Dithalama, Meyrick, 1888
treatment provided by
This group of four genera is characterized by five synapomorphies ( Figs 133-135 View Figure 133 View Figure 134 View Figure 135 ): presence of two forewing areoles formed by R veins (48: 1, six occurrences and one reversal); forewing vein R 5 runs from the distal areole and is stalked with veins R 2 -R 4 (49: 2, eight occurrences); posterolateral appendices are absent on male 8th sternite (86: 1, five occurrences and six reversals); the medial margin of the sacculus is upturned (110: 1, four occurrences); lamella antevaginalis is flap-like, flexible, formed by one plate (139: 1, 13 occurrences and two reversals). Within the group, the relationships are not resolved. Somatina eurymitra is incerta sedis and recognition of Isoplenodia renders Dithalama paraphyletic. These three taxa form the sister group to Somatina + Zythos .
Comments on systematics
This group of genera, although not found to be supported by unique synapomorphies ( Figs 134 View Figure 134 , 135 View Figure 135 ), appears to be rather distinctive. Cerata are absent in most cases, and the species have two areoles in the forewings. In the other group of genera (i.e. Scopula , Lipomelia and Problepsis ) the cerata are fully developed and in most species the forewings have only one areole.
Diagnosis: description is based on type species only (see ‘Comments on systematics’, below). Monophyly supported by five synapomorphies: transverse median line of wings is obscure (25: 1, 12 occurrences); posterior margin of male 8th tergite is concave, with two sclerotized lateral spines (88: 2, unique, Fig. 119 View Figures 118–132 ); medial margin of sacculus is not upturned (110: 0, three occurrences); presence of posteriorly directed lobe on top of vinculum with a medial ridge (115: 1, 15 occurrences); apices of wing-like juxta processes are fused to sacculus of valva (116: 2, seven occurrences).
Imago: wingspan 19–24 mm. Male antenna fasciculate, sensilla in single rows; female antenna fasciculate, simple. Pilifer present. Wing patterns variable, transverse lines ranging from almost straight to hardly recognizable; discal spot dark; terminal line discontinuous; wing patterns repeated on underside but indistinct. Forewing with two areoles; R 5 from distal areole, either stalked with R 2 -R 4 or straight from accessory cell. Outer margin hair pencil of male hindleg tibia present, inner either present or absent; distal spurs of hindleg tibia absent; tarsomeres shortened but not fused; claws either two in number or absent. Female hindleg tibia with two pairs of spurs.
Male abdomen and genitalia: pouch on male 2nd sternite round; anterolateral extensions present or absent. One membranous pouch between male 7th and 8th sternite. Male 8th sternite sclerotized; anterior margin elongated medially; laterally turned extensions or two blunt lobes on posterior margin; cerata, mappa and membranous posterolateral appendices absent ( Fig. 57 View Figures 55–79 ). Posterior margin of male 8th tergite concave with two sharp cerate-like projections or with two round lateral lobes ( Fig. 119 View Figures 118–132 ). Socii separate, setose. Ventral margin of tegumen with round lobes, separate or fused. Valvae symmetrical, variably sclerotized, anterior margin of sacculus medially upturned or levelled. Transtilla present. Anterior margin of juxta with wing-like processes, apex fused to sacculus of valva or absent. Vinculum enlarged . Aedeagus straight with one or several teeth, carina, at distal end; vesica simple, curved sac, without sclerotizations .
Female genitalia: lamella antevaginalis sclerotized, flap-like, flexible, medially elongated. Ostium bursae weakly sclerotized; ductus bursae wide, proximal part either membranous or sclerotized; ductus seminalis arises from ductus bursae. Corpus bursae elongated sac; signum either granulate, spines point away from centre or absent; long spines on inner surface of corpus bursae absent.
Distribution and species diversity: Australia and Tasmania. Four species identified tentatively ( McQuillan & Edwards, 1996). See Appendix under Dithalama .
Immature stages: unknown.
Comments on systematics: the genus is in need of revision, as was already noted by Prout (1920 -41). He speculated that Dithalama is closely related to Somatina and Autanepsia , and the latter monotypic genus should perhaps be combined with Dithalama . In this analysis Dithalama was recovered as paraphyletic with regard to Isoplenodia . The Dithalama + Isoplenodia connection, although not discussed earlier, is supported by a number of character absences ( Fig. 134 View Figure 134 ). In addition to Dithalama + Isoplenodia , the secondary loss of sclerotizations of vesica (125: 1), which is a derived feature in this analysis, has occurred outside of these taxa only in Tasmanian species Dasybela achroa and South African species Zygophyxia relictata , which were found to be unrelated to Dithalama . Absence of male hindleg claws (67: 0), pretarsus arolium (68: 0) and pulvillus (69: 1), on the other hand, are found also in a number of taxa in Zythos , Problepsis and Antitrygodes .
