Cymatopus femoralis, Masunaga, Kazuhiro & Evenhuis, Neal L., 2012

Masunaga, Kazuhiro & Evenhuis, Neal L., 2012, Two new species of the genus Cymatopus Kertész from the Mariana Islands (Diptera: Dolichopodidae), Zootaxa 3159, pp. 36-46 : 38-43

Cymatopus femoralis sp. nov.

( Figs. 1 , 2 A, 3A–B, 4, 5)

Type material. HOLOTYPE 3 labeled: Commonwealth of the Northern Mariana Islands: Saipan: Obyan Beach, 13.ii.2001, K. Masunaga leg. ( LBM). PARATYPES: SAIPAN: 213, 23Ƥ, same data as holotype ( LBM). Commonwealth of the Northern Mariana Islands: ROTA: 23, 5Ƥ, Swimming Hole, 12.ii.2001, K. Masunaga leg. ( LBM); 253, 36Ƥ, coral beach around Sunset Motel, 14°10.084'N, 145°10.577'E, 13.v.2004, R. Zack leg. ( WSU). Commonwealth of the Northern Mariana Islands: PAGAN: 13, 2Ƥ, west coast, limestone reef flat and tide pools, near Lukairu, 20.vii.2010, D.A. Polhemus leg. ( BPBM). GUAM: 53 2Ƥ, Inarajan Pool, 9.ii.2001, K. Masunaga leg. ( LBM); 33, Inarajan Village, beach at Aglayan Bay, Rt. 4 nr. Tipoco Cemetery, 13°16.232'N, 144°44.716'E, 2.v.2004, R. Zack leg. ( WSU); 673, 53Ƥ, Yona Village, beach area behind Togcha cemetery off of Rt. 4, 13°23.138'N, 144°45.517'E, 2.v.2004, R. Zack leg. ( WSU); 1Ƥ, Mangilao Village, University of Guam campus, Marine Biology Lab area, 13°25.714'N, 144°47.913'E, 20.v.2004, R. Zack leg. ( WSU); 73, 12Ƥ, Marizo Village, Achang Reef Flat Reserve off Rt. 4, sweeping beach, 13°14.853'N, 144°42.630'E, 8.v.2004, R. Zack leg. ( WSU); 153, 12Ƥ, Dededo, Haputo Beach, U.S. Naval Communications Station, 13°34.6'N, 144°49.8'E, F. Howarth, G. Brenner, D.A. Lapointe leg. ( BPBM); 133, 17Ƥ, Tanguisson Beach, 17.iii.2010, R. Englund leg. ( BPBM).

Etymology. The specific name, an adjective based on Latin femur, refers to the presence of long setae on the fore femur in both males and females.

Diagnosis. Small species (2.0– 2.6 mm in body length) with several strong ventral bristles on fore femur, male fore tibia with leaf-like bristle on anterior surface and with ventral side produced into long lobe with strong bristle on apex, and male fore tarsomere 4 produced basally into a lobe with many long marginal setae.

