Micropsectra logani, (JOHANNSEN)

Stur, Elisabeth & Ekrem, Torbjørn, 2006, A revision of West Palaearctic species of the Micropsectra atrofasciata species group (Diptera: Chironomidae), Zoological Journal of the Linnean Society 146 (4), pp. 165-225 : 196-199

MICROPSECTRA LOGANI (JOHANNSEN)

Tanytarsus (Micropsectra) logani Johannsen, 1928: 33 . Holotype £ (CUIC Type no. 2369) USA, Utah, Logan, Long River , J. G. Needham (no date on label). 2 paratypes ££ (CUIC Type no. 2369.1 & 2369.2) as holotype [all examined].

Micropsectra groenlandica Andersen, 1937: 34 . Lectotype £ by present designation (ZMUC) Greenland, Ella island, Ulvesø, St. 656, 17.vii.1935, F. S. Andersen. 5 paralectotypes: 1£, 1$, 1 Pex as lectotype; 2 L as lectotype, except Rundsø, 20.v.1934 [all examined]. Brundin (1947 as M. bidentata, 1949 ), Lindeberg (1970), Reiss (1968b) distribution and ecology. syn. nov.

Micropsectra utonaitertia Sasa, 1988: 21 . Holotype £ (NSMT, Sasa collection A125: 50) Japan, Hokkaido, Lake Utonai , 13.vi.1986, M. Sasa [examined]. syn. nov.

Additional material examined

1£ ( ZMUC), Faroe Islands, Eysterøy, Ejdevand, 12.v.1926; 1£ as previous, except Thorshavn, Sanatoriet Kryger, 5.vii.1926. Norway ( ZMBN): 6 LP££, 1 LP, 2 LP$$, 1 P$ & 1 LPex, Hordaland, Vaksdal, Ekse, 26.iv.1979, E. Willassen, 2,££, as, previous, except, terskelbasseng, 27.v.-3.vi.1988, T. Andersen; 7 P££, 4 P$$, 4 Pex & 5 L as previous, except 24.viii.1986, 6.ix.1987, 11.vii.1988, vii.1988, 24.vii.1985, 10.viii.1988, 13.vii.1988, 3.v.1989, Ø. A. Schnell; 2 L as previous except 9.v.1989, J. Håvardstun; 2 P & 2 P££ as previous except Bergovatn, 5.vi.1990, Ø. A. Schnell; 2 P££ & 4 Pex as previous except Askjelldalsvatn, 15.viii.1989, Ø. A. Schnell; 1£, Hordaland, Bergen, Håkonshellavegen 84, 1988, Ø. A. Schnell; 2 P££, Møre og Romsdal, Gjemnes, Litlevatn, 29.vi.1995, T. Schnell; 4 P££, Oppland, Valdres, Øvre Heimdalsvatn, 21–22.vi.1981, E. Willassen; 4 Pex, Oppland, Vågå, Nedre Sjodalsvatn, 14.vi.1989, Ø. A. Schnell; 1 P£, Sogn og Fjordane, Luster, Vigdøla, 30.vii.1987, G. A. Halvorsen; 2 L & 2 Pex, Sogn og Fjordane, Laerdal, Hallingskeidelv/Kvevatn, 30.viii.1971, Steine & Mossestad; 1£ (no. To33), Vest Agder, Vennesla, Skjerkedalsbekken at Åmdal, 6.vii.2001, T. Ekrem; 5££ ( VM), Norway, Oppland, Dovre, Atnaelv, Dørålseter, MT, 2.vii.1986 & 8.vii.1986, K. Aagaard & O. Hanssen; 9££ as previous, except at Skranglehaugan 8.vii.1986, 18.vii.1986, 26.vii.1986, 1.viii.1986, 9.viii.1986, 16.viii.1986; 1£ ( VM), Norway, Hedmark, Storelvdal, Atnaelv, Solbakken, MT, 17.vi.1986, K. Aagaard & O. Hanssen; 2££ as previous, except Storbekken, 7.viii.1988 & 15.viii.1988; 2££ as previous, except Folldal, Atnaelv,Vollen, 18.vi.1986; 2££ ( VM), Norway, Sør Trøndelag, Oppdal, Kongsvoll, Blesbekken, emergence trap, 17.vii.1979 & 9.viii.1982, J. O. Solem; 7££ ( VM) Nord Trøndelag, Høylandet, Skiftesåa, 11.vi.1986, 30.vii.1986, 13.viii.1986, 27.viii.1986, 3.ix.1986, K. Aagaard & O. Hanssen; 1£ as previous, except emergence trap, 17.vii.1988; 1£ ( VM), Norway, Møre og Romsdal, Rauma, Raudstøl, MT, 20.v.1992; 1£ as previous, except Skiri, 27.v.1995; 6££ as previous, except Fiva, 9.v.1992, 9.viii.1992, 12.vi.1995, 5.viii.1995, 24.viii.1995, 20.ix.1995. 1£ ( ZSM), Germany, Baden-Württemberg, Bodensee, Süssenmühle, ix.1962, F. Reiss; 1£ ( ZSM) Sweden, Lappland, Abisko, Torneträsk, 13.viii.1973, F. Reiss; 4££ ( ZSM) Sweden, Jämtland, Järpen, Kallsjön, 1.VI., George; 1£ ( ZSM), Austria, Niederösterreich, Gebhartsteich, 8.v.1978, H. Malicky; 2££ ( ZSM), Russia, Kamschatka, Kurilskoe Lake, 1.viii.1997, T. Travina; 1£ ( MHNL) Luxembourg, Oesling, E Holzthum, Bleesquelle (helocrene spring no. LUX qu 20, emergence trap (E2), 20.iv.1999, I. Schrankel; 1£ ( WG), Poland, Masuria, Mala Guja, 25.iv.1999, M. Sadowska; 1£ ( WG), Poland, Kashubia, Mirachowo, 16.iv.1998, W. Gilka.

