Spinivalva Moreira & Vargas

Brito, Rosangela, Goncalves, Gislene L., Vargas, Hector A. & Moreira, Gilson R. P., 2013, A new Brazilian Passiflora leafminer: Spinivalva gaucha, gen. n., sp. n. (Lepidoptera, Gracillariidae, Gracillariinae), the first gracillariid without a sap-feeding instar, ZooKeys 291, pp. 1-26 : 4-8

Spinivalva Moreira & Vargas gen. n. Figs 111

Type species.

Spinivalva gaucha Moreira and Vargas, sp. n\. by present designation.

Diagnosis.

Spinivalva males show several abdominal and genital features that in conjunction differentiate this taxon from all known gracillariid genera: 1) saccular extension of valva abruptly narrowing distally, forming a single, medially bent process bearing a stout sensillum at the apex; 2) aedeagus tubular, slender, straight and long, ending as a sharply pointed spine; 3) saccus with anterior process long and tubular; 4) two pairs of coremata, each with two unit types that are formed by an external hair pencil and a tubular, membranous, corrugated pouch. In the female genitalia, the circular ostium bursae is located near the anterior margin of sternum VII, having a membranous corpus bursae associated with an accessory bursa, with no signum. The larvae construct mines on the adaxial surface of passion-vine leaves; initially the mines are serpentine in shape but later in ontogeny become a blotch type. Unlike all known stages of other leaf-miner gracillariids, Spinivalva gaucha has no larval sap-feeding instars; all instars of its larvae have a conspicuous spinneret and mandibles of the chewing type, and feed on the palisade parenchyma after hatching. Pupation occurs outside the mine; the larva excretes numerous bubbles that are aligned on the lateral margins of the cocoon surface prior to pupation.

Description.

Adult (Figs 1-4). Male and female similar in size and color. Small moth, forewing length 2.78-3.61 mm (n = 5). Head (Fig. 2A): Vestiture moderately smooth, with a large, light-gray dorsal scale tuft that curves forward to the frons; scales slender, with apices slightly rounded. Eye relatively large, rounded, with dorsal margin slightly concave; vertical diameter ~ double minimum interocular distance across frons (n = 6). Antenna filiform, long, exceeding length of forewing; scape slightly elongate, ~ 2.4 × length of pedicel; flagellomeres completely encircled by single, dense row of slender scales. Labrum trilobed, pilifers well developed, triangular. Mandible absent. Haustellum naked, elongate, ~ 2.0 × length of labial palpus. Maxillary palpus short, smoothly scaled, 4-segmented; ratios of segments from base: ~1.0: 2.2: 3.6: 3.5. Labial palpus smoothly scaled, moderately long, bent anteriorly and upward; ratio of segments from base: ~1.0: 4.6: 0.3. Thorax:Forewing (Fig. 2B) lanceolate, with 12 veins, all arising separately from the cell and reaching the margin; L /W index ~ 7.3; retinaculum consisting of few subcostal, narrow, flat, longer, loosely coiled scales (Fig. 2C); discal cell ~ 0.8 × length of forewing (n = 4) ending near distal fifth of wing margin; R5-branched; R1 ending near proximal third of wing margin; M3-branched, CuA not branched, and faded basally; CuP weak proximally and not stalked, with 1A+2A that is well developed, extending past midlength of posterior margin. Hindwing (Fig. 2B) extremely lanceolate, L/W index ~ 9.6, ~ 1/8 forewing in length; male frenulum (Fig. 2D) a single stout bristle; female with frenulum divided at base, then fused for nearly its entire length and appearing as a single stout bristle; pseudofrenulum consisting of ~8 modified scales arising in two to three irregular rows near Sc+R1 ending at circa 1/5 anterior margin; Rs faded proximally, ending at circa 1/3 anterior margin; M and CuA unbranched, both faded proximally and weak distally, ending at circa 1/3 and 2/3 of posterior margin. Legs with tibial spur pattern 0-2-4; epiphysis present. Tibial length ratios (anterior / middle / posterior legs) ~ 0.55/0.85/1.0. Abdomen: Male with segments VII-VIII complex and reduced, except for enlarged tergum VIII; segment VII reduced to narrow, almost completely sclerotized ring; tergum VIII elongate, hoodlike, partly covering tegumen; sternum VII bearing two pairs of coremata, arising from distal apex of rodlike sclerites that protrude from intersegmentary membrane VII-VIII; each coremata (Fig. 3D) bearing two types of units - an external hair pencil (~ valva in length) and a tubular, membranous, corrugated pouch; pouches of anterior pair ~ ½ hair pencil in length; those of caudal pair double in size (near to hair pencil in length). Female postabdominal segments unmodified.

Male genitalia (Figs 3 A–C, 4A, B, D, E). Uncus absent. Tegumen broad, hood-shaped, mostly membranous, with shallow apical notch. Pair of long, distally narrower, membranous lobes arising ventrally beneath tegumen. Vinculum long, broadly V-shaped, extending laterally along base of valva. Saccus well developed, U-shaped; anterior process long and tubiform, ~1/2 length of valva, apex slightly capitate. Transtilla an arched, sclerotized plate joining bases of valvae. Juxta small, a dorsally concave, membranous plate, attached to middle of aedeagus. Aedeagus (Figs 3B, 4E) tubiform, slender, straight and long (~2 × valve length), slightly dilated caudally, with subapical, dorsally located concave aperture and ending as sharply pointed spine; entry of ductus ejaculatorius located at anterior end; vesica without cornuti. Valva (Figs 3C, 4A, B, D) broad at base, and deeply divided; costal margin relatively straight and distally rounded; cucullus densely covered by long piliform setae; sacculus with broad lobe abruptly narrowing distally, ending as a medially bent process with apex bearing a stout, blunt sensillum.

Female genitalia (Figs 3E, 4C, F). Sternum VII subtriangular; anterior margin linear; posterior margin with narrow notch. Tergum VIII subtriangular. Anterior apophysis with arms slightly curved, similar in length to posterior apophyses. Anal papillae connected dorsally, covered with long piliform setae and microtrichia. Ostium bursae moderately wide, located on anterior margin of sternum VII. Ductus bursa membranous, wider in middle, forming an accessory bursa ~ 1/3 length of corpus bursae. Corpus bursae membranous, gradually broadening posteriorly, ~ twice length of ductus bursae. Ductus seminalis membranous, narrow, inserted on distal portion of accessory bursa. Signum absent.

Etymology.

The genus name is derived from the Latin spina (spine) and valva (valve), in reference to the conspicuous spine-like process present on the male valvae. Gender feminine.