Chimarra rosavensis, Johanson, Kjell Arne & Espeland, Marianne, 2010

Johanson, Kjell Arne & Espeland, Marianne, 2010, Description of new Chimarra (Trichoptera: Philopotamidae) species from the Solomon Islands, Zootaxa 2638, pp. 25-43 : 41-42

Chimarra rosavensis , new species

Figs 10 , 51–53

Diagnosis: This species is unique among the Solomon Island Chimarra species in the genitalia, i.e. with anteroventral part of segment IX subrectangular in lateral view and inferior appendages subquadrangular in lateral view. Chimarra aureofusca from the Solomon Islands has similar inferior appendages, but in that species the anteroventral part of segment IX is sharply triangular, and tergum X has slender lateral lobes. The Australian species C. adaluma Cartwright, 2002 , and C. yoolumba Cartwright, 2002 , both have similarly shaped inferior appendages in lateral view, but these have a shorter segment IX.

Description: Wings ( Fig. 10 ): Forewings each 4.0 mm long, membrane uniformly grey; veins brown. Hind wings each 3.4 mm long, membrane uniformly pale grey; veins brown.

Male Genitalia ( Figs 51–55 ): Segment IX long, L-shaped in lateral view ( Fig. 51 ); each side with anteroventral part produced anterad into rectangular plate; in lateral view ( Fig. 51 ) each side with anterodorsal and anterior margins nearly straight, ventral margin weakly convex, without ventral process; below each preanal appendage posterior margin irregular; setae present along each posterior margin from well below preanal appendage; in ventral view ( Fig. 53 ) segment IX slightly longer than wide, nearly uniformly wide along its length, except incised at mid-length; anterolateral and posterolateral corners pointed; posterior margin widely and shallowly concave; anterior margin with wide triangular incision; in dorsal view ( Fig. 52 ) tergum IX short, forming membranous transverse band above tergum X; lateral margins undulating, each lateral plate narrow anteriorly. Dorsal plate, possibly representing anterior apodemes, visible in lateral view as vertical lobe immediately anterior of tergum X; in dorsal view ( Fig. 52 ) forming posteriorly pointing triangle. Preanal appendages originating from basodorsal margins of tergum X, nearly 0.1 mm long, directed posterad; with irregular shape in lateral view ( Fig. 51 ), forming shallow, irregular warts in dorsal view ( Fig. 52 ). Tergum X about as long as inferior appendages; divided into membranous mesal lobe and pair of sclerotized lateral lobes ( Figs 51, 52 ). Mesal lobe visible in lateral view as triangular tissue immediately above preanal appendages, about 1/3rd as long as lateral lobes ( Fig. 51 ), without setae; in dorsal view ( Fig. 52 ) located between lateral lobes, narrowing posteriorly, with narrow posteromesal incision. Lateral lobes without setae, originating from dorsal part of segment IX; in lateral view ( Fig. 51 ), each lateral lobe broad from base, rectangular, narrowing immediately before apex, oriented posteroventrad, apex rounded; in dorsal view ( Fig. 52 ), ventral part of each lateral lobe straight, tapering, nearly parallel apically; dorsal part apparently distinct from ventral part, forming converging processes with laterad-curving apices. Lateral lobes apparently fused basally; sensillae on lateral lobes not observed. Inferior appendages with short central plate ( Fig. 51 ); irregularly narrowing anteriorly in lateral view; inferior appendages forming pair of broad, nearly quadrangular plates on short basal stalk; each appendage with dark sclerotized ridge running along posterodorsal corner; each appendage with 2 dark sclerotized, irregular ridges present centrally on mesal face ( Fig. 51 ), forming dark spots and bands visible in lateral view; each appendage with almost straight dorsal and ventral margins; posterior margin with shallow dorsal and deep ventral incision ( Fig. 51 ). Sclerotized portion of phallic apparatus long; phallobase thick, occupying nearly half length of phallotheca; in lateral view 3 times thicker than cylindrical posterior part of phallotheca ( Figs 54 ); in ventral view ( Fig. 55 ) about 2 times thicker than cylindrical posterior part of phallotheca; posterior part of phallotheca cylindrical. Phallotremal sclerite complex large, thick, irregularly U-shaped in lateral view; in ventral view forming irregularly shaped plate; 2 large, posterad-pointing endothecal spines present distally in phallotremal sclerite complex.

Holotype male: Solomon Islands: Guadalcanal Province, Guadalcanal, Weather Coast, Kusumba Region, Talin River, 30 m S junction with Rosava River, 70 m, loc 19, 9 °36.724'S 159°41.234'E, light trap, 25.i.2008 [M Espeland].

Etymology. Rosavensis , from Rosava River, the type locality of the species.

Figures

FIGURES 2 – 10. Right forewing and hind wing of holotypes of new Chimarra species. 2 — C. maculata, new species; 3 — C. talinensis, new species; 4 — C. veveensis, new species; 5 — C. kolombangensis, new species; 6 — C. babarensis, new species; 7 — C. vitapinensis, new species; 8 — C. ventrospina, new species; 9 — C. solomonensis, new species; 10 — C. rosavensis, new species.

FIGURES 51 – 55. Chimarra rosavensis, new species, holotype, male. 51 — genitalia, left lateral; 52 — genitalia, dorsal; 53 — genitalia, ventral; 54 — phallic apparatus, left lateral; 55 — phallic apparatus, ventral.