Review of the New Caledonian species of Acritoptila Wells, 1982 (Trichoptera, Insecta), with descriptions of 3 new species

Abstract We review the New Caledonian representatives of the Australasian endemic hydroptiline genus Acritoptila, based on examination of a considerable collection of material in the Swedish Museum of Natural History and of types of previously established species. A key for identification of males is given and includes 3 species newly described here: A. parallela sp. n., A. forficata sp. n. and A. macrospina sp. n. For all New Caledonian species, male genitalia are illustrated, and for 5 associated females, distinctive features are illustrated and described.


Introduction
Among the microcaddisfly genera (Trichoptera: Hydroptilidae) found in the southwestern Pacific region, several have restricted distributions whereas others are common also in the Oriental Region or are cosmopolitan. Acritoptila Wells, 1982 is one of those For most of the species described by Kelley, new illustrations are given here, drawn from fresh material and corroborated by examination of the holotypes. Final instar larvae have been associated for two Australian species (Wells 1990) and for two New Caledonian species  and have abdominal segments III to VIII swollen and segments I and II forming a narrow "waist", superficially giving a appearance somewhat similar to the Hymenoptera petiole, a feature that distinguishes them from known larvae of Hellyethira (Wells 1985(Wells , 1997, which have the first 3 abdominal segments narrow. Several cases have been associated from pharate pupae and, similar to females, each is distinctive (Figs 30,32,34).

Material and methods
The basis of this study is the collection of New Caledonia material made by K.A. Johanson (abbreviated throughout as KAJ) and associates from the Swedish Museum of Natural History, Stockholm, Sweden where most of the material is deposited; a small number of specimens, including several paratypes are deposited in the Australian National Insect Collection. All holotypes are lodged in the Muséum National d'Histoire Naturelle, Paris, France. Specimens were collected with light traps and Malaise traps. One of the authors (AW) examined holotypes of Kelley's 6 species of Acritoptila deposited in the Bishop Museum in Honolulu, where they are stored as macerated specimens in glycerine in microvials.
Recently collected specimens were prepared for close study by maceration in KOH, then cleared in clove oil and mounted in Canada Balsam. Illustrations were prepared by methods described by Wells et al. (2013). A key is provided to adult males of New Caledonian species. Larvae and cases were associated from pharate adults.
Treatments of species are arranged in order such that those with most similar features are placed in close proximity. Terminology follows the recommendations of Oláh and Johanson (2010b), who argued for uniformity of terms across all Trichoptera taxa. Thus we have employed the terms "gonopods" and "subgenital processes" rather than "inferior appendages" and "subgenital plate"; these terms have been used in the two papers already published in this series of papers on New Caledonia Hydroptilidae (Wells and Johanson 2012;Wells et al. 2013).
Type species. Acritoptila globosa Wells, 1982, by original designation. Revised diagnosis. Hydroptilinae with antennae comprising 26-41 flagellomeres in male and 24-26 flagellomeres in female; in male abdominal sternite VII bearing slender subapical spine mesally; abdominal segment VIII shorter than VII, broad; abdominal segment IX deeply excavated mid-ventrally, often produced distally as stout lateral lobes; in male genitalia, gonopods fused at least partially, not forming claspers, with paired, generally slender, elongate spines ("parameres") laterally, arising from complex of internal apodemes, or with lateral margins of tergite X forming sclerotized spiny processes; phallic apparatus without titillator, often with complex spiny apical processes; in female, terminalia forming a short, broad oviscapt; final instar larvae laterally flattened, physogastric, head, thorax and first two abdominal segments slender, then abdominal segments increasing in size to fifth, decreasing distally from sixth, cuticle of head and thorax may have darkened bands or patches; case basically a laterally flattened purse of two equal valves, but shape and materials variable.

