Conchopus crassinervis, Masunaga, Kazuhiro & Saigusa, Toyohei, 2010

Masunaga, Kazuhiro & Saigusa, Toyohei, 2010, A revision of the Hawaiian and Wake Island species of the genus Conchopus Takagi (Diptera, Dolichopodidae), Zootaxa 2729, pp. 1-35 : 13-19

Conchopus crassinervis sp. nov.

( Figs. 7 , 8 , 9 , 18 c, 19b)

Diagnosis. Small-sized species (3.0– 3.9 mm in body length) characterized by 1st flagellomere 1.5 times as long as its basal thickness; halter yellow. In male, M1+2 thickened, apical section of M3+4 2.6 times as long as discal crossvein; fore tarsomere 1 with large basal lobe 2/5 as long as tarsomere 1, strong incision distal to basal lobe, minute ventral bristle beyond midlength, and moderately large apical swelling; longer dorsal bristle of fore tarsomere 2 situated 1/3 from base; mid tibia flattened, with long erect bristles and setae on anterior surface and long erect bristles on posterior surface; mid tarsomere 1 with a few long erect setae on anterior surface; apical 1/2 of ventral lobe of hypopygium narrow and parallel-sided.

Description. Male: Body length 3.2–3.9 mm; wing length 3.2–3.5 mm. Head: l.8–1.9 times as deep as long; frons, vertex, and upper half of occiput blackish-brown pollinose; frons with pair of tiny white spots between frontorbital bristles; ventral half of occiput thinly covered with dark brown pollen not entirely concealing dark greenish color of cranium; face and palpus pale ash-gray pollinose; proboscis dark brown with thin coating of grayish pollen along ventral margin of labella; face at narrowest part 0.2 times as wide as head, gradually widening dorsally and ventrally, widest ventral part nearly l.5 times as wide as narrowest portion. Proboscis 0.5–0.6 times as long as eye height. Antenna blackish brown, 0.6 times as long as head; 1st flagellomere 0.9–1.1 times as long as 2 basal segments together, and 1.5–1.8 times as long as thick; arista l.6 times as long as 3 antennal segments combined. Thorax: Pleura gray to dark-gray pollinose; mesonotum marked with dense coating of pollen; humerus dense grayishbrown pollinose; inverted Y-shaped mark deep velvety black with borders sharply defined, whitish area densely pollinose and ground color of integument entirely concealed; 1st dc on white area, 2nd dc on border near base of branch of black marking; presutural dark prolongation distinct, beginning from sutural bristle and reaching to base of lower presutural; supraalar area deep blackish brown, hardly separable from velvety black marking; prescutellar white marking elongate-triangular, basal portion somewhat incised by brown area of posterior calli, 4th dc on blackish area, 5th dc and 6th dc on border; dark incision of prescutellar white area triangular, with its top (anterior extremity) reaching to level of 5th dc, this dark triangle being 5/7 as high as prescutellar white marking. Postalar callus and scutellum dark grayish-brown pollinose. Chaetotaxy: acrostichals 9–14 in number, irregularly biserial in front, uniserial behind, ending midway between 1st and 2nd dc and level of 5th dc, reclinate before 4th dc, bent posteriorly near 3rd and 4th dc, erect or proclinate near 5th dc. Propleurals 4–5, mesopleurals 4–6, arranged in row close to upper part of hind margin of anepisternum, upper- and lowermost setulae strong, l–2 lowermost ones usually isolated from others and distributed at level of ventral extremity of basalare; metapleurals l–2 (mostly l). Scutellum with inner pair of strong bristles and 0–2 outer weaker bristles. Legs: Coxae and femora gray to dark gray pollinose, greenish tinge of femora slightly apparent when viewed from some directions. Tibia and tarsi blackish brown (fore tarsomere 1 partially brownish) with thin coating of dark gray pollen. Foreleg ( Figs. 7 a-b): Coxa clothed with irregular, tri- or quadriserial fine short setae on anterior surface, with another anterior row of weaker marginal bristles. Femur 4.8–4.9 times as long as thick, gradually tapered apically, clothed beneath with rather stiff bristles (slightly shorter than thickness of fore femur) towards base; preapical tubercle situated 0.3 from tip. Tibia slightly curved dorsally towards tip, preapical portion weakly swollen, about l.6 times as thick as narrowest part; 2 pairs of dorsal bristles sometimes distinct, anteroventral setae somewhat erect on apical 1/3, posteroventral setae weaker than anteroventral ones; anterior preapical mass of setulae fairly well developed. Tarsus short, 0.9 times as long as tibia. Tarsomere 1 short, almost straight along dorsal margin, incised in apical part of basal lobe; basal lobe well developed, nearly straight on basal margin, roundly constricted on ventral margin, 0.7–0.8 times as thick as long, 0.4 times as long as tarsomere 1, with 7–9 submarginal and 3–4 marginal setulae, these setulae rather short, also l–2 minute setulae on posterior surface of basal lobe; no strong ventral bristle on weakly raised ventral keel between apical swelling and basal lobe, this keel only ciliated with several weak setulae, subequal in length to each other; several stronger setulae appearing between apical swelling and this keel; apical swelling roundly produced distally (thickness at apical swelling 0.6–0.7 times that of basal lobe); anterior preapical cluster of setulae close to tip of tarsomere 1, but center of mass situated slightly basally from posterior preapical bristle. Tarsomere 2 with strong anterodorsal bristle 0.6 times as long as from base of tarsomere 1 and situated 0.4–0.5 of way from base of tarsomere 1, and with additional slightly shorter bristle at 0.5–0.6 of way from base. Tarsomeres 3 and 4 simple. Midleg ( Figs. 7 c, 19b): Coxa with row of many bristles from center of outer surface to anterodistal corner, uppermost bristle very strong, bristles on anterodistal corner dense and scattered. Femur distinctly curved ventrally beyond middle, considerably depressed in apical half, with almost straight posterior margin and gently arched anterior margin; thickness of basal portion of femur l.6–2.0 times of that of preapical portion; anteroventral row of setae much reduced, represented by a few strong, erect, subbasal bristles (strongest one slightly shorter than thickness of middle femur and situated on basal l/4, l–2 shorter ones situated more basally than this) and 0–2 weak setae on apical l/4; posteroventral row of setae also reduced, represented by 2 subbasal bristles (more apical one stronger, slightly longer than thickness of middle part of femur and situated slightly more basally than