Wormaldia McLachlan 1865

Muñoz-Quesada, Fernando J. & Holzenthal, Ralph W., 2008, Revision of the Nearctic species of the caddisfly genus Wormaldia McLachlan (Trichoptera: Philopotamidae), Zootaxa 1838, pp. 1-75 : 10-11

Wormaldia McLachlan 1865

Type species: Hydropsyche occipitalis Pictet, 1834 , subsequent selection of Ross (1949: 154).

Wormaldia McLachlan, 1865: 140 ; Ross 1949: 154 (subsequent designation of type species: Hydropsyche occipitalis Pictet, 1834 ); Kimmins 1955b: 68–70; Ross 1956: 38–46, 60–67; Fischer 1961: 31–55, 58–60, 70, 71; Fischer 1971: 187–201; Schmid 1982: 26, 31–34; Schmid 1991: 89, 92, 93, 97, 98; Schmid 1998: 10, 43–45; Armitage 1996: [work not paginated]; Sun and Malicky 2002: 521–522.

Dolophilus McLachlan, 1868: 301 (Type species: Dolophilus copiosus McLachlan, 1868 ); Betten 1934: 170 ( Dolophiliella Banks, 1930 , as subgenus of Dolophilus McLachlan 1868 ); Ross 1944: 292 ( Dolophiliella Banks, 1930 , and Paragapetus Banks, 1914 , synonyms of Dolophilus McLachlan, 1868 ); Ross 1949: 154 (as synonym of Wormaldia McLachlan, 1865 ); Ross 1956: 61; Fischer 1961: 45–55; Fischer 1971: 187.

Dolophiliella Banks, 1930: 230 (Type species: Dolophiliella gabriella Banks, 1930 ); Betten 1934: 170 (as subgenus of Dolophilus McLachlan, 1868 ); Ross 1944: 292 (as synonym of Dolophilus McLachlan, 1868 ); Ross 1956: 61; Fischer 1961: 45; Fischer 1971: 187.

Paragapetus Banks, 1914: 202 (Type species: Paragapetus moestus Banks, 1914 ); Ross 1944: 292 (as synonym of Dolophilus McLachlan, 1868 ); Ross 1956: 61; Fischer 1960: 33; Fischer 1971: 29, 188.

Doloclanes Banks, 1937: 168 , 169 (Type species: Doloclanes montana Banks, 1937 ); Kimmins 1955b: 68, 70 (as genus); Ross 1956: 43, 60, 61, 65, 66, 67 (as subgenus of Wormaldia McLachlan, 1865 ); Fischer 1961: 51; Fischer 1971: 201–203; Schmid 1989: 110, fig. 252; Schmid 1991: 89, 97, 98; Schmid 1998: 10 (as genus); Armitage 1996: [work not paginated] (as subgenus); Neboiss 1999: 285, 286, 289 (as genus); Sun and Malicky 2002: 521–522 (as synonym of Wormaldia McLachlan, 1865 ).

Gatlinia Ross, 1948: 22 (Type species: Gatlinia mohri Ross, 1948 ); Ross 1956: 65, 66 (as synonym of subgenus Doloclanes Banks, 1937 , in genus Wormaldia McLachlan, 1865 ); Fischer 1971: 201.

Nanagapetus Tsuda, 1942: 249 (Type species: Nanagapetus kisoensis Tsuda, 1942 ); Ross 1956: 65 (as synonym of subgenus Doloclanes , in genus Wormaldia McLachlan, 1865 ); Fischer 1971: 201.

Adult ( Fig. 133). Forewing length 3–8 mm. Body sclerites, including dorsum of head and thorax fuscous or brown, with small fuscous or brunneous setae. Head and palpi setose; antennae with lighter setae, annulated, shorter than forewings; each with scape stout, flagellum slender; ocelli present; maxillary palps each with segment V the longest, segment I the shortest, segment III longer than II and IV, II and IV subequal; labial palps shorter than maxillary palps, each with 3 segments, segment III longest, slender. Leg segments with small, fuscous or brownish setae; tibial spur formula 2-4-4. Forewings ( Figs. 12, 51, 58, 82) fuscous or brunneous, covered with small, fine, fuscous or brown setae, sometimes with small, scattered patches of lighter setae, each with discoidal cell short (dc absent in W. gabriella , Fig. 39); medial cell (mc) present in all Nearctic species; R 2 and R 3 veins sometimes fused (consisting of R 2+3, such that apical fork I absent in W. gabriella , W. lacerna , W. shawnee , and W.strota , Figs. 39, 58, 113, 120); M vein 3-branched [M 1, M 2, and M 3+4, with apical fork IV absent in W. hamata , W. laona , W. oconee , and W. thyria ; 4 of the 6 species of the W. thyria species Group (Table 1), Figs. 51, 65, 127, and fig. 3E of Morse et al. (1989)], or M vein 4-branched (M 1, M 2, M 3, and M 4, remaining Nearctic species, Figs. 12, 19, 25, 32, 39, 58, 74, 82, 90, 106, 113, 120). Hind wings ( Figs. 13, 59, 83): shorter than forewings, each with discoidal cell (dc) short, present in all Nearctic species; all R veins (R 1, R 2, R 3, R 4, and R 5) present in almost all Nearctic species, except for R 1 and R 2 veins sometimes fused (R 1+ 2 in W. mohri , Fig. 83), R 2 and R 3 veins sometimes fused (R 2+3 and apical fork I absent in W. gabriella , W. lacerna , W. shawnee , and W.strota , Figs. 40, 59, 114, 121); M vein 3-branched (M 1, M 2, and M 3+4, with apical fork IV absent) in all Nearctic species; apical forks II, III, and V present in all Nearctic species; anal vein 2A fused to 1A, resulting in 2A being atrophied beyond crossvein a 2 in all Wormaldia species ( Figs. 13, 83).

