A revision of the Neotropical caddisfly genus Ascotrichia Flint, 1983 (Trichoptera, Hydroptilidae)

A revision of the microcaddisfly genus Ascotrichia (Trichoptera, Hydroptilidae) is provided, including a generic diagnosis, illustrations, and descriptions of males. This genus is endemic to the Neotropical region and has been recorded from countries in northern South America. Adults of the genus are notable within the family for the contrasting black and green hairs on the forewings. A total of six species are treated, three described as new: Ascotrichia adirecta sp. n. (Brazil), A. hystricosa sp. n. (Brazil), and A. simoma sp. n. (Brazil).


INTRODUCTION
The genus Ascotrichia Flint, 1983 belongs to the family Hydroptilidae, the micro or casemaking caddisflies. The genus was originally established for two species: Ascotrichia frontalis Flint, 1983, the type species, and A. surinamensis (Flint), 1974, transferred from the genus Betrichia Mosely, 1939. Ascotrichia spangleri Oláh and Flint was described in 2012, bringing the total number of species contained within the genus to three (Holzenthal & Calor, 2017). The genus is endemic to the New World and its distribution includes northern and eastern South America (Table 1).
In the original description, Flint (1983) described a head with large posterior warts and a large setae-filled pocket anteriorly, a forewing with a basally enlarged R vein bearing a row of erect setae, and a 1, 3, 4 tibial spur formula. Structures of the maxillary and labial palpi were not described; no illustrations of the wings, head, antennae, or legs were provided. The description of the male genitalia referred to posteromesal points on sterna VI and VII, a broad sternum VIII with a posterolateral process, and a phallus with a midlength complex. More detailed features of the male genitalia and a forewing length of 4.5-5 mm were given in the species description of A. frontalis. Male genitalia features included a V-shaped ventromesal excision in the posterior margin of sternum VIII; a shallowly bifid, laterally flared apex to the subgenital plate; a single, slender, curved process arising ventrolaterally from segment IX; and mesally fused inferior appendages. Illustrations of the male genitalia were included in the description of the type species (Flint, 1983, figs. 111-114). Flint suggested that Ascotrichia may be most closely related to the including genitalia, were removed from specimens using microscissors and placed individually in carefully labelled Pyrex Ò test tubes (10 × 75 mm), each containing two to three ml of 85% lactic acid. Test tubes were then heated in a Fischer Scientific dry bath incubator at approximately 120 C for 30-35 min. At the end of this time, abdomens were carefully removed from the test tubes and rinsed in ethanol to gently flush away any remaining lactic acid. For some specimens, the head was also removed and cleared to more easily observe any possible modifications or eversible structures that may have been obscured by dense setae. Specimens were then examined following the methods outlined in Thomson & Holzenthal (2015). Specifically, cleared genitalia were placed in a standard glass microscope depression slide (1.5 cm diameter × 3 mm deep well) with glycerin and glass microbeads (average diameter 0.5 mm). The glass microbeads held the genitalia in place and allowed structures to be viewed in precise lateral, dorsal, and ventral positions. Genitalia were examined with an Olympus BX43 compound microscope at 250-500 × magnification. Due to their small size and reduced venation, the wings of Hydroptilidae do not provide reliable taxonomic characters (Marshall, 1979;Schmid, 1998). For these reasons, forewing length only has been provided in species descriptions.

Illustrations and descriptions
Specimen illustration and descriptions also followed the methods previously outlined in Thomson & Holzenthal (2015). Structures were traced in pencil with the use of an Olympus drawing attachment (model U-DA) mounted on the microscope. Pencil sketches were then scanned (Fujitsu ScanSnap S1500M scanner), edited in Adobe Photoshop (v.12.1; Adobe Systems Inc., San Jose, CA, USA), and used as a template in Adobe Illustrator (v.15.1.0, Adobe Systems Inc., San Jose, CA, USA) to be digitally inked. Electronic "drawing" was completed with the aid of a graphics tablet (Bamboo Pen; Wacom Company, Limited, Kazo, Japan). Species descriptions were constructed using the programme DELTA (Dallwitz, Paine & Zurcher, 1999), which uses a species × character state data matrix to produce natural-language descriptions and promote consistency in descriptive taxonomy. Description of female specimens has been deferred for several reasons. Since female specimens were not available for all the species addressed in this study, comprehensive female descriptions for each species were not possible. Of the females examined, no noticeable or informative differences were observed. While some female specimens were collected from the same locality and date as males, there is still some uncertainty of association. For these reasons, species descriptions reflect observation of male specimens only. Females, when available, were included in "Material examined" for the purpose of establishing a record of occurrence and because presumptive association may prove useful for future studies.

