Hyposmocoma kahamanoa Schmitz & Rubinoff, 2011, SP. NOV.
Creators: name: Schmitz, Patrick
name: Rubinoff, Daniel
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Cosmopterigidae
Hyposmocoma
Hyposmocoma kahamanoa

description: HYPOSMOCOMA KAHAMANOA SCHMITZ & RUBINOFF SP. NOV. (FIGS 1A, 2A, 3–5, 11A)   
 Material examined: HOLOTYPE ♂: [1] ‘H[AWAI]I: Oahu, Palolo stream | ‘cone’ case, IV-25-20[08] | em[ergence]. V-2-[20]08, #DR08D4 | leg [it]. P[atrick]. Schmitz, W [ill]. Haines’; [2] ‘ HOLOTYPE | Hyposmocoma | kahamanoa | Schmitz and Rubinoff’. Specimen in good condition. Deposited in the UHIM.   
 PARATYPES: 24 ♂, 15 ♀, with same data as holotype except date of emergence: 29.iv.2008 (1 ♂), 2.v.2008 (1 ♂), 9.v.2008 (1 ♀), 30.v.2008 (1 ♂, 1 ♀), 9.vi.2008 (2 ♂, one dissected PS168), 12.vi.2008 (3 ♂), 30.vi.2008 (1 ♀), 18.vii.2008 (1 ♂), 20.viii.2008 (1 ♀), #DR08D4, leg [it]. P[atrick]. Schmitz, W[ill]. Haines; 2 ♂, 1 ♀, HI: Oahu, Manoa Stream, cone case, 29.viii.2003 Emerg [e]d: 16.ix.2003 (2 ♂, one dissected PS163), 11.ix.2003 (1 ♀), [Daniel] Rubinoff; 1 ♀, HI: Oahu, Manoa Stream, coll[ection]: V-03, Em [erge]d: 18.viii.2003, Rubinoff, coll[ector].; 14 ♂, 8 ♀, HI: Oahu Isl [and]., ‘cone’, Kalauao Stream, 25.i.2004, Em [e]rg[e]d: 21/ 22.iv.2004 (11 ♂, 6 ♀),   
23.iii.2004 (1 ♂, dissected PS159), 8/ 15.iv.2004 (1 ♂, dissected PS164, 2 ♀, one dissected PS153), 27.iv.2004 (1 ♂), Rubinoff, coll. Deposited in BPBM, MHNG, UHIM, and USNM.  
 Diagnosis: Amongst the species of Hyposmocoma, H. kahamanoa is very similar to Hyposmocoma saccophora Walsingham, 1907, also endemic to the island of Oahu, in size and forewing pattern. However, it differs in males in having a shorter sclerotized hook on abdominal segment VII and in male genitalia in having sclerotized spur-like setae of different shape and length on each valva. Although the number of setae can vary amongst different specimens of H. kahamanoa, the setae on the right valva are 1/2 ¥ the length and on the left valva are thick and slightly curved apically and two ¥ the length of those found in H. saccophora. Hyposmocoma kahamanoa differs from Hyposmocoma kahaiao sp. nov., Hyposmocoma kawaikoi sp. nov., and Hyposmocoma uhauiole sp. nov. in the characters mentioned in the Diagnosis and Description of these species, below.   
