Key to World species
of Chaetolonchaea
(After McAlpine 1982)
1. Entire body dulled by silver-grey pollinosity, eye hairs relatively short …….2
-- Body mainly subshining black, eye hairs long to short ….. 3
2.
Prescutellar area (between base of scutellum and transverse row of strong
scutal setae) with 1-3 setulae, antennal flagellomere approx. twice as long as
wide, male frons silvery pruinose (NE China)
…. pruinosa Morge
--
Prescutellar area bare, antennal flagellomere 1.25 – 1.4 times as long as wide,
male frons dull greyish pruinose (NE China) …
pellicula Morge
3. Orbital
plate with one or more setulae, eye hairs very long in both sexes,
katepisternum usually with 3 strong setae, hind femur usually with 4-5
outstanding anteroventral setae, large, coarsely bristled, densely long
setulose species (Europe) …….. dasyops (Meigen)
-- Orbital plate bare, eye hairs short at least
in females, usually with 2 katepisternal setae, hind femur with 1-2
anteroventral setae, usually smaller body with sparser and shorter setulae …….
4
4. Eye hairs
long, in male about as long as the width of the parafacial, in female
distinctly longer than the width of an ommatidium, easily seen …….. 5
-- Eye hairs short, in male much shorter than
the width of the parafacial, in female not or scarcely longer than the width of
an ommatidium, sparse and scarcely discernable
……. 6
- Wing
narrow, scarcely 1/3 as wide as it is long, wing membrane and fringes of
calypteres brownish-yellow, abdomen relatively slender (Russian far east) ……. gracilis Czerny
-- Wing broad, distinctly more than 1/3 as wide
as long, wing membrane and fringes of calypteres pale yellow (N. America) ….. americana
McAlpine
6. Frontal
carina unusually broad, at narrowest point between bases of antennae fully 2/3
as wide as parafacial, prescutellar area with approx. 6-7 setulae, wing
membrane orange-yellow especially at base (Europe) ……. brevipilosa Czerny
-- Frontal carina narrow at narrowest point
between bases of antennae scarcely 1/3 as wide as parafacial, prescutellar area
with approx. 2-4 setulae, wing membrane creamy yellow (Europe) …………… pallipennis
(Zetterstedt)