Revised diagnosis.
Males are recognised by genitalic features (Figs 1, 2): in ventral view by the conical gonopods with rugose surfaces, ventral to the sharply mesally directed darkly sclerotized subgenital processes with a small median papilla bearing a pair of setae and parameres that are dilated subapically proximal to a narrow constriction; females are readily distinguished by the mid ventral elongate digitiform process on abdominal segment VIII (Figs 24,25). Males resemble most closely those of A. chiasma and A. csavar , all three species in lateral view having a pair of curved spines apically on tergite X. However, A. chiasma and A. csavar have paired sinuous elongate-slender parameres latero-ventrally, whereas in A. disjuncta these processes are constricted subapically and hooked apically; and A. disjuncta has well-developed apico-lateral lobes on abdominal segment IX.
Revised diagnosis. The males of this species are most closely similar to A. chiasma and A. csavar with which it shares the strongly reduced, fused form of the gonopods, and the slender, elongate ventro-lateral processes or parameres; but they can distinguished because in A. crinita the parameres are only slightly curved, not sinuous as in the other two species (Figs 3, 4). In addition, A. crinita lacks the sharp apico-lateral spines seen on tergite X of A. chiasma and A. csavar and A. crinita has a pair of lateral digitiform apically setose processes on tergite X. Females are recognised by the very dark apices of the paired lobes of sternite IX. Larval and pupal cases are rectangular purses (Fig. 32), obliquely sloped at each end, constructed of secretion with diatoms accreted smoothly into walls.
Remarks. Of all species of Acritoptila, A. crinita was collected most commonly by Johanson and colleagues in New Caledonia, often being taken in large numbers at sites in both the north and south. The males are readily recognised in ventral view by the fused, darkly sclerotized, rounded to heart-shaped ventral genitalic structure interpreted as the fused gonopods.
The features by which Oláh and Johanson (2010a) distinguished A. karika Oláh & Johanson, 2010a from A. crinita are "… segment X without sclerotized apical structures; fused ring-shaped gonopods without dorsal projection; basal plate with short digitiform processes; and apex of the phallic organ with a lobe-like complex (not with spine-like structures)"; A. karika has "Segment X … slightly sclerotized horizontal-ly…". This is simply another interpretation of the sclerotization displayed in the type of A. crinita. Acritoptila crinita also has fused gonopods without a dorsal projection, but has the basal plate (= bilobed processes of ) with short digitiform processes as in A. karika; and the phallic organ has the same apical features that can be interpreted as spiny or lobe-like. Hence we are synonymising A. karika with A. crinita. In fact, numerous male and female specimens identified as A. crinita were collected from the type locality of A. karika, and also at a site from which 2 paratypes were designated.
Revised diagnosis. Males of A. chiasma are similar to A. crinita and A. csavar, with which they share, in ventral view, the rather similar tongue-shaped form of the mid ventral genitalic structures interpreted as subgenital processes (Fig. 5). The males are distinguished from A. crinita by having spiny apical processes apico-laterally on tergite X (Fig. 6), which are hooked in A. csavar (Fig. 9), and simply curved in A. chiasma (Figs 6, 7). Neither A. chiasma nor A. csavar has the lateral setose processes seen on tergite X of A. crinita.
Male antennae each with 37-40 flagellomeres; forewing length, 2.0-2.1 mm (n=3). Remarks. The features separating A. chiasma from A. csavar are weak, but appear to be definitive. In the diagnosis of A. chiasma,  states that species "is most closely related to A. crinita", but has the tenth tergum "quite distinctive". However, A. chiasma more closely resembles A. csavar, both having gonopods of similar shape and stout spiny processes laterally on tergite X, whereas A. crinita has the gonopods forming a tight sphere and on tergite X has slightly sclerotized, weakly curved, lateral processes. A. chiasma differs from A. csavar in having in ventral the structure representing the fused gonopods more rounded, and in dorsal view the apical angles Abdominal segment X broad based, concave apically, with two small spines medially, and laterally an elongate apically setose process. Subgenital processes, in ventral view, in form of small conical lobes, each bearing a robust seta meso-ventrally; dorsally a pair of membranous setose lobes. Paired thread-like straight parameres extend distally from robust apodemes arising from base of segment IX. Phallic apparatus stout, constricted sub-apically, a strap-like band at apex. Female unknown.
Remarks. Upon examination, the holotype male was found to be identical in all respects with a group of specimens collected from the sites listed below, save in the form of the mid-ventral structure illustrated and described by Kelley (1989: 193) as "tongue-shaped in caudal view", yet shown as a small rounded structure in his figure of ventral view (Fig. 17, Fig. 11). In fact, in the type this structure has been broken off (from Kelley's fig. 7, it appears it may have been intact when he drew his lateral view). The few known specimens of A. glossocercus were all collected in northern New Caledonia (Fig. 35).
Description, male. Male antennae each with 27-29 flagellomeres, bicoloured, apical 4 segments pale, more proximally 11 dark, rest pale; forewing length 2.0-2.2 mm (n=6). Female antennae each with 24 flagellomeres; forewing length 2.1-2.2 mm (n=2). Male genitalia (Figs 13, 14). Abdominal segment VII bearing slender elongate spine midventrally. Abdominal segment IX produced posteriorly, forming parallel-sided lobes, in lateral view segment narrows abruptly towards rounded apices. Gonopods and subgenital processes in ventral view appear to be fused to form a plate, broad at base, constricted medially, bearing a pair of dark knob-like setae at apico-lateral angles. Paired thread-like almost straight parameres extend distally from robust apodemes arising at base of segment IX. Phallic apparatus narrow, dilated towards apex, a sharp, sclerotized spur at right angles apically. Female genitalia (Fig. 29). Abdominal segment IX in ventral view with a pair of lobes laterally and median anchor-shaped gland.
Etymology. parallela, named for the nearly parallel arrangement of several structures in the male genitalia.

