Pseudosmittia mathildae Albu

Ferrington Jr, Leonard C. & Saether, Ole A., 2011, A revision of the genera Pseudosmittia Edwards, 1932, Allocladius Kieffer, 1913, and Hydrosmittia gen. n. (Diptera: Chironomidae, Orthocladiinae) 2849, Zootaxa 2849 (1), pp. 1-314 : 209-215

Pseudosmittia mathildae Albu

( Figs. 80–82 )

Pseudosmittia mathildae Albu, 1968:4 ; Ashe & Cranston (1990: 223); Saether (2006: 37); Makarchenko & Makarchenko (2008: 219).

Pseudosmittia itachibifurca Sasa et Kawai, 1987: 54 ; Yamamoto (2004: 87).

Pseudosmittia amamibifurca Sasa, 1990 a:132; Saether & Ferrington (2003: 3); Yamamoto (2004: 87).

Pseudosmittia trilobata Langton, 1991:173 , pro parte, not Edwards.

? Pseudosmittia sp. B Strenzke, 1960b: 309 .

Pseudosmittia hibaribifurca Sasa, 1993: 80 ; Yamamoto (2004: 88) as P. itachibifurca Sasa et Kawai.

Pseudosmittia furudobifurca Sasa et Arakawa, 1994: 100 ; Yamamoto (2004: 88) as P. itachibifurca Sasa et Kawai.

Pseudosmittia (Nikismittia) shoufukuundecima Sasa, 1997: 42 ; Yamamoto (2004: 88) as P. itachibifurca Sasa et Kawai.

Diplosmittia amamibifurca (Sasa) ; Saether et al. (2000: 185).

Diplosmittia furudobifurca (Sasa et Arakawa) ; Saether et al. (2000: 185).

Diplosmittia hibaribifurca (Sasa) ; Saether et al. (2000: 185).

Diplosmittia itachibifurca (Sasa) ; Saether et al. (2000: 185).

Diplosmittia shoufukuundecima (Sasa) ; Saether et al. (2000: 185).

Diplosmittia sasai Makarchenko et Makarchenko, 2005: 376 .

Material examined: ITALY: Upper Italy, Lago di Margozza, 2 males, paratypes, 4.viii.1965, F. Reiss ( ZSM). GERMANY: Bavaria, an Tümpel Schäftlarner, Drift, 1 pupal exuviae, 14.viii.1983, F. Reiss ( ZSM). CHINA: Gansu, Kangxian, 1120 m a. s. l., 1 male, 2.viii.1986, X. Wang ( XW); Guangdong, Fughai, 1 male, 20.iv.1988, X. Wang ( XW). JAPAN: Honshu, Toyama Pref., Itachgawa River, holotype male of P. itachibifurca , 1. iv.1986, S. Nagai et al. (NMST, No. A 115: 03); Honshu, Toyama Pref., Lake Furudo, holotype male of P. furudobifurca , 23.viii.1993, M. Sasa & R. Arakawa (NMST, No. A 248: 37); Honshu, Toyama Pref., Kurobe, holotype male of P. shoufukuundecima , 30.iv.1996, M. Sasa (NMST, No. 326: 50); Honshu, Fukushima Pref., Lake Hibara, holotype male of P. hibarabifurca , 8.vi.1991, M. Sasa (NMST, No. A 223: 90); Nansei Archipelago, Kagoshima Pref., Amami-Oshima Is., Yakkachei River, holotype and paratypes males of P. amamibifurca , 18.iii.1989, M. Sasa & S. Hattori (NMST, holotype No. A 179: 21, paratypes Nos.179: 22–27). USA: South Carolina: Anderson County, Savannah River, Hartwell Tailwater, 2 males, 9.vi.1978, P. L. Hudson; Anderson County, Savannah River, Gregg Shoals, moist bank, 1 male, mature pupa, 1 pupal exuviae, 27.–28.ix.1980, P. L. Hudson; Anderson County, Savannah River, 4 miles below Hartwell Dam, moist bank, 6 males, 3 females, 1 pupal exuviae, 1 larva; Pickens County, Lake Keovee, 1 male, 5.iv.1975, P. L. Hudson. Georgia: Hart County, Savannah River, 4 miles below Hartwell Dam, 1 male, 2 females, 1 mature males pupa reared from larva, 1 mature female pupa, 6 pupal exuviae, P. L. Hudson; Hart County, Savannah River, Gregg Shoals, 1 male, 27.ix.1980, P. L. Hudson; Clarke County, Oconee River, Athens, 2males, 22.x.1978, P. L. Hudson; Clarke County, N. Oconee River near confluence with middle Oconee River, 1 male, 17.viii.1988, B. A. Caldwell; Chattahoochee County, Lower Ochile, 3 larvae, 14.xii.1983, M. W. Heyn. Alabama: Limestone County, Elk Creek Area, Wheeler Reservoir, 1 males, 2.x.1982, P. L. Hudson; Elmore County, Tallapoosa River, 1 mile South of Tallahassee, 2 males, 6.vi.1988, W. E. Garrett; Macon County, Eupharee Creek, 1.2 miles NNE of Franklin at Highway 49, 2 males, 10– 28.iii.1989, W. E. Garrett; Tallapoosa County, Sandy Creek, 2.2 miles WSW of Camp Hill at Highway 34, 1 male, 15.vi.1988, W. E. Garrett.