Morphological terminology
Morphological terminology used for male genitalia was adapted from Flint (1983). For simplicity, paired structures are discussed in the singular. Terminology for specific structures is indicated in Figs. 2 and 3. The wing venation terminology of Fig. 2E follows the Comstock-Needham system as interpreted by Ross (1956) and Marshall (1979).

Depositories
Types and material examined for this study are deposited at the Coleção Entomológica Professor José Alfredo Pinheiro Dutra, Departamento de Zoologia, Universidade Federal Specimen management followed the procedures outlined by Holzenthal & Andersen (2004). Each specimen deposited at the University of Minnesota Insect Collection (UMSP) that was examined during the study was affixed with a barcode label bearing a unique alphanumeric sequence beginning with the prefix UMSP. Holotype specimens being deposited at MZUSP were also affixed with a barcode label; this does not imply ownership by UMSP, but simply indicates that the specimen was databased at UMSP under that unique identification. Other specimens examined from other depositories were not given an additional UMSP barcode. Specimen-level taxonomic, locality, collection, and other information are stored in the University of Minnesota Insect Collection database using the software Specify 6.7.02 (Specify Collections Consortium, 2018).

New species names
The electronic version of this article in portable document form will represent a published work according to the International Commission on Zoological Nomenclature (ICZN), and hence the new names contained in the electronic version are effectively published under that Code from the electronic edition alone. This published work and the nomenclatural acts it contains have been registered in ZooBank, the online registration system for the ICZN. The ZooBank Life Science Identifiers (LSIDS) can be resolved and the associated information viewed through any standard web browser by appending the LSID to the prefix http://zoobank.org/. The LSID for this publication is: urn:lsid:zoobank. org:pub:F9DD3403-78C8-45E2-87C1-F485CD62F7AD. The online version of this work is archived and available from the following digital repositories: PeerJ, PubMed Central, and CLOCKSS.

Generic description
Genus Ascotrichia Flint, 1983Ascotrichia Flint, 1983 Diagnosis. The original generic description suggested that Ascotrichia may be most similar to Abtrichia, but can be distinguished by the lack of extremely modified basal antennal segments present in Abtrichia species (Flint, 1983). The most recent phylogenetic analysis suggested that Ascotrichia may be most similar to Costatrichia (Santos, Nessimian & Takiya, 2016); the two genera can be easily distinguished by the number of ocelli present, Ascotrichia males having two and Costatrichia males having three.
Description. Male. Length of forewing ca. 3.0-5.3 mm. Wings unmodified, lacking a pouch, bulla, or patches of scales; forewing broad basally, acute apically; hind wing narrow, more acute than forewing, with row of hooked setae basal to cross vein r (Fig. 2E), edges with long setal fringe along posterior margin. Head with two ocelli, bearing setae and pair of setiferous posterolateral warts; antennae generally simple and unmodified, all flagellomeres of similar size and shape ( Fig. 2A); observations of cleared heads did not reveal modifications as outlined in the original generic description. Maxillary palps with five segments; labial palps with three segments (Fig. 2B). Hind tibia sometimes with fringe of long setae down segment length, sometimes densely setose and resembling a bottlebrush; tibial spur count 1, 3, 4 (

