Pseudosmittia albipennis (Goetghebuer)

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 : 243-246

Pseudosmittia albipennis (Goetghebuer)

( Figs. 91 )

Dactylocladius albipennis Goetghebuer, 1921: 85 .

Spaniotoma (Smittia) curticosta Edwards, 1925: 364 ; Saether & Ferrington, 2003: 4.

Smittia (Orthosmittia) albipennis (Goetghebuer) ; Goetghebuer 1943: 111.

Smittia (Pseudosmittia) curticosta (Edwards) ; Goetghebuer 1943: 105.

Smittia albipennis (Goetghebuer) ; Ashe & Cranston 1990: 227.

Pseudosmittia albipennis (Goetghebuer) ; Saether & Ferrington 2003: 3; Langton & Pinder 2007: 136, figs. 71 D, 188 A, B. A. Pseudosmittia curticosta (Edwards) ; Strenzke 1960a: 464, Pinder 1978, Ashe & Cranston 1990: 223.

Material examined: BELGIUM: East Flanders, Bellem, Eeklo , holotype male, 13.v.1920, M. Goetghebuer ( IRSN) . WALES: Carnarvon, Llyn Gwynant , holotype male of curticosta , 13.vii.1914, F. W. Edwards ( BMNH) . SCOT- LAND: Arran, Corriegills , paratype male and head of paratype male, 2–4.vi.1919, F. W. Edwards ( NMS, BMNH) . GERMANY: Lower Saxony, Oldenburg, Neuenburger Urwald , 12 males or parts of males, 8 females or parts of females, 20 pupal exuviae, 2.v.1954, K. Strenzke (GP621–GP638) . ENGLAND: Loch near Brittner, 1 male, 29.vii.1979, P. Langton; East Sussex, Ashdown Forest , 1 larva, iv.1975, A. Hildrew ( BMNH) .

Diagnostic characters: The absence of superior and median volsellae combined with the presence of a subapical seta on the male antenna, antennal ratio of 0.6–1.0, presence of a crista dorsalis, both inferior volsella and the accessory lobe long and low, and virga minute and perhaps sometimes absent, will separate the male from other species of the genus. The female can be separated from other members of the genus by having Cu 1 straight, apical seta on antenna, third palpomere with 5–7 sensilla clavata, no postcubital fork, mid tibia with two spurs, tergite IX divided by triangular notch, gonocoxite without posterior corner, and seminal capsules without striations or microtrichia. The pupa differ from all other known pupae by having spinules on tergal conjunctives, but lacking spinules on sternal conjunctives. It also is characterized by having minute spine-like frontal setae, and segment IX without setae or spinules. The larva can be separated from other members of the genus by having three broad claws on each posterior parapod, antennal blade four times as long as width of basal segment, and no seta interna on the mandible.

Male imago (n = 7–9, except when otherwise stated)

Total length 1.41–1.87, 1.60 mm (4). Wing length 0.81–1.17, 0.91 mm. Total length/wing length 1.69–1.97, 1.81. Wing length/length of profemur 2.64–2.85, 2.75. Coloration blackish brown.

Head. AR 0.64–1.00, 0.76 (13). Terminal flagellomere ( Strenzke 1960a, fig. 1) 197–277, 227 µm (13) long, strong apical seta 27–46, 38 µm long. Temporal setae 4–7, 6 (12), consisting of 2–4, 3 (12) inner verticals and 2–4, 3 (12 outer verticals. Clypeus with 5–10, 7 (10) setae. Tentorium 96–126, 109 µm (12) long, 14–22, 16 µm (12) wide. Stipes 91–107, 99 µm (6) long, 26–34, 32 µm (4) wide. Palpomere lengths (in µm, n = 12–13): 16–23, 20; 23–30, 26; 39–57, 48; 55–75, 63; 112–133, 116. Third palpomere with 2–3, 2 sensilla clavata.

Thorax. Antepronotal lobes somewhat reduced medially, antepronotum with 1–3 (3) lateral setae. Dorsocentrals 10–13, 12; acrostichals 2; prealars 2–3, 3. Scutellum with 2–4, 3 setae.

