Ugandatrichia shinshiroensis, Ito & Nishimoto & Nishimoto, 2018

Ito, Tomiko, Nishimoto, Hiroyuki & Nishimoto, Futaba, 2018, First record of the tropical-subtropical genus Ugandatrichia Mosely (Trichoptera, Hydroptilidae) from a temperate zone, with description of a new species, Zootaxa 4370 (5), pp. 492-500 : 492-499

Ugandatrichia shinshiroensis sp. nov.

( Figs 1–6 )

Diagnosis. The males of this species are similar to those of U. cathyae Wells 1991 , described from Papua New Guinea, in having subquadrate inferior appendages, but differ in that 1) segment IX is greatly produced anterad (segment IX largely produced posterad in U. cathyae ); 2) the subgenital plate has 2 pairs of short acute processes laterally (subgenital plate rounded without any processes in U. cathyae ); and 3) each inferior appendage has a large V-shaped sclerite dorsally (such a sclerite is absent in U. cathyae ).

Description. Adult ( Figs 1A– 1I , 2A–2D , 5A ). Head without setal warts, setae numerous, scattered, densest near anterior margin, lateroposterior area, and mid dorsal area. Antennae light brown without banding. Forewings brown with many small light markings on dorsal surface and white long hairs on costal margins; hind wings light brown.

Male ( Figs 1A– 1I ). Length of each forewing and hind wing 3.1–3.7 mm and 2.5–3.2 mm, respectively (n = 5). Antennae 23–24-segmented and 1.4–1.9 mm long (n = 5). Forewings with apical forks II and III, hind wings with forks II, III, and V. Ventral process of sternite VII thick, long, turned ventrad at apical 1/3, truncate apically.

Genitalia ( Figs 1D– 1I ). Almost symmetrical except phallus. Segment IX large subtriangular and produced anterad in lateral view, subquadrate with broad anterior concavities in dorsal and ventral views. Dorsal plate membranous, round in lateral view, subquadrate with deep, U-shaped, median concavity in dorsal view. Subgenital plate distinctly longer than dorsal plate, broad-based, strongly tapered, and curved ventrad in apical half; with 2 pairs of short slender lateral processes medially, anterior pair directed anterad at first and then gently curved dorsolaterad in dorsal view, posterior pair directed laterad in dorsal view. Inferior appendages large subquadrate, gradually expanded posteriorly, each with 2 thick long setae near posterodorsal corner, many short setae on lateral surface and slender large V-shaped sclerite on dorsomesal surface. Phallus long, titillator encircling at half length, elongate posteriorly.

Female ( Figs 2A–2D ). Length of each forewing and hind wing 4.0– 4.5 mm and 3.4 –3.7 mm, respectively (n = 5). Antennae 23-segmented and 1.3–1.5 mm long (n = 5). Wing venation as for male. Ventral process of segment VI small. Segment VIII with 2 pairs of long marginal setae dorsally and 4 pairs of long marginal setae ventrally; ventral sclerite slender, long, weakly sclerotized, with subacute posterior end. Segment IX almost membranous, with very weakly sclerotized tergite. Segment X rounded apically, with cerci relatively long, almost same length as basal width of segment. Bursa copulatrix slender.

Pupa ( Figs 2E– 2I ). Milky white; rather flattened dorso-ventrally; male pupae length up to 3.5 mm, female pupae length up to 4.5 mm. Mandibles sharp, with very fine teeth on mesal blade. Antennae reaching abdominal segment II in male pupa and segment I in female pupa. Wing pads reaching abdominal segments VII–IX. Hook plates on abdominal segments III–VII: subtriangular hook plates near anterior edges of segments III–VII with 11–15 hooks each; round hook plates at posterior margins of segments III–V with 7–10 hooks each. Lateral fringes and anal processes absent.

Final instar larva ( Figs 3A–3G , 4A–4E ). Suberuciform, compressed laterally, length up to 4.8 mm, sclerotized parts light brown, other parts milky white.

Head. Uniformly light brown, rectangular, width up to 0.29 mm, ratio of length to width about 1.25; several primary setae very long, longest seta 1.3 times as long as head width; cardo transversely wide, anterior ventral apotome indistinct, posterior ventral apotome small, triangular. Antennae situated near anterolateral corners of head capsule, unsegmented, with apical sensilla and subapical setae. Mandibles stout, apices and teeth blunt, mesal brushes dense. Labrum weakly sclerotized, dense brushes of setae at anterior margin.

Thorax. Dorsum of each segment covered by 2 large square plates; plates light brown with black posterolateral corners on pronotum; number of setae on each side (n = 2) 8–11 on setal area 1 (sa 1), 3–5 on sa 2, and 8 on sa 3 of pronotum; 7–9 on sa 1, 4 on sa 2, and 5 on sa 3 of mesonotum; 8 on sa 1, 3–4 on sa 2, and 5–6 on sa 3 of metanotum. Prothorax and mesothorax ventrally each with pair of narrow, curved and transversely elongate sclerites. Thoracic legs moderately short, light brown with small dark parts on edge of each coxa; foretibial spurs paired, subacute apically; mid- and hind tibial spurs single, acute apically; other structures similar on all legs. Foretrochantin elongate, rectangular with irregularly produced margin. Episterna and epimera large, rectangular on meso- and metathoraces, pleural sutures indistinct.

