Bittacus bifurcatus Hua et Tan

Hua, Baozhen, Tan, Jiangli & Huang, Pengying, 2008, Two new species of the genus Bittacus (Mecoptera: Bittacidae) from China, Zootaxa 1749, pp. 62-68 : 62-65

Bittacus bifurcatus Hua et Tan , sp. n.

( Figs 1 –2)

Holotype: male, CHINA: SHAANXI: Xiabaiyun Temple (34°4 N, 107°44 E), alt. 1400 m, Mt. Taibaishan, 11.vii.2006, coll. B.Z. Hua.

Diagnosis

The new species is quite small in size, readily separable from its congeners by the peculiar two-branched aedeagal lobe, the epandrial appendages with distal half abruptly narrowed into an up-curved horn from lateral view, and the extremely long and slender gonostyles.

Description based on male holotype, pinned.

Head ( Fig. 1). Vertex, frons, rostrum, and antennae yellowish brown. Antennae 5.5 mm long, filiform with 17 hairy flagellomeres. Eyes brown with some irregular black patches; three ocelli in a triangle, projecting out of head surface in anterior view, shining reddish yellow; front mid ocellus prominently smaller than back lateral ones. Ocellar triangle black, with two long setae closely behind the mid ocellus.

Thorax. Pronotum dark brown with a black seta at each side along anterior margin (just behind lateral ocelli); meso- and metanotum shining dark brown, the most elevated parts nearly black with sparse yellowish setae; scutellum pale yellowish brown, each with two long setae near posterior margin; pleural and ventral surfaces unevenly blackish brown to brown, glossy, with a few short scattered setae. Coxae yellowish brown, bearing long setae of approximately 0.4 mm on anterior surfaces; mera yellowish brown; some short black setae on yellowish brown femora, tibiae, and tarsi; hind legs slightly darker.

Wings (Figs. 2A–B). Forewing 16.0 mm long, 3.6 mm wide; narrow, with obtusely angulated apex; Wing membrane hyaline, clear; pterostigma prominent; two nygmata on cells R4+5 and 1R5 each, but hard to see with naked eyes. Only one brown marking as a fleck near distal margin of vein CuP. Indistinct dark clouding at origin of radial sector (ORs), first fork of radial sector (FRs), origin of media from cubitus (OM), and along most cross veins, most noticeable along arc of cross veins extending from pterostigma to distal end of CuP. A clear thyridium with pale border at first fork of media (FM). Vein 1A terminating far before FM; cubical crossvein (cuv, cross vein between CuA and CuP) a little before FM. Anal crossvein (Av, apical cross vein between CuP and 1A) absent; one pterostigmal crossvein (Pcv) present. Hindwing 12 mm long, 3.0 mm wide; markings similar to forewings.

FIGURE 2. Bittacus bifurcatus , sp. n. male: A, forewing; B, hindwing; C, terminalia, lateral view; D, genitalia, ventral– caudal view; E, epandrial appendages, dorsal view. cuv—cubical crossvein; FM—first fork or branching of the media; FRs—first fork of radial sector; OM—origin of the media from CuA; ORs—origin of radial sector from R1; Pcvpterostigmal crossvein.

Abdomen of male (Figs. 2C–E): Terga 2–5 sordid yellowish brown, terga 6–8 shining black; tergum 9 modified to epandrial appendages, abruptly paler than tergum 8, sordid yellowish brown; the corresponding sterna similarly colored, except for sternum 9 shining black; gonocoxites dark brown. Epandrial appendages divergent with distal half abruptly narrowed into an up-curved horn from lateral view, only a quarter as wide as base (Fig. 2C), bearing long setae at curved area and apex, and several small thick black spines along inner surface at mid-dorsal corner of appendages and inner surface of narrow apex (Fig. 2E); a few small spines along ventral margin of horn. Tergum 10 as a saddle-shaped dorsal plate with each anterior corner narrowly extending posteroventrad and then curved dorsad around base of cercus to form a large roughly triangular area mesal to cercus, with no setae. Upper branch of proctiger protruding between bases of epandrial appendages, with rounded apex with a bundle of setae; lower branch of proctiger short and strongly curved, pointed toward apex. Cerci medially long, extending to midlength of narrow apical part of epandrial appendages. Gonocoxites with a deep V-shaped membranous area mid-apically. Gonostyles extremely long and slender compared with its congeners, with an inner process at basal fourth and bearing numerous short brown setae, gradually tapering towards apex (Fig. 2D). Aedeagus with an elongate greatly coiled penisfilum. Aedeagal lobe broad and long, with a long and slender branch at apical third of the lobe.

Female. Unknown.

Distribution: Shaanxi Province, China.

Etymology. The specific name bifurcatus is derived from the Latin, bi - (two) and furcatus (branching), referring to the bifurcated aedeagal lobe.