Material examined: HOLOTYPE ♂: [1] ‘H[AWAI]I: West Maui | Maui Land and Pineapple | Honolua Stream, elev[ation]. 900 m | ‘burrito’ case, I-6-[20]06, em[ergence]. II-20 -[20]06, #DR06A8 | leg[it]. D[aniel]. Rubinoff’; [2] ‘ HOLOTYPE | Hyposmocoma | waihohonu | Schmitz and Rubinoff’. Specimen in good condition except for broken antennae. Deposited in the UHIM.

PARATYPES: 9 ♂, 11 ♀, from Maui Island, Hawaii, USA; 2 ♂, 4 ♀ (one dissected, PS151), same data as holotype; 3 ♂, 3 ♀, same data as holotype except date of emergence: 11.ii.2006 (2 ♂, one dissected PS150), 17.ii.2006 (2 ♀), 21.ii.2006 (1 ♀), 3.iii.2006 (1 ♂, dissected PS158); 4 ♂, 2 ♀, HI: W[est]. Maui Isl [and]., Iao V [al]l[e]y. St [rea]m., ‘burrito’, 11.ix.2004, Em [e]rg[ence]: 1.x.2004 (1 ♂), 6.x.2004 (1 ♀), 10.x.2004 (1 ♂), 18.x.2004 (1 ♀), 28.x.2004 (1 ♂), 15.xi.2004 (1 ♂), Rubinoff, coll[ector]; 2 ♀, HI: W[est]. Maui, Waiehu stream, ‘burrito’, 22/ 25.ix.2008, em[ergence]. 3.xi.2008, #DR08I3B, coll. C[ynthia]. King. Deposited in BPBM, UHIM, and USNM.

Diagnosis: Hyposmocoma waihohonu is a relatively small mostly uniform dark brown to dark grey species. Amongst the species of Hyposmocoma, H.

waihohonu can be easily separated by the combination of its size and coloration.

Description: Male (N = 9) (Figs 13B, 18). Wingspan 8.4–9.7 mm (holotype: 8.6 mm). Head mostly dark brown becoming dark grey on vertex and off-white on frons. Haustellum with off-white scales. Maxillary palpus reduced. Recurved labial palpus mostly dark brown dorsally and off-white ventrally, with off-white ring on second segment apically. Antennal flagellum dark brown; scape dark brown with off-white ring apically, antennal pecten present with up to eight thin setae. Thorax, tegula, and metascutellum dark brown. Foreleg coxa off-white; femur dark brown; tibia and tarsomeres dark brown with off-white ring at middle and apex of tibia, and apex of tarsomeres I– V. Midleg as foreleg, spurs off-white. Hindleg as midleg, but ground colour more silver grey. Forewing with dark brown to dark grey background, with more or less conspicuous dark brown markings as pair of spots medially (often fused in darker specimens), disconnected from each other along diagonal, and a small spot postmedially in midline; indistinct offwhite markings as a small notch subapically on costal margin and another opposite on inner margin. Hindwing uniformly dark grey with fringe greyish brown. Subcostal brush absent. Abdomen dorsally dark brown to dark grey; ventrally off-white, with tuft of long dark-grey scales on each side of genitalia. Sclerotized hook absent. Genital flaps very large, membranous, rounded, broad and thin.

Male genitalia (N = 2) (Fig. 18). As for H. aumakuawai.

Female (N = 9). Wingspan 8.9–9.4 mm. Frenulum with three acanthae. Antennae slightly thinner than that of male. Otherwise externally like males.

Female genitalia (N = 1) (Fig. 20D). As for H. aumakuawai.

Larval case (N = 86). Burrito-shaped structure, 4.0– 5.5 mm in length, as H. aumakuawai.

Etymology: The name H. waihohonu, from the Hawaiian, wai, water, refers to its aquatic lifestyle, and hohonu, deep, refers to the habit of this species to frequent deep, central stream channels.

Biology: Adults were reared from amphibious casemaking larvae. Case-bearing larvae were collected during the day on rocks in the streams on the western volcano of the island of Maui in January, September, and November This species was frequently observed in deep water in the central channel of the streams in which is occurs, although, like all aquatic species, it is frequently found resting above the water line. This may be in part a function of our relative ease in finding Diagnosis: Hyposmocoma moopalikea is most similar in forewing markings to H. aumakuawai sp. nov., and H. parda (Butler, 1881), but it differs from these species in having on the forewing scattered yellowishorange scales and a conspicuous pair of spots outlined by off-white scales. In addition, it differs from H. aumakuawai in the absence of a sclerotized hook on abdominal segment VII.

larvae out of the water rather than when submerged and under rocks in the middle of fast flowing streams.

Distribution: Known only from the Hawaiian Island of Maui where it is presumed to be endemic of the streams of west Maui (Honolua, Iao, and Waiehu streams).

Remarks: Parasitoids (N = 10 from #DR09I3B) were reared from some larvae and have been identified as belonging to the genus Euderus of the Eulophidae (Hymenoptera). This species appears to be the sister taxon to the aquatic burrito species, H. moopalikea, restricted to the south side of east Maui.