Orthotrichia subrhomba Zhou & Morse

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 : 37-38

Orthotrichia subrhomba Zhou & Morse , sp. nov.

Figs 28–32

Material. Holotype ɗ, Fujian Province, Jiu-qu-xi (118°01'12"E, 27°27'00"N), elev. 220 m, 1990-v-30, Coll. J. C. Morse, Liu Chang-Ming, Huang Jian. Paratype: 1ɗ, same data as holotype.

Etymology. The Latin prefix " sub -" means "almost“ and the word “rhomba“ means “diamond", referring to the nearly diamond shape of the right posterolateral process of segment IX.

Description. Male. Antennae 23–24-segmented. Anterior wing length 1.7 mm. Ventral process of segment VI short spine in lateral view (as in Fig. 22 ). Ventral process of segment VII absent.

Male genitalia ( Figs 28–32 ). Anterior margin of segment IX irregularly curved, with shallow rectangular excision in dorsal view ( Fig. 30 ), bluntly convex in ventral view ( Fig. 31 ), broadly excised in trapezoid in left lateral view ( Fig. 28 ) and with triangular excision in right lateral view ( Fig. 29 ); left posterolateral process absent ( Fig. 28 ), right posterolateral process nearly diamond-shaped with its vertical axis about 2 times as long as that of its longitudinal axis its ventral projection long, beak-like in right lateral view ( Fig. 29 ). Tergum X (X) fused with segment IX in dorsal view ( Fig. 30 ), its left margin longer than right margin, its apex obliquely excised, its left distal end produced in strong ventral hook; dorsal spine of X arising near center of its base, hook-like, directed downward and to right. Inferior appendages (inf. app.) asymmetrical ( Fig. 31 ), each appendage broad at base and fused in subquadrate plate, right appendage deeply and broadly excised, divided into 2 slender branches, its inner one long, curved slightly upward, with apex bare and extending beyond tergum X, its outer branch 5/6ths as long as its inner branch and bearing apical seta; left inferior appendage 3/4ths as long as inner branch of right inferior appendage and bearing apical seta. Bilobed process (bil. pr.) forming widely separated pair of slender, tube-like branches positioned above bases of inferior appendages, each branch with apical seta. Paramere spine (pa.) long, slightly longer than dorsum of IX+X. Phallus ( Fig. 32 ) slender, with basal portion about 2.5 times as long as distal portion, distal portion enlarged, twisted, foliaceous, titillator encircling phallus 1 time.

Diagnosis. This species is not assignable to any group. It is somewhat similar to Or. vertumnus Malicky & Chantaramongkol, 2007 , from Thailand, in the general shapes of segment IX and the phallus, and in the presence of a tube-like bilobed process, but differs in that 1) tergum X has a well developed, hook-like dorsal spine (without a dorsal spine in Or. vertumnus ) and 2) tergum X has its left distal end produced in a strong hook (both distal ends straight in Or. vertumnus ).

Distribution. Type locality only.

Figures

FIGURES 28 – 32. Orthotrichia subrhomba, sp. nov., male genitalia. 28, left lateral view; 29, right lateral view; 30, dorsal view; 31, ventral view; 32, 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.