamma ) to extremely long, sometimes (e.g., S. dimidiata ) over four times as long as aedeagus; spinelike cornuti located in distal portion of vesica, invariably with one or two cornuti much larger than others, sometimes (e.g., S. servula ) with a single large, spinelike cornutus only.

Female. FW length 5 14.0–27.5 mm. Head: Similar to male; antenna ciliate, shaft narrow, slightly tapered toward apex.

Thorax: Similar to male.

Forewing (pls. 33–35): Somewhat broader than male, outer margin more rounded; pattern similar to male, colors somewhat less intense.

Hind wing (pls. 33–35): Broader than male; frenulum comprising two bristles; pattern similar to male, colors somewhat less intense.

Abdomen: Shorter and wider than male.

Terminalia (347D, 348E, 349C, 350E, 351E, 352E, 353D): Tg7 large, broad, slightly narrower posteriorly, posterior margin with a deep, U-shaped excavation; St7 similar in size and shape to Tg7, but posterior margin simple, without a mesal excavation; Tg8 completely membranous; AA moderately long to short, often extremely thin; A8 pleuron membranous, with thin, straplike sclerites along anterior margin; PP long, extremely thin, sometimes bent slightly downward; PA moderately large, a small lobe present near dorsal margin; region of PVP membranous; area below ostium forming a wide, sclerotized plate, its margins wrapping upward; DB moderately long and wide to extremely long and thin, membranous; CB broadly ovate, large; basal two-thirds of CB with a heavily sclerotized region, its surface deeply rugose; CB sometimes spinose ( S. auriflamma ) or finely spiculate ( S. angustimargo ) at base; signum small, roughly ovoid, with a set of internal spines, these variable in size, sometimes long and robust ( S. superba , S. auriflamma ), rarely short ( S. gigantea ).

DISTRIBUTION: The majority of Scea species are endemic to high Andean cloud forests, usually at elevations above 2000 meters. Some, such as S. bellona from Peru, have been recorded as high as 4000 meters. Exceptions to this rule include S. auriflamma , found in low- to midelevation forests of southeastern South America, and S. torrida , endemic to dry forest habitat in southwestern Ecuador (fig. 304) at 1900 meters. In Andean South America, Scea species inhabit the Pacific as well as the eastern slopes. The genus is absent from Central America, and none occur in the Amazon Basin.

BIOLOGY: The immature stages of four Scea species have been discovered (table 6). Scea caterpillars are unique among Josiini in showing a dense covering of secondary setae over the body (pl. 39Q; Miller and Otero, 1994; Miller, 1996). As is typical for josiines, the head capsule is smooth and glassy (see fig. 358A, B), but in Scea the head is often completely black, without the black-andwhite patterns found elsewhere in the tribe. Adult morphology in S. auriflamma , S. angustimargo , and S. torrida varies somewhat from other Scea species. It will be important to determine whether their immature morphology differs as well.

Unlike Lyces and Josia , whose members seem to favor particular Passiflora subgenera, the host-plant list for Scea does not show an obvious taxonomic pattern (table 6). Scea larvae have been recorded from three different Passiflora subgenera. Their hosts include glabrous species, such as P. mollissima and P. manicata , as well as pubescent ones, such as P. bauhinifolia . As host-plant associations are gathered for additional Scea species, generalizations regarding Passiflora preferences will perhaps become apparent.

DISCUSSION: The cladistic analyses undertaken here demonstrate that what had previously been considered three genera— Scea Walker , Thirmida Walker , and Cyanotricha Prout —should instead be subsumed within a single genus. Scea of previous authors is paraphyletic with respect to both Thirmida and Cyanotricha , so the latter are proposed as new synonyms.

Scea , arising in a derived phylogenetic position within the Josiini (figs. 7, 283), is undoubtedly monophyletic. Its members exhibit traits unique for the Josiini . For example, the large, intricately folded, sclerotized area at the base of the female CB (e.g., figs. 347D, 351E) does not occur elsewhere in the Dioptinae , but is found throughout Scea . The female signum also has a unique shape (e.g., figs. 347D, 350E). In the majority of species, the male vesica is extremely long (e.g., figs. 347E, 351D). Other potential synapomorphies include the presence of larval secondary setae (pl. 39Q), noted above. Two species with Scea -like wing patterns— vulturata and solaris (pl. 30)— which had formerly been placed here, show none of the morphological characteristics of Scea , and have been transferred to Lyces .

Nonhomologous wing-pattern similarities often misled early dioptine taxonomists ( Hering, 1925; Seitz, 1925). The wings of Scea provide a particularly poignant example. Not only can Scea mimics be found in other Lepidopteran families, such as the Arctiidae (pls. 34, 35) and Geometridae , but mimics occur within the Dioptinae as well. For example, my cladistic analyses reveal that two species formerly placed in Scea — nudata Hering and obliquaria Warren —instead belong in their own genus, Notascea (pls. 31, 32). The cladogram (fig. 283) is equivocal with regard to two equally plausible hypotheses: One suggests that the similar-appearing wings of Scea and Notascea evolved through convergence, perhaps as a result of Müllerian mimicry. An equally parsimonious explanation is that the terminal clade of the Josiini (Clade 24; fig. 7), Notascea + Josia + Scea , had a common ancestor with a Scea -like wing pattern, and this was subsequently modified in Josia , whose members evolved wings with longitudinal stripes (pls. 32, 33).

The genus name Scea is attributed to Walker (1854), who described it for a single species— auriflamma Hübner. As is typical of Walker’s generic descriptions, he left us little to go on. However, a single trait of the labial palpus, ‘‘second joint much longer than the first’’, is a synapomorphy for the genus (appendix 4). Subsequent authors added taxa to Scea if their wing patterns resembled those of S. auriflamma . Bryk (1930) listed 12 species, and Hering (1943) described another. I have transferred four of those to either Lyces or Notascea . Concordantly, Thirmida Walker contained five species and Cyanotricha Prout contained two ( Bryk, 1930). By placing those genera in synonymy with Scea , and by describing a new species, torrida , the number of included taxa is now 19, making this genus roughly equal in size to Josia (appendix 2).

Although Walker described both Scea and Thirmida in the same publication (1854), I have chosen Scea as the valid generic name because it has been more commonly used. Scea also has page priority over Thirmida (p. 293 vs. p. 466). Initially ( Walker, 1854), Thirmida included a single species, dimidiata Walker. Most recently ( Bryk, 1930), it contained five: dimidiata Walker , grandis Druce , circumscripta Hering , superba Druce , and venusta Dognin. ‘‘ Thirmida ’’ venusta is here placed incertae sedis in the tribe Dioptini . The remaining four taxa are referred to Scea as new combinations.