Diagnosis: monophyly supported by eight synapomorphies: absence of pilifer (character and character state 0: 1, unique); ventrolateral sensilla on proximal part of male flagellomere are in multiple rows (8: 1, nine occurrences); absence of anterior ventral lamina of metathoracic metafurca (52: 1, six occurrences); absence of opening on male metathoracic dorsal sclerite (58: 1, character state ‘present’ shown in Fig. 112 View Figures 109–117 , unique); fusion of male hindleg tarsomeres 1–5 (66: 1, two occurrences); cerata are fully developed (79: 2, three occurrences, two reversals); mappa is bare 83: 2 (four occurrences); ventral margin of tegumen is unmodified, straight (100: 0, three reversals).
Imago: wingspan c. 16 mm. Head smooth-scaled; male antenna fasciculate; sensilla arranged in multiple rows, proximal row elongated. Pilifer absent. Wings light brown, transverse lines weakly expressed; discal spot dark; terminal line discontinuous, equally wide; underside light fuscous. Forewing with two areoles; R 5 from distal areole, stalked with R 2 -R 4. Opening on male metathorax dorsal sclerite absent. Outer margin hair pencil of male hindleg tibia short; inner absent; tarsomere segments 1–5 fused, claws absent. Female hind tibia with 2 + 2 spurs.
Male abdomen and genitalia: anterolateral extensions on male 2nd sternite absent. One membranous pouch between male 7th and 8th sternite. Anterior margin of male 8th sternite elongated medially; cerata symmetrical; mappa constricted at base; membranous, posterolateral appendices absent. Posterior margin of male 8th tergite concave. Socii rudimentary, short. Ventral margin of tegumen straight. Valvae symmetrical, soft, setose, valvula and sacculus separate. Anterior margin of sacculus medially upturned, covered with pointing setae. Transtilla present. Juxta weakly sclerotized, narrow at base, but with long wing-like processes. Vinculum enlarged , dorsally narrow, v-shaped ( Fig. 33 View Figures 30–54 ). Aedeagus curved ventrally, with long caecum; without sclerotizations.
Female genitalia: unknown.
Distribution and species diversity: known from Madagascar only. One species.
Immature stages: unknown.
Biology: unknown. Comments on systematics: the genus is retained as valid but only tentatively (see comments on Dithalama ). Prout speculated that Isoplenodia might be of a close relative of the African genera Epicosymbia and Isoplenia , on the basis of two forewing areoles, and long ciliated male antenna. This was not supported in this analysis and the condition of two forewing areoles (48: 1) was shown to be a very homoplastic character. I. arrogans was found to have cerata-like structures laterally on the male 8th sternite, but these are immobile and without apical setae, contrary to other studied material. Examination of female structures could give further clues about the systematic position of this species.
Diagnosis: monophyly supported by three synapomorphies: sacculi of valva are asymmetrical (105: 1, seven occurrences); valvuli of valva are asymmetrical (108: 1, seven occurrences); anterior margin of juxta is with wing-like processes, apex is fused to sacculus of valva (116: 2, seven occurrences).
Imago: wingspan 23-33 mm. Male antenna fasciculate; proximal row of sensilla sometimes weakly elongated, those sensilla in single rows. Female antenna fasciculate, simple. Pilifer present. Wing patterns variable, colour ranging from white to reddish-yellow, greyish-brown in many species; often irrorated with dark scales; dark band on forewing termen between transverse anterior and median lines in many species; transverse lines dentate, straight or sometimes modified, taking unusual forms; discal spot weak, dark; iridescent scales usually absent, glossy in few species; terminal line usually discontinuous, equally wide; patterns often repeated on underside, fuscous, sometimes absent. Forewing with two areoles; R 5 from distal areole, stalked with R 2 –R 4 or straight from cell. Outer and inner margin hair pencil of male hindleg tibia usually present, outer concealed in a furrow formed by long scales in many species; apical spurs usually absent, sometimes two; tarsomeres normally developed, 5- segmented; two claws. Female hind tibia with 2 + 2 spurs.
