The New Caledonian genus Caledonotrichia Sykora (Trichoptera, Insecta) reviewed, with descriptions of 6 new species.

The New Caledonian endemic hydroptilid genus Caledonotrichia Sykora (Trichoptera) is reviewed and 6 new species are described: Caledonotrichia bifida, Caledonotrichia capensis, Caledonotrichia minuta, Caledonotrichia ouinnica, Caledonotrichia sykorai and Caledonotrichia vexilla. Together with the established species for which revised diagnoses are given, these raise to 11 the number of species known in this genus. The new species, females of 3 species, and several unusual larval cases are examined and described for further insight into relationships of this enigmatic genus. A key to species is provided.


Introduction
The Trichoptera fauna of freshwaters on the small south-western Pacific island of New Caledonia exhibit high levels of endemism at the species level. In addition, 7 genera are endemic, among which is one hydroptilid genus, Caledonotrichia Sykora, 1967. As part of a revision of all New Caledonian Hydroptilidae (Wells and Johanson 2012, and in prep.), this genus is reviewed here. The first 2 species in the genus Caledonotrichia Sykora were C. illiesi Sykora, 1967and C. minor Sykora, 1967, both from a locality near Col d'Amieu in the Province Sud (southern province). Nothing more was published on the genus until J. Marshall in her 1979 review of Hydroptilidae included a brief diagnosis and, not surprisingly given the features identified as diagnostic, was unable to assign the genus to any of the Hydroptilinae tribes that she recognised. In 1989, 2 additional species of Caledonotrichia were described by Kelley: C. charadra Kelley, 1989, smallish and rather similar to C. minor, and a distinctive, much largerbodied species, C. extensa Kelley, 1989. Next, several larvae were described by Wells (1995): a curious early instar larva with greatly modified head setae -cephalic 'horns', and mature larvae with dome-shaped cases, both attributed to Caledonotrichia illiesi, as well as an unassociated early larva without cephalic horns. Oláh & Johanson (2010) added a fifth species, C. nyurga Oláh & Johanson, 2010. Adults of several additionalnew species in Caledonotrichia were collected by A. Wells in late 1998, and extensive light-and Malaise-trapping by K.A. colleagues from 2001-2006 yielded others. This present study is based mainly on these two collections, although between 1996 and 2000, N. Mary collected extensively in her study on macroinvertebrates of New Caledonian streams (Mary 2002). Mary's surveys concentrated on aquatic stages and, as few pharate adults were among the hydroptilids collected, most specimens were identifiable only to genus. This was unfortunate since in addition to the fixed dome-shaped cases of the form described by Wells (1995), the samples included further unusual larval cases, identifiable as those of species of Caledonotrichia. These are purse-shaped and cylindrical cases constructed of 2 equal valves, with distinct dorsal and ventral sides, some with dorsal vents. One purse-shaped form is made of sections of moss microphylls placed flat in a manner similar to that described by Cairns & Wells (2008) for Scelotrichia willcairnsi Cairns & Wells, 2008, a NE Queensland Stactobiini species, that not only makes its case from moss microphylls, but also feeds upon them. These New Caledonian cases differ, however, in having towards each end of one seam, a protruding 'stalk', presumably for attachment to the substratum; on the outer side of each stalk is a well-defined opening facing towards the end of the case. A pharate adult female has 34 antennal segments. Among known species only C. illiesi and C. nyurga have antennae with so many segments, and C. illiesi has domeshaped cases. This may be the case of C. nyurga. A second purse-shaped case also made of moss microphylls but this time without dorsal vents, is constructed of small moss microphylls, all bristling out neatly from the surface of the case and giving it a porcupine-or echidna-like appearance. The larvae conform with those of Caledonotrichia, but no further identification is possible. The third case type, identified from pharate adults, is that of C. extensa. These cases (Fig. 70) comprise two valves, both smoothly rounded, and constructed of silk secretion only. They more or less form a cylinder, but are tapered and flattened towards each end, terminating in a bract-like overhang. Each end has a pair of triangular prominences on the upper seam around openings that face towards each end of the case. Similar dorsal prominences shielding vents occur on the cases of 3 Australian species (see Wells 1997): in Hellyethira forficata Wells, 1997, an otherwise ovoid case constructed of sand grains and silk; Orthotrichia armata Wells, 1997, a ribbed, secretion case; and O. tyleri Wells, 1997, a case that is almost identical in shape to the case of C. extensa. These three species have been collected from northern Australian billabongs (anabranchs) and streams, all of which have very warm waters where oxygen levels might be expected to be low at times. The vents may be an adaptation that, together with undulations of the body, assists water circulation in the case and thus improve ventilation. Small dorsal openings are seen also in the dome-shaped cases of Caledonotrichia illiesi (Wells 1995: figs 11, 12), possibly serving a similar function for their inhabitants.