Diagnostic characters

Micropsectra logani can be separated from other species in the atrofasciata group by the following combination of characters: Adult male with AR c. 1.2; frontal tubercles minute to very small; anal point well developed, apically very thin and pointed, knob between crests absent, microtrichia between crests present; superior volsella with small to large field of microtrichia on stem, few long microtrichia ventrally on setiger; digitus long, digitiform, reaching beyond median margin of superior volsella; median volsella long, thin, reaching well beyond superior volsella, apically pointed, with about 25 dorsomedially directed, spoonshaped lamellae on distal 1/3, setiform lamellae along whole length medially. Pupa with short cephalic tubercles; thoracic horn long with comparatively short chaetae on at least distal 3/4; prealar tubercle prominent, triangular; small dorsal field of granulation on mid thorax; large rectangular, dorsal, unpigmented area on posterior half of thorax; strong spines in patches on tergite III and on tergite IV (in the longitudinal, lateral extensions); spinules and points in patches on tergite V; shagreen in patches on tergite VI; patches on tergite VI of smaller size than patches on tergites IV–V; microtrichia sometimes present between spine patches on tergite III; dorsolateral comb of segment VII narrow with 4 (5) well separated, equally long, marginal teeth. Larva with small, triangular spur on antennal pedestal; antennal segment 1 c. 200 µm long; comparatively high AR (c. 2.0) and LOR (c. 4.2); labral seta SII and clypeal seta S3 simple; MVR about 0.9.

Description

Adult male. Measurements and ratios in Table 1.

Coloration. Body and legs brown with darker pedicels, vittae on mesonotum, postnotum, median anepisternum II, preepisternum and epimeron II; scutellum light brown, halteres pale.

Head. Antenna with 13 flagellomeres. Frontal tubercles present as minute dots or small (c. 6 µm); temporal setae in 1 row; palpomere 3 with 2–5 sensilla clavata in subapical pit.

Thorax as in Figure 3D .

Wing. Subcosta and media bare, brachiolum with 2–3 setae, squama bare.

Legs. Pulvilli minute to small. Fore tibia with small scale, 15–37, 25 µm long spur; middle and hind tibial combs c. 20 µm long; middle tarsomere Ta 1 with 4–7, 5 sensilla chaetica; Ta 5 thicker than Ta 4 in all legs.

Hypopygium ( Fig. 12A, B ). Anal tergite with tergite bands separate, posteriorly directed, reaching crests of anal point; 5–8, 6 median tergite setae placed on an elevated hump anterior to anal point base; 7–14, 11 ventral apical setae. Anal point comparatively long, with low slightly curved anal crests, apex thin, pointed; knob between crests absent; microtrichia between crests present; relatively large microtrichia free area at base. Superior volsella roundish with 8–10, 9 dorsal and 2–3, 2 median setae on setiger, 1 strong seta on stem; small to large field of dorsal microtrichia on stem and few long microtrichae ventrally on setiger. Digitus long, digitiform, reaching beyond median margin of superior volsella. Median volsella comparatively long, thin, pointed, with medially directed setiform and spoon-shaped lamellae, c. 25 spoon-shaped lamellae on distal half; stem reaching well beyond superior volsella. Inferior volsella with low dorsoapical swelling, bearing numerous distal setae. Inner margin of gonocoxite with 3–4 strong setae.

Pupa. Coloration: pupal exuviae brownish with dark brown apodemes; cephalothorax, TVIII and anal lobe darker; large, rectangular pigment-free area dorsally in posterior half of thorax. Measurements in Table 2.

Cephalothorax ( Fig. 12C, D ). Cephalic tubercle present, small; pedicel sheath tubercle absent. Thoracic horn fairly long with numerous comparatively short chaetae on at least distal 3/4; precorneals arranged in triangular pattern, the 2 anteriormost setae situated closer to each other than to the third, anterior precorneal shorter than other two; 1 median antepronotal, 2 lateral antepronotals (1 sensillum basiconicum); 2 pairs of dorsocentrals, anterior pair shorter and weaker than posterior pair, setae of each pair equally strong. Very little granulation present along median suture line. Prealar tubercle present, usually triangular; nose of wing sheath weak.

