Holotype ♂: Methana, Greece, 550 m, e.l. 6.xii.2012, leg. Henderickx.

Paratypes: 18 ♀ Methana, Greece, N 37.611348, E 23.365761, 550 m, e.l. Nov.- Dec. 2012 and 2014, leg. Henderickx.

The holotype and two paratypes will be deposited in the “Staatliches Museum für Naturkunde Karlsruhe” (SMNK), Germany. The other paratypes are deposited in the private collections of WA and M. Weidlich (Neißemünde, Germany).

We gratefully dedicate this nice new species to Jan Keersmaekers, Mol (Belgium), who joined HH on the Greek expeditions and helped collect the cases with his son Tom.

(Fig. 1a). Wingspan 11 mm. Head appearing hairy, frons and vertex with rough yellowish brown scales of variable length; external ocelli present; labial palp reduced to 3 segments; antenna thread-like with 26 segments; regularly short ciliated. Forewing length 5 mm; ground colour yellowish grey, basally and postdiscally with 2 broad interrupted brownish bands; at inner margin two distinct spots of ground colour; submarginally the veins with darker brownish scales forming a distinct reticulate pattern; costal margin with a series of dark brownish spots. Scales moderately broad, with 3–4 dentations (class 5 after Sauter 1956); fringe scales long, light greyish, becoming distinctly longer at the last third of inner margin; narrow, with 3-4 dentations. Hindwings uniform dark greyish, slightly glossy, scales narrow (class 2 after Sauter 1956). Venation hardly visible under magnification, with 10 veins from discal cell; accessory cell present, intercalary cell absent. Forelegs with tibial epiphysis, midlegs with one pair of apical tibial spurs, and hindlegs with medial and apical tibial spurs.

Figure 1. 

Pseudobankesia keersmaekersi sp.n. a. ♂ holotype; b. ♀ paratype; c. ♀ larval case; d. detail of case decoration with insect debris and land molluscs; e. ♀ on larval case; f. larval case decoration with land mollusks.

Male genitalia

(Fig. 2b) typical for Pseudobankesia (Fig. 3), resembling the likely most-closely related genus, Taleporia. Tegumen conical, flat, indented distally, and with two downward-directed lobe-shaped sharp pointed appendages; clasper of sacculus short, broad, and with a distinctly pointed process distally; saccus often very short, but also medium-sized and pointed in other species; valva folded distally, extending beyond distal end of tegumen, more slender than in Taleporia, covered with hair and short spines. Phallus short and thin, curved, with setae in the distal half. Genital index (phallus length / valva length) 1.02 (n = 1).

Figure 2. 

a. Pseudobankesia keersmaekersi sp.n. paratype female, head and legs after maceration in 20% KOH; b. male genitalia of Pseudobankesia keersmaekersi sp. n., holotype.

Figure 3. 

a. Pseudobankesia arahova Stengel, 1990, ♂, Greece, Sterea Ellas, Parnassos Mts., e.l. 22.v.2002, leg. Weidlich (coll. M. Weidlich); b. Pseudobankesia darwinii Stengel, 1990, ♂, holotype, Greece, Peloponnese, Mt. Helmos, e.l. 8.vi.1989, leg. Stengel (coll. Museum Witt Munich).

(Fig. 1b). Wingless. Length 5.5–6.0 mm (excluding ovipositor), body segments creamy yellowish. Dorsally head and thorax brownish and sclerotized; each segment covered with fields of blackish hair; ventrally less sclerotized. Eyes black, very small; antenna with 13–15 segments. Anal hair-tuft undulated, yellowish grey. Legs with 2–3 tarsal segments, spur of third tibia absent or very short.

Female genitalia with antrum and antevaginal plate distinctly sclerotized, two pairs of long apophyses, lateral plates triangular, pointed, postvaginal plate indistinct.

Male length 9 mm, width 3 mm, female length 9–12 mm, width 4–5 mm, distinctly triangular in cross section. Light greyish brown, sparsely covered with plant debris and sand (Fig. 1c–f). The edges of the often broad cases are mostly ornamented/accentuated with organic material, the larval opening with larger invertebrate parts (i.e. ant debris and small land molluscs). It is especially remarkable that several specimens used minute juvenile snails of the family Zonitidae to decorate the cases at the larval opening.

Based on the differentiation in the DNA barcode, P. keersmaekersi is well separated from the other species in the genus (Fig. 4). The nearest species is P. kresnensis Weidlich (2016a), with a distance of 7%. The distances to the next closest species of the genus are 8% to P. aphroditae Weidlich & Hendericks (2002), 11% to P. lichenaria Weidlich (2016), 12% to P. vernella (Constant, 1899) and 14% to P. alpestrella (Heinemann, 1870) (Table 1). No genetic data are available for P. arahova Stengel (1990) and P. darwinii Stengel (1990). In the future, sampling of Pseudobankesia species should be increased to include more specimens per species, as well as other species in the genus.

Figure 4. 

Neighbour-joining barcode tree showing the clustering of seven Pseudobankesia and two Bankesia species with another psychid species Dahlica mannii as the outgroup (scale bar = 2%).

Placement of the new species in Pseudobankesia is based on the regular ciliation of the antennae of the male. Those of the probably most-closely related genus Bankesia have brushes of long hairs basally on both sides of each segment. On the other hand, females of P. keersmaekersi sp. n. have long antennae with 13–15 segments, while those of Bankesia species have short antennae with only 3–6 segments. The male genitalia of Bankesia are very different from those of Pseudobankesia. They are flat in general appearance and the tegumen is narrow, conical, and slightly indented, while the genitalia of Pseudobankesia are much higher in lateral view and the tegumen is more or less triangular. The valvae are long and slender, much more slender than in Pseudobankesia and like them protrude considerably beyond the distal end of the tegumen. The clasper of sacculus is sharply extended, thorn-shaped, curved inwardly, while that of Pseudobankesia is short and broad with a distinctly pointed process distally. The phallus is very thin, two-thirds length of valva, almost straight and not curved as in Pseudobankesia, in which it is tubular and slightly enlarged caudally with setae in the distal half. Further, as far as we know, the genus Bankesia is distributed only in western and south-western Europe and the presence of a Bankesia species in Greece seems unlikely. However, recently Bankesia cephalonica Weidlich, 2016b, was described from an Ionian island, Kefalonia.

P. keersmaekersi is one of the larger Pseudobankesia species (wingspan 11 mm). The male (holotype) is distinctly characterized by its remarkable colouration and the very special wing pattern which is unique within the whole genus. Therefore, it cannot be confused with males of other Pseudobankesia species (Table 2). The geographically close Pseudobankesia species P. darwinii and P. arahova (Fig. 2a,b) differ from P. keersmaekersi sp.n. in the distinctly darker colouration and the remarkable female cases, which are broader.