Species descriptions
Ascotrichia frontalis Flint, 1983 Diagnosis. Ascotrichia frontalis is similar to A. hystricosa sp. n.; both species have subapical spines present on the posterolateral process of sternum VIII. Ascotrichia frontalis can be distinguished by the absence of subapical spines on the ventral process of segment IX (Figs. 3A and 3D), which are present in A. hystricosa.
Description. Male. Length of forewing 4.0-5.3 mm (n = 64). Dorsum of head brown with light yellow setae; thorax brown with brown setae dorsally, yellow laterally, brown ventrally; leg segments brown with brown setae; some specimens observed with densely setose, bottlebrush hind tibia (Fig. 1). Forewings covered with fine light yellow setae on basal 1/3, distal 2/3 with fine brown setae and patches of varying size of light yellow setae (Fig. 1). Genitalia. Abdominal sternum VI mesoventral process elongate, slender. Abdominal sternum VII mesoventral process digitate. Sternum VIII with posterior margin produced in broadly rounded apex; in ventral view posterior margin concave, with narrow mesal emargination; posterolateral process long, slender, with dark, pointed, stout apical spine and small preapical spine on inner face. Segment IX anterolateral margin convex, posterolateral margin slightly produced mesally; dorsally, anterior margin concave, posterior margin very shallowly convex (almost straight); mesal process slender, digitate, apically setose; ventral process arched mesally with apex extending ventrad, apex pointed and darkly sclerotized; in ventral view, process extends mesally with apex bending distally at a near-right angle. Tergum X with lateral sclerite with crenulate posterior margin; membranous apex suborbicular. Subgenital plate slender in lateral view, with ventral production subapically; broad ventrally with subtriangular apical emargination. Inferior appendage rounded basally and with slight apical hook, dorsal surface sparsely setose; ventrally fused, with small apical incision. Phallus apex with pair of membranous dorsal lobes. Etymology. Frontis, Latin for "brow, forehead," likely referring to the large seta-filled pocket in the head observed by Flint.
Ascotrichia adirecta Thomson, sp. n. Diagnosis. This species is unique within the genus due to the absence of the ventral process on segment IX, which is present on all the other Ascotrichia species (Fig. 4A).
Ascotrichia simoma Thomson, sp. n. Diagnosis. Ascotrichia simoma sp. n. is unique within the genus due to the apex of the ventral process on segment IX extending dorsally (Fig. 6A). In all other species in the genus, the apex of this process extends either distally or ventrally. Description. Male. Length of forewing 4.8-5.1 mm (n = 10). Dorsum of head with dark brown setae, some yellow setae apically near antennae; thorax brown with dark brown setae dorsally, light yellow laterally; leg segments brown with brown setae; no specimens observed with densely setose, bottlebrush hind tibia. Forewings covered with fine light yellow setae on apical 1/3, distal 2/3 with fine brown setae and patches of varying size of light yellow setae. Genitalia. Abdominal sternum VI mesoventral process elongate, slender, in ventral view apex slightly bulbous. Abdominal sternum VII mesoventral process short, knife-like, in ventral view slender and digitate. Sternum VIII with posterior margin produced in rounded apex; in ventral view posterior margin acutely concave; posterolateral process slender, extending straight posteriad, apical 1/4 darkly sclerotized. Segment IX anterolateral margin convex, posterolateral margin slightly produced mesally; dorsally, anterior margin shallowly concave, posterior margin shallowly concave; mesal process digitate, extending dorsad, apically setose; ventral process slender, slightly sinuous, apex extending dorsad, apex darkly sclerotized, in ventral view apex slightly curved inward. Tergum X with lateral sclerite divided into simple dorsal sclerite and larger ventral sclerite with shallowly crenulate posterior margin; membranous apex divided into amorphous dorsal lobe and amorphous ventral lobe. Subgenital plate broadest basally, with crenulate dorsal margin, apex truncate with small apicodorsal production; in ventral view with apex slightly flaring outwards and shallowly concave emargination. Inferior appendage with basal hump, single mesodorsal seta, apex with small dorsal hook; ventrally fused, with narrow emargination reaching 1/4 the total length creating two digitate lobes, lobe apices touching. Phallus apex amorphous, with possible internal structures obscured from view. Diagnosis. Ascotrichia spangleri is most similar to A. surinamensis, due to the branched ventral process on segment IX, which is simple in all other species in the genus. Ascotrichia spangleri can be distinguished by the absence of three strong spines on the ventral branch of the process (Fig. 7A), which are present in A. surinamensis.
Description. Male. Length of forewing 3.0-4.7 mm (n = 6). Dorsum of head with light yellow setae apically and dark brown setae basally; thorax brown with brown setae; leg segments brown with brown setae; no specimens observed with densely setose, bottlebrush hind tibia. Forewings covered with fine dark brown setae mottled with light yellow-green setae on apical 1/3, distal 2/3 dark brown with small patches of light yellow setae. Etymology. Presumably named after Paul Spangler, one of the collectors of the holotype specimen.
Ascotrichia surinamensis (Flint, 1974)  surinamensis (  surinamensis can be distinguished by the presence of three strong spines on the ventral branch of the process (Fig. 8A), which are absent in A. spangleri.

CONCLUSIONS
This revision doubles the number of known species within the microcaddisfly genus Ascotrichia (Trichoptera, Hydroptilidae) from three to six. All three of the new species are known only from collections made in Brazil. This highlights the need for more taxonomic research focused on insect fauna in both the country of Brazil specifically, but also in South America in general. Both fieldwork and surveys of unidentified specimens in already-existing insect collections need to be conducted in order to establish a better picture of the insect diversity contained within South America.