Abdomen ( Fig. 12E, F ). TII almost covered by shagreen except mediolaterally and in one posteromedian oval patch; pedes spurii B on TII obvious; hook row about half as long as segment width. Spines of TIII in large, laterally curved patches in posterior half of tergite, shagreen extensively distributed lateral and anterior to spine patches, and often in between. Patches of TIV consisting of spinules in anterior patches with spines in longitudinal, lateral extensions which are slightly laterally curved posteriorly; shagreen present laterally to anterior and longitudinal patches. Patches of TV similar to those of TIV in shape, somewhat shorter, consisting only of spinules and points. Patches of TVI similar to those of TIV and TV in shape, or rather oval, consisting only of shagreen, patches distinctly shorter than patches on TIV–V. TVII and TVIII with weak anterolateral patches of shagreen, TVII sometimes with additional pair of oval median shagreen patches. Segment I with 3 D and 1 V setae; segment II with 3 D, 4 V, 2 L, 1 lateral semitaenia; segment III with 5 D, 4 V, 1 L, 2 lateral taenia; segment IV with 5 D, 4 V, 1–2 L, 1–2 lateral taeniae; segment V with 5 D, 4 V, 3 lateral taeniae; segment VI with 5 D, 4 V, 4 lateral taeniae; segment VII with 5 D, 4 V, 4 lateral taeniae; segment VIII with 1 dorsal taenia, 1 ventral taenia, 5 lateral taeniae; anal tergite with 1 dorsal taenia. Two pairs of small sensorial setae medially on TII–VII; 1 pair of Osetae present anteriorly on sternites II–VII. Anal lobe with evenly convex lateral margins, fringe with about 450–500 µm long taeniae in 1 row. Posterolateral comb of segment VIII ( Fig. 12G ) narrow, with all marginal teeth equally long.

Larva. Head capsule well sclerotized and dark brown. Live individuals were not available for examination, but Andersen (1937) describes them as pink. Total length 9 mm ( Andersen, 1937). Measurements and ratios in Table 3.

Head ( Fig. 12H–L ). AR about 2.0; antennal pedestal with short triangular spur; antenna with segments 1– 2 well sclerotized, segments 3–5 pigmented, antennal seta placed at about half length of antennal segment 1; Lauterborn organs small, on pedestals; LOR about 4.2; SII, some chaetae, chaetulae and S3 all simple, some chaetae pectinate; mentum with well developed lateral notches on somewhat pale median tooth; ventromental plates evenly curved with obvious striation along whole length; premandible with 2 robust teeth, inner tooth broader, well developed brush; mandible with pecten mandibularis slightly convex; postoccipital plate well developed, subtriangular.

Body. Anterior prolegs with long, simple spines; hind prolegs with c. 50 simple hooks in two rows; L2 simple, long; anal segment with 4 anal tubules; supraanal seta c. 140 µm long; procercus with one short and one long (c. 200 µm) dorsal seta, with 2 short and 4 long anal setae (n = 2).

Remarks

Examination of the type material and the original descriptions of M. logani , M. groenlandica and M. utonaitertia ( Johannsen, 1928; Andersen, 1937; Sasa, 1988) revealed that the three species are synonymous. A lectotype for M. groenlandica is hereby designated to stabilize nomenclature. Micropsectra logani apparently is quite widespread in the Holarctic region; it has been recorded throughout Europe, from the Far East of Russia, the Faroe Islands, Scandinavia, and from Greenland, Utah, Alaska, Montana, Colorado, New Mexico, Pennsylvania and the Yukon Territory in the Nearctic region (J. E. Sublette, pers comm.). In Scandinavia, the species appears to inhabit lakes and slow-flowing waters, including streams, whereas in central Europe it is recorded from the profundal of lakes and coldwater springs only (see Reiss, 1968a). Flying midges have been recorded from late April to early October, and it is probable that M. logani has more than one generation per year in southern Scandinavia and central Europe.

DNA of the specimen from Vennesla has been isolated and will also be used in future molecular systematic analyses.

Figures

Figure 3. Morphology of species in the atrofasciata species group. A, wing (Micropsectra atrofasciata). B, head (M. atrofasciata). C, fore, mid and hind tibiae (M. atrofasciata). D, thorax (M. logani).

Figure 12. Micropsectra logani. A, hypopygium. B, superior, median and inferior volsellae. C, pupal thorax. D, pupal frontal apotome. E, pupal abdominal segments II–VI, dorsal. F, pupal abdominal segments VIII–IX. G, posterolateral combs of pupal segment VIII. H, larval antenna. I, larval premandible. J, larval mandible. K, postoccipital plate of larval head capsule. L, larval mentum, ventomental plates and setae submenti.