 Description: Male (N = 25) (Figs 1A, 5). Wingspan 7.6–9.0 mm (holotype: 9.0 mm). Head adorned with large, shiny, dark grey scales on occiput becoming beige on vertex and frons. Haustellum with beige scales. Maxillary palpus reduced. Recurved labial palpus mostly dark grey dorsally and beige ventrally with some sparse beige scales on segments, and on second segment apically. Antennal flagellum dark grey; scape dark grey with beige scales ventrally and forming disrupted ring apically, antennal pecten present with up to four thin setae. Thorax, tegula, and metascutellum dark grey. Foreleg coxa beige; femur dark grey; tibia and tarsomeres dark grey with beige ring at middle and apex of tibia, and apex of tarsomeres I, II. Midleg as foreleg, spurs beige. Hindleg as midleg, but ground colour more silver grey. Forewing dark grey with sprinkling of dark grey scales on a pale beige background, dark grey markings as pair of spots medially (often fused in darker specimens), disconnected from each other along diagonal, and a more or less conspicuous small spot postmedially in midline; cream markings as a small notch subapically on costal margin and another opposite on inner margin. Hindwing and fringe uniformly silver grey. Subcostal brush absent. Abdomen dorsally dark grey; ventrally beige, with tuft of long beige scales on each side of genitalia. Sclerotized hook (pseuduncus sensu Zimmerman, 1978) small with distinct sclerotized ring on segment VII. Genital flaps (epiptygmata sensu Zimmerman, 1978) membranous, rounded, broad and thin, emerging on both sides apically of sclerotized sternum VIII.   
 Male genitalia (N = 4) (Fig. 5). Uncus and gnathos absent, but replaced by uncus-like processes attached to tegumen (brachia sensu Zimmerman, 1978), right process elongate and thin, sickle-shaped, curved ventrally, apically pointed, with small notch at 1/3 length, about eight ¥ length of left process. Tegumen wide, heavily sclerotized, dorsoventrally flattened. Valvae symmetrical, with long and slender arms, enlarged apically, bent upward in the middle, adorned with setae arranged comb-like along dorsal margin, with sclerotized spur-like setae of same length apically rounded on right valva, and large sclerotized spurlike setae on left valva, being six ¥ length of those on right valva; number of spur-like setae vary amongst specimen studied, three right and three left, three right and two left, or two right and two left. Phallus large, heavily sclerotized, slightly bent to the right, blunt tipped, with large bulbous base; vesica without spines or cornuti. Anellus with two symmetrical lobes, thin, angled upward, both adorned with small setae until apex, right lobe very slightly enlarged apically.   
 Female (N = 15). Wingspan 8.8–9.8 mm. Frenulum with three acanthae. Forewing background colour dark grey with indistinct dark grey markings. Antennae slightly thinner than that of male. Otherwise externally like males.   
 Female genitalia (N = 1) (Fig. 11A). Papillae anales short. Apophyses thin and straight; posterior apophyses, very long about five ¥ length of anterior apophyses. Ostium-bearing process heavily sclerotized and very large, externally protruding, snail-shell shaped curled to the left, with broad base. Ductus bursae long and of small girth. Corpus bursae oval and elongate, with light scobination; signum absent. Inception of ductus seminalis very enlarged, cylindrical, situated behind of corpus bursae. Apical margin of sternum VII with broad U-shaped emargination medially forming a bowl encompassing ostium-bearing process with patches of dense scales situated laterally.   
 Larva (Figs 3, 4). Length 4.5–5.0 mm (N = 58). Body pale yellow, textured with microconvolutions; head capsule amber; prothoracic shield amber, gradually darkening posteriorly, mesothorax and metathorax with pale amber patches similar to prothoracic shield; pale brown patches on thoracic segments as a hori- zontal elongated patch in middle and a perpendicular elongated patch posterior to coxa (on some larvae inconspicuous); pinacula pale yellow; anal plate amber; setae with pale brown, circular, and very slightly raised sockets. Head (Figs 3A–C, 4D): semi- hypognathous, textured with slightly raised, confluent, polygonal ridges except on area between adfrontal sclerites (Fig. 4A); adfrontal sclerites widened distally, frontal setae