Agonopterix carduncelli Corley, sp. n.

Buchner, Peter, Corley, Martin & Junnilainen, Jari, 2017, Three new species and one new subspecies of Depressariinae (Lepidoptera) from Europe, ZooKeys 684, pp. 119-154 : 125-130

Agonopterix carduncelli Corley, sp. n.

Type locality.

Portugal, Algarve, Boliqueime, 70 m, 37°8'N; 8°1'W.

Holotype.

♂, Portugal, Algarve, Boliqueime, 24.xi.2011, M.J. Dale | Agonopterix carduncelli Corley Holotype | slide MD01355, DEEUR photo 0758 A. carduncelli | DNA barcode id. TLMF Lep 07015. Specimen to be deposited in NHMUK.

Paratypes.

Portugal: 1 ♂, Algarve, Boliqueime, 20.xi.2010, M.J. Dale, gen.prep. DEEUR 0757, in coll M.J. Dale; 1 ♂, Algarve, Mexilhoeira Grande, Cruzinha, 15.v.2011 ex l. iii.2011, Carthamus (Carduncellus) caeruleus , leg. M.F.V. Corley, DEEUR 0777, in coll. M. Corley; 1 ♀, same data but emerged 23.v.2011, gen. prep. DEEUR 0776, in coll. M. Corley; Spain: 1 ♂, Cuenca, Izotely, 30.ix.2008, leg. L. Srnka, gen. prep. DEEUR 2183, det. P. Buchner; Greece: 1 ♀, Messalongi Galatas, 5.v.2007, W. Schmitz, DEEUR 4404, det. P. Buchner; Morocco: 1 ♂, 1 ♀, High Atlas, Ifrane, 30.vi.1972, leg. F. Hahn, gen. prep. DEEUR 1983 (♂) bzw DEEUR 1980 (♀), det. P. Buchner; 1 ♂ same locality, 2.vii.1972, G. Friedel (ZSM), gen. prep. DEEUR 1677, det. P. Buchner.

Diagnosis.

The characteristic shape of segment 2 of the labial palp and the absence of a posterior crest on the thorax are features shared with a few other species mostly with similar coloration. A. straminella (Staudinger, 1870) is most similar with black dot at base of dorsum and black terminal dots together with paler hindwing, but lacks cell dots. Forms of A. carduncelli sp. n. without evident cell dots require genitalia examination to distinguish them from A. straminella . Other related species have better developed cell dots. In the male genitalia, A. carduncelli sp. n. is recognisable by the longer curved cuiller and broader valva in comparison with related species. The female is unique among European Agonopterix in the absence of a signum.

Description. Adult (Figs 8-9). Wingspan 19.5-21 mm. Head dull ochreous-buff, face creamy buff. Labial palp segment 2 with only the distal half rough-scaled and furrowed, pale buff with scattered light brown scales, segment 3 pale buff or ochreous-buff. Antenna with scape dull ochreous-brown, proximal part of flagellum ochreous-buff, ringed grey-brown, distally grey-brown. Thorax dull ochreous-buff often with darker median line, without posterior crest. Forewing pale ochreous-buff with faint pinkish tinge when fresh, with a variable amount of scattered light brown and blackish scales, particularly along veins towards termen and sometimes also in cell and between dorsum and fold; a black or brown dot at base of dorsum, a small dot in cell at two-fifths and usually another at end of cell; terminal spots dark grey-brown; a faint grey-brown stripe stretching through subdorsal area ending in a wider patch below end of cell; cilia pale ochreous-buff with weak cilia line. Hindwing light grey, darker in outer half; cilia light greyish ochreous with indistinct cilia lines. Legs pale ochreous-buff, foreleg blackish on upper side of tibia and part of tarsus. Abdomen light greyish buff.

Variation: Some specimens have many more scattered dark scales than others. The subdorsal spot can be distinct or dull pale brown; the cell dots may be obsolete, or if developed may still be indistinct due to the abundance of scattered scales; the development of the subdorsal streak is variable.

Male genitalia. (Fig. 12). Similar to related species, but gnathos almost exceeding socii by its own length, valva broader and smooth-sided, slightly curved, tapered to rounded apex; cuiller curving outwards at middle, parallel-sided, round and slightly wrinkled at apex, crossing four-fifths width of valva, longer than in related species due to broader valva. Fig. 13 shows male genitalia of the other six pallorella group species for comparison.

Female genitalia. (Fig. 14). Anterior margin of sternite VIII nearly straight, not bulging, ostium just beyond middle of plate; ductus bursae smooth, gradually expanding to corpus bursae; signum absent.

