Conchopus menehune, 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 : 24-27

Conchopus menehune sp. nov.

( Figs. 13 , 14 , 18 e)

Diagnosis. Small-sized species (2.9–3.4 mm in body length) similar to C. minutus sp. nov. and characterized by 1st flagellomere being 1.5 times as long as its basal thickness; halter yellow. In male, M1+2 thickened; apical section of M3+4 2.3 times as long as discal crossvein; fore tarsomere 1 with small but broad basal swelling 1/4 as long as tarsomere 1, strong ventral bristle situated 1/3 from base, and strongly produced apical swelling; longer dorsal bristle of fore tarsomere 2 subbasal, situated 1/5 from base; mid tibia cylindrical, without long erect bristles and setae on anterior and posterior surfaces; mid tarsomere 1 short setose; ventral lobe of hypopygium simple, slightly produced distally.

Description. Male: Body length 2.9–3.4 mm; wing length 2.7–3.5 mm. Head: l.7 times as deep as long; face at narrowest point 0.16 of head width, more strongly widening ventrally than dorsally, widest ventral part l.8–1.9 times as wide as narrowest point. Proboscis 0.5 times as long as eye height. Antenna 0.6 times as long as head; 1st flagellomere 1.1–1.2 times as long as two basal antennal segments together. Thorax: Mesonotum viewed from above, humerus paler, only slightly darker than notal white markings, anterolateral whitish areas barely tinged with bluish green along posterior margin; inverted Y-shaped marking deep velvety black, with borders sharply defined; 1st dc on white area, 2nd dc on border; prescutellar white marking moderately wide, gradually constricted anteriorly beyond 5th dc, anterior margin of this marking without bluish tinge, 5th and 6th dc on lateral margins. Chaetotaxy: acrostichals 4–11 in number, ending posteriorly between level of 1st dc and point midway between 1st and 2nd dc, all reclinate. Propleurals 4–5; mesopleurals 7–11, ending ventrally in strong setula located below ventral margin of basalare; metapleurals 1–3. Scutellum usually with only pair of strong bristles, but sometimes with 1–2 weaker outer bristles. Foreleg ( Fig. 13 a-b): Setae on anterior surface of coxa dense, plus outer row of 8–9 bristles. Femur 4.3–4.8 times as long as basal thickness; preapical tubercle situated 0.3 from tip. Tibia only slightly curved dorsally towards tip, preapical portion distinctly swollen, l.9–2.1 times as thick as narrowest part of tibia; both antero- and posteroventral setae equally lengthened on apical half of tibia, longest bristles 1.2–1.7 times as long as midlength thickness of tibia, posteroventral setae slightly inclined; 2 antero- and 2 posterodorsal bristles usually well developed; anterior preapical mass of setae extensively developed. Tarsus 1.2 times as long as tibia. Tarsomere 1 somewhat elongate, 1/4 of length of tarsus, strongly arched dorsally; basal lobe well developed, short but very strongly produced ventrally, with more or less truncate ventral margin, 1.2 times as thick as long, 0.2 times as long as tarsomere 1, with 8–9 submarginal setulae and 4 marginal setulae, these setulae rather long; ventral bristle very strong, 1.5–1.7 times as long as thickness of tarsomere 1 through base of bristle, situated 1/3 from base; a few weak setulae before ventral bristle, these much weaker than marginal setulae of ventral lobe; apical swelling of tarsomere 1 prominent, the most strongly produced ventrodistally of any Hawaiian species of Conchopus (thickness of tarsomere 1 at apical swelling slightly less than that at basal lobe); anterior preapical cluster of setulae shifted basally, center of cluster at 3/7 from tip of tarsomere 1. Tarsomere 2 with strong anterodorsal bristle 1/3 as long as tarsomere, located 0.3 from base of tarsomere, 1–2 additional shorter bristles between this bristle and midlength of tarsomere. Tarsomeres 3–5 simple and slender. Mid- and hindlegs: Almost as in C. minutus . Middle femur more weakly curving posteriorly, and its ventral bristles longer (posteroventral bristles towards base being 2/3 as long as femur thickness); posteroventral setae of hind tibia curved anteriorly and appressed. Wing ( Fig. 18 e): Elongate, nearly 3 times as long as broad, costa more strongly arched on apical half; ratio of M1 to apical section of M1+2 2.5– 2.8; ratio of middle section of M3+4 to apical section of M3+ 4 l. 5–l.7. Abdomen: Each subventral cluster of sternum 5 consisting of 4–5 spine-like bristles. Membranous portion of pedunculate process of sternum 6 slightly more than half as long as process itself, with anterior margin of latter concave beyond midlength. Hypopygium ( Figs. 14 a-d): Cercus slender, widest 0.2–0.3 of way from tip. Ventral lobe 4 times as long as wide; posterior process of ventral process without distinct lamellate dentation. Female. Similar to male, but face at narrowest point 0.25 times as wide as head. Proboscis 0.41 times as long as eye height. Relative lengths of tarsomeres 1–5 35:25:17:9: 17 in foreleg; 57:29:17:11: 18 in midleg; 55:50:25:15: 20 in hindleg. Wing: Apical section of M3+4 2.2 times as long as discal crossvein. Body length 3.0– 3.1 mm; wing length 2.9–3.4 mm.

Material examined. HOLOTYPE ɗ, Po‘ipu beach, Kaua‘i, 6.xii.2002, K. Masunaga leg. ( BPBM). PARA- TYPES ( BPBM, LBM, BLKU): Kaua‘i: 1ɗ, 10.vii.1937, Barking Sands, E.C. Zimmerman leg.; 20ɗ5Ψ, Po‘ipu Beach, 6.xii.2002, K. Masunaga leg.; 2ɗ, Po‘ipu Beach, 8.xii.2002, K. Masunaga leg.; 2ɗ, Po‘ipu Beach, 9.xii.2002, K. Masunaga leg.; 1ɗ1Ψ, Ke‘e Beach, 9.xii.2002, K. Masunaga leg. Nihoa: 3ɗ4Ψ, 11.vi.1923, ex. ppl salt water, E.H. Bryan, Jr. leg.; 1Ψ, 13.vi.1923, E.H. Bryan, Jr. leg.

Distribution. Hawaiian Islands (Kaua‘i and Nihoa).

Etymology. The species is named after a dwarf in Hawaiian legend; treated here as a noun in apposition.

Remarks. This new species most closely resembles Conchopus minutus sp. nov. in having the thickened M1+2 and M1, short setose mid tibia in males, but the male of the latter has the following combination of characters different from those of the present new species: mesonotum viewed from above darker, prescutellar white marking slightly narrower, inverted Y-shaped marking with brownish tinge; setae on anterior surface of fore coxa sparser; and ventral bristle of male fore tarsomere 1 situated near midlength of the tarsomere.

Figures

FIGURE 13. Conchopus menehune 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.

FIGURE 14. Conchopus menehune sp. nov., (a) ventral lobe; (b) cercus; (c) hypandrium in lateral view; (d) 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.