Pseudosmittia brevifurcata (Edwards)

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 : 248-251

Pseudosmittia brevifurcata (Edwards)

( Fig. 93 )

Orthocladius (Dactylocladius) brevifurcatus Edwards, 1926: 781 .

Spaniotoma (Smittia) brevifurcata (Edwards) ; Edwards, 1929: 365.

Smittia (Orthosmittia) brevifurcata (Edwards) ; Goetghebuer 1943: 111.

Pseudosmittia brevifurcata (Edwards) ; Saether & Ferrington, 2003: 3; Langton & Pinder 2007: 137, fig. 71 C, 187 C.

Material examined: ENGLAND: Dorset, Swanage , in great numbers hovering in flocks over boulders on the seashore, lectotype male, here designated, 6.ix.1906, Lt. - Col. Yerbury ( BMNH) ; Somerset, Porlock Weir , flying on shore between tide marks, paralectotype male, 10.vi.1922, F. W. Edwards ( BMNH) ; Dorset, Ringstead , 1 female, 19.viii.1939, F. W. Edwards ( BMNH) . FRANCE: Villefranche sur laise Demaric , 3 males, 23.vii.1956, M. Bequaert ( IRSN) . SPAIN: Mallorca, Arenal Grove , rock-pool, 4 males, 6–14.vi.1957, M. Bequaert ( IRSN) . SLOVENIA: Istria, S. Rabac , 2 males, 4–5.ix.1979, E. G. Burmeister ( ZBM)

Diagnostic characters: The imagines are characterized by having 7–12 sensilla clavata in a more or less distinct sensillum capitatum, postcubital fork, straight Cu 1, 14–23 dorsocentrals and 5–11 prealars. The male has an anal point without setae and tongue-shaped inferior volsella; the female apical antennal segment with strong seta, divided tergite IX and apparently postcubitus not forked.

Male imago (n = 8–11, except when otherwise stated)

Total length 1.76–2.25, 1.95 mm. Wing length 0.94–1.23, 1.08 mm. Total length/wing length 1.75–1.88, 1.80. Wing length/length of profemur 2.54–2.81, 2.68. Coloration blackish brown.

Head ( Fig. 93 B ). AR 0.76–1.38, 1.04. Terminal flagellomere 234–340, 265 µm long; apex of antenna darker than base. Temporal setae 5–7, 6, consisting of 2–4, 3 inner verticals and 2–4, 3 outer verticals, no postorbitals. Clypeus with 8–13, 9 setae. Cibarial pump and stipes as in Fig. 93 C . Tentorium 103–133, 115 µm long, 18–25, 22 µm wide. Stipes 91–114 µm long, 23–46, 28 µm wide. Palpomere lengths (in µm): 18–25, 22, 23–41, 30, 46–75, 61, 57–71, 67, 101–133, 118. Third palpomere ( Fig. 93 D ) with 7–12, 9 sensilla clavata in a more or less distinct sensillum capitatum.

Thorax. Median antepronotal lobes only slightly reduced, antepronotum with 2–4, 3 lateral setae. Dorsocentrals 14–23, 19, and partially biserial, acrostichals 2, prealars 5–11, 9, and 6 specimens with anterior prealars. Scutellum with 8–12, 10 setae.

Wing ( Fig. 93 A ; Edwards 1926 fig. 1e, 1929 plate 18, fig 18). VR 1 1.57–1.85, 1.73; VR 2 1.22–1.46, 1.37. Anal lobe weak, but often slightly projecting. Costal extension 9–25, 12 µm long. R 4+5 ending well proximal to apex of M 3+4; Cu 1 straight. Brachiolum with 1 seta, R with 2–6, 4 setae, other veins bare.

Legs. Spur of front tibia 37–49, 42 µm long, spurs of middle tibia 23–32, 28 µm and 18–30, 23 µm (5) long, of hind tibia 43–55, 48 µm (4) and 21–27, 24 µm long. Width at apex of front and middle tibiae each 18–30, 26 µm, of hind tibia 39–48, 42 µm. Comb of 12–15, 13 setae, shortest seta 23–32, 27 µm long, longest seta 37–50, 44 µm long. Lengths and proportions of legs as in Table 69.