Diagnostic characters: The bilobed gonostylus will separate the species from all other Pseudosmittia . The female is distinguished by lacking apical antennal seta combined with having tergite IX divided by median dark line or undivided. The pupa is the only known pupa of the Pseudosmittia complex with nose on the wing sheath. It is also characterized by having tergite IX with longitudinal ridge carrying 2–3 rows of strong points, and genital sac of both sexes with spinules. Posterior parapods of larva with 8 claws, 15–18 µm long; antennal blade subequal in length to width of basal antennal segment and longer than length of basal antennal segment.

Male imago (n = 10, except when otherwise stated)

Total length 1.25–1.60, 1.47 mm (8). Wing length 0.69–1.06, 0.83 mm (29). Total length/wing length 1.71–1.82, 1.77

(8). Wing length/length of profemur 3.32–3.48, 3.41. Coloration brownish black.

Head ( Fig. 80 B ). AR 0.29–0.82, 0.50 (32)(0.39 in holotype according to Albu, 0.29–0.32 in P. amamibifurca ,

0.64–0.84 in P. itachibifurca and P. shoufukuundecima according to Sasa). Terminal flagellomere 120–278, 175 µm

(32) long. Temporal setae 3–7, 4 consisting of 0(?)–2, 1 inner verticals, and 2–5, 3 outer verticals. Clypeus with 5–7, 6

setae. Cibarial pump and stipes as in Fig. 80 D . Tentorium 71–94, 81 µm long, 11–16, 14 µm wide. Stipes 64–94, 73

µm long, 14–25, 20 µm wide. Palpomere lengths (in µm): 11–21,16; 23–27, 25; 39–58, 48; 49–71, 60; 71–94, 82.

Third palpomere ( Fig. 80 C ) with 2–3, 2 lanceolate sensilla clavata.

Thorax. Antepronotal lobes reduced medially, with 1–2, 1 lateral setae. Dorsocentrals 5–8, 6; acrostichals 2,

prealars 1–3, 3. Scutellum with 4 setae.

Wing ( Fig. 80 A ). VR 1.27–1.42, 1.34. Anal lobe at most slightly indicated. Costal extension 14–39, 20 µm long.

R 4+5 ending proximal to apex of M 3+4; Cu 1 slightly sinuate. Brachiolum with 1 seta, other veins bare.

Legs. Spur of front tibia 21–32, 28 µm long, spurs of middle tibia 9–13, 11 µm and 8–10, 9 µm long, of hind tibia 25– 34, 29 µm and 9–14, 12 µm long. Width at apex of front and middle tibiae each 14–21, 18 µm, of hind tibia 23–33, 26 µm. Comb of 10–12, 11 setae, shortest setae 14–16, 15 µm long, longest setae 21–27, 25 µm long. Lengths and proportions of legs as in Table 50.

Hypopygium ( Fig. 80 F–H ; Albu 1968, fig. 1; Sasa 1990 a, fig. 20; Yamamoto 2004 fig. 21d). Anal point 9–34, 21 µm long, with setae and microtrichia to apex; tergite IX with 3–13, 8 setae; laterosternite IX with 2–3, 3 setae. Phallapodeme 46–59, 53 µm long; transverse sternapodeme 37–50, 42 µm long, no oral projections. Virga ( Fig. 80 E ) 14–25, 18 µm long. Gonocoxite 98–137, 168 µm long; inferior volsella and accessory lobe both developed and reaching to 0.71–0.95, 0.82 and 0.78–0.91, 0.87 gonocoxite length, respectively. Gonostylus 39–48, 42 µm long with 41–50, 46 µm long, variable sinuate lobe with pectinate margin visible only in some views ( Fig. 80 G, H ); megaseta 7– 10, 9 µm long, sometimes apparently lost and maybe occasionally absent. HR 2.50–3.06, 2.80; HV 3.21–3.84, 3.48 (8).