Abdomen. Flattened laterally (compressed), middle of abdomen swollen. Tracheal gills, humps, lateral fringes, and lateral tubercles absent. Ovoid chloride epithelia with narrow borders on terga IV–VIII. Dorsal sclerite of segment IX rectangular with 3 pairs of long and 1 pair of short setae. Single median gill on posterior margin of segment IX. Lateral sclerites of segment X long, rectangular, with 2 pairs of long setae and 1 pair of short setae. Anal claws directed anterolaterad, without accessory hooks.

Case ( Figs 2I , 4F, 4G , 5D, 5E ). Case of final instar larva composed of 2 symmetrical valves with anterior and posterior slit openings, each valve consisting of elongate, more or less concentrically arranged pieces of filamentous algae; length up to 6 mm. Pupal cases with inner elliptical chamber (semipermeable cocoon); case tightly attached to substrates by secretion at 2 edges for many pupae (solid arrows in Fig. 2I ) or at 4 corners for few pupae (solid and dotted arrows in Fig. 2I ).

Holotype: Japan, Honshu, Aichi: Male, Shinshiro-shi , Toyooka , Ichinose , Ôtsutani-gawa River , near river mouth (34˚59’26”N, 137˚37’29”E, 129 m above sea level), 29.vi.2013, H. Nishimoto & F. Nishimoto, light trap (CBM-ZI 165980).

Paratypes. 5 males, 5 females, same data as holotype (CBM-ZI 165981–165990).

Other specimens examined. Japan, Honshu. Aichi: 2 males, 8 females, same data as holotype ; 12 males, 34 females, type locality, 18.vii.2013, T. Ito, light pan trap; 5 males, 3 females, type locality, 20.ix.2013, T. Ito, light trap; 10 males, 18 females, type locality, 20.ix.2013, H. Nishimoto & F. Nishimoto, light trap; 9 males, 110 females, type locality, 1.vi.2014, H. Nishimoto & F. Nishimoto, light trap; 3 males, 2 females, 41 pupae, 13 final instar larvae, type locality, 1.vi.2014, H. Nishimoto & F. Nishimoto, with rearing (adults emerged on 2–4.vi.2014); 90 males, 98 females, type locality, 17.vii.2014, H. Nishimoto, light trap; 70 males, 55 females, type locality, 13.ix.2014, H. Nishimoto & F. Nishimoto, light trap; 3 males, 3 females, type locality, 13.vi.2015, H. Nishimoto & F. Nishimoto, light trap; 2 females, Shinshiro-shi, Toyooka, Ichinose, Ôtsutani-gawa River, Moritopia Public Inn , 155 m a.s.l., 2.x.2012, T. Ito & S. Inaba, light trap ; 1 female, Shinshiro-shi, Tsukudemoriyoshi, Toukaizu-gawa River , 22.ix.2013, H. Nishimoto & F. Nishimoto, light trap ; 3 females, Toyota-shi, Tatsuhara-cho, Kawai, Dantogawa River , 2.viii.2013, H. Nishimoto & F. Nishimoto, light trap. Shiga : 2 females, Higashi-omi-shi, Eignji, small tributary of Kanzaki-gawa River , 380 m a.s.l., 6.ix.2013, T. Ito, light trap. Mie : 1 male, 2 females, Inaba-shi, Daian-cho, Ishigure-minami, 380 m a.s.l., 3.viii.2014, H. Morita; 1 male, same locality, 30.viii.2014, H. Morita. Shikoku. Kochi : 2 males, Sukumo-shi, Kurokawa, Nakasuji-gawa River , 80 m a.s.l., 22.ix.2015, S. Inaba ; 1 female, Mihara-mura, Yunoki, Shimizu-gawa River , Mihara-bashi Bridge , 96 m a.s.l., 22.ix.2015, S. Inaba.

Etymology. The specific name refers to the type locality.

Distribution ( Fig. 6 ). Japan, Honshu (Aichi, Shiga, Mie) and Shikoku ( Kochi).

Ecology ( Fig. 5 ). Abundant adults of Ugandatrichia shinshiroensis were collected at light traps in the type locality in 2013 and 2014. The light traps were mainly operated at a bridge over the Otsutani-gawa River near the confluence of the Ure-gawa River. At this site, the stream was about 6 m wide and 8 cm deep on average, with rapidly flowing water, the substrate was bedrock, partially covered with moss. Here, we attempted to collect the immature stages with a fine mesh hand net by rubbing on moss-covered and bare rock surfaces in riffle areas from early spring through autumn in 2013 and 2014. The samples were brought back to the laboratory and identified under a binocular microscope, but the larvae thought to belong to Ugandatrichia were not found. On 1 June 2014, we finally succeeded to collect many large purse-like cases of Ugandatrichia on small loose rocks (5–15 cm in long axis) which were inserted into crevices (15–20 cm deep) in the bedrock. Most of the cases were firmly attached to rocks. Pupae were present in the cases; several cased final instar larvae were also found in the same rocks. Over the course of this study, the pupal or final instar larval cases were found only in May to June (early summer). These observational data may indicate U. shinshiroensis has a univoltine life cycle, while the long flight period of the adults from June to October suggests the possibility that this species has 2 to 3 generations per year or the adults might be long lived.

