The genus Neotherina Dognin (Geometridae, Ennominae) in Costa Rica

Abstract So far, two species of Neotherina Dognin have been recorded in Costa Rica. Neotherina imperilla (Dognin) occurs primarily at altitudes between 1100 and 1700 meters and Neotherina callas (Druce) which is widely distributed above 1100 meters. A third, new species, Neotherina xanthosa Sullivan and Chacón is described from altitudes above 2400 meters. Heterogeneity of the genus is discussed.


Introduction
The neotropical ennomine genus, Neotherina Dognin, contains eight species, four of which were recently moved into the genus from other genera (Pitkin 2000). One additional species appears to be misplaced in the genus but so far, no apomorphic characters have been defined for Neotherina. Superficially, the species look like species currently placed in Nephodia Hübner and Lambdina Capps, both of which likely are paraphyletic assemblages. Pitkin (2002) figures the adult male and female genitalia of N. callas (Druce), and the male genitalia of N. imperilla (Dognin) from the Central Cordillera of Colombia. The latter is currently considered to be the senior subjective synonym of the type species, Neotherina inconspicua Dognin, described from Lino, Panama. Pitkin et al. (1996) list the species of Neotherina occurring in Costa Rica (callas, imperilla) and state that there is a third, possibly undescribed, species there too. It is this latter species that we describe here, and also discuss the generic relationships of the species currently placed in Neotherina.

Materials and methods
Photographic methods used herein are described in Sullivan and Adams (2009). Procedures for dissecting and preparing genitalia follow those of Lafontaine (2004). DNA sequencing of the barcode fragment of the COI gene was carried out at the Canadian Center for DNA Barcoding, Guelph, Ontario. Barcode sequences were compared by nearest neighbor analyses as implemented on the Barcode of Life Data systems website (Ratnasingham and Hebert 2007).

Repository abbreviations
Specimens were examined from the following collections: Remarks. Pitkin (2002) indicated that Neotherina has no apomorphies that adequately define it and that it is closely related to Evita Capps, Lambdina and Nepytia Hulst. She transferred four species into the genus from other genera (Trygodes Guènee, Eusarca Hübner) based in large part on the structure of the aedeagus (pointed, sinuous, posterior process and usually with a subterminal process as well). She considered the transfer provisional based on the uncertainly of the monophyly of Neotherina. One species, N. noxiosa Dognin, was removed from the genus by Pitkin because it lacks a furca, a process originating near the dorsal margin of the juxta that defines the Ourapterygini into which Neotherina has been placed. Superficially, Neotherina species are similar to species placed in Lambdina and Nephodia (Nephodiini), but the monophyly of those genera is uncertain. The monophyly of the Ourapterygini versus Nephodiini is also questionable, since characters separating the two tribes are based largely on characters of the furca (Pitkin 2002, see also Sihvonen et al. 2011).

Neotherina imperilla (Dognin, 1911)
http://species-id.net/wiki/Neotherina_imperilla Figure 1 Remarks. Two specimens in the INBio collections were identified as N. imperilla by Linda Pitkin during her work on the Ennominae of Costa Rica (Pitkin et al. 1996). Superficially they resemble the type (USNM) except that the type is quite faded. The species looks very much like those currently placed in the genus Lambdina. The ground color is orange brown with distinct medial and postmedial lines crossing the forewings. The scaling on the head, thorax and abdomen is orange with the region between the antennal bases and collar being brighter in color. There is no dorsal tuft on the metathorax. Notable characters include the male bipectinate antennae and small orange spots distal of the junction of the postmedial line and the anal edge of the forewing and proximal to the medial line and anal edge of both wings. There is a very small extension at vein M3 of both wings. The genitalia of a male from the IN-Bio collection (Fig. 1b, c) closely resembles that of the male figured in Pitkin (2002) but there appear to be slight differences in the shape of the uncus and perhaps in the structures of the vesica (not everted in Pitkin (2002). The female genitalia (Fig. 1e) are figured for the first time but there is no female from the type locality at the USNM for comparison. Since few geometrid species are shared between the Costa Rican and South American fauna (Janzen, Brehm and Sullivan, unpubl. data), the taxonomic status of Costa Rican N. imperilla should be re-evaluated when more study material becomes available. Diagnosis. The wing pattern of N. imperilla is similar to many species in Lambdina, Nephodia, and unplaced species that occur at similar altitudes. It may be distinguished by the rounded apex and orange-brown color of the forewings. Similar (probably undescribed) species have a more pointed apex and the ground color is reddish or purplish.