Male abdomen and genitalia: pouch on male 2nd sternite round, posterior margin often invaginated; anterolateral extensions usually present. Small lateral pouches between sternites 3 and 4 rarely present. Usually one, sometimes two membranous pouches between male 7th and 8th sternite. Male 8th sternite variable, x-shaped and heavily sclerotized in many species; anterior margin elongated medially or bifurcate; cerata usually absent ( Fig. 56 View Figures 55–79 ), sometimes present as fully developed; mappa absent, setose or bare; posterolateral appendices usually present. Male 8th tergite posterior margin concave, with two round lobes or sharp projections ( Fig. 120 View Figures 118–132 ). Socii separate, covered with long setae. Ventral margin of tegumen unmodified, rarely with small round or elongated projections. Sacculus and valvula of valva separate, with pronounced asymmetry; valvula shape varies from wide, blunt-ended to narrow, long, with sharp apex; medial and lateral margin of sacculus often with upturned projections. Anterior margin of juxta with wing-like processes, apex rarely free, instead fused to sacculus in most species, and sometimes asymmetrical; sometimes juxta processes functionally replacing sacculus of valva. Transtilla narrow weakly sclerotized band, rarely wide. Vinculum enlarged , symmetrical and usually convex. Aedeagus bent, sometimes with small projections near apex; vesica complex, with several large, often twisted diverticula ( Fig. 31 View Figures 30–54 ); variably sclerotized but rarely with distinct cornuti.
Female genitalia: lamella postvaginalis usually absent; lamella antevaginalis large, sclerotized, medially invaginated, flap-like structure in most species. Ostium bursae weakly sclerotized. Ductus bursae usually coiled, weakly sclerotized. Ductus seminalis opens from corpus bursae neck. Corpus bursae ovoid sac; signum elongated, made of separate spines, rather large compared to size of corpus bursae.
Distribution and species diversity: from Africa to the Oriental region and Australia. Forty-four species and several subspecies, although see ‘Comments on systematics’.
Immature stages: I have been unable to find any references. Nakamura (1994) described the pupa of Somatina indicataria (Walker) , but the taxon is considered to belong to Scopula in the present study.
Biology: S. anthophilata has been recorded from Gardenia jasminoides and Randia dumetorum (Rubiaceae) and Rosa (Rosaceae) . Somatina omicraria and S. virginalis have been recorded from the Oleaceae genus Jasminum ( Robinson et al., 2002) .
Comments on systematics: Sterrhinae species with two areoles on the forewings have traditionally been considered to belong to Somatina , in contrast to Problepsis and Scopula , which have one areole. Since this character was shown to be homoplastic in the present study (48: 1), and as both states occur in many lineages, Somatina was considered to be a polyphyletic assemblage of species, as noted by Inoue (1992), with many species formerly ascribed to it shown to belong to either Problepsis or Scopula .
While the remaining species should be revised against the generic descriptions given here and, if necessary, transferred to the appropriate genera (see Appendix for examples), Somatina is, however, likely to be a monophyletic group of species. It has a number of characteristic, although not unique, features. One such feature is the anterior margin of the juxta that is fused to sacculus of the valva (116: 2). The male of S. anthophilata , the type species of the genus, has small lateral pouches between sternites 3 and 4 ( Holloway, 1997), although as these were not seen in other studied taxa, this autapomorphy was not coded. Traditionally, Somatina has been considered a close relative of Scopula or Problepsis (e.g. Prout, 1920 -41, 1934-39), but in the present study species of the redefined genus are associated with Zythos . This connection is supported by the sclerotized posterior part of male 8th sternite (85: 1, Fig. 59 View Figures 55–79 ), which is found elsewhere only in Dithalama desueta , and by the presence of parallel folds on the vesica (132: 1, 129), found also in a few Scopula taxa. Several characters, e.g. the structure of the socii and signum, indicate a close relationship with Scopula .
Somatina irregularis and S. eurymitra were considered incertae sedis, but were retained in their traditional generic combinations, as they did not group together with the recognized genera. Somatina irregularis grouped together with Scopula haemaleata , sharing with it a number of unique features, such as a bifurcated cerata (82: 1) and a juxta with long processes laterally (117: 1). Somatina eurymitra , meanwhile, showed affinities with Somatina and Problepsis ; for example, the male 8th tergite is concave with two sharp lateral projections (88: 3), a feature typical of Somatina , while the cerata fused with the mappa (80: 1) is a common condition in Problepsis . Females of S. eurymitra were not available for study. It remains to be tested whether these taxa actually represent larger monophyletic groups.
