Xanthochorema bifurcatum Schmid, 1989

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 : 90-93

Xanthochorema bifurcatum Schmid, 1989

Figs 36-47

MATERIAL EXAMINED. — New Caledonia: 1 female, Province Johanson] ( NRM, alcohol); 1 female, Province Sud, Monts Kog- Sud , Monts Koghis , ca 300 m S Koghi Restaurant , 22.18288°S, his, ca 800 m S Koghi Restaurant , 22.18311°S, 166.50564°E, 166.50073°E, 407 m, 02-16.XI.2003, Malaise trap, loc 005 [KA 460 m, 10-26.XI.2003, Malaise trap, loc 019 [KA Johanson] Johanson] ( NRM, alcohol); 1 male, Province Sud, Réserve spéci- ( NRM, alcohol); 1 male, Province Sud, stream crossing way to ale de faune de la haute Yaté, along road on southern part of Ma- Sanatorium 2.3 km E St. Laurent, ca. 150 m upstream bridge, rais de la Rivière Blanche, stream draining to Marais de la Rivière 22°04.484’S, 166°19.910’E, 15-30.XI.2003, Malaise trap, loc Blanche, 2.25 km SW Pont Pérignon, 180 m, 6.XI-16.XI.2003, 027 [KA Johanson] ( NRM, alcohol); 1 female, Province Sud, Malaise trap, loc 010 [KA Johanson] ( NRM, alcohol); 1 male, Monts Kouanémoa, along Nouméa-Yaté road, 2.0 km E Pic Mo- Province Sud, Monts Kouanémoa, on road between Nouméa uirange, 20 m upstream road, 22°12.356’S, 166°40.798’E, 220 and Yaté, 2.0 km E Pic Mouirange, 22°12.356’S, 166°40.798’E, m, 15-16.I.2004, Malaise trap, loc 120 [KA Johanson] ( NRM, 220 m, 7-16.XI.2003, 16-30.XI.2003, Malaise trap, loc 014 [KA alcohol) .

DIAGNOSIS. — Xanthochorema bifurcatum is easily distinguished from all other Xanthochorema species in the genitalia, especially by the basally bifurcated parapod with two long branches. The females are separated from all other congeners by having the filament arising from segment V about equal in length to segment V, and by genitalic characters listed below.

DESCRIPTION OF THE MALE (Figs 36-42). — 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 around 1.8 x as long as sternite V, arising anteroventrally on segment, oriented posteriorly, cylindrical along its length, sharply narrowing at basal onethird. Sternite VI with pointed process arising medially on segment, more than half as long as segment VI; cylindrical, with incised apex in ventral view, covered by microtrichia.

Genitalia: segment IX with triangular anterior margin in lateral view; slightly concave anteroventrally; anterodorsal margin nearly straight, posterior margin sharply narrowing at dorsal one-third; setae scattered on posterior onethird; inner margin concave in dorsal view; in ventral view posterior margin concave, anterior margin with broad lateral processes; anterior margin ellipsoid, posterior one-third with setae scattered on the surface. Proctiger in lateral view slightly longer than gonocoxite, broad, parallel sided, with truncated apex; in dorsal view lateral margins parallel, slightly divergent distally, apex with medial incision. Lateral process of proctiger club shaped, almost as long as proctiger height, oriented posteriorly and covered by setae. Filipod cylindrical in lateral view, oriented slightly posterodorsad, straight, about as long as gonocoxite; apex slightly club shaped, covered by long setae; setae towards apex shorter; slightly curved inwardly in dorsal view. Preanal appendage short, slightly club shaped, setose, slightly diverging from filipod. Parapod basally bifurcate, lateral branch oriented posteroventrally, long and slender; medial branch about as long as coxopodite, oriented posteriorly, triangular protrusion at mid-length; apex bifurcate; dorsal process

36

38 MBUFSBM QSPDFTT

38-42

FIGS 36-42. Xanthochorema bifurcatum Schmid, 1989 , male. 36, abdominal segments IV-VI,lateral view. 37, pointed process of abdominal sternite VI, ventral view. 38, genitalia, lateral view. 39, genitalia, dorsal view. 40, genitalia,ventral view. 41, phallus, lateral view. 42, phallus, ventral view. Scale bars = 1 mm.

oriented dorsally and about half as long as posteroventrad oriented ventral process; setae present at midlength. Gonocoxite with coxopodite and harpago; in lateral view, coxopodite with convex dorsal margin and minutely concave ventral margin; apex nearly rounded, covered by setae; in dorsal and ventral view distally divergent, lateral margins convex and medial margins concave; apex pointed laterally; mesal area with setae; harpago in lateral view club shaped, with scattered short setae and oriented slightly posteroventrally; in dorsal and ventral views spine shaped, inwardly curved with pointed apex; basal antero-medially directed protrusion present. Phallus in lateral view slightly arched, bifurcate posteriorly; dorsal branch long and cylindrical; ventral branch long and club shaped, with a long sclerotized spine, apex slightly undulate; sperm channel slender; aedeagus widely triangular; phallus in ventral view parallel sided; aedeagus cylindrical with slightly incised apex; pair of lateral, sclerotized, spine-shaped processes present immediately below apex; long sclerotized spine protruding from apex.

DESCRIPTION OF THE FEMALE (Figs 43-47). — Abdomen with a cylindrical filament on segment V, about as long as segment V. Sternite VI with short, pointed process arising posteriorly on segment; triangular, with apex truncate in ventral view.

Genitalia: posterior margin of segment VII concave in ventral view, medially with numerous small setae and with long setae in lateral position. Tergite VIII about half as long as tergite IX, triangular in lateral view; anterior margin slightly convex in ventral view, posterior margin strongly ellipsoid, with two groups, each with 4 strong setae medially; sternite VIII with strongly sclerotized anterior margin, extended posteriorly into more membranous area, in ventral view with pair of medially directed, slightly sclerotized, rounded, posterior lobes each bearing numerous setae. Dorsobasal part of sternite VIII with laterally produced narrow folds oriented posteroventrally in lateral view and posterodorsally in ventral view. Segment IX nearly rectangular, forming a chamber being open ventrally and surrounding

43

45-47

FIGS 43-47. Xanthochorema bifurcatum Schmid, 1989 , female. 43, abdominal segments V-X, lateral view. 44,pointed process of abdominal sternite VI, ventral view. 45, genitalia, lateral view. 46, genitalia, dorsal view. 47, genitalia, ventral view. Scale bars = 1 mm.

softer parts of genitalia; posterior half setose; in dorsal and ventral view tapering posteriorly; inwardly folded in ventral view, folds with setae. Soft segment X consists of a posterior, weakly defined pair of rounded lobes, and an anterior well-defined pair of lobes with cercus. Spermatheca forms a composite structure within segment IX; in lateral view broad and irregular, widest at midway; in dorsal and ventral view composed by two medially incised, large lobes; in ventral view, medially with pair of posteriorly parallel, and anteriorly strongly diverging sclerotized bands.