Distribution and biology.
Nothing is known about the life history of this species. It has been collected on the western slope of the Cordillera Volcánica de Guanacaste, the western slope of the Cordillera de Tilaran, both western and eastern slopes of the Cordillera Volcánica Central and both slopes of the Cordillera de Talamanca and the Fila Costeña. Most specimens at INBio (44) come from 1100-1700 m on the western slopes but this may reflect the absence of collecting access to eastern slopes above 900 m. Remarks. This moderately common species is found at altitudes between 1100 and 2800 meters throughout Costa Rica. The forewing appears to be truncated at the tip because there are well-developed extensions of vein M3 in both wings; Females are noticeably larger than males. Adults of this and the following species are shown in Fig.  2. The female genitalia were figured by Pitkin (2002) and are shown in Figs 3c, 5a, 5b. There is a well-defined collar on the ductus and a distinctive signum on the bursa. The male genitalia (Figs 3a, 3b, 5d) are typical for the tribe Ourapterygini in having a welldeveloped furca, but have few other distinguishing characters for tribal classification.
Diagnosis. This species is unlikely to be confused with any other species in Costa Rica except N. xanthosa because of the characteristic wing shape. The wings are diaphanous and overlaid by a distinct pattern seen only in this species and in N. xanthosa (Fig.  2). It can be separated from the latter by the darker more grayish color and its smaller size, with a male forewing length of 18.95 mm (18- Etymology. The name refers to the yellowish-brown ground color of the maculation. Diagnosis. The species is similar only to N. callas, which it can be distinguished from by its yellowish-brown color and larger size (Fig. 2). Certain identification is best made by dissection of a male and examination of the spinulose terminal portion of the furca. In N. xanthosa it is about half the length of the furca (Fig. 5e), whereas in N. callas it is approximately one fourth as long as the furca (Fig. 5d). The female signa on the bursae differ in shape as well (compare Figs 5a,5b,5c). N. xanthosa also differs from N. callas (GenBank accession numbers JF855657; JF855658; JN268704; HM878904) by 5.6% in its DNA barcode.
Description. Male. Fig. 2c, 4a,b,c, 5e. Head -Palps very small, barely extending above middle of eye, scaling straw colored basally becoming chocolate on 2 nd and 3 rd segments. First segment more than 2 × length of second segment which is more than 2 × length of third segment. Frons brown yellow, square, yellow  extending to collar; eyes hemispherical; ocellus absent; tongue normal. Antennae bipectinate, pectinations long at base (5 × shaft width) tapering distally to unpectinated discs in last 8 segments (56-58 segments); bipectinations toward apex with rami swollen distally, more basal bipectinations tubular, not swollen distally. Rami almost chocolate brown, dorsal shaft with scaling brown. Rami originate ventrally just lateral of midline. Scape brown yellow. Thorax and abdomen-Scaling slender, brown and off-white, distinct pad of yellow-brown scales at distal end of metathorax. Dorsal abdominal scaling off white and brown, shorter, thicker scales with multiple points distally (usually 3). Underside similar. Terminal scales on each segment brownish forming poorly-differentiated rings. Legs covered with tightly adhering band and brown scales, those of spurs darker, spurs short, epiphysis slender, long but slightly shorter in length than femur and extending slightly past distal end of femur. Leg scaling extremely difficult to remove. Proportions of leg segments typical. Wings-Forewing venation with two areoles beyond cell, WL 22.03 mm (21-22 mm, N=7). Wing pattern very similar to that of N. callas but ground color in N. callas gray, whereas in N. xanthosa it is brownish yellow.
Forewing tip appears scalloped because M3 is extended and there is a similar but smaller extension at M3 on hindwing. Wings of N. callas similar. Male genitalia (Fig. 4b,c, 5e) -Uncus slightly hooked, pencil-like, tapering to a broad base and forming an inverted T. Tegumen very broad, vinculum narrow. Gnathos with arms poorly defined but expanding medially to a broad medial area supporting three or more rows of well-defined spines, extending in height to width of medial pad. Small spines along lateral edge of pad. Furca deflects to right bearing hair-like bristles on inner 20-30%. Furca curves medially, rounded tip. Juxta small, basal area with posterior point. Area medial to furca arm granulated. Valva bulging medially, tapering to tip. Costa sclerotized, broad forming blade-like process at tip of valva. Medial 40% of valve with moderately long setae. Anal edge of valve with bulge medially then tapering to subapical tip. Anellar extensions of costa do not join medially. Female. Figs 2d, 4d,e, 5c. Antenna filiform, otherwise similar to male but slightly larger (WL 23.15 mm;(22)(23)(24)(25)n = 22). Female genitalia (Fig. 4e, 5c) -Anal papillae slightly pointed and rounded terminally. Posterior apophyses long, 2 × longer than anterior apophyses. Posterior vaginal plate sclerotized and broadly rounded posteriorly. Anterior plate unsclerotized at base. Ductus bursae short with sclerotized plate dorsally forming collar-like structure. Ductus moderately short. Corpus bursae sac-like with well-defined signum. Dorsal signum round, hollow with star-like basal collar of 13 prongs or points. Center deeply invaginated. Ductus ejaculatorius originates on upper part of corpus bursae below collar on ductus bursae.
Distribution. Known from above 2400 m in the Talamanca and the Central Volcanic ranges in Costa Rica. In flight throughout the year.
Remarks. Nothing is known about the biology of this species, or that of any other Neotherina species. Its range probably extends into the other mountain ranges in Costa Rica and northern Panama.

Discussion
The three species of Neotherina now known from Costa Rica form a heterogeneous assemblage. Wing shapes for N. callas and N. xanthosa are identical, but very different from those of N. imperilla. Of the remaining species, N. melia (Druce), N. simplissima (Dyar) and N. atomeria (Schaus), currently a synonym of N. callas, are extremely similar to N. callas and may be conspecific. Neotherina axona (Druce), consequens (Prout), inconspicua (Dognin) (currently a synonym of N. imperilla), nomia (Druce) and carbania (Druce) seem to be a heterogeneous assemblage but we have not dissected nor barcoded most of them. The genitalia examined to date do not present characters apomorphic for Neotherina. Barcoding of geometrid specimens from Costa Rica and Ecuador (Janzen, Sullivan, Brehm, unpubl. data) has revealed very few shared species. Likewise, genital dissections show little overlap between apparent conspecific specimens from western Colombia and Costa Rica (Sullivan,  unpubl. data). Additional collections are needed to determine if populations of supposed N. imperilla from Costa Rica are conspecific with those from the type locality, Mt. Tolima, in Colombia.
Neotherina callas and N. xanthosa together with N. melia, N. atomaria, and N. simplissima seem to form a natural group. When additional data on food plants, barcodes, and genitalia of the remaining species currently placed in Neotherina are available, the "callas complex" may require a new genus.