Oospila bulava Lindt & Viidalepp

Lindt, Aare & Viidalepp, Jaan, 2015, Oospila bulava, a new emerald geometrid moth from South America (Lepidoptera, Geometridae, Geometrinae), Zootaxa 4058 (1), pp. 142-144 : 142-144

Oospila bulava Lindt & Viidalepp , sp. nov. (Figs A–C)

Holotype: female, Ecuador, Napo prov., Carlos Julia, 950 m, 10.02.2008, 01º15’33”S, 77º49’27”W, Type id. TAMZ 0094300 (A. Lindt). Paratypes: 1♂, Bolivia, Puerto Chore, 230 m, 0 8.10.2010, 16°59’55”S, 64°09’07”W (slide 259) (A. Lindt); 1♀, Bolivia, Sarapiumi, 850 m, 28.10.2010, 15º24’43”S, 68º04’57”W (slide 289) (A. Lindt); 1♂, Bolivia, Refugio Volcanes, 1460 m, 25.11.2013, 18°07’32”S, 63°35’53”W (A. Lindt); 1♀, Peru, Tarapoto, 1000 m, 05– 0 6.12.2003, 06º27’30”S, 76º17’15”W (A. Lindt).

The holotype is deposited in the EMNH (Estonian Museum of Natural History’s) collection, Tallinn, Estonia. The paratypes are deposited in the Estonian Museum of Natural History’s collection, in the private collection of A. Lindt, and in the IZBE insect collection housed in the Estonian University of Life Sciences.

Diagnosis. Wings semi-transparent, plain green with fine brownish strigulation and a thin white marginal line; blotches absent. Slender valva, with a long, apically bulbed and spiculose appendage; sternite A8 with two triangular, pointed projections to its posterior edge.

Description. Moths (Fig. A): Wingspan, males 19–22 mm, females 25–26 mm. Head: The palpi are brown, projecting before the frons; the frons is brown below and dark brown above; the interantennal fillet is white with scattered red-brown scales; and the vertex is green with a reddish-brown line between. The antennae in both sexes are pectinated, antennal shaft is light brown. Diameter of the shaft is 0.2 mm; the length of internal and external rami at the tenth antennal segment in the male is 0.75 mm and 1.0 mm, and in the female 0.5 mm and 0.65 mm, respectively. Thorax and abdomen: The thorax and abdomen are green, abdominal tergites 1–5 bear large dark brown crests which are ringed with white and inlaid by some long white hairscales. The male hind legs are slender, without a hair pencil and with one (distal) pair of spurs. The wings are light green, with some long green hairscales embedded between flat scales, being less numerous in the hindwings, and sparsely striated transversely with brown. The costal edge of the forewing is lined in light brown, and the marginal line is blackish on both wings, accompanied by a white line which is thicker on veins and edged proximally by sparse rose and dark scales. The fringe is white and rosy. The distal margin of forewings is slightly convex, and that of hindwings evenly rounded, but in some females it is slightly elbowed at vein M3. The forewings have small dark discal spots; the hindwings have pairs of a tiny dark and a small oblong white discal spot.

FIGURES A–C. A. Oospila bulava , sp. nov., male. B. Oospila bulava , sp. nov., male genital capsule, aedeagus and sternite A8. C. Oospila bulava , sp. nov., female genitalia.

Male genitalia (Fig. B): The uncus is reduced, the socii are large, roundish oblong, and the gnathi short, hooked and pointed. The tegumen is squarish, and as long as the V-shaped vinculum. The anellar complex is fused with the dorsal margin of transtilla. The juxta is short, with the bases of sacculi touching between the juxta and the saccus. The valva is slender, and the sacculus has an apical, pointed process lacking but two small roundish projections between the saccular lobe and ventral edge of the valvula present instead. There is a long, stout, apically clubbed appendage arising from the base of the valva near costa, being a little longer than the valvula. The ventral margin of the valvula and the distal half of the sacculus are roughly setose. The distal end of the aedeagus is cut truncate and has one cornutus on a long, folded vesica. The posterior margin of the sternite A8 has two broad, triangular projections separated by a sharp, V-shaped medial excision; the edges of this excision are sclerotized.

Female genitalia (Fig. C): The outstandingly large, U-shaped sterigma, with its inner edge of outer opening sharply defined and sclerotized, is characteristic. The ostium is small and roundish, and the ductus bursae long, tubular, and delicately folded longitudinally. The corpus bursae is oval and large, with a small, transverse, bicornuate signum. The anterior apophyses are reduced.

Discussion. In facies, the moth is similar to, but slightly larger than, O. delacruzi f. restricta Warren and O. euchlora Prout , especially in the reduction of the submarginal pattern on the wings, but differing in: the scaling of wings, which is lighter green and semi-transparent; in the fine brown striation of both wings; and in the presence of sparse, long green hairscales on the wings. In the male genitalia, a long, distally bulbed appendage to the valva is characteristic of many species from different species groups of Oospila ( Cook & Scoble, 1995) , e.g. the O. quinquemaculata group, the O. albicoma group, and the large O. trilunaria group. These species usually have wings with beige, brown, or blackish markings, usually in form of blotches, or as a submarginal band. However, the species of the O. quinquemaculata group have a looped gnathos, while a pair of hooked gnathi occurs in O. bulava sp. nov. The species of the O. albicoma group have two processes to the apex of the valva, and the anellar complex is rhomb-shaped, pointing both dorsally and ventrally ( Cook & Scoble, 1995).

The Oospila trilunaria group is composite, containing some subgroups and species triplets. There are some species included with plain green wings ( O. dicraspeda Prout ; O. altonaria Jones ; O. tricamerata Prout ; O. decoloraria (Walker) ; O. pellucida Prout, 1916 ). These species were revised by Cook & Scoble (1995). The comparison of primary and subsequent descriptions of these species revealed that the characters of wing shape and markings of O. pellucuda , as given by Prout (1916), closely fit with those of the new species in the semi-transparent scaling on wings, combined with the sparse and fine dark strigulation, and with the white, thin marginal line (differing in the absence of pink pigment and in lacking the second white discal spot on the hindwings of the new species).

O. pellucida and O. bulava , sp. nov., share some characteristics in the genitalia, such as slender valvae, the squarish tegumen, and the bases of sacculi separating the juxta and vinculum. However, O. pellucida differs in the shape of the appendage to the valva, which tapers distally, in the shape of juxta and sacculus. The sternite A8 also has a specific shape. Female genitalia of both species have a large sterigma which is kidney-shaped in O. pellucida and longer Ushaped in the new species. The sterigma is much smaller in O. pelluc ida ( Cook & Scoble, 1995). Differences in the genitalia structures are clear enough to confer the status of a new species.

Biology. The specimens were collected from October to February in tropical rainforests in lowlands and up to 1500 m in elevation on the eastward-facing mountain slopes of the Andes.

Etymology. The word 'bulava' means an ancient Russian reigning, threatening and fighting tool (club in English), which is similar to the long appendage (the "ampulla" as defined by Cook & Scoble (1995)) to valva in the described species,.The gender is feminine.

The senior author is thankful to Dr Dirk Lloyd who kindly revised the English in the article. The field work of the first author was financed in part by the Estonian Museum of Natural History. The senior author's study was partially funded by grant 9174 of the Estonian Science Foundation and by institutional research funding (IUE21-1) of the Estonian Ministry of Education and Research.