Wing ( Fig. 91 A ; Strenzke 1960a, fig. 2). VR 1.39–1.49, 1.42. Anal lobe reduced. Costal extension 21–57, 39 µm long. R 4+5 ending far proximal to apex of M 3+4; Cu 1 slightly curved. Brachiolum with 1 seta, other veins bare.

Legs. Spur of front tibia 34–59, 40 µm long, spurs of middle tibia 14–30, 20 µm and 11–18, 15 µm long, of hind tibia 33–46, 39 µm and 14–18, 17 µm long. Width at apex of front tibia 21–27, 23 µm, of middle tibia 21–27, 24 µm, of hind tibia 27–39, 34 µm. Comb of 12–15, 13 setae, shortest setae 18–23, 22 µm (6) long, longest setae 30–37, 33 µm (6) long. Lengths and proportions of legs as in Table 67.

Hypopygium ( Fig. 91 C, D ; Strenzke 1960a, fig. 3, Pinder 1978, fig. 137d). Anal point 23–37, 30 µm (15) long; tergite IX with 6–12, 8 (11) setae; laterosternite IX with 1–3, 3 (11) setae. Phallapodeme 53–64, 57 µm (14) long; transverse sternapodeme 53–64, 60 µm (13) long, oral projections indicated. Virga apparently 5–16, 9 µm long, very weak and perhaps often absent. Gonocoxite 119–139, 128 µm (16) long; superior volsella absent; inferior volsella low, reaching to 0.67–0.76, 0.72 (15) gonocoxite length, accessory lobe low and reaching to 0.83– 0.92, 0.88 (15) gonocoxite length. Gonostylus 53–61, 57 µm (16) long; megaseta 7–9, 8 µm (16) long. HR 2.08– 2.39, 2.25 (16), HV 2.48–3.23, 2.80 (4).

Female imago (n = 6–7, except when otherwise stated)

Total length 1.22–1.50, 1.35 mm. Wing length 0.67–0.76, 0.72 mm. Total length/wing length 1.75–2.06, 1.88. Wing length/length of profemur 2.79–2.96, 2.90. Coloration as in male, but scutellum pale yellowish brown.

Head. AR 0.42–0.48, 0.46. Lengths (in µm) of flagellomeres ( Strenzke 1960a, fig. 4): 41–48, 45; 30–34, 33; 32–35, 34; 29–32, 31; 59–87, 67. Temporal setae 4–5, 5, including 2–3, 2 inner verticals, and 2–3, 2 outer verticals. Clypeus with 6–9, 7 setae. Tentorium 75–94, 88 µm long, 9–11, 10 µm wide. Stipes 71–87, 79 µm m long, 18–25, 23 µm wide. Palpomere lengths (in µm): 14–18, 17; 21–23, 22; 37–46, 42; 41–62, 53; 80–103, 93. Third palpomere with 5–7, 6 lanceolate sensilla clavata.

Thorax. Antepronotal lobes some what reduced medially, lateral setae of antepronotum 1 (2). Dorsocentrals11– 13, 12, acrostichals 2, prealars 3. Scutellum with 3–4, 4 setae.

Wing ( Fig. 91 E ; Strenzke 1960a, fig. 6). VR 1.32–1.41, 1.38. Anal lobe reduced. Costal extension 80–103, 89 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 13–24, 19 non-marginal setae, costal extension with 7–14, 8 non-marginal setae, R with 5–7, 6, R 1 with 1–2, 1, R 4+5 with 4–6, 5 setae, other veins bare.

Legs. Spur of front tibia 21–30, 25 µm long, spurs of middle tibia 16–21, 18 µm and 11–18, 12 µm long, of hind tibia 30–41, 35 µm and 14–18, 15 µm long. Width at apex of front tibia 21–25, 23 µm, of middle tibia 21–24, 23 µm, of hind tibia 30–37, 33 µm. Comb of 11–13, 13 setae, shortest setae 16–21, 18 µm long, longest setae 25– 32, 18 µm. Lengths and proportions of legs as in Table 68.