( FIGS 5 View Figures 1–25 , 34 View Figures 30–54 , 59 View Figures 55–79 , 83 View Figures 80–99 , 101, 103 View Figures 100–108 , 114 View Figures 109–117 , 121, 124, 125, 129, 131, 132 View Figures 118–132 , APPENDIX)
Diagnosis: monophyly supported by 20 synapomorphies: iridescent scales of wings are restricted to a few rows, excluding discal spots (16: 3, unique); iridescent scales of wings are glossy and longitudinally grooved (17: 1, unique, Fig. 101 View Figures 100–108 ); discal spot of forewing is not unicolorous and dark (19: 1, six occurrences);discal spot of forewing is lunular (20: 2, two occurrences); presence of a spot at vein endings at forewing margin (40: 1, two occurrences); absence of hair pencil on inner margin of male hind tibia (61: 1, seven occurrences); male hindleg is with one claw only (67: 1, unique, Fig. 114 View Figures 109–117 ); absence of pretarsus arolium on male hindleg (68: 0, six reversals); two pouches are present between male 7th and 8th sternites (76: 1, four occurrences, Fig. 59 View Figures 55–79 ); absence of posterolateral appendices on male 8th sternite (86: 1, five occurrences, five reversals); posterior margin of male 8th tergite is convex (88: 4, unique, Fig. 121 View Figures 118–132 ), posterolateral margin of male 8th tergite has two membranous appendices (90: 1, Fig. 121 View Figures 118–132 ); absence of setae on socii (96: 0, unique); anterior margins of tegumen are dorsally fused (101: 1, unique, Fig. 125 View Figures 118–132 ); absence of transtilla (102: 2, unique); valva have symmetrical sacculi (105: 0, two occurrences); valvula of valva lies ventral of sacculus (107: 1, unique, Fig. 124 View Figures 118–132 ); valvuli of valvae are symmetrical (108: 0, two occurrences); anterior margin of juxta is without wing-like processes (116: 0, nine occurrences); signum has a bare zone laterally on both sides of median ridge (135: 1, unique, Fig. 131 View Figures 118–132 ).
Imago: wingspan 32-40 mm. Male antennae fasciculate, sensilla in single rows; female antennae fasciculate, simple. Pilifer present. Sensilla styloconicae forming serrate lining at distal end of proboscis. Chaetosemata prominent. Wing pattern variable, often with fine striations on extensive areas of wings; costa and middle parts often olive grey; often with longitudinally grooved iridescent scales on outer half of forewing, excluding discal spots ( Fig. 101 View Figures 100–108 ); subterminal shaded line and terminal line touching each other at fore- and hindwings in many species; discal spots dark, often lunular on forewings; pale markings on anterior side of hindwing discal spots in many species; terminal line discontinuous, equally wide, dark spot at vein end at forewing margin; underside often unicolorous, ranging from light brown to light orange. Forewings with two areoles; R 5 from distal areole, either stalked with R 2 –R 4 or straight from accessory cell. Hair pencil of outer margin of male hindleg tibia present, point of origin prominent; inner margin hair pencil absent; tarsomeres normally developed; one claw ( Fig. 114 View Figures 109–117 ); arolium absent; pulvillus present. Female hindleg tibia with 2 + 2 spurs.
Male abdomen and genitalia: pouch on male 2nd sternite round, large; anterolateral extensions present. Two membranous pouches between male 7th and 8th sternite. Male 8th sternite heavily sclerotized, anterior margin bifurcate; posterior margin with blunt extensions or medial projections; cerata, mappa and membranous posterolateral appendices absent ( Fig. 59 View Figures 55–79 ). Male 8th tergite posterior margin convex, with two membranous appendices on posterolateral margin ( Fig. 121 View Figures 118–132 ). Genitalia capsule oval. Socii wide, separate, without setae. Ventral margin of tegumen slightly curved inwards. Valvae symmetrical, valvula and sacculus separate; anterior margin of sacculus medially upturned or levelled; valvula moved ventrad of sacculus ( Fig. 124 View Figures 118–132 ), often curved dorsally. Transtilla absent; instead, anterior margins of tegumen are fused dorsally ( Fig. 125 View Figures 118–132 ). Anterior margin of juxta without wing-like processes. Vinculum enlarged . Aedeagus almost straight, apex with small blunt extension; vesica prominent, long, often with long lateral diverticulum and sclerotized parallel folds.
Female genitalia: lamella antevaginalis flap-like, flexible, medially either concave or bilobed. Ostium bursae heavily sclerotized. Ductus bursae membranous, coiled; ductus seminalis arises from ductus bursae. Corpus bursae an elongate sac; signum often with narrow medial, sclerotized strip followed by bare zone ( Fig. 131 View Figures 118–132 ) and granulate field of separate spines on both sides laterally.
Immature stages: unknown.
Distribution and species diversity: from India to Papua New Guinea. Morphologically, a compact genus with 11 species.
Biology: adults occur predominantly in the understorey of lowland rain forests and have been collected from carrion-baited pitfall traps ( Holloway, 1997). The serrated distal end of the proboscis indicates an adaptation to piercing. Frequently taken from secondary forests as well ( Chey, 1994).
Comments on systematics: Prout (1920 -41), followed by Holloway (1997), considered Zythos to be a close relative of Ignobilia on the basis of striated facies and pale underside of wings. In the present study Zythos is associated with Somatina (see Discussion under that genus).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.