Sorting of Caledonotrichia adults is fraught. Females are generally very closely similar in appearance and usually we have made little attempt to sort them. To illustrate general form we figure and describe several that have been associated tentatively. Males of most species are difficult to identify, too, without close scrutiny of individual specimens under a compound microscope; this is not feasible for sizeable samples. However, on the basis of morphology of male genitalia the species fall into two distinct species groups -an 'illiesi group' and an 'extensa group'. The three 'extensa group' species are relatively easy to identify when in alcohol. The males all have abdominal segment IX strongly triangular in shape and C. extensa is the largest of all congeners. Caledonotrichia nyurga and C. sykorai have elongate processes apico-mesally on abdominal sternite VIII, and C. nyurga has antennae with distinctive rounded to urn-shaped distal segments. Identifying males of the other group is more difficultmainly because the genitalia are very hairy and often withdrawn into abdominal segment IX, and in preserved specimens the two lobes of the gonopods are usually folded tightly towards the body, obscuring all other genitalic structures. The only way to identify them with certainty is by macerating the genitalia. Males of four species, however, can be identified by the scales on the wings, although these may be deciduous or simply lost due to abrasion when collected. Caledonotrichia minor, C. ouinnica sp. n. and C. capensis sp. n. all have scales on the forewing only; C. charadra has them on both fore-and hind wings. The extent of the scale patches can be used to separate these first three listed species. The scales are possibly androconial scales, involved in scent dispersal and in the male lekking behaviour was observed in the field in this group that appear to be primarily diurnal in behaviour. Specimens of several species were collected (by AW) in bright sunlight as they (predominantly males) rested, ran or flew around on emergent rocks or on riparian vegetation, usually in small groups. Similar diurnal behaviour is exhibited by some species in the Stactobiinae genera Chrysotrichia Schmid, 1958 andScelotrichia Ulmer, 1951, and some of these have scales on their wings (Wells and Huisman 1993).
The peculiarly diverse case forms seen in Caledonotrichia are more or less paralleled in the Stactobiinae, which share with Caledonotrichia features such as head with tentorium complete, mesoscutellum with transverse suture and, on the forewing, a welldeveloped jugal lobe, features not noted by Marshall (1979), possibly because they are probably plesiomorphic.
Recent authors such as Morse (2012) and Holzenthal et al. (2007), when considering Hydroptilidae relationships or classification, have also failed to place Caledonotrichia, leaving it in incertae sedis in family Hydroptilidae. A sister group relationship between Caledonotrichia and the Australian Maydenoptila was postulated by Wells (1995). Both have the above plesiomorphic features and their males have bilobed gonopods, with one lobe of the pair with a mesal process of some kind; in both the phallic apparatus varies in form between species, some with one or more associated parameres, others simple; and most species of Maydenoptila and at least three of Caledonotrichia have abdominal segment IX strongly triangular in ventral view. Females in both genera have similar slender, elongate abdominal terminalia. Although Caledonotrichia and Maydenoptila share many features, they exhibit some notable differences. The wings of Caledonotrichia are narrower than those of Maydenoptila, with the venation considerably reduced. No known species of Maydenoptila is modified in this way; indeed, most have wings that are somewhat broader than those of many Hydroptilinae, and with venation more complete than most. Another notable difference is the occurrence of scent scales or androconia on wings of males of some Caledonotrichia; these are not known to occur species of Maydenoptila. Evolution of scales on wings may be a phenomenon that sometimes occurs when species diverge in sympatry such as may be the situation from time to time on islands -wing scales are found in a Lord Howe Island species of Orphninotrichia Mosely, but not in any of the Australian mainland species (Wells 1999(Wells , 2010; an Oxyethira species with scattered scales on the hind wing was described by Johanson et al. (2011) from the island of Espiritu Santo, Vanuatu. Wing scales occur also in stactobiine taxa such as Chrysotrichia and on wings of a number of Neotropical leucotrichiine species, too.
The distribution of Maydenoptila in south-western and eastern Australia suggests that it could be Gondwanan in origin and Caledonotrichia could have a similar origin. Thus, if Caledonotrichia and Maydenoptila are members of the Stactobiinae, they probably evolved from an early stactobiine lineage. Note, however, that contrary interpretations are given by Harris & Armitage (1997) who, in their study of the Neotropical genus Nothotrichia Flint, 1967 concurred with Kelley (1992) in placing that genus with Caledonotrichia and Maydenoptila in the basically Neotropical 'tribe [sic] Ochrotrichiinae'. Relationships of these genera remain to be tested by studies based on molecular data.
