Ekboarmia atlanticaria (Staudinger, 1859)

Skou, Peder, Stuening, Dieter & Sihvonen, Pasi, 2017, Revision of the West-Mediterranean geometrid genus Ekboarmia, with description of a new species from Portugal (Lepidoptera, Geometridae, Ennominae), Nota Lepidopterologica 40 (1), pp. 39-63 : 44-47

Ekboarmia atlanticaria (Staudinger, 1859)

atlanticaria atlanticaria Staudinger, 1859, Stettiner Entomologische Zeitung 20 (7-9): 218, ( Boarmia ?). Syntypes 3 ♂♂, 3 ♀♀ (MNHU), 1 ♂ (ZFMK; genitalia dissected by E. Wehrli, prep. number 5199). Spain: Andalusia, near Chiclana (examined externally, illustrated also in Albers & Warnecke (1941), plate II, figs. 9, 12 (on p. 332).

=atlanticaria gracilis Albers & Warnecke, 1941, Mitteilungen der Münchner Entomologische Gesellschaft 31 (1): 115, pl. 4, fig. 40, ( Boarmia ). Syntypes 4♂♂, 5 ♀♀ (2 syntype ♂♂ in Universität Hamburg, Centrum für Naturkunde, Germany), [Morocco]: Mehedya (examined externally, based on a photograph in the original description). Downgraded from subspecific rank of Ekboarmia atlanticaria gracilis (for instance Scoble 1999; Leraut 2009) to synonymy with Boarmia (?) atlanticaria atlanticaria Staudinger, 1859 (syn. n.), based on the absence of distinct morphological or molecular structures and adjoining distribution area. See Remarks.

atlanticaria holli Oberthür, 1909, Ètudes de Lépidoptérologie comparée 3: 412, pl. 27, fig. 152, ( Hemerophila ). Holotype male (ZFMK), Algeria: Alger [Originally as sp.] (examined, including genitalia, dissected by E. Wehrli, prep. number 5193). Infrasubspecific names, probably unavailable: pallidior Lucas, 1956 (f.).

Examined non-type material.

139 specimens (100♂♂, 39♀♀; data provided in a Suppl. material 1).

External characters and abdomen

(Figs 8, 9, 13). Wingspan 19-27 mm, medium-sized species in the genus. Wings grey-brown, forewing medial area darker brown, general appearance somewhat smooth, slightly glossy. Forewing with antemedial line inclined, deeply V-shaped and acutely angled back towards base but often this part very narrow and only weakly visible. Forewing medial line narrow, often strongest and approaching postmedial line near inner margin. Forewing postmedial line dark-brown to blackish, inclined, weakly dentate on veins, shallowly curved inwards between veins, dark brown, deeply V-shaped and angled towards base (along vein M1) near apex, angled again towards apex before reaching costa. Forewing postmedial line not angled outwards at inner margin and medial area narrow. Dark brown to blackish streak in forewing subapical area, often appearing as an extension of postmedial line. Outer margin bordered with whitish. Subterminal line mostly present, but indistinct, dark grey or brown, more or less parallel and close to termen. Terminal line blackish, narrow, often discontinuous, stronger at vein endings. Fringes uniform grey-brown. Hindwing medial line weakly curved, strongest near inner margin, often absent towards costa. Area between medial and postmedial lines often darker than remaining wing surface. Hindwing postmedial line weakly dentate, more strongly curved outwards than medial line, outer margin whitish. Hindwing subterminal line grey or brown, diffuse. Forewing discal spots blackish, small, distinct. Hindwing discal spots smaller. Wings below grey-brown, medial lines diffuse. Postmedial line discontinuous, with blackish dentation, discal spots and terminal line blackish. Course of postmedial line differs from that of upperside, antemedial line hardly visible. Frons, collar, thorax and abdomen concolorous with wings. Antennae concolorous with wings dorsally. Morphological structure of antennae, hindtibia, tympanal organs, tergites and sternites of abdomen as mentioned in generic description.

Variation.

Spring generation much larger. Wings vary from grey-brown to different shades of brown. Medial area sometimes completely suffused with dark grey or brown. Terminal line can be continuous or discontinuous. Very rarely specimens occur with stronger dentation on postmedial line and/or a shallow incision near inner margin, producing a somewhat fascinataria -like appearance. We consider such specimens to fall within intraspecific variation of atlanticaria . The male syntype of atlanticaria from Andalusia in coll. ZFMK shows this feature.

Male genitalia

(Fig. 18). Uncus narrow, elongated, apex round. Socii absent. Gnathos arms fused ventrally, upturned, plate-shaped, surface rather smooth, margin round. Valva evenly narrowing towards apex, costa sclerotised, apical part of valva with narrow, setose ridge. Juxta arms large, rather narrow, dentate at apex only, base solid. Saccus elongated, upturned medially. Phallus narrow, caecum very short. Longer phallus apex elongate-oval, becoming bent when vesica is everted. Vesica enlarged at base, everts at c. 135 degree angle, without cornuti.