Abdomen. Tergite I bare, T II with 6–10, 8 setae, T III–VII each with 8–12, 10 setae, T VIII 6–8, 7 setae. Sternite

I–VI not measurable, S VII with 4–6 (2) setae, viii with 17–30, 23 setae.

Genitalia ( Fig. 91 F ; Strenzke 1960a, figs. 7, 8). Gonocoxite relatively large, without caudal projection, with 4–7, 5 setae, including 2–4, 3 strong and 2–5, 2 weak setae. Tergite IX strongly divided, with microtrichia in posterior 1/2–2/3, and with altogether 11–14, 13 (5) setae. Cercus 43–55, 50 µm long. Apodeme against gonocoxite 62– 69, 68 µm long. Seminal capsule dark in anterior 4/5, ovoid; 59–64, 61µm long, excluding 5–9, 8 µm (4) long neck, 48–53, 51 µm (5) wide, microtrichia not observed. Notum 59–66, 60 µm long.

Pupa

Total length 1.55–2.20, 1.88 mm (18) long. Exuviae tinged with yellow on cephalothorax, abdomen colorless.

Cephalothorax ( Strenzke 1960b fig. 9). Frontal seta spine-like, about 3 µm long. Longer setae on cephalothorax up to 50 µm long. Distance between Dc 1 and Dc 2 95–145, 118 µm (7), between Dc 2 and Dc 3 5–20, 10 µm (8), between Dc 3 and Dc 4 5–20, 10 µm (8).

Abdomen ( Fig. 91 G, H ; Strenzke 1960b fig.10, 11). Tergite I bare; T II–IX with coarse shagreen covering most of tergite, with stronger anterior and posterior spinules. Sternites I– IV and IX bare, S V–VII with weak spinules in anterior and posterior bands, S VIII with median band of few to several spinules. Genital sac of both sexes without spinules. Tergal conjunctive III/IV with 15–26, 19 (14) spinules; IV/V with 20–42, 30 (15); V/VI with 21–37, 29 (15); VI/VII with 21–31, 20 (16) spinules. Sternal conjunctives bare. Segment IX without setae. Genital sac of male surpassing tergite by 70–90, 75 µm (13).

Fourth instar larva (n = 1)Total length 4.68 mm. Head capsule length not measurable.

Head. Antenna as in Fig. 91 I and Strenzke (1960b fig. 12). Length of antennal segments (in µm): 10, 3.5, 2.5, 2.5. AR 1.10. Basal antennal segment 11.5 µm wide; blade 40 µm long; accessory blade 4.5 µm long. Apical style of second segment 5 µm long. Premandible ( Fig. 91 J ; Strenzke 1960b fig 13) 53 µm long. Mandible ( Fig. 91 K ) 89 µm long; with 3 inner teeth without dorsal teeth; seta subdentalis 3 µm long; seta interna absent. Mentum as in Fig. 91 L , with 4 pairs of lateral teeth, median tooth 23 µm wide, ventromental plate 14 µm wide on flattened mentum. Postmentum 78 µm long

Abdomen. Anterior parapods missing. Length of posterior parapods not measurable, each with 3 broad claws ( Strenzke 1960b fig. 14a), the longest 23–25 µm long. Longer anal tubules 34 µm long, 46 µm wide at base, shorter tubules 27 µm long, 39 µm wide at base.

Distribution

The species is known from Belgium, Britain, Denmark, Finland, Germany, Ireland and Luxembourg ( Saether & Spies 2004, Paasivirta 2007).

Figures

FIGURE 91. Pseudosmittia albipennis (Goetghebuer). A–D. Male. A—wing; B—hypopygium, dorsal aspect; C—hypopygium, ventral aspect.; D—gonostylus. E, F. Female. female. E—wing; F—genitalia, dorsal view. G, H. Pupa. G—posterior tergites; H—posterior sternites. I–L. Larva. I—antenna; J—premandible; K—mandible; L—mentum.