Setodes hinumaensis Katsuma 2009

Katsuma, Nobuyuki, 2018, The genus Setodes Rambur (Trichoptera, Leptoceridae) in Japan, Zootaxa 4407 (2), pp. 191-212 : 197-202

Setodes hinumaensis Katsuma 2009

( Figs. 4A–4H , 5A–5J , 10B )

Setodes hinumaensis Katsuma 2009 , 41–44, male, female, Honshu (Iwate, Ibaraki) ; Tanaka 2012, 10, male, Honshu (Akita) .

Diagnosis. The males and females of S. hinumaensis are similar to those of S. ujiensis ( Akagi 1960) , but they are distinguishable from the latter by the following characteristics. In males, segment X is sword-like in lateral view in S. hinumaensis but sickle-like in S. ujiensis . The lower-most branches of the inferior appendages are twice as long as segment IX in S. hinumaensis , but they are nearly 1.3 times as long as segment IX in S. ujiensis . In females, the anal opening appears on the basoventral surface of segment X in S. hinumaensis , but on the basal 1/4 of the ventral surface of segment X in S. ujiensis . The larva of S. hinumaensis shares the presence of sclerotized, spiny anal prolegs with other Japanese species of this genus, but several characteristics sets it apart: Abdominal gills are absent in S. hinumaensis , but present in S. argentatus and S. minutus . The head and pronotum lack distinct markings in S. hinumaensis but bear dark spots in Setodes sp. SB. The morphological characteristics of the S. hinumaensis pupa are similar to those of S. argentatus , with some exceptions: The labrum is protruded anteriorly in S. hinumaensis , but not in S. argentatus ; abdominal gills are absent in S. hinumaensis , but present in S. argentatus .

Adult. Head and body very pale. Forewings each 6.0– 7.1 mm long (n = 20) in male, 6.2–7.2 mm (n = 20) in female, covered by pale golden hair with many silver spots. Black spot present on each nigma. Wing venation typical for genus.

Male genitalia. Segment IX longitudinally short dorsally, long ventrally with many strong setae. Segment X sword-like in lateral view, divided into two long lobes in dorsal view, directed caudad, each apex pointed. Preanal appendages oval in lateral and dorsal views, with many short setae. Inferior appendages each divided into four branches; upper-most branch clavate, curved downward, with digitate lobe ventromesally; upper middle branch finger-like in lateral view, directed dorsocaudad, with small lobe ventromesally; lower middle branch triangular in lateral view, directed caudad; lower-most branch slender, twice as long as segment IX, curved posterodorsad. Phallobase oval in lateral view; phallicata abruptly bent downward midway, with pair of sclerotized lobes laterally, tapered subapically. Paramere spines absent.

Female genitalia. Segment VIII with pair of large sternal pockets posteroventrally. Segment IX broad ventrally, with pair of round bulges anteroventrally. Segment X triangular in lateral view, tongue-shaped in dorsal view. Anal opening strongly sclerotized, appearing on basoventral surface of segment X. Preanal appendages triangular in lateral and dorsal views, with many short setae. Lamellae each with two lobes; dorsomesal lobe semicircular in lateral view, fringed with many short setae; ventrolateral lobe bean-shaped in lateral view, bearing 7–8 short spines on knob-like lobe posteromesally. Gonopod plate situated on posteroventral margin of segment IX, pale. Spermathecal sclerite hood-like in ventral view.

Final instar larva. Length up to 6.5 mm. Head 0.71 mm long, 0.46 mm wide (n = 4), oblong in dorsal view, mostly pale yellow but white around eyes, with muscle scars on posterior half and frontoclypeal apotome; ventral apotome rectangular, slightly restricted in middle. Pronotum rectangular in dorsal view, divided into two sclerites by mid-dorsal ecdysial line; each sclerite dark brown with muscle scars, bearing 17–20 setae anteriorly and 6–8 setae on middle. Mesonotum very pale, oval in dorsal view, divided into two sclerites by median ecdysial line; each sa 1 darkly pigmented, bearing 10–12 setae, one long seta on each sa 2, 5 setae on each sa 3. Metanotum not sclerotized, sa 1 fused as single setal area and collectively bearing 8 setae, one short seta on each sa 2, 7–8 setae on each sa 3. Legs setose; forelegs shortest and stout; hind legs longest, each tibia divided into two parts of equal length. Abdomen without gills. Dorsal sclerite of segment IX sclerotized but pale, round apically with 5 pairs of setae. Lateral sclerites crescent-shaped in caudolateral view, each with 6–7 short and 3–4 tiny spines on lateral margin. Dorsal plates semicircular, each with many tiny spines on lateral margin, bearing one long seta and 5 short setae basally. Anal opening surrounded by 28–30 digitate spines. Anal claws sclerotized, each with two accessory hooks dorsally.