Description of larva. Head dark brown; prothoracic plate, thoracic legs and anal plate shining black; body deep purplish brown; pinacula black. Full grown larva a little exceeding 20 mm.

Molecular data.

Data of barcoded specimens. TLMF Lep 06978 (658 bp.[0n], ♂, Portugal, Mexilhoeira Grande, Cruzinha, 37°10'N; 8°37'W, leg. larva iii.2011 from Carthamus ( Carduncellus ) caeruleus , e.p. 23.v.2011, leg., cult. and coll. M. Corley P9827); TLMF Lep 06994 (620 bp.[0n], ♀, Portugal, Mexilhoeira Grande, Cruzinha, 37°10'N; 8°37'W, leg. larva iii.2011 from Carthamus ( Carduncellus ) caeruleus , e.p. 15.v.2011, leg., cult. and coll. M. Corley P9824, gen. prep. DEEUR 0776); TLMF Lep 07015 (658 bp.[0n], ♂, Holotype, Portugal, Algarve, Loulé, Boliqueime, 70 m, 37°8'N; 8°1'W, 24.xi.2011, gen. prep. MD01355, leg. and coll. M.J. Dale); TLMF Lep 07017 (658 bp.[0n], ♂, Portugal, Algarve, Boliqueime, 37°7'N; 8°9'W, 20.xi.2010, leg. and coll. M.J. Dale, gen. prep. DEEUR 0757).

Neighbour-joining analysis shows Agonopterix multiplicella (Erschoff, 1877) (BOLD:AAF7196, TLMF Lep 19102) as the nearest neighbour with 1.83% p-distance and A. straminella (BOLD:ABZ7581) as the second nearest neighbour with 2% p-distance. Intraspecific variability, based on present knowledge, 0.16% within the Portugese population. So far, genetic data are available only from Portugese specimens.

Differences in DNA barcodes arise over time through chance mutations. Such stochastic events sometimes lead to fairly unrelated species appearing as nearest neighbours. This is evidently the case with A. carduncelli sp. n. and A. multiplicella . The latter species has none of the characters of the pallorella group.

Etymology.

The species name, a noun in genitive case, is derived from the larval food-plant Carthamus [= Carduncellus ] caeruleus ( Asteraceae ).

Distribution.

Currently known only from Portugal, Spain, Greece and Morocco, but potentially more widespread around the Mediterranean with its food-plant.

Bionomics.

The larva feeds in the tips of shoots of Carthamus caeruleus (L.) C. Presl in late March before the flowers develop. Larvae from Algarve collected on 17 March 2011 emerged in captivity in May. Small larvae were collected on 25 March 2017 (Portugal, Beira Litoral, Ansião, M. Corley and J. Nunes) and reared on by J. Nunes. Two reached the final instar (Figs 15-16) but succumbed to parasitoids.

Remarks.

Agonopterix Hübner, 1825 with around 245 species ( Wikipedia 2017) mainly in the Holarctic region is the largest genus in Depressariidae . Unlike Depressaria , male genitalia are rather similar throughout the genus. Easily defined groups within the genus are less obvious than in Depressaria , but there are some such groups. One of these is the pallorella group which includes several closely related species all feeding on Asteraceae tribe Cynareae and sharing similar pale ochreous coloration, forewings without defined basal patch, oblique pair of dots reduced to one or absent, labial palp character istic with appressed scales on underside of segment 2 in proximal half, distal half with forward projecting scales making a triangular tuft, thorax without posterior crest. The species of this group are A. pallorella (Zeller, 1839), A. kaekeritziana (Linnaeus, 1767), A. bipunctosa (Curtis, 1850), A. broennoeensis Strand, 1920, A. straminella (Staudinger, 1870) and A. squamosa (Mann, 1864). A few other described taxa are synonyms of the above mentioned species. However one species has been previously overlooked and is described here as A. carduncelli sp. n.

The existence of an Agonopterix feeding on Carthamnus in Algarve, Portugal was suspected from the late 1990s when empty spinnings were found by M. Corley on the plant in late April. After Michael Dale found an adult of an undescribed species in 2010, a visit to Algarve in March 2011 by M. Corley targeting larvae on this plant was successful, resulting in two reared adults (see paratypes).

Two reared specimens (which survived the deterioration of their larval food-plant after M. Corley returned to England), show a grey-brown tinge in place of scattered dark scales and lack the row of terminal dots, but these features are shared by some of the Moroccan specimens.

Corley (2002) mentions a specimen without signum from Setúbal, Portugal in MNHN which was considered to be a possible aberration of A. mendesi Corley, 2002. As the signum is not known to be absent in any other Agonopterix species, it is extremely probable that this specimen belongs to A. carduncelli sp. n.