Neoperla sabah Zwick

(Figs. 6‐10)

Neoperla sabah Zwick, 1986a:7 . Holotype ♂ (Bernice P. Bishop Museum, Honolulu), North Borneo, 19 km N Kalabakan [Sabah]

Material examined. Brunei Darussalam: Temburong District, Sungai Belalong, Kuala Belalong Field Studies Centre, 04.54822 ° N, 115.15823 ° E, ALS B36‐08, A.L. Sheldon, 2 ♂ (BPS). Same site, ALS B29‐08, 23 June 2008 , A.L. Sheldon, 1 ♂, 1 ♀ (BPS) .

Adult habitus. General color yellow brown. Head mostly pale but with brown arcuate mark behind ocelli and area between ocelli dark; M‐ line area and anteromedian area of frons slightly darker than background pigment (Fig. 6). Basal antennal segments pale brown, flagellum darker. Femora pale, tibiae darker; wing membrane pale amber, veins brown.

Female. Forewing length 10.5 mm. Posterior margin of sternum 8 unmodified (Fig. 7). Receptacular stalk Cshaped and almost completely armed internally with closely packed brown scales (Fig. 8); vagina slightly constricted near midlength.

Egg. Length from tip of lid to rim of anchor pole, ca. 225.0 μm; diameter, ca. 147.5 μm. Most of egg body covered by narrow, spiral striae (ca. 18 in lateral view) separated by narrow, punctuate sulci (Fig. 9). Base of anchor arises from center of convex, impunctate plate covering anchor pole; margins of plate scalloped with small projecting teeth over base of each striation (Fig.10). Lid punctate with tiny aeropyles over entire surface.

Remarks. Zwick (1986a) described this species from five males taken at two localities in Sabah. These are the first specimens taken in Brunei Darussalam. The female association is based on a common pattern of brown pigment behind the ocelli. Eggs are similar to those of N. rougemonti (Zwick 1986a) but have spiral striae rather than straight ones.