In support of future studies on New Caledonian Hydroptilidae, we provide diagnoses and descriptions for all known species of Caledonotrichia, along with an identification key to adult males. Other hydroptilid genera found in New Caledonian freshwater systems -Paroxyethira, Hellyethira, Acritoptila and Oxyethira -are (Wells & Johanson 2012), or will be, treated elsewhere.

Material and methods
Adult specimens were collected in light traps and Malaise traps situated near running waters, swept from riparian vegetation or from emergent boulders and cobbles in streams, or 'dabbed' using an alcohol-dipped finger tip. Specimens were prepared for study as Canada balsam slide mounts following the methods of Wells (1980). Male genitalia are illustrated in line drawings and also, for species for which suitable slides are available, as images derived using the digital imaging software AutoMontage. This duplication of effort allow readers to understand the morphology of the male genitalia of Caledonotrichia species and will aid identifications. Descriptions are based primarily on males. Specimens in this study are deposited in the following repositories:  Sykora (1967: 585); Marshall (1979: 221); Kelley (1989: 194); Wells (1995: 224).

MNHP
Type species. Caledonotrichia illiesi Sykora, by original designation. Revised description, male. Head wider than long, in dorsal view variably rounded to subrectangular; 3 ocelli present; antennae with 22-37 flagellomeres in male, 20-24 flagellomeres in female; tentorium complete, posterior bridge well developed, dorsal arms vestigial; maxillary palps with 2 basal and fourth segments short, other segments elongate; clypeus bearing a dense brush of setae. Forewing length 1.0-3.5 mm, broad to narrowly acuminate, with or without patches of specialised scent scales (androconial scales); jugal lobe present; hind wing with or without scales; venation of both wings modified to a greater or lesser extent, width of wings variable, generally slender with apices acuminate. On thorax, mesoscutellum with transverse suture; metascutellum triangular. Tibial spur formula 0,3,4. Female terminalia forming slender, elongate oviscapt. Male genitalia with abdominal segment IX well developed, broadly to narrowly shield-shaped, or triangular in ventral view and triangular in lateral view. Tergite X membranous, short, longer than wide. Gonopods bilobed, dorsal lobe irregularly elongate, subquadrate to rectangular or rounded, usually longer than ventral lobe, usually bearing a digitiform mesal process, ventral lobe triangular to bean-shaped, or narrowly leaf-shaped; in axil between dorsal and ventral lobe usually a small, rounded, setate process and basally on ventral lobe, a strong elongate seta. Subgenital processes (or plate) in form of pair of sclerotised rods which, in lateral aspect, strongly sinuate. Phallic apparatus elongate, with or without associated parameres.

Caledonotrichia illiesi
Revised diagnosis. In many respects males of C. illiesi resemble the smaller C. minuta sp. n., and C. bifida sp. n., having wings without scales and both lobes of gonopods are rounded, but are readily recognized by their large size, more robust in appearance, have thick brushes of short black setae dorsally on head and have elongate antennae about equal in length to body. In the male genitalia (Figs 21-22, 30-32) the subgenital process forms simple, straight sclerotised rods, and the elongate seta in the axil between the upper and lower lobes of each gonopod terminates in a round apical knob (arrow in Figs 21,22). In the female terminalia ( Fig. 71) abdominal sternite VII has a triangular prominence apico-medially, and a membranous collar; segment X is triangular.
Material examined. Diagnosis. Males very closely resemble C. illiesi and C. bifida sp. n., both of which have wings without scales and both lobes of gonopods rounded, but C. minuta differs from C. illiesi by smaller size and far less robust appearance, antennae shorter than wings, and in male genitalia dorsal lobe of gonopods more broadly rounded and bat-shaped, and from C. bifida sp. n. by having ventral lobes of gonopods almost equal length to dorsal lobes, dorsal lobes more broadly rounded, and sclerotised rods of subgenital process with only small irregularity subapically, not bifid apically as in C. bifida sp. n.
Female terminalia (Fig. 72). Abdominal segment VII bearing fringe of dense short setae distally and apically a short, membranous collar bearing sparsely arranged setae marginally, sternite with a small medial prominence apically; abdominal segments VIII-X forming slender telescopic oviscapt.
