Helicopsyche meander, Johanson & Pham, 2012

Johanson, Kjell A. & Pham, Hong-Thai, 2012, Three new species of Helicopsyche (Trichoptera, Helicopsychidae) from northern Vietnam, with a key to Helicopsyche species of Vietnam, European Journal of Taxonomy 6, pp. 1-10 : 5

Helicopsyche meander sp. nov.

Fig. 2

Diagnosis

Helicopsyche meander sp. nov. is most similar to H. lamnata sp. nov., H. anaktangga Malicky, 1995 , H. anaksaku Malicky, 1995 , H. minyas Malicky & Nawvong ( Malicky et al. 2004) and H. cymodoce Schmid, 1993 , particularly due to the presence of two-segmented maxillary palps in combination with the nearly similar shape of the gonopods in lateral view. The new species is distinguished from H. anaktangga , H. anaksaku , H. minyas and H. cymodoce by the pointed apex of tergum X in lateral view; and from H. lamnata sp. nov., H. anaksaku and H. minyas by the more strongly S-shaped gonopods. It is furthermore separated from H. lamnata sp. nov. by the absence of a central posterior process of segment IX.

Etymology

Meander, named after the shape of the gonopods, resembling a meandering river.

Material examined

Holotype ♂

VIETNAM: Vinh Phuc Prov, Me Linh District , stream near Ngoc Thanh Village , Melinh Station for Biodiversity , 21°23'28.2"N, 105°42'46.7"E, 233 m, Malaise trap 4-12 Apr. 2011, loc#VN001, leg. K.A. Johanson, P.H. Thai & T.T. Du ( NHRS, alcohol) [DNA voucher IP7].

Description

MAXILLARY PALPS. Two-segmented, with distal segment slightly longer than basal segment. Pair of interantennal setal warts semi-spherical, elevated. Each scapus about as long as each basal segment of maxillary palps. Spur formula 1,2,4; each foreleg spur slightly shorter than each first tarsomere.

LENTH. Forewing 3.7 mm, hind wing 2.8 mm (N = 1).

MALE ABDOMEN AND GENITALIA. ( Fig. 2 ) Sternal process VI about one-eighth as long as sternum VI, straight, oriented posteroventrad; slightly tapering in lateral view ( Fig. 2A ); pointed in ventral view ( Fig. 2B ). Segment IX about 1.5 x taller than long in lateral view ( Fig. 2C ); each anterior lobe of segment IX ( Fig. 2C ) irregularly narrowing anteriorly in lateral view, asymmetrical, oriented anterad; anterodorsal margin almost straight; anteroventral margin concave ( Fig. 2C ); in dorsal view, inner margin forming narrowly ellipsoid cavity ( Fig. 2D ); in ventral view, without central posterior process ( Fig. 2E ); inner margin forming wide, almost rectangular cavity; lateral apodemes nearly horizontal ( Fig. 2C ), each parallel-sided along their length, meeting anterior margin; sub-marginal line present above lateral apodemes; tergal transverse apodemes present, fading immediately above superior appendages; sternal transverse apodeme present along posterior margin of segment IX ( Fig. 2C ). Transverse plate absent. Tergum X, in lateral view, oriented posteroventrad ( Fig. 2C ), slightly sigmoid, tapering towards mid-length, apex strongly club-shaped, slightly curving dorsally ( Fig. 2C ); in dorsal view ( Fig. 2D ), deeply and widely divided into pair of parallel-sided and parallel-running branches, with 3 pairs of equally long megasetae in apical group, starting well before apex of gonopods in lateral view ( Fig. 2C ). Superior appendages club-shaped ( Fig. 2C ), oriented ventrad. Primary branch of gonopods, in lateral view ( Fig. 2C ), with basal part oriented posterad before strongly bending dorsad, angling posterad at half-length, apical part produced mesad above tergum X; almost parallel-sided along their length; anterior margin smooth, strongly concave; dorsal and posterior margins undulating. Secondary branch of gonopods absent. Basomesal lobes long, tuboid, each with pair of apical setae; sigmoid in lateral view ( Fig. 2D ), parallel-sided with diverging apex in ventral view ( Fig. 2E ). Basal plate, in lateral view ( Fig. 2C ), curving anteroventrad, narrowing along its length from posterior to anterior end, slightly produced beyond anteroventral margin of segment IX in lateral view ( Fig. 2C ); widely triangular in ventral view ( Fig. 2E ). Phallic apparatus, lateral view, irregularly tube-shaped along its length ( Fig. 2F ), apex about as broad as base; nearly straight after mid-length; in ventral view, with basis narrow ( Fig. 2G ); widest after mid-length; endotheca weakly produced, posteroventral part not sclerotized, except single, weakly sclerotized triangular processes distally of phallic sclerite.

Figures

Fig. 2. Helicopsyche meander sp. nov., ♂ holotype. A. abdominal sternum VI, lateral view. B. abdominal sternal process VI, ventral view. C. genitalia, lateral view. D. genitalia, dorsal view. E. genitalia, ventral view. F. phallus, lateral view. G. phallus, ventral view.