Orthotrichia cornuta Zhou & Yang

Lei, Zhou, Lian-Fang, Yang & Morse, John C., 2010, Six new species and 1 new species record of Orthotrichia (Trichoptera: Hydroptilidae) from China, Zootaxa 2560, pp. 29-41 : 31-32

Orthotrichia cornuta Zhou & Yang , sp. nov.

Figs 7–11

Material. Holotype ɗ, Sichuan Province, Shi-mian County, Li-zi-ping Nature Preserve, Ca-luo-xiang Town, unnamed trib. of Hai-zi-gou stream, 200 m W of 3rd-level Hydropower Station, 4.3 km S of G108 from 2600.8 km stone marker (102°22'08"E, 29°08'27"N), elev. 1384 m, 2005-vi-30, Coll. Sun Chang-Hai, Zhou Chang-Fa, C. J. Geraci.

Etymology. The Latin word " cornuta " means "horned", in reference to the mesal processes of the inferior appendages being horn-like in ventral view.

Description. Male. Distal ends of antennae lost, only 21 segments remaining. Anterior wing length 4.0 mm. Ventral process of segment VI short spine in lateral view (as in Fig. 22 ). Ventral process of segment VII absent.

Male genitalia ( Figs 7–11 ). Anterior margin of segment IX entire, straight in dorsal view ( Fig. 9 ), but deeply excised in “V” shape in right pleural region ( Fig. 8 ) and shallowly excised lateroventrally in left pleural region ( Fig. 7 ), such that venter of IX forming asymmetrically triangular plate ( Fig. 10 ); posterolateral processes of IX (p.l. pr.) slender, each apically acute, left process curved caudoventrad and right process curved caudodorsad. Tergite X fused with segment IX in dorsal view ( Fig. 9 ), with its right margin longer than left one, narrowed near middle then slightly twisted to left, with its apical margin obliquely truncate; in right lateral view ( Fig. 8 ), tergum X tilted dorsad apically and obviously swollen subapically, with its apical margin raised, resembling sunshade; dorsal spine (d. s.) flat, triangular, positioned at the basal right corner of X ( Fig. 9 ). Inferior appendages (inf. app.) stout, asymmetrical, mitten-like in ventral view, each with broader lateral apex protruded and bearing 1 setae distally, left inferior appendage more or less parallel-sided and angled laterad and much longer than right one, right inferior appendage triangular, and each inferior appendage with horn-like mesal “thumb,” their acute apices meeting each other in ventral view ( Fig. 10 ); bilobed process asymmetrically V-shaped, with short stem in ventral view ( Fig. 10 ), its left lobe straight, directed caudolaterad, bearing long apical setae, and its right lobe curved mesad 90º and with long erect seta arising on caudolateral angle dorsally. Paramere spine (pa.) long, slightly shorter than genitalia. Phallus ( Fig. 11 ) slender, basal portion is about 2 times as long as distal portion, its apex slightly enlarged and bilobed, with titillator circling phallus 1 time.

Diagnosis. This species is clearly a member of the Or. costalis Group and is somewhat similar to Or. terpsichore Malicky & Chantaramongkol, 2007 , from Thailand, in the general shapes of segment IX and the inferior appendages. It differs in that 1) tergum X has a flat, triangular, dorsal spine (without dorsal spine in Or. terpsichore ); 2) inferior appendages are asymmetrical, mitten-like, with the left appendage longer than the right one, and the apices of the thumb processes acute, meeting each other in ventral view (almost symmetrical, the apices of the thumb processes curved mesad and not meeting each other in ventral view in Or. terpsichore ); and 3) the right lobe of the bilobed process is curved mesad in 90º (straight in Or. terpsichore ).

Distribution. Type locality only.

Figures

FIGURES 7 – 11. Orthotrichia cornuta, sp. nov., male genitalia. 7, left lateral view; 8, right lateral view; 9, dorsal view; 10, ventral view; 11, phallus. Abbreviations explained in text.

FIGURES 17 – 22. Orthotrichia terpsichore Malicky & Chantaramongkol, 1997, male genitalia. 17, left lateral view; 18, right lateral view; 19, dorsal view; 20, ventral view; 21, phallus; 22, left lateral view of ventral process of segment VI. Abbreviations explained in text.