Bergiantina, Blas & Navarro, 2010

Blas, Germán San & Navarro, Fernando, 2010, Bergiantina, a new genus of agaristid moth (Lepidoptera: Noctuidae), Zootaxa 2562, pp. 24-44 : 25-26

Bergiantina new genus

Type species: Metagarista hilzingeri Berg , by present designation.

Included species: Metagarista hilzingeri Berg ; Bergiantina intermedia new species; Bergiantina parva new species; Erocha trita Druce ; Heterocampa dolens Druce ; Aucula schausi Jörgensen ; Bergiantina familiae new species; and Euthisanotia magnifica Schaus.

Diagnosis. Bergiantina is readily separated from all other South American taxa by its bipectinate antennae in males and deeply biserrate antennae in females, characteristic white patches or stripes associated with the postmedial line in the forewing, and abdomen with a black dorsal crest on tergite 1. Bergiantina is the only agaristid genus in the region to have the valves moderately asymmetrical in male genitalia. The aedoeagus has an apical sclerotized horn-like dorsal projection that is smooth, rugous, or covered by a number of small denticles. In the female genitalia the ductus bursae is extremely thin and more than three times the length of the anterior apophysis, unique in the Agaristinae .

Description. Adults ( Figs. 1–14). Head: Front with a rounded prominence, with a truncate conical central process of projected edges and a central corneous plate covered by small hairs. Palpus oblique upwards, anterior margin of first and second segments bordered with long hairs, third segment covered by scales. Eyes smooth. Antenna bipectinate in males and deeply biserrate in females. Proboscis completely developed. Thorax: Dorsal and ventral surfaces covered with hairs. Femora and tibiae surrounded by long hairs. Forewing ( Fig. 15) length: males 19.5–25.8 mm; females 21.5–26.1 mm, relatively broad, with termen evenly rounded; pattern somewhat variable between species, usually with distinct white stripes associated with antemedial and postmedial lines in the forewing, B. schausi with this pattern reduced to three white patches associated with the postmedial line. Vein CuA 2 from approximately 3/4 length of discal cell; M2, M3, and CuA1 approximate; M2 and M3 closer together than to CuA 1; discal cell concave apically; M 1 originates from areola or near junction with discal cell; areola small; R 5 and R 3 +R 4 stalked from end of areola; R 2 from anterior angle of areola. Hindwing ( Fig. 15) vein CuA 2 at approximately 2/3 length of discal cell; Rs and M 1 approximate or short stalked dorsal to discal cell; M 3 and CuA 1 approximate; discal cell concave; M 2 weak, arising at the middle of discal cell. Abdomen with a basal crest on first tergite, with long black hairs that reach the second tergite. Male Abdomen ( Fig. 16): Tergite 8 almost completely sclerotized with a weakly sclerotized oval area placed anterior-medially. Sternite 8 subrectangular, well sclerotized, lateral margins concave and anterior corners projected laterally. Prominent black dorsal abdominal crest on tergite 1. Basal trifine hair pencils absent. Male genitalia ( Figs. 18–26). Uncus relatively short, between 1/4 and 1/3 as long as valve, slender, down-curved, end abruptly sharpened, curved ventrally as a tiny hook, or straight backward as a spine, sometimes apex rounded. Anal tube wide, sclerotized ventrally. Tegumen have posterior lobes with several degrees of development. Juxta elongated, proximal margin convex; distal half with one weakly sclerotized oval depression on each side. Saccus absent. Valves with costal edge convex in ventral half and concave on apical half; sacculus well differentiated, from almost 1/2 to 1/3 valve length and from 3 to 5 X as long as wide; valve moderately asymmetrical, with a more or less oval depression on apical half, with one to four processes; right valve with apex rounded with two terminal knobs or slightly constricted, ear-shaped and without knobs; left valve with distal margin of apex greatly enlarged or evenly rounded, with a terminal quadrangular projection, absent in some species; corona, clasper, and costal processes absent. Aedoeagus ( Figs. 27–46) posterior 1/3 membranous, with three sclerotization zones: apically produced into a sclerotized horn-like dorsal projection smooth, rugous, or covered by numerous small denticles; and with two sclerotized lateral plates: left plate with one or two lateral teeth and a terminal tooth of equal or greater size than lateral ones and the right plate without teeth; some species with left plate reduced and without any tooth; vesica of aedoeagus absent. Female genitalia ( Fig. 17): Papillae anales long, narrow, triangular, from 2/3 to approximately the same length as anterior apophysis, from 1/5 to 1/3 as wide. Segment 8 uniformly covered with short hairs. Diameter of the ostium bursae 2/5 as long as anterior apophysis; antrum narrowing gradually to 1/6 width of its posterior end, forming an elbow in dorsal-anterior direction, posterior end with a sclerotized band-shaped ring. Ductus bursae membranous, thin, more than 3X length of anterior apophysis. Corpus bursae elongated, teardrop shaped; ductus seminalis at juncture of ductus bursae and corpus bursae.