Pupa. Length up to 7.3 mm. Head width 0.78 mm (n = 2); vertex with 3 pairs of nipple-like protuberances; labrum rhomboidal in dorsal view, with 5–6 long setae around margin and 5–6 short setae apically; mandibles sclerotized, each with 10–11 teeth mesally and 2 short setae basolaterally. Paired abdominal hook plates present near anterior margins of segment III–VI and posterior margin of segment V, each with 2 or 3 small sclerotized hooks. Abdominal gills absent. Dorsum of segment IX with pair of nipple-like protuberances used to secure long antennae, each bearing one long seta and 3–4 short setae. Anal processes paired, long and slender, each with many short setae in basal half of internal margin; pair of mesal projections produced about 1/2 length of anal processes, triangular in dorsal view, with semi-parallelogram shape in lateral view, each bearing 6–7 tiny spines. In male, rudiments of inferior appendages arising on segment IX ventrolaterally, crossing each other at apical 1/4.

Case. Length up to 7.5–7.8 mm. Larval and pupal cases constructed of tiny rock fragments, slightly curved and tapered. In pupal case, anterior and posterior ends closed by small rock fragments and silken membrane with central opening anteriorly.

Distribution. Honshu (north to central).

Japanese name. Hinuma-seto-tobikera.

Specimens examined. Additional records since Katsuma (2009). Ibaraki: 1♀, Fujii-gawa-dam, Shirosatomachi, 21.viii.2010, N. Katsuma ; 1♂, Sato-gawa, Ochiai-cho, Hitachiota-shi, 11.vi.2011, N. Katsuma; 8 larvae, 4.v.2011, Hinuma-gawa, Minamikoizumi, Kasama-shi, N. Katsuma; 2 larvae 4 pupa, 2.vii.2011, ibid, N. Katsuma , 2♂, emerged 10.vii.2011, ibid, reared by N. Katsuma . Niigata: 1♀, 7.ix.1966, Hamochiohashi, Sado-shi, S. Sakurai ( CBM).

Remarks. This species belongs to the Setodes hungaricus Species Group ( Schmid 1987) since the male tergum X is deeply divided into 2 long sclerotized lobes and the inferior appendages are multibranched rather than fused with each other ( Katsuma 2009).

Figures

FIGURE 4. Setodes hinumaensis Katsuma 2009, A–E: male. 4A, right fore- and hind wings, dorsal. 4B–4E, male genitalia (from Katsuma (2009)): 4B, left lateral; 4C, phallus, left lateral; 4D, dorsal; 4E, ventral. 4F–4H, female genitalia (from Katsuma (2009)): 4F, left lateral; 4G, dorsal; 4H, ventral. Abbreviation: an. op. = anal opening. Scale: A = 1 mm, B–H = 500 µm.

FIGURE 5. Setodes hinumaensis Katsuma 2009. 5A–5D, final instar larva: 5A, head and pro-, meso-, and metanota, dorsal; 5B, head, ventral; 5C, left legs (fore-, middle-, hind legs), posterior; 5D, anal prolegs, right caudolateral, right anal claw enlarged, right lateral. 5E–5H, pupa: 5E, head and pronotum, dorsal, left mandible enlarged; 5F, caudal appendages, dorsal, mesal projection of right anal process enlarged; 5G, caudal appendages, left lateral; 5H, abdominal hook plates, dorsal. 5I–5J, case: 5I, anterior; 5J, left lateral. Abbreviation: d. sc. IX = dorsal sclerite of segment IX. Abbreviations: IIIa, IVa, Va, VIa = anteriorhook plates of abdominal segments III,IV,V,and VI, respectively;l. sc. = lateral sclerite;d.pl.= dorsal plate; sa1, sa2, sa3 = setal areas 1, 2, and 3, respectively; Vp= posterior hookplates of abdominal segment V.Scale:A–G, I,J = 1mm, H =500 µm.

FIGURE 10. Japanese Setodes species, A–D: adults. 10A, S. chirotheca sp. nov. 10B, S. hinumaensis Katsuma 2009. 10C, S. shirasensis Kobayashi 1984.10D, S. argentatusMatsumura 1907.Scale:5 mm.