Hypopygium ( Fig. 93 F ; Edwards 1926 fig. 1a). Anal point 32–53, 39 µm long, with weak microtrichia to apex; tergite IX with 6–13, 9 setae; laterosternite IX with 3–5, 3 setae. Phallapodeme 53–71, 63 µm long; transverse sternapodeme 34–53, 46 µm long, no oral projections. Virga ( Fig. 93 E ) 23–37, 26 µm long. Gonocoxite 135–181, 148 µm long; indication of superior volsella with orally directed curled microtrichia; inferior volsella tongue-shaped, and reaching to 0.62–0.70, 0.66 gonocoxite length. Gonostylus 55–73, 61 µm long with rounded preapical crista dorsalis; megaseta 9–10, 9 µm long. HR 2.22–2.65, 2.45, HV 2.90–3.69, 3.22.

Female imago (n = 1)

Total length 2.00 mm. Wing length 1.12 mm. Total length/wing length 1.79. Wing length/length of profemur 2.70. Coloration yellow with dark confluent vittae and dark scutellum, preepisternum and postnotum.

Head. AR 0.48. Flagellomere lengths (in µm): 64, 48, 48, 50, 101. Fifth flagellomere with apical strong seta lost. Temporal setae 6, consisting of 2 inner verticals, 3 outer verticals and 1 postorbital. Clypeus with 10 setae. Tentorium 126 µm long, 15 µm wide. Stipes 112 µm long, 32 µm wide. Palpomere lengths (in µm): 32, 34, 62, 69, and lost. Third palpomere with about 12 sensilla clavata in sensillum capitatum. Coronal suture complete.

Thorax. Antepronotal lobes reduced medially, antepronotum with 4 lateral setae. Dorsocentrals 20, acrostichals 2, prealars 9 in two groups, 3 anterior and 6 posterior. Scutellum with 10 setae.

Wing. VR 1.78. Postcubitus apparently not forked. Anal lobe weak, but present. Costal extension 69 µm long. R 4+5 ending slightly proximal to apex of M 3+4; Cu 1 straight. Brachiolum with 1 seta, costa between FR and apex of R 4+5 with 8 non-marginal setae, costal extension with 5 non-marginal setae, R with 7 setae, R 1 with 4, R 2+3 and R 4+5 with 13 setae, other veins bare.

Legs. Spur of front tibia 34 µm long, spurs of middle tibia 32 µm and 27 µm long, of hind tibia 52 µm and 23 µm long. Widths not measurable. Comb of 14 setae, 27–37 µm long. Lengths and proportions of legs as in Table 70.

Abdomen. Tergite I bare; T II–VIII each with 12–16, 14 setae. Sternites I and II bare, S III with 6 setae, S IV–

VI each with 10–11 setae, S VII with 14 setae, S VIII with about 28 setae.

Genitalia. Gonocoxite with 3 strong setae and 5 weaker setae on weak posterolateral projection. Tergite IX divided, with altogether about 16 setae. Cercus 80 µm long. Seminal capsule about 60 µm long, 22 µm wide, microtrichia not observed. Notum 88 µm long.

Pupa and larva

Unknown.

Remarks

There is a large variation in the number of prealar setae in the males studied. The number is particularly high in the specimens from Mallorca where there is an anterior group of 2–4 prealars, 1–2 median prealars, and 4–6 posterior prealar setae. The lectotype only has 5 posterior prealar setae. However, in the specimen from France both anterior and posterior prealars are present and in the female tentatively associated by Edwards there also are anterior prealars. The association of the female is fairly certain. Although the female does not have a postcubital fork, the numerous dorsocentrals and prealars together with the numerous sensilla clavata in a more of less distinct sensillum clavatum reinforce the association.

This species as well as the next is rather different from the lamellata subgroup and may be better placed in the brachydicrana group.

Ecology and distribution

Although the larvae are unknown they are likely to be marine.

The species is known from England, France, Spain, Slovenia and the Azores.

Figures

FIGURE 93. Pseudosmittia brevifurcata (Edwards), male. A—wing; B—head; C—cibarial pump and stipes; D—third palpomere; E—virga; F—hypopygium, left dorsal aspect, right ventral aspect.