Hyposmocoma laysanensis Schmitz and Rubinoff

Schmitz, Patrick & Rubinoff, Daniel, 2009, New species of Hyposmocoma (Lepidoptera, Cosmopterigidae) from the remote Northwestern Hawaiian Islands of Laysan, Necker, and Nihoa, Zootaxa 2272, pp. 37-53 : 38-41

Hyposmocoma laysanensis Schmitz and Rubinoff , sp. nov. Figs. 1 , 12 , 20

Material examined. Holotype ɗ: [1] ‘H[ AWAI]I: Laysan, Guano Rock | “cone” case, III-25 -[20]08 | em[ergence]. VI-17 -[20]08, #DR07C22 | leg[it]. C[ynthia]. King’; [2] ‘ HOLOTYPE | Hyposmocoma | laysanensis | Schmitz and Rubinoff’. Specimen in perfect condition. Deposited in the UHIM. Paratypes: 46 ɗ, 44 Ψ, from Laysan Island, Hawaii, USA; 4 ɗ, 5 Ψ, with same data as holotype except date of emergence: IV-2 -[20]08 (2 ɗ), IV-8-08 (1 ɗ), IV-16-08 (1 ɗ, 5 Ψ); 1 Ψ, HI: Laysan, Guano Rock, Camp Pritchardia, “cone case”, III-24-08, em. IV-2-08, #DR08C21, leg. C. King; 1 Ψ, HI: Laysan, Guano Rock, “cone case”, III-25-08, em. IV-28-08, #DR08C23A, leg. C. King; 1 ɗ, HI: Laysan, Guano Rock, “cone case”, III-25-08, em. IV-28 - 0 8, #DR08C24A, leg. C. King; 38 ɗ, 33 Ψ, HI: Laysan, Guano Rock, “cone case”, IX-19 -[20]07, em. IX-27 - 0 7 (1 Ψ), IX-28-07 (1 ɗ), X-3-07 (2 ɗ, 2 Ψ, one dissected PS124), X-8-07 (2 ɗ, 2 Ψ), X-11-07 (1 Ψ), X-13-07 (2 Ψ, one dissected PS125), X-15-07 (1 ɗ, 1 Ψ), X-22-07 (1 Ψ), X-26-07 (1 ɗ, 1 Ψ), X-27-07 (1 ɗ, 1 Ψ), X-29 - 0 7 (2 ɗ), X-30-07 (1 Ψ), X-31-07 (1 ɗ, 1 Ψ), XI-2-07 (1 ɗ, 2 Ψ), XI-5-07 (5 ɗ, 6 Ψ), XI-6-07 (3 ɗ, 4 Ψ), XI- 7-07 (4 ɗ), XI-8-07 (1 ɗ, 2 Ψ), XI-9-07 (1 Ψ), XI-13-07 (3 ɗ, 2 Ψ), XI-15-07 (2 ɗ, 2 Ψ), XI-24-07 (2 ɗ), XI- 27-07 (1 ɗ, dissected PS122), XI-30-07 (1 ɗ), XII-5-07 (1 ɗ), XII-17-07 (1 ɗ, dissected PS121), I-7-08 (1 ɗ), II-19-08 (1 ɗ), #DR 07I2 E, leg. C[indy]. Rehkemper; 2 ɗ, 4 Ψ, HI: Laysan, Guano Rock, “cone case”, IX-15 - 0 7, em. X-17-07 (1 Ψ), X-29-07 (1 Ψ), X-31-07 (1 ɗ, dissected PS123, 1 Ψ), XI-5-07 (1 Ψ), XI-6-07 (1 ɗ), #DR 07I2 D, leg. M[ike]. Richardson; 1 ɗ (dissected PS123), HI: Laysan, Guano Rock, “cone case”, IX-15-07, em. XI-7-07 (1 ɗ), #DR 07I2 C, leg. M. Richardson. Deposited in BPBM, MHNG, UHIM, and USNM.

Diagnosis. Among all the species of Hyposmocoma from the NWHI, H. laysanensis can be easily separated by the combination of its size, distinct pattern, and coloration. The species is relatively small compared to the others inhabiting this remote island chain (wingspan between 5.2 and 7.7 mm). Also, the spotted pattern and the beige-brown coloration that confer excellent camouflage to the resting adult on the sandy background found on Laysan Island are unique for the NWHI Hyposmocoma .