about equal in length, AF2 above apex of frons, AF1 below; F1 slightly closer to AF1 than to C1, AF1 and F1 at least two ¥ longer than AF2; C1 and C2 of same length; clypeus with five pairs of setae, three pairs on medial half, two on distal half; mandible simple (Fig. 4D), shallowly notched, bearing pair of subequal setae on outer surface near condyle, and with four distinct distal teeth; sensilla types and arrangement on antenna (Fig. 3B) and on maxillary palpi (Fig. 3C) similar to those of other Gelechioidea (for references, see Schmitz & Landry, 2006). Six stemmata in genal area, arranged in an arc with six caudad, stemmata 2, 3, 4 close together in straight line with stemma 5 separated from 4, 6 by width of a stemma; substemmatal setae about equal in length; S3 posteroventrad to S2, S2 approximate to stemma 3, and S1 approximate to stemma 5; A-group setae above gena, A1 and A3 at least three ¥ longer than A2; L1 very short and posterodorsad to stemma 2; P1 anteroventrad to AF2, P2 posterodorsad to P1, P1 about seven to eight ¥ longer than P2. Thorax (Figs 3E, 4A): T1 with L-group trisetose, surrounded by prothoracic shield; setae anterior to spiracle; L 1 in between and equidistant to L2 and L3, about 2.5 ¥ lengths of L2 and L3; SV-group setae of same length on anterior part of elongate pinaculum; coxae nearly touching, V1s posteroventrad of coxae; segments of leg smooth, very long, with sparse hair-like spines, claw single (Fig. 3E); shield with SD 1 in straight line with XD2 and XD1; SD1 about same length then L1; XD2 and D2 about equal in lengths; XD2 about 2.5 ¥ length of XD1, at same distance from XD1 as from SD1; XD1 about same length as D1 and SD2; D 1 in straight line with D2 and XD2, posterior to SD2 and D2; SD 2 in straight line with SD1. T2–T3 (Fig. 4A): D2 about two ¥ length of D1, both on small pinaculum; SD1 about five ¥ length of SD2, both on small pinaculum; L1 about three ¥ longer than L2, both on small pinaculum, L3 slightly shorter than L2, posterior to or in vertical line with SV1; D1, D2, SD1, SD2, L1, and L2 surrounded by pale brown patch similar to prothoracic shield; SV1 on anterior part of elongated pale brown patch; V1s on T2–T3 about equal distance apart (not shown), at least 1.5 ¥ distance between V1s on T1. Abdomen (Figs 3C, F, G, 4B, C): A1–A2 (Fig. 4B): D2 about 1.5 ¥ length of D1; SD1 above spiracle on A1, and slightly anterodorsad to spiracle on A2, about of same length than D2; SD2 minute and anterodorsad to SD1; spiracle on A1 of same size than those on A2–A7; L1 about five ¥ length of L2, both on same pinaculum, below and slightly posterior to spiracle; L3 about same length as L2, posterior to, or in vertical line with L1 and L2; SV-group unisetose on A1 and bisetose on A2, on same pinaculum; V1s equal distance apart (not shown), at least two ¥ distance between V1s on T2–T3. A3–A10 (Figs 3C, F, 4C): A3–A6 with four pairs of little prominent prolegs, crochets uniordinal, in ellipse (Fig. 3C); setae as A1–A2, except all setae at least only half the size; A7 as A3–A6, except L3 closer to L1 and L2; A8 as A7 except spiracle slightly larger than on previous segments (Fig. 4C); A9 with D1, D2, and SD1 of equal lengths and in straight line, with D2 equidistant to both setae; L-group setae also nearly in straight line with D1, D2, and SD1; L1 small, about two ¥ length of L2, on same pinaculum; L3 of same length as L2; SV1 slightly shorter than L1; V1s as previous segments; A10 (Fig. 4C): anal plate with D1, D2, and SD2 equal in lengths, SD1 slightly longer; crochets of proleg uniordinal, in ellipse.   
 Larval case (N = 290) (Fig. 2A). Cone-shaped structure, 7.0– 12.5 mm in length, cases of young larvae may be very small (< 1.0 mm), small and thin, decorated with beige, brown, and black bits of sand woven with silver silk filaments; bicoloured, paler beneath and darker above, dorsally brown silk peppered with varying degrees of black usually resulting in dark brown overall colour, dorsal side encrusted with lichen, algae, and diatoms giving a coarse appearance, ventral side silver and remarkably smooth with occasional black mottling; aperture of case covered with an operculum decorated with small pebbles, or sand grain fastened by silk, that can be closed tidily by the larvae with its mandibles from the inside; background colour ranging from dark brown to black.   
