Bittacomorphella pacifica Alexander 1958

Fasbender, Andrew & Courtney, Gregory W., 2017, A revision of Bittacomorphinae with a review of the monophyly of extant subfamilies of Ptychopteridae (Diptera), Zootaxa 4309 (1), pp. 1-69 : 40-43

Bittacomorphella pacifica Alexander 1958

Bittacomorphella pacifica Alexander, 1958: 49 –50 (original description) Bittacomorphella pacifica Alexander, Alexander 1965: 98 (catalog)

Bittacomorphella pacifica Alexander, Alexander 1967: 171 (illustration) Diagnosis. Adult ( Figs. 7 c, 12). Legs with white confined to distal tip of 1st, 2nd & 3rd tarsomeres., paramere straight, subaedeagal sclerite of aedeagus with dorsal tooth.

Description. Larvae and pupae unknown. Adult. Measurements (n=5). Overall length 10.45mm (9.68– 11.16mm); head width (n=3): 0.85mm (0.82–0.89mm), height, 0.81mm (0.74–0.87mm), length 0.45mm (0.38– 0.53mm); antenna flagellum length 6.78mm, flagellomere proportions: 1.00, 0.70, 0.70, 0.70, 0.70, 0.70, 0.67, 0.67, 0.56, 0.56, 0.51, 0.48, 0.43, 0.43, 0.43, 0.40, 0.40, 0.35, 0.35, 0.08; maxillary palpus length 1.95mm; palpus segment proportions: 0.28, 1, 1.52, 0.96, 3.68; thorax length 1.49mm (1.31–1.67mm), height: 1.42mm (1.34– 1.55mm); wing length 7.38mm (6.70–8.30mm), width (n=4): 1.59mm (1.41–1.85mm); R3+4+5 stem 0.54mm straight, R4+5 stem 1.55mm, R4 after fork 1.16mm, R5 after fork 1.13mm, R3+4+5:R4+5-stem:R4 1.00, 3.03, 2.3, r-m 0.25mm, M distal to r-m 2.50mm, Mdistal:R3+4+5 5.13:1.00, R4:Mdistal 0.06, 1.00, CuA2 1.08mm; leg proportions, femur 1.0, 1.01, 1.04; tibia 0.96, 0.94, 1.04; tarsomeres, foreleg 0.53, 0.18, 0.13, 0.03, 0.03; midleg 0.56, 0.20, 0.14, 0.03, 0.03; hind leg 0.68, 0.23, 0.15, 0.03, 0.03; abdomen length: 8.81mm (8.00– 9.96mm), Male tergite proportions 1.00, 3.37, 1.98, 1.87, 1.53, 0.78, 0.14; male genitalia width: 0.76mm, height 0.71mm. Frons medial suture indistinct, most prominent between antennal bases. Antennal scape with three setiform sensilla midway along anterior margin; 20 flagellomeres. Face narrow, incised by clypeus nearly to dorsal margin. Hypopharynx subconical triangular, directed anterior-ventrally. Labium extending beyond clypeus. Labella partially fused medially. Antepronotum dorsal margin rounded. Scutum glabrous, pollinose, fuscous. Scutellum muddy yellow, prescutellum absent. Mediotergite ruddy-brown. Paratergite poorly developed, narrow, scythe-like. Sub-paratergal membrane subquadrate, lightly sclerotized, anepisternal suture absent. Pleurites ruddy brown. Wing membrane with scattered macrotrichia on distal 1/10 of wing, in cells R1+2, R3, R4, R5, M; veins C to wing apex, Sc, R s, R1, R3, R4 & R5 after forking and distal portion of M with macrotrichia; alula undeveloped. Posthalter poorly developed protrusion, free of webbing. Coxae yellow, overall leg coloration brown. White banding confined to distal tip of 1st, 2nd & 3rd tarsomeres. Empodium notched proximally. Abdominal tergites and sternites ruddy brown. Male. Epandrium about 1.5x as wide as long; weakly bowed dorsally, rarely with weak internal suture present, posterior corner subobtuse, internal fold arcing weakly anteriorly, ending near medial margin of posteriomedial style; posterior margin emarginate across 1/2 of medial margin, posteromedial style blunt triangular lobule. Epandrial claspers evenly tapering along length to sub-acute point, curved sub-circularly dorsoanteriorly. Parameres glabrous, dorsoventrally flattened basally; distal portion dorsoposteriorly directed acute straight spine tapering to fine point. Gonocoxite conical, expanding to gonostylus. Gonostylus 1.5x length of gonocoxite, moderately expanded at base, inner apex sensilla single row of 10–11 along distal-medial surface, arising from dorsal margin anteriorly and shifting ventrally posteriorly; three additional sensilla on medial surface near gonocoxite. Basal division of hypandrium with medial suture present to lacrimiform membranous region; terminal division wellarticulated, proximal portion dorsally cupped pouch longer than wide; apical portion lateral margins fused to narrow tube, width narrower than proximal portion, end closed. Aedeagus with sperm sac as described for subfamily, except lateral membranous windows highly reduced. Lateral ejaculatory process broad and triangularly winglike, swept-anterior, apex rounded, dorsolaterally compressed at base, rotating to completely laterally compressed apex, low longitudinal ridge present on posterior surface emerging from ventral section; ventral lobe small, rounded, not incising sperm sac. Ejaculatory apodeme teardrop shaped, expanding to rounded apex. Aedeagal sclerites not tapered. Apical apodemes simple, dorsoanterior extension of subaedeagal sclerite articulating only on posterior margin. Subaedeagal sclerite ventral arm triangular, apex directed anterior; external portion narrow tapering, curved dorsally towards apex, dorsal surface with broadly triangular denticle immediately prior to apex. Female. Epigynium trapezoidal, flat dorsally, posterior margin straight, lateral margins straight, posterior margin indistinct, medial suture indistinct. Cerci articulation indistinct, dorsal margin weakly convex, apex broadly rounded, ventral margin slightly convex, with an even arc; apical cylindrical nodule with single elongate trichoid sensilla medially; cercus epigynium ratio 0.5, 1. Hypoproct trapezoidal, narrowing posteriorly, base with heavily sclerotized subtriangular lobe directed posteriorly. Genital fork T-shaped, lateral apices weakly curved anteriorly. Hypogynium quadrate, posterior corners triangular lobes, hypogynial valves not distinguishable, medial notch absent.