Description. Male (n=47) ( Figs. 1 , 12 ). Wingspan 5.2–7.7 mm (Holotype: 7.0 mm). Head with browntipped beige scales converging toward midline on occiput. Base of haustellum with beige and dark-brown scales. Maxillary palpus reduced. Labial palpus recurved upward with off-white scales ventrally and darkbrown scales dorsally, off-white ring apically on second segment, and long slender dark-brown third segment with sometimes sparse off-white scales at base. Antennal flagellum dark brown, with off-white ring at apex on first flagellomere; scape mostly dark brown with off-white scales ventrally and forming ring apically, antennal pecten present consisting of three thin setae. Thorax mostly dark brown with brown-tipped beige scales at collar and apex of tegula; metascutellum beige. Foreleg dark brown with off-white ring at middle and apex of tibia, and apex of tarsomeres I, II, and V. Midleg as foreleg, spurs off-white. Hindleg as midleg, but more grayish brown and with off-white rings at apex of tarsomeres I–V. Forewing basally mostly dark brown with three more or less distinct dark-brown markings as a postbasal patch above midline, another submedian patch under midline, and a spot medially on midline, often joined together, reaching 0.5 length of forewing, and usually disconnected from basal patch; otherwise with brown-tipped beige scales, sometimes dense enough to appear as dark-brown spots in middle of postmedian and submarginal regions. Hindwing and fringe off-white. Subcostal brush absent. Abdomen dorsally uniform beige; ventrally off-white, with tuft of long off-white scales on each side of genitalia. Sclerotized ring strongly developed across entire sternum VII with sclerotized hook arising on right side (pseuduncus sensu Zimmerman 1978), elongate, slightly curved at apex, large basally and narrowing apically to blunt apex. Genital flaps (epiptygmata sensu Zimmerman 1978), membranous, rounded, broad and thin, arising on both sides apically of sclerotized sternum VIII.

Male genitalia (n=3) ( Fig. 12 ). Uncus and gnathos absent, but replaced by uncuslike processes attached to tegumen (brachia sensu Zimmerman 1978); right process elongate, curved ventrally, apically pointed, about 6 X length of left process. Tegumen wide, heavily sclerotized, dorsoventrally flattened. Valvae symmetrical, each forming long and slender arm slightly bent upward adorned with setae disposed comblike along dorsal margin, slightly broadened distally, with three sclerotized spurlike setae sequentially longer distally on each valva, the setae on left valva being 4– 5 X length of minute setae on right valva. Phallus slightly bent to right, stout, blunt-tipped, heavily sclerotized, slightly down curved; vesica without spines or cornuti. Anellus with two symmetrical lobes, thin until apex, both adorned with small setae, with two or three very long setae at apex.

Female (n=44). Wingspan 6.4–7.3 mm. Frenulum with 3 acanthae. Antennae slightly thinner than that of male. Otherwise externally like males.

Female genitalia (n=2) ( Fig. 20 ). Papillae anales short, lightly sclerotized and setose, slightly longer than wide. Anterior and posterior apophyses thin and straight, posterior apophyses about 2.5 X length of anterior apophyses. Ostium bursae heavily sclerotized, externally protruding, snailshell shaped with broad base. Ductus bursae long and of narrow girth. Corpus bursae oval and elongate, with light scobination; signum absent. Inception of ductus seminalis very enlarged, cylindrical, situated at posterior end of corpus bursae. Apical margin of tergum VIII with broad emargination medially.

Larval case (n=529). Cone-shaped structure, 4.5–6.0 mm in length, small and thin, decorated with bits of sand, and probably guano, woven with silk filaments; aperture covered with operculum decorated with small pebbles, or sand grains fastened by silk; background color ranging from off-white to gray.

Etymology. The name of H. laysanensis is derived from that of the type locality, the island of Laysan.

Biology. All adults were reared from case-making larvae. Larvae were collected during the day on rocks, the latter sometimes disposed in a pile, on the island of Laysan in March and September. When disturbed, larvae were observed to tightly close the operculum of their case with their mandibles. The abundance of the cases suggests that the species is very common on Laysan. Parasitoids were reared from some larvae and have been identified as belonging to the Eupelmidae (n=5) and Pteromalidae (n=2) (Insecta: Hymenoptera ). Most species of cone-cased bearing Hyposmocoma in the younger main Hawaiian Islands live in streams and are aquatic (Rubinoff 2008), making the dry habitat of this species unusual.

Distribution. Known only from the NWHI of Laysan where it is presumed to be endemic.

Figures

FIGURE 12. Male genitalia of Hyposmocoma laysanensis from specimen on slide PS 122. A. Tegumen, ventral aspect; B. Sclerotized hook on abdominal segment VII, ventral aspect; C. Valvae with phallus, ventral aspect. FIGURE 13. Male genitalia of Hyposmocoma ekemamao from specimen on slide PS 138. A. Tegumen, lateral aspect; B. Valvae with phallus, ventral aspect.

FIGURES 1 – 8. Holotypes of Hyposmocoma spp., adult males. 1. H. laysanensis; 2. H. ekemamao; 3. H. opuumaloo; 4. H. mokumana; 5. H. nihoa; 6. H. kikokolu; 7. H. menehune; 8. H. papahanau.

FIGURES 20 – 26. Female genitalia of Hyposmocoma spp., ventral aspect 20. H. laysanensis (slide PS 124); 21. H. ekemamao (slide PS 139); 22. H. opuumaloo (slide PS 134); 23. H. mokumana (slide PS 126); 24. H. nihoa (slide PS 133); 25. H. kikokolu (slide PS 127); 26. H. menehune (slide PS 136).