Pljushtchia prima, new moth genus and species from Tadjikistan (Lepidoptera: Geometridae)

A new genus and species of geometrid moths from Tadjikistan is described and its position in the taxonomic structure of the subfamily Larentiinae is analysed. The new genus is grouped, based on the parsimony analysis of 38 morphological characters, to coniferous-feeding genera of the tribe Cidariini as follows: (Thera (Pennithera (Protothera (Pljushtchia gen. n. Heterothera)))). Pljushtchia is characterised by the antennae, unipectinate in males and flat, serrate in females, by a reduced haustellum, the venation of wings and the structure of the genitalia. The Thera firmata species group is validated as a genus Protothera. The tribe Cidariini includes four groups of related genera and is most speciose in southeastern Asia.


Description
Frons strongly bulged, projecting about one-half of the diameter of eye.Eyes in female smaller than in male.Palpi shorter than diameter of eye, haustellum reduced.Male antennae shortly unipectinate up to apical segments, pectinations a little longer than diameter of flagellum; female antennae flattened and saw-toothed in middle part.Mesotibia with one pair of spurs, hind tibia with two pairs.Hind leg with tarsus about one fourth shorter than tibia.Venation (Fig. 2): forewings with two radial accessory cells; R2-R4 and R5 from apex of accessory cell, M1 from its posterior margin; discal vein concave, M2 arises nearer to M1 than M3.Hind wings with Rs and M1 stalked, discal vein twice angulate, M2 branching nearer to M3 than to M1. External androconial modifications on wings and abdomen absent, pregenital segments not modified, sternite A8 rectangular and slightly longer than sternite A7.
Male genitalia (Fig. 3).Tegumen characteristically longer than vinculum, uncus length about 2/3 of tegumen length.Rudiment of socii as two small hairy pads attached to uncus base.Armature symmetrical.Valva with dentate projection of ventral margin and characteristic concavity between the projection and rounded apex, with an additional small triangular projection in centre of the concavity.Harpe absent.Dorsal arms of vinculum broad and massive, saccus markedly constricted laterally.Aedeagus shorter than valva, straight, one bundle of long and one bundle of short spine-shaped cornuti on vesica.Juxta large, plate-shaped, provided with a pair of slender appendages, reaching but not fused to bilobed dorsobasal projections of costa.These lateral appendages of juxta are treated as homologuous with labides.
Etymology.Pljushtchia gen.n. (gender feminine) is dedicated to the collector, lepidopterist I. Pljushtch.Viidalepp & Kostjuk, Wing span 23.0-26.0mm in males, 21.0-24.0mm in females.Thorax and abdomen light brownish grey, posterior margin of first tergite lined blackish.Ground colour of forewing light brown in males; antemedian, median and postmedian lines thin, blackish, surrounded by sparse whitish scales.Antemedian line slightly jagged, median rectangularly broken at Sc towards fore margin of wing, and postmedian line smoothly curved from costa to vein M3. Medial field, between antemedian and postmedian lines, twice as wide as submarginal field.Discal spot con-  trasting black, surrounded by a paler patch, apical stripe brownish, weak.Marginal line greyish, cut paler at veins; fringe fairly chequered paler and darker grey.Hind wings light greyish brown with darker greyish brown postmedian band and small blackish cell-spot.Wings colour is darker greyish in males, with transverse lines more contrasting, whereas in females more uniformly lighter brownish.Male and female genitalia: see the description of the genus and Figs 3-4.

Pljushtchia prima
Etymology.Pljushtchia prima is the first species in the genus.

Analysis of generic characters
The character spectrum of the described species is rich in apomorphies (bulged frons; unipectinate antennae in male and serrate antennae in female; broad ostium, short ductus and tiny corpus bursae without signum in female).The reduction of palpi and secondary loss of haustellum rarely occur within Larentiinae.Prout (1930Prout ( -1938) ) described the reduction of mouthparts in adult moths of some African genera (Conchylidia Guenée, [1858]; Trimetopia Guenée [1858]; Chionopora Prout, 1922) and Janse (1932Janse ( -1935) ) recorded this phenomenon in the genus Lycaugidia Hampson, 1895.Species of these genera are confined to arid areas, and we are allowed to assume this character as a phenotypical reaction to environment conditions.Celonoptera Lederer, 1862, a monobasic, systematically isolated genus, confined to the Mediterranean area and having a vestigial haustellum, is probably allied to Trimetopia (Prout, 1930(Prout, -1938)).Similarly, "winter moths" from the genera Operophtera Hübner, [1825] and Malacodea Tengström, 1869, accommodated to activity in unfavourable, cold weather conditions, also have reduced mouthparts.
Apophyses posteriores in female are usually twice the length of apophyses anteriores in the Larentiinae, but they appear of the same length in the new genus.However, reduced or shortened anterior apophyses often characterise the Xanthorhoini and Larentiini.The genera of the Larentiini share the presence of a calcar, unpaired, dorsal process of juxta with the Xanthorhoini, but do not have abdominal coremata, which are well developed in the latter.A pair of slender appendages arising laterally from juxta, labides, is a synapomorphic character of the Operophterini and Cidariini.These appendages are dorsally fused in the Operophterini, constituting a roof above juxta, but shorter and free in the Cidariini.A large juxta with fair labides in Almeria kalischata (Staudinger, 1870) from the Western Mediterranean is somewhat similar to that in Pljushtchia.
Labides in the tribes Rheumapterini, Melanthiini, Perizomini and Eupitheciini (for the two last tribes, see Miro-780 Fig. 5.The cladogram derived from successive weighting approach using Hennig86.The numbers of nodes, below; the number of supporting character state changes, above the node.nov, 2004) arise from the basal costal corner of the valva, branching dorsally and towards middle of juxta and joining to, but not fusing with juxta.
In summary, we have found characters defining the genus Pljushtchia in various larentiine tribes, but most often in the Cidariini.The shape of juxta in Pljushtchia is typically cidariine.