Description. Male. Body length 2.0– 2.4 mm; wing length 2.2–2.4 mm. Head: 1.7 times as high as long, 0.9 times as wide as high. Frons wide, metallic green with grayish brown pollinosity; frontal bristle 0.8 times as long as ocellar bristle. Ocellar tubercle distinct, with 2 strong ocellar bristles and 2 minute postocellar setae. Occiput metallic green with grayish pollinosity. Postocular ciliation uniserial, erect, black, becoming thinner and shorter toward apex. Postgena with many long, slender setae. Face and palpus brown with dense grayish pollinosity, tinged with green. Face at narrowest part 0.1 times as wide as head. Palpus 1.5 times as long as wide, clothed with long setae on lower margin. Proboscis short, 0.3 times as long as eye height. Antenna brown; scape as long as deep, bare; pedicel 1.2 times as long as deep; 1st flagellomere 1.4 times as long as basal thickness, with some setulae; arista microscopically plumose, apical, 4.6 times as long as 1st flagellomere. Thorax: Dark brown with grayish white pollinosity. Thoracic bristles black. Chaetotaxy: no acrostichals; 5 dorsocentrals, 5th dc 1.4 times as long as scutellum; 1 each of postpronotal, posthumeral, sutural, postsutural, supra-alar, and postalar setae; notopleuron with 2 setae, upper one 2.1 times as long as lower one. Proepisternum with 2–3 setae. Scutellum with pair of strong inner marginal bristles and pair of weak outer marginal setae. Legs: Coxae concolorous with pleura. Fore trochanter, apical part of femur, basal part of tibia, and tarsomeres 1 to 5 pale brown. Middle and hind tibiae and tarsomeres brown with rather weak, grayish pollinosity. Foreleg ( Figs. 4 A–F): Coxa with row of several short, strong setae on anterior surface, these becoming shorter toward apex, with additional row of thin setulae on inner side. Femur 5.4 times as long as basal thickness, 1.1 times as long as tibia, tapering gradually toward apical third, then curving ventrally. Femur with row of tiny anterodorsal and anterior setae; row of anteroventral setae, of which 4 located on basal third and 2 on apical third; 2 rows of ventral setae on basal 2/3, of which anterior setae very short and narrowly-spaced and posterior ones long, strong, and widely-spaced; row of long posteroventral setae on basal 2/3, these setae becoming thicker toward apex, and also 1 subapical posteroventral seta; 2 rows of posterior setae; row of posterodorsal setae. Tibia with lobe on ventral apical portion, 2.3 times as long as midlength thickness of tibia, with seta on apex 0.7 times as long as length of lobe. Tibia also with anterior black foliate bristle on basal third; row of dorsal setae, including 2 long ones, on basal 1/5; 1 row each of anterodorsal, posterior, and posterodorsal setae; and 2 rows of erect ventral setae. Tarsomere 1 long, 2.4 times as long as tarsomere 2. Tarsomere 2 with 2 long anteroventral setae at middle and 2 long anterior setae subapically. Tarsomere 3 with 1 row each of dorsal, anterodorsal, and anterior setae, of which apical setae of latter 2 rows strong; row of erect, anteroventral setae; and 1 row each of tiny posterior and posteroventral setae. Tarsomere 4 modified, being produced basally into lobe with many long marginal setae. Tarsomere 4 also with anterior setae becoming longer toward apex, 1 long posterodorsal seta on apical third, and row of tiny posteroventral setae. Relative lengths of tarsomeres 1-5: 73:31:21:14:10. Midleg: Coxa with conspicuous outer seta at middle, and several setae near tip on anterior surface. Femur as long as tibia. Tibia and tarsomeres 1–5 simple, relative lengths of tarsomeres 1–5: 65:31:20:10:10. Hindleg ( Figs. 4 G– H): Coxa with conspicuous outer seta at midlength and long seta on anterior apex. Trochanter with 2 long ventral setae. Femur as long as tibia, with long ventral seta near base. Tibia with long dorsal seta subapically. Tarsomeres 1–5 simple, relative lengths 67:36:20:10:10. Wing ( Fig. 3 A): Long, narrow, and darkened. Apical section of M3+4 2.6 times as long as discal crossvein. Calypter pale brown with pale brown fringe. Halter yellowish brown. Abdomen: Abdominal terga tinged green with grayish pollinosity and with short, black setae. Sterna lacking conspicuous setae and processes. Hypopygium ( Fig. 5 ) small and compact, with dense grayish pollinosity; hypandrium short, its apex bifid, with strong lateral bristle; surstylus wide and short, with hook-shaped bristle on ventral side of apex and several setae on distal margin; cercus tapered, ventral margin curved ventrally, with long setae. Female. Similar to male except: Body length 2.0– 2.6 mm; wing length 2.2–2.5 mm. Face at narrowest part 0.1 times as wide as head. Proboscis 0.3 times as long as eye height. Femur of foreleg with row of strong anteroventral and ventral setae. Tibia lacking leaf-like bristle. Tibia with ventral apical lobe 0.7 times as long as middle thickness of tibia, and with two strong, black anterodorsal setae at midlength and 2 rows of ventral setae, of which anterior ones longer. Tarsomere 1 with long anteroventral seta at base. Relative lengths of tarsomeres 1–5 of foreleg: 41:19:16:10:10, midleg: 51:23:16:9:10, and hindleg: 44:22:13:7:10, hindleg. Wing with apical section of M3+4 2.3 times as long as discal crossvein ( Fig. 3 B).

Remarks. Externally, this new species is most similar to Cymatopus calcaratus , which is known only from Christmas Island (Indian Ocean), but C. calcaratus has the following set of characters different from those of the new species: legs yellow with coxae, femora, and tibiae slightly blackened dorsally; cercus very long, 1.5 times as long as height of hypopygium (cf. Parent 1935).

Distribution. Commonwealth of the Northern Marianas (Pagan, Saipan, Rota); Guam ( Fig. 1 ).

Figures

FIGURE 1. Map of Guam and the Northern Mariana Islands. Names of islands from which the present samples were taken are underlined.

FIGURE 2. Adult males of Cymatopus species in lateral view. (A) C. femoralis sp. nov.; (B) C. ventralis sp. nov.

FIGURE 3. Wings of Cymatopus species. (A) C. femoralis sp. nov., 3; (B) C. femoralis sp. nov., Ƥ; (C) C. ventralis sp. nov., 3; (D) C. ventralis sp. nov., Ƥ.

FIGURE 4. Cymatopus femoralis sp. nov., legs of male, SEM. (A) Fore leg in anterior view; (B) Fore femur and tibia in anterior view; (C) Fore tibia in anterior view, showing diagnostic leaf-like bristle; (D) Tip of fore tibia in anterior view; (E) Fore tarsomeres 2 – 5; (F) Fore tarsomere 4; (G) Hind leg in posterior view; (H) Hind femur and tibia in posterior view. Scale bars: 50 – 500 μm.

FIGURE 5. Cymatopus femoralis sp. nov., male genitalia. (A) Hypopygium in lateral view; (B) Cercus in lateral view; (C) Surstylus in lateral view; (D) Hypandrium in ventral view.