Female genitalia

(Fig. 22). Papillae anales slightly elongated, setose. Apophyses posteriores longer (about 1.6 ×) than apophyses anteriores. Lateral arms of lamella antevaginalis weakly sclerotised. Lamella postvaginalis weakly sclerotised, rounded plate with caudal, acute process. Ductus bursae very short, fluted, colliculum long, narrow. Corpus bursae elongated, oval, without sclerotisations. Signum distinctly stellate, of medium size.

Subspecies

holli. The holotype is large, greyish-brown (Fig. 13i). In ZFMK is a series of distinctly smaller specimens, collected later in the year, probably a similar phenomenon of seasonal variation as for taxon gracilis , see Remarks. The specimens from Tunisia (Fig. 13j, k) are reared and it is therefore difficult to form a judgement upon them. DNA barcodes of Tunisian specimens are distinct from other Ekboarmia atlanticaria specimens (see under Genetic data). No specimens from Algeria were available for DNA barcoding. Historically the subspecies has been delimited to occur in Tunisia and Algeria. We do not propose formal changes to the current classification because more research is needed.

Distribution and abundance

(Fig. 17). West-Mediterranean. In Europe only in southwestern Iberian Peninsula, the Balearic Islands, and Sardinia. There is also a record of a single specimen from southern France, undoubtedly a migrant from outside the known distribution area, of which the closest is the Balearic Islands. Outside Europe, in Morocco, Algeria, and Tunisia. In Europe a somewhat local but not rare species, which can be found in limited numbers in its localities.

Phenology.

Multivoltine. Recorded from early March to early November with a few additional records in late January, February, and December. Larvae have been found in February ( Staudinger 1859), in March, and mid October (M. Corley, pers. comm.). Hibernation probably takes place as egg, larva, and pupa, or a combination of these. The moths are nocturnal and both sexes come readily to light.

Biology.

Larva monophagous. It has been found on Juniperus phoenicea ( Staudinger 1859; Zangheri 1968; Corley 2004).

Habitat.

In a variety of habitat types where the foodplant occurs, including coastal dunes as well as non-sandy inland localities. From sea level up to 300 m; according to Redondo et al. (2009) up to 500 m.

Genetic data.

BIN: BOLD: AAD7906 (n=11 from Morocco, Portugal and Spain including the Balearics belonging to nominal subspecies) (Fig. 26). In Tunisia (putative subsp. holli) with two separate, sympatrically occurring BINs (BOLD: ABZ3161, n=3) diverging by 1.0% and (BOLD: ABZ6474, n=2) and by 2.2% from the Iberian and Moroccan populations. Ekboarmia sagnesi samples were nested within Ekboarmia atlanticaria groups (only short sequences available for the former, see Ekboarmia sagnesi ). Distance from Ekboarmia miniaria 3.5% and from Ekboarmia sagnesi 1.5%.

Similar species.

Forewing postmedial line weakly dentate and not angled outwards towards posterior margin in Ekboarmia atlanticaria (strongly dentate or zigzag-shaped and sharply angled outwards towards posterior margin in Ekboarmia fascinataria ). Forewing medial area narrow at posterior margin in Ekboarmia atlanticaria (wide in Ekboarmia fascinataria ). The not closely related Menophra harterti (Rothschild, 1912) has striated hindwings and forewing postmedial line is continuous, reaching wing margin below apex. The medial area of the not closely related Ecleora solieraria (Rambur, 1834) is not dark and hindwing postmedial line is rather straight (see Flamigni et al. 2007 for illustrations).

Remarks.

Taxon gracilis from Morocco has been considered valid at subspecies level (e.g., Scoble 1999; Leraut 2009). The description of taxon gracilis was based on a series of nine males and females, collected in August and November, and the specimens are very small and dark greyish-brown. In our opinion type specimens belong to a summer or autumn generation, probably developed under dry conditions. Wet conditions in winter and spring yield larger specimens (see Fig. 13g). Same hypothesis has been presented by Wehrli (1943 in Wehrli 1939-1954). One specimen from Moroc co was available for barcoding and it nested within Ekboarmia atlanticaria subsp. atlanticaria specimens from the Iberian Peninsula. Due to similarity in barcodes, adjunct geographical distribution on the opposite sides of Straits of Gibraltar, and presumably seasonal variation of external appearance, we synonymize Boarmia atlanticaria gracilis Albers & Warnecke, 1941 with Boarmia (?) atlanticaria atlanticaria Staudinger, 1859.