Japanese name. Shinshiro-ô -hime-tobikera.

Remarks. Until now, all of 33 species of the genus Ugandatrichia have been described from tropical and subtropical zones of Africa, Asia, and Papua New Guinea ( Morse 2017). This is the first record of this genus from the temperate zone and from the Palearctic region. The males of this species are more similar to those of an eastern Papua New Guinean species (from Bougainville Island) than any species in Asia, including southern Japan, since the inferior appendages of this species are short and broad.

Final instar larvae and their architecture have been described for 2 African and 6 Asian species ( Scott 1976; Vaillant 1984; Malicky 1999; Hsu & Chen 2002; Laudee 2004, 2008; Ito & Ohkawa 2012). In general appearance, the larvae of the 2 African species resemble beetle larvae (particularly those of the coccinellid Vedalia ), having large stout sclerites on the thorax and abdomen, whereas those of the 6 Asian species are rather similar to rhyacophilid caddis larvae, having the abdomen cylindrical. The larva of U. shinshiroensis is apparently different from the known larvae, because it is a typical hydroptilid, with the abdomen flattened laterally (compressed) and swollen (taller) in the middle.

Among final instar larvae of species of Ugandatrichia , there appear to be 3 different life forms: (a) 6 fixed tube case makers in Asia ( Malicky 1999; Hsu & Chen 2002; Laudee 2004, 2008; Ito & Ohkawa 2012); (b) a casebearing species in central Africa, U. africana Marlier and Vaillant (Vaillant 1984) ; and (c) a free-living species in southeastern Africa, U. rhodesiensis Scott (Scott 1976) , but which make tube-like fixed cases just prior to pupation. The final instar larva of U. shinshiroensis conforms in general to the central African species (b), but differs since U. africana makes a dorsoventrally flattened (depressed) case.

In general, case architecture is characteristic at the generic level with some variations in case materials, but few genera exhibit a plurality of life forms such as seen in Ugandatrichia ( Wiggins 1996; Wallace et al. 2003; Waringer & Graf 2011). Careful examination of all life stages is needed to elucidate the monophyly and true taxonomic status of this genus.

Figures

FIGURE 1. Ugandatrichia shinshiroensis, male. 1A, right wings, dorsal; 1B, head and thorax, dorsal; 1C, head and mouth parts, left lateral; 1D, ventral process of segment VII, left lateral; 1E, genitalia, lateral; 1F,same, dorsal; 1G, same, ventral; 1H, left inferior appendage, dorsal; 1I, phallus, left lateral.Abbreviations:apsp = anterior process of subgenital plate (paired); dp = dorsal plate; ia = inferior appendage (paired); II, III, V = apical forks II, III, and V; ph = phallus; ppsp = posterior process of subgenital plate (paired); sp = subgenital plate; ti = titillator; VII–IX = abdominal segments VII–IX.

FIGURE 2. Ugandatrichia shinshiroensis, female, pupa, and pupal case. 2A–2D, female: 2A, right wings, dorsal; 2B, abdominal segments VI–X, left lateral; 2C, abdominal segments VII–X, ventral; 2D, bursa copulatrix, ventral. 2E–2H, pupa: 2E, habitus, dorsal; 2F, left mandible, dorsal; 2G, right hookplate on segment IV; 2H, righthook plate on segment IV.2I, pupal case, dorsal (for explanation of arrows, see text). Abbreviations: II, III, V = apical forks II, III, and V; VI–X = abdominal segments VI–X.

FIGURE 3. Ugandatrichia shinshiroensis, final instar larva: 3A, habitus, right lateral; 3B, head, dorsal; 3C, same, ventral; 3D, left antenna, dorsal; 3E, left mandible, dorsal; 3F, labrum, dorsal; 3G, chloride epithelia, dorsal.

FIGURE 4. Ugandatrichia shinshiroensis, final instar lava and larval case. 4A–4E, final instar larva: 4A, pro- and mesothorax,ventral;4B, rightthoracic legs and pleura,right lateral; 4C, tarsus and tarsal clawof right foreleg, rightlateral; 4D, abdominal segments IX and X, dorsal; 4E, right anal leg, right lateral. 4F–4G, case:4F, right lateral; 4G, dorsal.

FIGURE 5. Ugandatrichia shinshiroensis, adult, habitat and pupae in field. 5A, adult; 5B, type locality; 5C, microhabitat of pupae and larvae (crevice) indicated by one of authors (FN); 5D, pupae on a stone in crevice; 5E, same, enlarged. Scale bars = 5 mm.

FIGURE 6. Distributions of 3 species of Ugandatrichia in Japan and neighboring area.Distributions of U. nakijinensis and U. taiwanensis from Ito and Ohkawa (2012).