Material examined. Remarks. This species appears to be widespread and often abundant but, like most of the Caledonotrichia species, is hard to identify with certainty unless it is mounted on a microscope slide. Thus, only a small number of specimens are designated as paratypes. Considerable numbers of these tiny mostly jet black caddisflies, with shiny silver areas of setae on their wings, most of them males, were seen running around in bright sunlight on exposed rocks at waterfalls. Fig. 74 shows a locality where a large number of specimens, mostly males, of this species were collected by sweep net.
Material examined. Diagnosis. Males are recognised by the presence of a tiny jet black spot on the forewing between veins R and M, formed by a cluster of androconial scales; but it is particularly distinguished from all other species by maxillary palps with dense brush of elongate setae on the first segment and bristle-like setae on other segments which give the palps a bottlebrush-like appearance (Fig. 15), including the otherwise closely similar C. minor which has maxillary palps of the usual form with fewer and shorter straight setae, the forewings are less attenuate apically and the area of scales over the fork in M larger.

Caledonotrichia minor Sykora http://species-id.net/wiki/Caledonotrichia_minor
Revised diagnosis. Males of C. minor share with those of C. charadra, C. capensis sp. n. and C. ouinnica sp. n. the presence of androconia on the forewing only (Fig. 5), and are distinguished from these species by the size of the single patch of scales, which forms a small dark area proximally, though larger than the tiny black spot of C. ouinnica, whereas C. charadra and C. capensis sp. n. have large areas; in the male genitalia (46)(47), as in C. charadra and C. capensis, the ventral lobes of the gonopods in ventral view are triangular, but the sclerotised rods of the ventral processes are bilobed and broadly flared apically (arrow in Fig. 39), whereas the other two species have just a small subapical irregularity. The forewing of C. minor is not as slender as that of C. ouinnica, which tapers to an acute apex. Revised description, male. Male head rounded as in C. capensis sp. n. (Fig. 1). Antennae with 24-28 flagellomeres (n=5); flagellomeres elongate cylindrical. Maxillary palps with basal 2 segments short and rounded, rest cylindrical: segment 3 about 3× maximum width, segment 4 length about 2× width, and 5 elongate slender, length almost 6× width. Forewing (Fig. 5)  Remarks. The mature larva illustrated by Wells (1995: 226, fig. 2) is typically stactobiine, its case a round dome that is attached to the rock surface.
Etymology. In reference to the vexatious problem of distinguishing this species from others primarily on the basis of internal features.
Remarks. Males of this small jet black species were collected in bright sunlight as they ran about on an emergent rock in the stream. The three cases collected with the single pharate male pupa from Rivière Bleue, resemble closely those described by Wells (1985: 11) for C. illiesi, having a broad flat margin to the case; however, they lack dorsal vents on the dome seen in that species.
Wings. Forewing (Fig. 8) length, 1.0-1.7 mm (n=5); bearing elongate patch of black scales (androconia) medially reaching almost from leading proximal angle to about two-thirds wing length, and separate small patch close to proximal margin; costal margin hairs straight. Hind wing bearing small rather scattered black scales, more slender than those of forewing.
Paratypes: 5 males, same data as for holotype (one on slide) (ANIC). Etymology. Named for the type locality, Rivière du Cap.
Remarks. The specimens of this species were collected as they ran about in sunlight on the surfaces of emergent rocks in the stream.
Revised diagnosis. Like C. capensis males have scale patches on both fore-and hind wings (Figs 9-10), a feature that distinguishes it from C. minor and C. ouinnica, both of which have scale patches on the forewings only; in the genitalia (Figs 54-56) the triangular shape of ventral lobes of the gonopods of C. charadra closely resembles the arrangement in C. capensis sp. n. and C. vexilla sp. n. but in C. charadra the dorsal lobes are quadrilateral, rather than elongate rectangular or subrectangular as in those two species, and the paramere associated with the phallic apparatus is more gently curved.
Additional information, male. Male head rounded as in C. capensis. Male antennae with 24-26 flagellomeres; flagellomeres elongate rectangular. Male maxillary palps as for C. capensis. Male forewing length, 1.5-1.9 mm (n=10). Fore-and hind wings both bear rectangular patch of black scales proximally (Figs 9-10), although these may be shed or lost due to abrasion.
Remarks. Several features noted on examination of the type specimen of C. charadra that were not mentioned by Kelley (1989) were scales on wings and the subapical irregularity on the ventral processes, that gives the apex a hooked appearance when seen in lateral view. In addition, while the type specimen has scales on the forewing only, we are assuming that the scales were lost from the hind wing as, in other respects, the more recently collected specimens conform to the type but have scales on both wings.
Material examined. Holotype male: New Caledonia: mountain stream up Boulari River (BPBM) [entire animal macerated and stored in vial].

Revised diagnosis.