Revised diagnosis.
In having the parameres branched, A. planichela resembles A. forficata, sp. n. however in A. forficata the parameres are more slender and the mesal branch is the shorter, finer branch and closely associated with the lateral branch whereas in A. planichela the lateral branch is shorter and finer than the lateral branch, and A. planichela lacks the pronounced lateral lobes on abdominal segment IX seen in A. forficata sp. n. A. planichela shares with A. ouenghica and A. macrospina sp. n. the feature of curiously modified knob-like setae on the fused, non-sclerotized gonopods, but neither of those species has branched parameres. Male antennae damaged in only specimens at hand; forewing length, 2.1 mm (n=1).
Remarks. Only a single specimen was collected despite the extensive field work. Thus, with the 3 identified by , 4 specimens are now known, all from the southern province.
Etymology. Named for the forked appearance of the parameres.

Remarks.
Only 3 specimens of this species are known, from two widely separated localities, one in the south, the other in the north. Acritoptila ouenghica Wells http://species-id.net/wiki/Acritoptila_ouenghica Fig. 20 Acritoptila ouenghica Wells (1995: 235). described as "tab-like" by Wells (1995) but in the two other species more knob-like. Unlike other New Caledonian congeners, A. ouenghica lacks the free parameres, the parameres instead appear to be fused laterally as broad sclerotized margins on tergite X, although in cleared specimens these clearly arise from stout apodemes. Male antennae each with 30-33 flagellomeres; forewing length 1.9-2.2 mm (n =8).
Remarks. Very few specimens of A. ouenghica were taken in all the recent collecting -one specimen from the south and several from the north (Fig. 35)  Diagnosis. The males of this species differ from all other New Caledonian species in having among genitalic structures stout, sclerotized asymmetrical parameres, in ventral view sharply angled mesally. Description, male. Antennae each with 26-31 flagellomeres, with large sensilla placodea on surfaces; forewing length 1.9-2.0 mm (n=5).
Male genitalia (Figs 21-23). Abdominal segment VII bearing a slender elongate process mid-ventrally. Abdominal segment VIII shorter than IX. Abdominal segment IX in lateral view broader than long, in ventral view widely excavated apico-mesally. Gonopods in ventral view in form of discrete triangular lobes, each with a small  are grateful to the authorities at Direction des Ressources Naturelles (Nouméa, New Caledonia) and the authorities at the Environment Division, Department of Economic Development and Environment, Province Nord (Koné, New Caledonia) for supporting the project with collecting and export permits. Dr. Christian Mille (Institut Agronomique néo-Calédonien, Station de Recherches Fruitières de Pocquereux, Laboratoire d'entomologie, La Foa, New Caledonia) was always enthusiastically helpful during the collecting on New Caledonia. Access for A. Wells to laboratory facilities at the Australian National Insect Collection, Canberra is gratefully acknowledged, and for computer facilities AW thanks Australian Biological Resources Studies. The Bishop Museum, Honolulu, and particularly Shepherd Meyers, kindly hosted A. Wells' visit in 2013 and facilitated access to the Kelley types. Two referees are thanked for useful advice.