strongest anteroventral bristle), l (rarely 2) middle bristles (as long as thickness of mid femur or slightly shorter), and 2–3 bristles on apical l/4; femur also with 3–4 anterior bristles on apical l/3 and subventral preapical bristle on each side. Tibia depressed dorsoventrally, in middle l.5 times as wide as thick, evenly but weakly sinuate posteriorly, slightly clavate preapically. Chaetotaxy of tibia: all long bristles and setae erect; row of upper anterodorsal setae normal, ending in normal seta; 4–5 anterodorsal bristles longer towards tip (longest one l.5 times as long as width of middle tibia); row of lower anterodorsal setae normal, ending in slightly longer seta; anterior row consisting of normal setae on basal l/2–2/5 and 5–6 fine, curved, long setae (3 times as long as width of middle tibia); anteroventral row consisting of normal setae basally but more or less erect, stiff setae on apical 4/5, and ending in strong bristle (1.5 times as long as width of middle tibia); posteroventral row of normal setae on basal half and more or less erect sparse setae on apical half and ending in strong bristle (1.5 times as long as width of middle tibia); posterior row consisting of normal setae on basal 1/3, 6–7 strong bristles on apical 2/3 (longer towards tip, longest one l.7–1.8 times as long as width of middle tibia, usually with l–2 setae between bristles), and ending in strong preapical bristle (l.5–1.6 times width of middle tibia); lower posterodorsal row of normal setae with very long preapical hair-like bristles (3.0–3.3 times width of mid tibia); one subbasal and 1 near middle of tibia; upper posterodorsal row of normal setae with strong preapical bristle (1.5 times as long as width of mid tibia). Tarsomere 1 with 2–4 long erect anterior setae (ca 2/3 as long as tarsomere 1), l–3 shorter posterior bristles, and some stiff preapical setae. Tarsomeres 2–5 slender and simple. Hindleg: Coxa with strong distal bristle and one weak subapical seta on outer surface, and fine long seta at anterodistal corner. Femur slightly sinuate ventrally towards tip, distinctly curved posteriorly, thickest at basal l/4, then gradually tapered apically, antero- and posteroventral rows of setae reduced into fewer than 10 setae each, mostly distributed in basal half of femur, longest anteroventral setae nearly l/3 as long as thickness of hind tibia longest posteroventral ones 2/3 as long as thickness of hind femur. Tibia almost straight, with weak posteroventral preapical process slightly longer than thickness of hind femur and with tip only slightly exceeding tip of tibia, 2 antero- and 2 posterodorsal short bristles (basal ones l/4 of way from base, apical one beyond midlength), and sometimes additional posterodorsal bristle l/4 of way from tip; anteroventral setae suberect and as long as thickness of hind tibia, posteroventral setae curved and closely pressed to leg integument; among preapical setae, lower anteroventral one fine and long (as long as width of hind tibia), anteroventral one strong. Wing ( Fig. 18 c): Entirely pale gray, with brownish tinge on basal half of space C and basal cell 1, most of veins and fold along M1+2 and M1 blackish brown. Wing somewhat broad, 2.8–3.0 times as long as wide, with costa weakly arched, basal 1/3 of R2+3 and R4+5 thickened towards base, thicker than middle of Sc; R2+3 gently diverging from R4+5 towards tip for basal 3/5, then parallel with R4+5 for apical 2/5. M1 thickened from basal l/3 of discal cell to basal 1/3–2/5 of M1, upper side of this thickened portion overlapped by wing membrane from posterior side; discal crossvein slightly oblique; ratio of M1 to apical section of M1+2 1.6–1.8; ratio of middle section of M3+4 to apical section of M3+ 4 l. 7– 1.8. Halter yellow; bristles and setae black. Abdomen ( Fig. 8 a-c): Abdominal terga gray to dark-gray pollinose, tergal integument slightly appearing when viewed from some directions; terga evenly clothed with short setulae. Sternum 1 widely and strongly emarginate anteriorly, fused with sternum 2 along most of hind margin; sterna 2–3 normal; sternum 4 with pair of distal subventral bristles, not spine-like, but easily distinguished from other setae, and with strong seta at each posterolateral corner. Sternum 5 with pair of subventral clusters of 1–2 spine-like bristles; subventral row consisting of a few longish setae mixed posteriorly with scattered setae widely covering posterolateral portion of sternum; hind marginal stiff setae weakly curved at tips; posterolateral spines strong. Sternum 6 nearly 1.6 times as wide as long (excluding apodemal process), with anterior margin 2/3 as long as posterior margin, lateral margins weakly rounded, distal membranous area large, and pair of anterior apodemal processes slender and divergent from each other. Pedunculate process of sternum 6 long; with membranous club short and thick, 0.5 times as long as process itself, and in profile anterior margin evenly convex, posterior margin convex in basal half, then almost parallel with anterior margin, distal margin truncate with bluntly angled anterodistal and rounded posterodistal corners; spinules of anterolateral surface prominent, those of anterior surface small and compact, posterior surface densely but minutely tuberculate, each tubercle with short, pile-like process. Hypopygium ( Figs. 9 a- e): Epandrium and tergum 8 with more whitish pollinosity than other terga. Cercus l.3 times as long as height of epandrial capsule, slender and very elongate, broadly and shallowly emarginate on inner margin, widest at apical l/ 4, with apical portion gently tapered apically and curving outwardly. Ventral lobe 0.7 times as long as cercus, flattened rather laterally, weakly dilated apically in basal half, then produced into short anterior process and long, parallel-sided posterior process nearly 0.5 times as long as whole length of process. Hypandrium 0.6 times as long as ventral lobe, ventral margin very convex basally; anterior process of hypandrium tapered apically, bearing bristle on outer surface (not on anterior margin); posterior process much shorter than anterior one, with large lamellate dentation at middle of anterior margin. Female: Similar to male, but face at narrowest portion 0.28 times as long as head. Proboscis 0.54 times as long as eye height. Relative lengths of tarsomeres 1–5 30:21:14:10: 15 in foreleg; 57:30:18:11: 15 in midleg; 50:50:25:14: 20 in hindleg. Wing: apical section of M3+4 1.9 times as long as discal crossvein. Body length 3.0– 3.7 mm; wing length 3.3–3.6 mm.