Female imago (n = 5, except when otherwise stated)

Total length 1.16–1.53, 1.33 mm. Wing length 0.68–0.78, 0.72 mm. Total length/ wing length 1.78–2.01, 1.82 (4). Wing length/length of profemur 3.23–3.31, 3.29. Coloration brownish black.

Head. Antenna as in Fig. 81 B . AR 0.33–0.44, 0.39 (4). Lengths (in µm) of flagellomeres (n = 4): 48–62, 53; 37– 43, 39; 37–43, 40; 37–46, 40; 57–66, 62. Temporal setae 3–5, 4; including 1 inner vertical, and 2–4, 3 outer verticals. Clypeus with 6–9, 8 (6) setae. Tentorium 57–80, 73 µm long, 8–10, 9 µm wide. Stipes 55–71, 64 µm (4) long. Palpomere lengths (in µm): 18–25, 20; 23–27, 25; 43–53, 48; 55–64, 61; 78–91, 85. Third palpomere with 2 lanceolate sensilla clavata. Coronal suture 16–55, 43 µm (4) long, nearly absent to nearly complete.

Thorax. Antepronotal lobes as in male, lateral setae 1 (2). Dorsocentrals 7–9, 8, acrostichals 2, prealars 3. Scutellum with 4 setae.

Wing ( Fig. 81 A ). VR 1.25–1.33, 1.31. Anal lobe weak. Costal extension 34–48, 43 µm long. R 4+5 ending proximal to apex of M 3+4; Cu 1 straight. Brachiolum with 1 seta; costa between FR and apex of R 4+5 with 4–9, 6 nonmarginal setae; costal extension with 3–5, 4 non-marginal setae; R with 4–6, 5 setae; R 1 with 0–1, 1; R 4+5 with 4–5, 4 setae, other veins bare.

Legs. Spur of front tibia 19–23, 21 µm (4) long, spurs of middle tibia 11–14, 12 µm and 9–11, 10 µm long, of hind tibia 30–34, 31 µm and 11–16, 13 µm (4) long. Width at apex of front tibia 16–21, 18 µm, of middle tibia 21–25, 23 µm, of hind tibia 27–34, 30 µm. Comb of 11–12, 11 setae, shortest setae 14–21, 17 µm long, longest setae 25–30, 28 µm long. Lengths and proportions of legs as in Table 51.

Abdomen. Tergite I bare; T II–VII each with 7–12, 10 setae; T VIII with 6–10, 8 (4) setae. Sternite I and II bare, S III–VII each with 2–6, 5 setae; S VIII with 14–21, 19 setae.

Genitalia ( Fig. 81 C–H ). Gonocoxite relatively well developed, without long posterior corner; with 4–5, 4 strong and 2–3, 2 weak setae. Tergite IX undivided or usually with a median line, with altogether 8–12, 8 setae. Segment X with more or less pronounced sharply triangular corners. Cercus 55–64, 60 µm (7) long. Apodeme against gonocoxite 46–60, 59 µm long. Seminal capsule moderately dark, ovoid; 50–69, 57 µm (6) long, 41–46, 42 µm wide, microtrichia not observed. Notum 66–80, 73 µm (7) long.

Pupa (n = 9–12)

Total length 1.71–2.03, 1.84 mm. Exuviae nearly colorless, with slight yellowish tinge only on margins.

Cephalothorax. Frontal apotome, thorax and wing sheath smooth. Longer precorneals, ventral median antepronotal and longer dorsocentral setae about 45–70 µm long. Frontal seta, dorsal median antepronotal, lateral antepronotal, shorter precorneal, and shorter dorsocentral setae all about 20–35 µm long. Distance between Dc 1 and Dc 2 5–27, 15 µm; between Dc 2 and Dc 3 3–14, 7 µm; between Dc 3 and Dc 4 10–21, 15 µm. Wing sheath with nose ( Fig. 82 A ).

Abdomen ( Fig. 82 B–E ). Tergite I with anterolateral shagreen; T II–VIII with strong anterior and posterior, weaker median shagreen, caudal spinules as spines on VII and VIII; T IX with median longitudinal ridge carrying about 10–30, 18 marginal spines in 2–3 rows. Sternites I–III bare, or weak spinules present on II and III; S IV–VIII with anterior spinules, more extensive on VIII (about 1/2 segment); S IX with shagreen on most of segment including genital sac of both sexes. Tergal conjunctive II/III with 0–2, 0 spinules; III/IV with 19–37, 24; –IV/V with 21–43, 29; V/VI with 25–51, 30; VI/VII with 21–36, 28; VII/VIII with 0–2, 0 spinules. Sternal conjunctive III/IV with 0–14, 5 spinules; IV/V with 14–34, 24; V/VI with 23–46, 32; VI/VII with 15–45, 30; VII/VIII with 0–26, 13 spinules. Anal segment without setae, male genital sac ( Fig. 82 B ) wide and truncate at apex.

