Xanthochorema nathaliae, Espeland & Johanson, 2008

Espeland, Marianne & Johanson, Kjell Arne, 2008, New species and descriptions of females of the New Caledonian endemic genus Xanthochorema (Trichoptera, Hydrobiosidae), Mémoires du Muséum national d'Histoire naturelle 197, pp. 79-98 : 81-84

Xanthochorema nathaliae n. sp.

Figs 1-12

MATERIAL EXAMINED. — New Caledonia. Holotype: male, E Pouembout, 21°07.474’S, 165°06.781’E, 470 m, 8.I.2004, Province Sud, Monts Kouanémoa, on road between Nouméa loc 113, Malaise trap [KA Johanson] ( NRM, alcohol); 1 female, and Yaté, 1.5 km E Pic Mouirange, 22°12.545’S, 166°40.246’E, Province Sud, Couvelée River at Haute Couvelée, 2.8 km SV 143 m, 9.XI.2003, loc 018, light trap [KA Johanson] ( MNHN, summit of Mt. Piditéré , 3.5 km NNE Dumbéa, 22°07.488’S, alcohol). Paratypes: 1 male, 1 female, Province Sud, Monts Ko- 166°28.034’E, 27 m, 28.XI.2003, loc 51, light trap [KA Johanghis, ca 1.0 km from road RT1 between Nouméa and Dumbéa, son] ( NRM, alcohol); 2 females, Province Sud, Tamoa River , water reservoir about 100 x 100 m diameter, 22°10.919’S, 700m S road RT1 between Nouméa and La Foa, 22°04.518’S, 166°29.182’E, 91 m, 10.XI.2003, loc 20, light trap [KA Johan- 166°16.592’E, 19.XI.2003, loc 33, light trap [KA Johanson] son] ( NRM, alcohol); 1 male, Province Nord, Forêt Plate , Ouen- ( NRM, alcohol) .

dé River, at 2.5 km WNW summit of Katépouenda, 23.3 km

DIAGNOSIS. — Xanthochorema nathaliae n. sp. is similar to X. johnwardi n. sp. but is easily distinguished in the genitalia in lateral view, by the reniform shape of the coxopodite and, in dorsal view, by the ellipsoid inner margin of segment IX. The females are separated by the nearly oval shape of sternite VIII in lateral view.

DESCRIPTION OF THE MALE (Figs 1-7). — Abdomen with internal gland situated in posterior part of sternite IV and anterior part of sternite V, connected to lateral filament on sternite V; filament more than twice as long as sternite V;

arising anteroventrally on segment and oriented slightly posterodorsad; cylindrical along its length; sharply narrowing at about half length, covered by microtrichia. Sternite VI with short pointed process arising posteriorly on segment, covered by microtrichia; triangular in ventral view.

Genitalia: segment IX in lateral view with nearly straight anterodorsal margin and strongly convex posteroventral margin, posterior two-thirds covered by strong setae; in dorsal view with inner margin widely ellipsoid; in ventral view posterior margin distinctly produced medially and laterally, medially with small incision; anterior margin slightly concave. Proctiger nearly straight in lateral view, broad, about as long as coxopodite, posterior one-third widening posterodorsally; apex rounded; in dorsal view acuminate, gradually narrowing anteriorly before widening. Lateral process of proctiger absent. Filipod cylindrical in lateral view, oriented posterodorsally, slightly curved ventrally, about the length of the coxopodite; apex club shaped, covered by setae mostly on ventral margin; in dorsal view sigmoid, posterior one-third nearly straight. Preanal appendage short, club shaped, covered by setae, almost covering basal part of filipod. Parapod broad, short, directed posteroventrad; a fold is present near ventral margin; apex slightly obtuse,

3-7

FIGS 1-7. Xanthochorema nathaliae n. sp., male. 1, abdominal segments IV-VI, lateral view. 2, pointed process of abdominal sternite VI, ventral view. 3, genitalia, lateral view. 4, genitalia, dorsal view. 5, genitalia, ventral view. 6, phallus, lateral view. 7, phallus, ventral view. Scale bars = 1 mm.

with dorsal incision; posteroventral margin covered by setae. Gonocoxite without harpago; coxopodite reniform in lateral view, with nearly straight ventral margin and convex dorsal margin, setae present along ventral margin; in dorsal and ventral view inwardly hooked; inner margins slightly undulate and converging distally; lateral margins convex; ventral margins concave in ventral view, mesal area with strong setae. Phallus slightly sigmoid in lateral view; widest at midlength, gradually narrowing anteriorly and posteriorly, except constricted at about two-thirds its length; small protrusion present ventrally at one-third its length, below basal part of sperm channel; sperm channel slightly articulated, slender, gradually narrowing posteriorly; aedeagus thorn shaped, curving dorsally; parallel along basal one-third in ventral view; irregularly widening before narrowing towards rounded apex; laterally protruded at anterior one-third; aedeagus cuspidate.

DESCRIPTION OF THE FEMALE (Figs 8-12). — Abdomen has a pair of cylindrical filaments on segment V (not shown in figure); about 1.8 x longer than segment V and covered by microtrichia. Sternite VI with minute, pointed process arising posteriorly on segment; process triangular in ventral view.

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FIGS 8-12. Xanthochorema nathaliae n. sp., female. 8, abdominal segments V-X, lateral view. 9, pointed process of abdominal sternite VI, ventral view. 10, genitalia, lateral view. 11, genitalia, dorsal view. 12, genitalia, ventral view. Scale bars = 1 mm.

Genitalia: posterior margin of segment VII, ventral view, slightly concave with strong setae. Tergite VIII about half the length of tergite IX; in lateral view, nearly rectangular, slightly pointed anteroventrally, in dorsal view anterior margin straight, posterior margin strongly convex; sternite VIII strongly sclerotized; in lateral view irregularly oval, apex with about 8 setae; in ventral view, lateral margins slightly converging distally, posterolateral corners distinctly produced posteriorly; a pair of rounded, slightly sclerotized posterior lobes present posteromedially, with setae and mesal protrusion. Segment IX nearly rectangular, apical half covered by setae, posteroventral setae longest; in ventral view segment IX nearly fully covered by sternum VIII, inwardly folded, fold with setae; a pair of laterally produced rounded lobes with setae. Soft segment X consists of two pairs weakly defined rounded lobes, basal pair with small cercus. Spermatheca forms composite structure within segments VII-IX; in lateral view nearly parallel-sided, slightly curving upwards; anterior nearly parallel-sided part in dorsal and ventral view, with minute folds around opening of ductus bursa copulatrix; sclerotized dorsal part continues posteriorly into sclerotized posterior process being quite broad in lateral view, deeply and widely incised posteriorly in dorsal and ventral views.

ETYMOLOGY. — The name nathaliae is dedicated to Dr. Nathalie Mary (Corneilla del Vercol, France), one of the pioneers in establishing knowledge on the ecology of New Caledonian Trichoptera , and for describing Xanthochorema paniensis together with Dr. John Ward.