Male genitalia ( Figs. 1–5). Sternum VII with or without process posteromesally. Tergum VIII usually straight anteriorly, diversely developed posteriorly. Sternum VIII with or without process posteromesally. Segment IX, when viewed dorsally, reduced to narrow, lightly sclerotized transverse band, with anterior margin straight or concave; when viewed ventrally, straight or concave anteriorly, diversely developed posteriorly. Segment X membranous, unilobate, usually triangularly elongate for Nearctic species (nearly subtriangular in W. arizonensis and W. planae ) projected posterad, parallel with superior appendages; varying in shape and structure from simple segment to complex segment grouping various lobate processes (in W. arizonensis and W. planae ). Superior appendages elongate, usually digitate. Inferior appendages each 2-segmented, when viewed laterally basal segment generally elongate, rectangular, wider and stouter than apical segment; when viewed ventrally, pair of basal segments united anteriorly, separated posteromesally by a V-shaped or Ushaped emargination; apical segment generally elongate, with apicolateral or apical patch of short, black, spines. Phallus, when viewed laterally, usually pistol-shaped, widest basally, tapering from middle to apex, membranous apically, very lightly sclerotized, with visible, internal sclerites ( Figs. 5, 10).

Female genitalia. Abdomen rounded, tapering from segments VII to segment XI. Abdominal segment VII longer than segments VIII–XI combined. Abdominal segments VII and VIII each with distinct sternum and tergum. Abdominal segment IX membranous, simple, shorter than tubular segment X. Abdominal segment XI small, tubular ( Armitage 1996; Schmid 1982: figs. 156–161; Schmid 1991: fig. 27; Schmid 1998: figs. 109– 115).

Pupa. Length 5–12 mm. Mandible with at least one conspicuous tooth subapically in addition to apical tooth ( Ross 1944: figs. 160–161). Abdominal segment III with one or two pairs of dorsal hook plates. Abdominal segment IV with one pair of dorsal hook plates. Abdominal segment V with two pairs of dorsal hook plates (e.g., Wiggins & Currie 2008: 17.120). Abdominal gills absent ( Ross 1944; Wiggins & Currie 2008).

Larva. Length 10–15 mm. Body: stout, subtubular, elongate; head, thorax, and abdomen well developed and differentiated, with occasional setae. Head: sclerotized, elongate, subrectangular or suboval; antennae very small; eyes small; anterior margin of frontoclypeal apotome usually symmetrical, but may be slightly concave or convex; labrum wider apically, anterior margin straight, setose; setae no. 18 conspicuous, placed ventromedially. Thorax: pronotum sclerotized; meso- and metanota membranous, mesothorax larger than metathorax; legs long, subequal, slender, tarsal claws stout, curved, bifurcated subapically; fore trochantins sclerotized, projected freely, each forming short process; coxae elongate, tubular, simple, without projections. Abdomen: elongate, about 2 times as long as head and thorax together, stout, without gills, but anal papillae present; segment IX without dorsal sclerite ( Morse & Holzenthal 2008; Ross 1944; Wiggins 1996).

Retreats. The larvae of Wormaldia construct tubular retreats of silk, which have a small opening facing into the current ( Wiggins 1996: fig. 8.2F). The tubular retreat has several layers of meshes. The mesh opening is elongate and rectangular and its size is about 0.4 x 3.7 µm (microns). The layers of mesh are overlapped diagonally, thereby reducing the size of the mesh openings and resulting in a very fine meshed net ( Wallace & Malas 1976b: figs. 18–19; Merritt et al. 2008a; Nielsen 1942; Philipson 1953; Ross 1944; Wallace & Malas 1976a; Wiggins 1996). In general, the pupal retreat or cocoon consists of a modification of the larval retreat.

Biology. Adults of the Nearctic species of Wormaldia are small (forewing length 3–8 mm; Fig. 133) with blackish or brown coloration. They are usually associated with vegetation around small streams in forested, mountainous areas. They are primarily nocturnal in habit. The larvae of Wormaldia are usually encountered on rocks or sticks in running waters. They build silken tubular retreats in which they freely move and in this way feed by cleaning fine organic particles from the tube’s inner surface ( Wiggins 1996).

Remarks. Adults of the genus Wormaldia are distinguished from the other genera of Philopotaminae by the particular arrangement and shape of the anal cells of the hind wing. This consists of the hind wing with anal vein 2A fused to 1A, resulting in 2A being atrophied beyond crossvein a 2 ( Figs. 13, 83; Ross 1956: fig. 20). Larvae of Nearctic Chimarra , Wormaldia , Dolophilodes , and Fumonta can be distinguished based on the key provided by Morse & Holzenthal (2008); the larva of Sisko is unknown. Larval descriptions of European species can be found in the work of Lepneva (1970). Ross (1944) provided a key to Nearctic Chimarra , Dolophilodes (as Trentonius ), and Wormaldia (as Dolophilus ) pupae. Weaver et al. (1981) described the pupa of Fumonta major (as Dolophilodes ); the pupa of Sisko is unknown.