Cladistic analysis
The preliminary investigation of wing venation and male genitalia (the presence of labides arising from juxta) allows us to associate the new genus Pljushtchia with the tribe Cidariini.The working hypothesis was checked by a cladistic analysis of the character spectra of 31 ingroup species and Stamnodes depeculata as an outgroup species for tree rooting (see Appendix).Forbes (1948) suggested that the genus Stamnodes Guenée, 1858 is the most primitive among Nearctic Larentiinae.
The parsimony analysis yielded one completely resolved and most parsimonious tree (length 398 steps, ci = 0.70, ri = 0.83) when the option 'mh' was used and the initial tree was used in successive weighting (two iterations 'xsteps w' with 'mh*' and 'bb*').The tree (Fig. 5) was rerooted and visualised by means of the application "Treeview" (Page, 1996) and studied using the Hennig86 options "xsteps c" and "xsteps h".The support of nodes (Fig. 5 and Table 3) is presented according to Hennig86 option "xsteps h".
The basal group of genera includes Ecliptopera, Chloroclysta and Dysstroma, sharing relatively large genital armatures and rich ornamentation on aedeagus vesica.In the dendrogram by Choi (1997, Fig. 46), Dysstroma and Chloroclysta appear as sister-groups and Ecliptopera as the most basal ingroup genus.
Results of the cladistic analysis allow to assume the combination of the new genus Pljushtchia with the tribe Cidariini, using the sequence (Thera (Pennithera (Protothera (Pljushtchia Heterothera)))).
The genus Protothera Viidalepp, 2003 (type species Geometra firmata Hübner, 1822) differs from Thera in quadripectinate male antennae (Table 1).Antennal pectinations are long, slender and branching opposite (shorter, stronger, and branching opposite in Heterothera, slender but branching alternate in Pennithera Viidalepp, 1980) (Choi, 2000).In female genitalia ductus bursae is short, plate-shaped and nearly as wide as corpus bursae; in Thera, Heterothera and Pennithera, ductus bursae is usually tubular and considerably slenderer than the corpus bursae.In some Heterothera species, exceptionally, sterigma, ductus and corpus bursae are heavily sclerotised and dark (Viidalepp, 1980).Seven additional autapomorphic characters listed for P. firmata by Choi (1997) appear to be synapomorphic for Protothera if the sister-species of P. firmata, P. ulicata Rambur, 1834 is included in the matrix and analysis.The position of Protothera and Heterothera + Pljushtchia as sister-groups in the cladogram supports the treatment of the former as an independent genus.1825 (s.lat.) on the basis of the wing venation.Choi (1997,1998,2000) did not use venation characters in his cladistic analyses.In spite of that, his results are in good accordance with the genus-level taxonomy by Prout.(ci = 0.50, ri = 0.66).
8. Forewing, underside: specialised scales or hairtufts absent (0); hair tufts present in anal field (1); flecks of specialised scales present near origin of CuA2 (2).The presence of androconial hair pencils is synapomorphic for Polythrena and Trichodezia Warren, 1895 (Hashimoto, 1995) (also for some Asiatic genera allied to Eustroma), that of specialised scales near the base of Cu2 is an autapomorphy of Gandaritis.(ci = 0.50, ri = 0.60).9. Hind wing, underside: specialised hair tufts absent (0); present at wing base or in anal fold (1).The presence of tufts of hair-like scales on underside of hind wing is supposedly associated with androconial glands.It is a synapomorphy of Pareustroma and Hysterura in the Cidariini.The presence of specialised scales in forewings, hind wings and on sternite VII is an autapomorphy of Trichobaptria Prout, 1914, a monobasic genus similar to Trichodezia (Hashimoto, 1995).(ci = 1.00, ri = 1.00).
19. Male genitalia: relation of costa to valvula on inner wall of valva.The border of costa to valvula demarcated by a longitudinal rib (0); costa and valvula separated by a furrow (1); costa and valvula smoothly fused (2).The presence of lacinia costae (Sibatani et al., 1954) is prevailing within the Cidariini, whereas the presence of a (distally rounded) membranous furrow between the costa and valvula characterises the Lampropteryx-Colostygia clade.The inner wall of valva is well fused in Eulithis, Lobogonodes and Hysterura.(ci = 0.50, ri = 0.71).

TABLE 1 .
. The genera are associated with herbs or deciduous vegetation and are speciose in East Asia.However, Cosmorhoe and Colostygia are confined to the Mediterranean area.Comparison of morphological characters of the genera Protothera, Pennithera, Heterothera, Thera and Pljushtchia.