Type material examined. Holotype. UNITED STATES. WASHINGTON. Pierce Co. Mt. Rainier, Wash. 4700 ft., Jul. 21 1940, H.&M. Townes, Lower spec . ♂ = Holotype [pinned 1 ♂, head and genitalia on slide; USNM]. Paratypes. Same locality as holotype [pinned 1 ♀, same pin as holotype; USNM)]. CALIFORNIA .

Siskiyou Co. Castle Crags, 6.vii.1953, coll. C.P. Alexander [pinned 2 ♂ on same pin; slide 1 ♂; USNM] . OREGON. Yamhill Co. Dayton, 19.ix.1946, coll. K.M. Fender [pinned 1 ♂; USNM] .

Other material examined. CANADA. BRITISH COLUMBIA. Robson , 5.vi.1938, coll. H.H. Foxlee [pinned 1 ♂, 1 ♀; UMMZ] . UNITED STATES. OREGON. Benton Co. Mid Parker Creek , 8.viii.1981, coll. G.W. Courtney [alcohol 1 ♂; ISIC] ; Clackamas Co. Mt. Hood, 29.vii.1921, coll. A.L. Melander [pinned 1 ♂; USNM] ; Douglas Co. 3 mi. E. Reedsport , Schofield Slough, 23.iv.1964, coll. J.D. Vertrees, J. Schuh [pinned 1 ♂; WSU] . WASHINGTON. Snohomish Co. Everett, 4.vii.1924, coll. A.L. Melander [pinned 2 ♂; USNM] ; Thurston Co. Olympia, 10.vi.1891, no collector [pinned, 1 ♀; WSU] .

Taxonomic notes. Bittacomorphella pacifica can be distinguished by the combination of a pollinose scutum, straight, needle-like parameres and a dorsal tooth-like projection on the subaedeagal sclerite of the aedeagus. Many specimens determined as Bl. sackenii are actually this species.

Distribution. Fig. 19 a.

Figures

FIGURE 7. Bittacomorphine male wings. a. Bittacomorpha clavipes; b. Bi. occidentalis; c. Bittacomorphella pacifica Alexander; d. Bl. sackenii Von Röder; e. Bl. furcata sp. nov.; f. Bl. esakii Tokunaga; g. Bl. fenderiana; h. Bl. jonesi Johnson; i. Bl. nipponensis Alexander; d. Bittacomorphella thaiensis Alexander. All scale bars 1 mm except “ b ” (2 mm).

FIGURE 19. Nearctic Bittacomorphella distributions. a. Bl. pacifica; b. Bl. furcata (star & square) and Bl. sackenii (circles); c. Bl. fenderiana; d. Bl. jonesi. Stars indicates type locality.