Micropsectra longicrista, Stur & Ekrem, 2006

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 : 199-200

MICROPSECTRA LONGICRISTA SP. NOV.

Holotype £ ( ZSM), Germany, Bavaria, Bodensee, Sipplingen, 8.v.1965, F. Reiss: 15 paratypes: 1£ as holotype except 31.iii.1966; 2££ ( ZSM), no locality, 7.iii.1967, F. Reiss; 1£ ( ZSM), Germany, Schleswig- Holstein, Ostholstein, Vierersee-Quelle, 1.v.1969, F. Reiss; 1£ ( ZSM), Germany, Bavaria, Bodensee, Hödinger Tobel, 14.viii.1964, F. Reiss; 8££ (6 MGDL, 2 ZMBN), Luxembourg, Gutland, SE Dellen, Waldrand, rheohelocrene spring no. LUXqu21, emergence trap (E5), 27.vii.1999, 24.viii.1999, 7.ix.1999, 21.ix.1999, 5.x.1999, 19.x.1999 & 3.xi.1999, I. Schrankel; 1£ Luxembourg, Gutland, SW Kopstal, rheocrene spring no. LUXqu24, emergence trap (E7), 19.x.1999, I. Schrankel; 1£ ( ZSM) Algerie, Tikjda, 15.viii.1941, Clastrier.

Etymology

From Latin longus (long) and crista (crest); to be treated as a noun in apposition, and referring to the long anal crests on the adult male hypopygium.

Diagnostic characters

Micropsectra longicrista can be separated from other species in the atrofasciata group by the following combination of characters: adult male with frontal tubercles small; antennal ratio c. 0.8; pulvilli small, reaching base of claws; anal point well developed, long, apically blunt, knob between long crests minute; superior volsella with large field of microtrichia on stem, setiger large, roundish, with dorsoapical ‘nose’, several long microtrichia in small field ventrally on setiger anterior to base of digitus, no apparent wrinkles ventroapically on setiger; digitus thin, somewhat thicker in the middle, apex blunt, reaching well beyond median margin of superior volsella; median volsella long and moderately thick, tip reaching past posterior margin of superior volsella, evenly tapered in distal half, with about 30 dorsomedially directed spoon-shaped lamellae on distal half, setiform lamellae along whole length medially.

Description

Adult male. Measurements and ratios in Table 1.

Coloration: Thorax with light greenish ground colour, slightly darker scutum; abdomen completely pale greenish; eyes brown, antenna yellowish.

Head. Antenna with 13 flagellomeres. Frontal tubercles present, small (7–12, 10 µm long); temporal setae in one row; palpomere three with 4–7 sensilla clavata in bundle.

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

Legs. Pulvilli small, reaching base of claws. Fore tibia with small scale, spur 25–28 µm long; middle and hind tibial combs 18–20 µm and 22–28, 24 µm long, respectively; middle tarsomere Ta 1 with 2–4 sensilla chaetica.

Hypopygium ( Fig. 13A–C ). Anal tergite with tergite bands separate, posteriorly directed, reaching crests of anal point; 4–6 median tergite setae placed on an elevated hump anterior to anal point base; 12–16, 14 ventral apical setae. Anal point long, robust, with long, slightly curved anal crests, apex long, apically blunt; knob between crests minute; comparatively small microtrichia-free area around base. Setiger of superior volsella roundish with apical ‘nose’, 6–9, 7 dorsal and 2–3 median setae on setiger, 1 strong seta on stem; large field of dorsal microtrichia on stem and several long microtrichae ventrally on setiger, anterior to base of digitus; ventroapically wrinkles absent from setiger. Digitus, long, reaching well beyond median margin of superior volsella, apically pointed. Median volsella long, moderately thick, evenly tapered in distal half, with medially directed setiform and spoon-shaped lamellae, c. 30 spoon-shaped lamellae on distal half; stem reaching beyond posterior margin of superior volsella. Inferior volsella slightly club-shaped with small median and dorsoapical swelling, bearing numerous distal setae. Inner margin of gonocoxite with 3–4 strong setae.

Pupa and larva unknown.

Remarks

Micropsectra longicrista has been collected only from coldwater springs in Germany and Luxemburg. The localities in Luxemburg are rheohelocrene and rheocrene springs, respectively, which both are quite cold, evenly flowing and shaded by deciduous trees, but somewhat different in their water chemistry. The site LUXqu21 is in contrast to LUXqu25 not influenced by limestone, and the water conductivity is low (63 µS/cm compared to 621 µS/cm) ( Gerecke et al., 2005). The surrounding vegetation at LUXqu21 is mainly oak (beech at LUXqu25), and this spring is somewhat disturbed by wild boars ( Gerecke et al., 2005).

Figures

Figure 13. Micropsectra longicrista sp. nov. A, hypopygium. B, anal point, semilateral view. C, superior, median and inferior volsellae.