Revison of Palaearctic species of the genus Chersodromia Walk. (Diptera, Empididae)
Chvála M.
Acta Entomologica Musei Nationalis Pragae 39: 55-138, 1977
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Abstract: The present paper is a revision of the Palaearctic species of the genus
Chersodromia Walker, 1849 based on the study of the type specimens and
considerable documentary material from various European Museums and
Institutions. The Chersodromia species are coastal species, penetrating only
rarely inland. Altogether 24 species are known recently from the Palaearctic
region but this number is far from definite, the finding of many new species may
be anticipated especially along South European, North African and Asiatic
coasts. 34 species are known at the present time in the world, the genus is
mostly Holarctic in distribution, 8 species are Nearctic, 1 species is known
from Panama and 1 from the Hawaii. All species are separated into four natural
groups of species, viz., hirta-group, cursitans-group, speculifera-group and
incana-group. The Palaearctic species represent, from the zoogeographical point
of view, 3 provisional specific isolated groups which may be roughly
characterized as North European (7 species), South European (14 specie&)
and North East Asiatic (3 species). The Nearctic fauna forms
2 zoogeographically isolated groups of species, the first is distributed along
the Atlantic coast (3 species), the second one along the Pacific coast
(5 species). Two species are described as new to science, C. hackmani sp.n.
from Kamtchatka and C. flavipes sp.n. from Spain. A lectotype is designated for
C. difficilis Lundbeck, 1910; C. gratiosa Becker, 1908; C. beckeri Melander,
1928; and for C. colliniana Frey, 1936; the holotype of C. amaura (Becker, 1902)
is identified. Female of C. nigrosetosa Chvála, 1970 is described for the
first time.
Key words: Diptera, Empididae, revision, Palaearctic, catalogue, zoogeography, key to species, new species, Kamtshatka, Russia, Far East, Spain,