 Etymology: The name H. kahamanoa is derived from the Hawaiian, kaha, edge, that refers to the edge of the stream habitat, and the Mānoa stream, which flows through the Mānoa Valley on the island of Oahu, where this species was collected for the first time by D. R. in 2004.   
 Biology: Adults were reared from amphibious casemaking larvae. Case-bearing larvae were collected during the day on rocks in streams on the island of Oahu in January, April, May, and August, and are probably present year round. They were found above and under the water line mostly in small holes covering the porous volcanic rocks, always at places where the sun breaks through the tree canopy, probably promoting the growth of algae and lichens on the rocks. Heavily shaded areas of the streams do not appear to be suitable habitat for the larvae. Adults can be observed during the day, but apparently are not attracted to light even if a black light trap is placed beside a stream where they occur abundantly.   
 The larvae rest on emergent rocks in the middle and edges of the streams where they feed on lichens, and especially fresh and dried algae, but they can also dive for long periods of time in order to feed on algae. When under water they secure themselves with silk, which can be used by the larva as a life-line if it becomes dislodged by pulling on the strand in order to reattach to the rock. The most likely explanation for the respiration strategy is a direct diffusion of oxygen through the hydrophilic skin along the abdomen. This is supported by the fact that no tracheal gills were observed on the body of the larvae like those found for example in aquatic species of Acentropinae (Solis, 2008). In addition, temporary oxygen storage in the form of a trapped air bubble in the case was found rarely, despite multiple dissections (N = 20). The tracheal system appears to be unmodified with no reduction in the diameter of the spiracles, being morphologically open (Fig. 3F), that might confer on the larvae a peripneustic tracheation (Welsh, 1922). Additionally, details of the exocuticle, or integument (Fig. 3G), show that it is smooth with simple rounded protuberances of the cuticular surface (Reichholf, 1976), rather than composed of tiny hydrophobic cuticular hair-like structures, also called microtrichia (Solis, 2008), that make up the plastron of hydrophobic larvae in species of Acentropinae (Wichard, Arens & Eisenbeis, 2002; Speidel, 2005; Solis, 2008). Therefore, the combination of the small size of the larvae, their occurrence strictly in well-oxygenated, fastmoving streams, and the hydrophilic microstructure of their cuticle suggests that the aquatic larvae probably rely on direct diffusion when submerged. Laboratory experiments confirm that the larvae die quickly in stagnant water (in a matter of hours), but are able to survive for weeks forcibly submerged in a well-oxygenated aquarium (Rubinoff & Schmitz, 2010)   
 Distribution: Known only from streams (Manoa, Palolo, Kalauao streams and certainly others) in the Ko‘olau mountains of eastern Oahu where it is presumed to be endemic.   
 Remarks: Based on differences in male genitalia, this species may represent the new species 26 of Zimmerman (1978) collected near the head of Kawailoa Gulch in the Ko‘olau range and described (mistakenly according to Zimmerman) by Walsingham (1907) as a paratype of H. saccophora. We are supported in our observation by the fact that H. kahamanoa seems to be endemic to the Ko‘olau range on east Oahu, whereas H. saccophora appears to be endemic to the Waianae range on west Oahu. Finally, the two Oahu species are not only allopatric but ecologically very different; H. kahamanoa is strictly aquatic, being found in and around streams of the Ko‘olau range, whereas H. saccophora inhabits dry open rocky terrain in the Waianae mountains. Parasitoids were reared from some larvae and have been identified as belonging to the Eupelmidae (N = 2) and Pteromalidae (N = 2) (Hymenoptera: Chalcidoidea).
description: Published as part of Schmitz, Patrick & Rubinoff, Daniel, 2011, The Hawaiian amphibious caterpillar guild: new species of Hyposmocoma (Lepidoptera: Cosmopterigidae) confirm distinct aquatic invasions and complex speciation patterns, pp. 15-42 in Zoological Journal of the Linnean Society 162 (1) on pages 17-23, DOI: 10.1111/j.1096-3642.2010.00676.x, http://zenodo.org/record/5440227