Pelecystola Meyrick, 1920

Davis, Steve & Davis, Donald, 2009, First report of the old world genus Pelecystola in North America, with description of a new species (Lepidoptera, Tineidae), ZooKeys 25 (25), pp. 69-78 : 70-71

Pelecystola Meyrick

Pelecystola Meyrick, 1920: 103 . Type species: Pelecystola decorata Meyrick, 1920 . Zularcha Meyrick, 1937: 75 . Type species: Zularcha melanochares Meyrick, 1937 . Neurozestis Meyrick, 1938: 25 . Type species: Neurozestis polysticha Meyrick, 1938 .

Adult. Moderately large-sized tineid moths with forewing lengths 5.4–10 mm.

Head (Figs 2–3): Vestiture rough; vertex and frons densely covered with erect, piliform scales with acute apices. Antenna simple, ciliate, bipectinate in P. strigosa Moore , ̴ 0.5– 0.6× length of forewing; scape slightly flattened, smoothly scaled, with pecten consisting of 6–25 bristles; flagellum with a single row of moderately broad scales dorsally on each segment. Eye moderately developed; interocular index ̴ 0.6; frons broad. Ocellus absent. Pilifer undeveloped. Mandible vestigial. Galea reduced, ̴ 0.9–1.0× length of maxillary palpus. Maxillary palpus elongate, 5-segmented, with apical segment minute; length ratio of segments from base: 1.0: 0.9: 1.0: 3.75: 0.3–0.4. Labial palpus well developed; length ratio of segments from base: 1.0: 3.2: 1.7; vestiture relatively smooth dorsally, moderately rough ventrally with 2–8 dark, elongate bristles arising mostly laterally along segment 2.

Thorax: Forewing (Fig. 4) moderately slender, W/L ratio ̴ 0.35, apex moderately rounded. Venation well preserved with most veins distinct. Forewing venation variable, usually with all 5 branches of R present and separate; Rs2 absent in P. decorata, Rs 3 and 4 stalked in P. decorata and P. strigosa ; accessory cell distinct, mostly closed; M1–3 all separate; CuA1–2 well preserved; CuP indistinct for most its length; A1 and 2 with basal fork, then fused nearly 2/3 their length; male retinaculum an elongate, basal, ventral fold, curled distally; female retinaculum consisting of a loose concentration of elongate hairs from ventral base of Sc. Hindwing W/L ratio ̴ 0.4; M1–3 all separate; CuA1 and 2 well developed; 1A + 2A well preserved; 3A distinct; frenula a single stout bristle in male, 2 tightly appressed bristles in female. Legs with tibial spur pattern of 0–2–4; epiphysis well developed, more than half the length of foretibia; tibial spurs of unequal lengths.

Abdomen: Without specialized structures; S2 apodemes slender, nearly straight, elongate, ̴ 0.5–0.7× length of S2. Male coremata and female corethrogyne absent.

Male genitalia: Uncus usually deeply bilobed, superficially bilobed in some African species. Gnathos absent. Vinculum and tegumen a relatively broad ring, with lateral fusion indistinct; saccus usually short, more elongate in P. polysticha . Valva deeply divided into two (cucullar and saccular) lobes; an elongate, slender stalk arising from extreme base of costal margin of valva which enlarges apically to form a spatulate tip bearing a pectinifer consisting of a single row of minute spines. Juxta absent. Aedoeagus usually a slender, moderate to elongate cylinder; cornuti absent.

Female genitalia: Ovipositor elongate, telescoping. Posterior apophysis ̴ 1.7–1.9× length of anterior pair. Ventral pseudapophysis absent. Ostium bursae a sclerotized ring located near anterior margin of sternum 8. Ductus bursae slender, exceeding length of anterior apophysis, with lightly sclerotized antrum. Corpus bursae relatively large, ̴ 0.5–0.7× the length of ductus bursae, mostly membranous, with a V-shaped signum consisting of a pair of slender arms converging and partially fused posteriorly.

Discussion. The generic and subfamily relationships of this aberrant genus are uncertain. Gozmány and Vári (1973) suggested that Pelecystola could be included within the Scardiinae based on superficial characters, a conclusion also followed by Sakai (2002). A specimen of the new species, P. nearctica , along with numerous other genera of Tineidae , have been sequenced for five nuclear genes as part of the Lepidoptera Tree of Life project, supported by the U.S. National Science Foundation. Results from these sequences have yet to be analyzed, but it is hoped that they might provide better resolution of the subfamily relationships of Pelecystola . As pointed out by Gozmány and Vári (1973) and others, Pelecystola is largely characterized by the peculiar pedunculate pectinifers arising on long stalks from the costal base of the male valvae. As discussed by S. and D. Davis (2009), few tineid genera are known to possess a pectinifer on the valva. Of those that do, the slightly more complex pectinifers of the South American genus Falsivalva resemble those of Pelecystola the most in arising on slender stalks from the extreme base of the valvae. However, the two genera share little else in common. The male genitalia of Falsivalva differ from that of Pelecystola and all other Tineidae in the extreme development of a greatly lengthened and almost completely divided tegumen ( Davis and Davis 2009). In addition, the female genitalia of Falsivalva lack signa.