As noted by Kelley (1989) C. extensa is distinctive in being larger than any other species; as in males of C. nyurga antennae are extremely long, just exceeding length of body, but in contrast to that species the segments (Fig. 19) tend to be more elongate, inverted urn-shaped, not bead-like, and the longest segments are about 6× as long as wide; maxillary palps (Figs 11-12) with segments 1 and 2 round, segments 4 and 5 length about 8× width, segment 3 length about 1.5× length of each of terminal segments, swollen apically and bearing area of sensilla apico-dorsally (Fig.  12); male genitalia are clearly visible under a dissecting microscope, with abdominal sternite IX deeply concave distally, ventral lobes of gonopods rounded, bearing row of stout dark setae on mesal margin, not narrowly membranous and leaf-like as in C. nyurga, or slender and finger-like as in C. sykorai sp. n.
Genitalia 66). Abdominal segment IX in ventral view almost triangular, strongly tapered and narrowly rounded anteriorly, a deep concavity on posterior margin of sternite. Tergite X narrow, elongate, straight sided, rounded apically. Gonopods with ventral lobe length 1.5X width, bearing stout setae on mesal margin and apically, dorsal lobe elongate club-shaped, a row of sclerotised short setae subapicomesally, most distal pair bent sharply, axillary seta long, slender, apically acute. Sclerotised rods of subgenital process straight, slightly sculptured apically. Phallic apparatus straight, elongate, slender, with a dorsal crease along two-thirds length and with associated spine-covered apical membrane. Case of mature larva (Fig. 70). Cigar-shaped, with a pair of dorsal vents and at each end a bract-like overhang. Cased larvae of C. extensa were associated via pharate adults, and demonstrate that unlike the larvae of C. illiesi that live in fixed domeshaped cases, larvae of C. extensa are mobile, carrying their cases about. These portable cases are cigar-shaped, tapered at each end and comprise two identical secretion valves, clearly with an upper and lower side. In common with cases of C. illiesi, however, cases of C. extensa have dorsal vents, although in C. extensa these are larger openings, situated near the ends of the dorsal seam of the two valves and opening away from the case.
Additional material examined. New Caledonia: 1 cased larva, Ouarou River, source of Tchamba R., N of Ponerinouen, 25.viii.1965, F. Starmühlner (ROM);prepupae, pupae, middle Tchamba R., below Tchamba, 26.viii.1965, F. Starmühlner (ROM);8 males, Nerihouen River, St Ives, Reg. Ponérihouen, 27.viii. 1965, F. Starmühlner (ROM);larvae, pupae, St Ives Reg. Ponérihouen, 27.viii. 1965, F. Starmühlner (ROM) Revised diagnosis. Males of this species are recognised in mixed collections by the clearly visible genitalia (Figs 61-63, 69), a consequence of the deep excision of the posterior margin of sternite IX, and also by the moniliform distal segments of the antennae. Caledonotrichia nyurga is smaller-bodied than both C. extensa and the otherwise similar C. sykorai sp. n. with which it shares the feature of a pronounced mesal process on the posterior margin of sternite VII, though in the latter species the mesal process is far shorter than in C. nyurga and elongate triangular. Caledonotrichia nyurga also differs from C. sykorai by the very slender anterior extension of abdominal segment IX, broader ventral lobes of gonopods, and the less sharply excised abdominal tergite IX. Additional information, male. Head, rounded as in C. capensis. Antennae (Fig. 18) with 25-39 flagellomeres; flagellomere shape variable; distal flagellomeres moniliform, proximal flagellomeres elongate cylindrical. Maxillary palps with basal 2 segments short and rounded, rest cylindrical: segment 3 slightly shorter than segment 4, segment 5 slender, elongate with length about 10× as long as width and equal to length of  Diagnosis. Closely resembling C. nyurga, but males differing in having the posterior margin of sternite IX only shallowly concave, the anterior extension of abdominal segment IX shorter and broader; and gonopods with ventral lobes narrower and dorsal lobes stout, as wide at apex as close to base; both C. sykorai and C. nyurga can be separated from C. extensa by their smaller size and presence of the elongate ventral process on the posterior margin of sternite VII. Females have the apical margin of abdominal sternite VII rounded, without the membranous collar seen in C. illiesi and C. minuta.
Description, male, female. Head rounded, as in C. capensis (Fig. 1). Antennae ( Fig. 17) with 24-25 flagellomeres, of form seen in C. illiesi and most other species of Caledonotrichia with flagellomeres elongate cylindrical. Maxillary palps similar to those in males of C. nyurga, but terminal segment shorter, relatively, but still exceeding length of segments 3 or 4 which are subequal.