Type material. HOLOTYPE ɗ, Poipu beach, Kaua‘i, 6.xii.2002, K. Masunaga leg. ( BPBM). PARATYPES ( BPBM, LBM, BLKU): Kaua‘i: 3ɗ9Ψ, Kokee, 4–6.viii.1961, Miyatake & Yoshimoto leg.; 1ɗ, Barking Sands, 10.vii.1931, E.C. Zimmerman leg.; 225ɗ202Ψ, Poipu beach, 6.xii.2002, K. Masunaga leg.; 70ɗ55Ψ, Poipu beach, 8.xii.2002, K. Masunaga leg.; 106ɗ150Ψ, Poipu beach, 9.xii.2002, K. Masunaga leg.

Distribution. Hawaiian Islands (Kaua‘i).

Etymology. The specific name is an adjective derived from a combination of the Latin crassus (thick) and nervus (vein), referring to the thick male wing veins.

Remarks. This new species somewhat resembles Conchopus minutus sp. nov., C. menehune sp. nov. and C. pacificus sp. nov. in having the thickened M1+2 and M 1 in the males, but the males of the latter three species have the following combination of characters different from those of the new species: the strong ventral bristle on fore tarsomere 1; the short setose mid tibia and tarsomere 1.

Figures

FIGURE 7. Conchopus crassinervis sp. nov., legs of male: (a) distal part of tibia, tarsal segments 1 – 2 of left foreleg in posterior view; (b) right foreleg in anterior view; (c) left middle femur in anterior view.

FIGURE 8. Conchopus crassinervis sp. nov., male abdominal sterna: (a) 2 nd (top) to 5 th (bottom); (b) pedunculate process in lateral view; (c) sternum 6.

FIGURE 9. Conchopus crassinervis sp. nov., male genitalia: (a) hypopygium; (b) ventral lobe; (c) cercus; (d) hypandrium in lateral view; (e) hypandrium in dorsal view.

FIGURE 18. Male wings of species of Conchopus: (a) Conchopus acrosticalis (Parent); (b) Conchopus ciliatus sp. nov.; (c) Conchopus crassinervis sp. nov.; (d) Conchopus minutus sp. nov.; (e) Conchopus menehune sp. nov.; (f) Conchopus pacificus sp. nov.