Fourth instar larva (n = 2–3)

Total length 2.30–2.57 mm. Head capsule length 0.17–0.21 mm. Head capsule yellowish brown. Body probably yellowish white.

Head. Antenna as in Fig. 82 F . Length of antennal segments (in µm): 8.5–9; 3.5; 2–2.5; 2.5. AR 0.95–1.11. Basal antennal segment 11–12.5 µm wide; blade 11–16 µm long; accessory blade 5.5 µm long. Sensilla basiconica 2–3.5 µm long. Subapical style of second segment 2.5–3.5 µm long. Premandible ( Fig. 82 G ) 41–43 µm long. Mandible ( Fig. 82 H ) 67–79 µm long; with 3 inner teeth, basal tooth somewhat hooked, no dorsal teeth, seta subdentalis and seta interna absent. Mentum as in Fig. 82 I , median tooth 18 µm wide, ventromental plate 10–11 µm wide in flattened mentum. Postmentum 59–64 µm long.

Abdomen. Anterior parapods nearly completely fused, 32–55 µm long, each with about 25–30 longer claws. Posterior parapods 32–64 µm long, each with 8 claws, 15–18 µm long. Anal tubules about 25 µm long.

Third instar larva (n = 1)

Total length 1.85 mm. Head length 0.14 mm.

Head. Length of antennal segments (in µm): 7, 3.5, 2, 2. AR 0.94. Basal antennal segment 10.0 µm wide, blade 13 µm long, accessory blade 4.5 µm long; sensilla basiconica 2 µm long. Subapical style of second segment 3 µm long. Premandible 33 µm long. Mandible 57 µm long. Median tooth of mentum 14 µm wide, ventromental plate 7 µm in flattened view. Postmentum 41 µm long.

Abdomen. Anterior parapods 32 µm long, each with about 25 longer claws. Posterior parapods 32 µm long, each with 8 claws, each about 18 µm long.

Remarks

P. itachibifurca ( Sasa & Kawai 1987, Sasa 1989a, Sasa 1988b) may represent a different species since the AR is indicated to be 0.64–0.84 and the gonostylus is said to be lacking a megaseta. However, non-Japanese specimens show an AR of 0.42–0.60 and a variation of 0.29–0.84 is not unusual for other species of Pseudosmittia . As shown by Yamamoto (2004: 88) the megaseta is present.

P. sasai is said to differ by having the inner branch of gonostylus wide and pectinate. However, the inner branch may appear relatively narrow and smooth in some views, wide and pectinate in other views. Both in some specimens from Georgia, USA, and some from China, one gonostylus appear to have the inner branch slender and smooth, the other, being in a different position, wide and showing the pectination.

P. amamibifurca could be regarded as a subspecies since the AR is lower than in other populations and the Nansei Archipelago is in the Oceanic (Indo-Pacific) Region and the only record outside the Holarctic Region.

P. mathildae differs from most members of the genus in having a bifurcate gonostylus and, on the basis of the male imago, could have been placed in a separate genus or perhaps included in Diplosmittia . However, the immature stages show the species is an a typical member of the Pseudosmittia complex with a larva which could place it also in Hydrosmittia .

Ecology and distribution

The larvae from the USA are from the moist banks along rivers and streams and the larva mentioned by Strenzke as Pseudosmittia sp. B , which is most likely the larva of P. mathildae , was collected from water saturated peat in a bog. The species is known from Austria, Finland, southern Germany, northern Italy, Romania, Russia, China, Japan including the Nansei Archipelago, and in the USA from South Carolina, Georgia and Alabama. One of the collections from China, Guangdong, is from well within the Oriental Region.

Figures

FIGURE 80. Pseudosmittia mathildae Albu, male. A—wing; B—head; C—third palpomere; D—cibarial pump and stipes; E—virga; F—hypopygium, left dorsal aspect, right ventral aspect; G—H, gonostylus, different views

FIGURE 81. Pseudosmittia mathildae Albu, female. A—wing; B—antenna; C—genitalia, lateral view; D—ventrolateral lobe; E—dorsomesal lobe; F—apodeme lobe; G—genitalia, ventral view; H—genitalia, dorsal view.

FIGURE 82. Pseudosmittia mathildae Albu, immatures. A—pupa, wing sheath; B—male pupa, genital sac; C—female pupa, genital sac; D—male pupa, posterior tergites; E—female pupa, posterior tergites; F—larval antenna; G—larval premandible; H—mandible; I—mentum.