Etymology. This genus has been named in honor of naturalist Carlos Berg, one of the more prominent Lepidopterists of the 19th century in Argentina. Feminine.

Immature stages and hosts. Little is known of the immature stages and feeding habits of these species. Bourquin (1958) described the immature stages of Bergiantina hilzingeri (Berg) , whereas Berg (1882) and Pastrana (2004) stated some larval foodplants. From information in the existing bibliography, these species appear to be restricted to members of the Onagraceae and Vitaceae .

Distribution. Species of Bergiantina occur from Ecuador, Peru, southern Brazil, Bolivia, to Argentina ( Figs. 47 and 48).

Discussion. Bergiantina consists of three species previously placed in Aucula : Aucula schausi, Euthisanothia magnifica , and Metagarista hilzingeri ; two species placed before on Erocha : Heterocampa dolens and Erocha trita ; and three new species Bergiantina intermedia , B. parva , and B. familiae . The first three species were retained in their original genera by Todd and Poole (1981) because they lacked the characters defining Aucula . Subsequently, Poole (1989) excluded these species from Aucula s. str., by placing them in Aucula 'of authors' as implicitly incertae sedis. Kiriakoff (1977) mentions that those species of Erocha were not congeneric with the rest and that Todd was planning a revision of those species. The description of Bergiantina reflects those earlier decisions of Todd and Poole (1981) and Kiriakoff (1977) in which we agree. We separate the species in two groups based on differences of the male genitalia: the hilzingeri group and schausi group. Maybe these are separated subgenera, but as there is a great superposition on color pattern between species of these groups, they have been left as “groups”.

Todd and Poole (1981) described a new species Aucula lolua with genitalia uniquely different from other species of the genus. Its morphological characters were examined in order to evaluate the possibility to include this species within Bergiantina . The male antenna of A. lolua is serrate; forewing ground color dark reddish brown and with only a hint of white scales on distal third; underside concolorous, with basal and subterminal yellow spots and hindwing with black marginal band that extends all along the margin of the wing. The forewing color pattern of the species of Bergiantina is more complex, with patches and transversal lines; also the hindwing marginal band does not extend through the anal margin. In addition, the male genitalia are also different: in Aucula lolua the valves are symmetrical, without any internal processes, and with a medial-ventral knob on each valve, and tegumen without posterior-lateral lobes. Due to these differences we maintain A. lolua in its original genus until further analysis.

In Figure 15 we correlate the Hennig/Comstock vein terminology with that used by Kiriakoff/Herrich- Schäffer. Kiriakoff (1977) used whether hindwing vein 6 (M1) and 7 (Rs+R5) were short-stalked or unstalked to distinguish genera that are closely related to Aucula . For species included in this study, veins M1 and Rs+R5 can be short-stalked or unstalked, even in specimens of the same species. Hence, we do not use the relation of these veins as diagnostic characters.