Xanthochorema christinae, 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 : 84-87

Xanthochorema christinae n. sp.

Figs 13-23

MATERIAL EXAMINED. — New Caledonia. Holotype: male, Pro- Paratype: 1 female, Province Sud, Mt. Dzumac, source stream of vince Sud, Dumbéa River , branche nord, 2.2 km SE summit of Ouinné River , near cross-point to mountain track, 22°02.073’S, Mt. Piditéré , 22°07.503’S, 166°29.899’E, 25 m, 21.I.2004, loc 166°28.460’E, 810 m, 18.XI-4.XII.2003, loc 30, Malaise trap [K 124, light trap [KA Johanson & C Pöllabauer] ( MNHN, alcohol). A Johanson] ( NRM, alcohol.)

DIAGNOSIS. — Xanthochorema christinae n. sp. is distinguished from all other Xanthochorema species in the genitalia by having parapods being cylindrical and longer than the coxopodite, and with a strongly posterolaterally curved, cylindrical apex. Females are separated from the other species by the filament on segment V being only as long as segment V and, in the genitalia, by characteristics listed below.

DESCRIPTION OF THE MALE (Figs 13-18). — 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 1.3 x longer than sternite V, arising anteroventrally on segment and oriented posteroventrad; cylindrical along its length, sharply narrowing at basal one-third. Sternite VI with short, pointed mesoventral process, about one-quarter the length of segment VI, arising posteriorly on segment.

Genitalia: segment IX in lateral view with nearly straight anterodorsal margin and slightly convex posteroventral margin, posterior one-third covered by strong setae; in dorsal view with inner margin transversely ellipsoid, long setae present at postero-lateral margins; small process present at antero-lateral margin; in ventral view posterior margin slightly produced and with a cleft medially, anterior margin with broad lateral processes alongside the straight anteromedian margin, posterior one-third covered by strong setae. Proctiger in lateral view slightly shorter than gonocoxite, broad with ventral margin straight, dorsal margin slightly convex, posterior one-quarter widening posterodorsally, dorsolateral fold with setae at basal one-third; apex pointed; in dorsal view lateral margins parallel, except slightly divergent distally; pair of lateral folds with setae present at basal one-third; apex flat, slightly undulating, with dorsal incision. Lateral

14-18

FIGS 13-18. Xanthochorema christinae n. sp., male. 13, abdominal segments IV-VI, lateral view. 14, genitalia, lateral view. 15, genitalia, dorsal view. 16, genitalia, ventral view. 17, phallus, lateral view. 18, phallus, ventral view. Scale bars = 1 mm.

process of proctiger absent. Filipod cylindrical in lateral view, oriented postero-dorsad, basally slightly curving dorsally basally, about as long as coxopodite; covered by long setae; apex slightly club shaped, shorter setae at apex; sigmoid in dorsal view. Preanal appendage short, club shaped, covered by setae, aligned parallel with filipod. Parapod narrow, slightly longer than coxopodite, slightly curved ventrad, nearly cylindrical; mediodorsal margin slightly undulate with rounded process at apical one-third; apex narrowly cylindrical, strongly curved posterolaterally; postero-median margins covered by setae; aligned nearly parallel in dorsal view; sharply narrowing at apical one-third and curving strongly laterally. Gonocoxite with well-developed coxopodite and harpago. Coxopodite with convex dorsal margin and concave ventral margin in lateral view, directed postero-dorsad; apex slightly pointed; setae present at posterior twothirds; in dorsal and ventral view diverging distally, lateral and medial margins convex; a rounded, medially directed lobe with strong setae present at apex; mesal area with strong setae; harpago axe-head shaped in lateral view, with few long setae; cylindrical in dorsal and ventral view, strongly curved inwardly with rounded apex. Phallus arched downward in lateral view, broadest at anterior one-third, gradually narrowing posteriorly, slightly widening at apex; small protrusion present ventrally at one-third its length, sharp protrusion present dorsally at two-thirds its length; apex undulate, with pair of dorsally curved sclerotized spines. Sperm channel broad. Aedeagus cylindrical, slightly hooked anteriorly at apex, curved dorsad. Phallus parallel-sided in ventral view, with triangular lateral protrusions at three-quarters its length. Aedeagus cylindrical.

DESCRIPTION OF THE FEMALE (Figs 19-23). — Abdomen with cylindrical filament on segment V about as long as segment V. Sternite VI with minute, pointed process arising posteriorly on segment and being widely triangular in ventral view.

Genitalia: posterior margin of segment VII slightly undulating in ventral view, with numerous small setae. Tergite VIII short, about one-quarter the length of tergite IX; triangular in lateral view; in ventral view anterior margin slightly convex; posterior margin strongly truncated. Sternite VIII with strongly sclerotized anterior margin extending posteriorly

19

21-23

FIGS 19-23. Xanthochorema christinae n. sp., female. 19, abdominal segments V-X, lateral view. 20, pointed process of abdominal sternite VI, ventral view. 21, genitalia, lateral view. 22, genitalia, dorsal view. 23, genitalia, ventral view. Scale bars = 1 mm.

into more membranous area; postero-medially with pair of slightly sclerotized, bluntly thorn-shaped lobes, each bearing numerous setae in ventral view. Dorsobasal part of sternite VIII with laterally produced, broad folds oriented postero-ventrally in lateral view; folds running about in parallel in ventral view. Segment IX nearly rectangular; forms a chamber being open ventrally and surrounding softer parts of the genitalia, posterior half setose; in dorsal and ventral view slightly tapering posteriorly; folded inwardly in ventral view; folds with setae. Segment X comprises two pairs weakly defined, rounded lobes with numerous setae, the basal pair with cercus. Spermatheca forms a composite structure within segments VII-IX; in lateral view nearly parallel-sided, widening strongly posteriorly, with minute folds around the opening of ductus bursa copulatrix; anterior part has slightly sclerotized parallel bands in dorsal view and transverse sclerotized bands in ventral view; broad lateral lobes visible in dorsal and ventral view; with two long, transverse, parallel, sclerotized medial bands in ventral view.

ETYMOLOGY. — This species is named after Dr. Christine Pöllabauer (ERBIO, Nouméa, New Caledonia), in recognition of her great help during the sampling of this species, and for contributing with knowledge about the New Caledonian freshwater fauna in general.