40 BRITISH BLOOD-SUCKING FLIES
light reddish-brown tint, with the scutellum yellowish, and the size is smaller
than in C. fascipennis (average wing-length about 1-4 mm.). The male of
C. pallidicornis differs from C. fascipennis in the much less hairy wings, the
cubital fork being entirely bare or with only a very few hairs.
C. pallidicomis is apparently a common and widely distributed species in
Britain ; the British Museum collection includes examples from the following
c o u n t i e s :—DEVON, GLAMORGAN, SALOP, HERTS., WESTMORLAND, CUMBERLAND,
BUTE, CROMARTY. Specimens taken by the late Col. J. W . Yerbury
at Dingwall and Porthcawl were labelled " red-handed," and " troublesome
biter."
Culicoides odiatus Austen
This was described from two females taken in Palestine which are generally
similar to C. pallidicornis, but with the thorax very much darker brown, the
scutellum as dark as the remainder of the thorax. A female from SALOP
(Church Stretton), and a male from S. DEVON (Dartmouth), closely resemble the
Palestine type, and are provisionally noted here as perhaps C. odiatus, but they
may be merely dark specimens of C. pallidicornis.
Culicoides cubitalis sp. n.
This species is separated from C. fascipennis and its allies chiefly on characters
of the male genitalia, as described and figured in the appendix (p. 139).
Externally the male very much resembles C. fascipennis, and differs definitely
from C. pallidicornis in having the wing more hairy, with numerous hairs in
the cubital fork. The wing has two white patches on the front margin,
separated by the blackish spot on the radial cells as in other similar species,
but here the two spots are about equal in size and both fairly broad ; when the
wing is viewed obliquely against a dark background a faint pale streak can be
seen between the media and cubitus, and an indistinct pale area on each side
of the lower branch of the cubital fork, but there is no trace of pale spots
round the apex of the wing. The female of this species has not been identified
with certainty ; it is probably extremely similar to that of C. pallidicornis.
Male specimens, definitely identified as this species by study of mounts of
the genitalia, are in the British Museum from the following localities :—HERTS. :
Letchworth, viii. 18 (type); Radwell, vi, 18. NORTHUMBERLAND: Crag Lough,
viii. 23. ARRAN : Pirnmill and Catacol, vi. 19. CROMARTY : Dingwall, vil.
09. The species is probably as widely spread and common as C. pallidicornis.
Culicoides simulator sp. n
(Fig. 12)
In general appearance this species is somewhat intermediate between C.
pictipennis and C. truncorum, with both of which it agrees in having the thorax
uniformly dull brownish (with at most a faintly indicated median dark line),
the legs pale, and the wings greyish with pale markings. It further agrees
wdth C. truncorum, and differs from C. pictipennis in having the second radial
NEMATOCERA—CERATOPOGONIDAE 41
cell entirely dark and no pale spot in the base of the median fork. The main
external distinctions from C. truncorum are that the pale spots round the
apical margin of the wing are larger and more distinct—there is a well-defined
pale area before the lower branch of the cubital fork, and the thoracic hair is pale.
Apart from this the male genitalia (described and figured in the appendix) are
FIG. 12.—Culicoides simutaior sp. u. Wmg oi ^ from Oxford.
quite different from those of C. truncorum and resemble those of C. analis
more closely. For description of genitalia see p. 136.
Only three specimens of this species have been taken up to the present : a
male at Knebworth, HERTS., vi. 1922 (type), and a femal e at OXFORD, 12 vi. 15
{A. H. Hamni), and another female at Epsom, SURREY, 15 vii. 36 {B.Jobling).
In the female from Epsom the pale spots are much smaller than in the one
illustrated.
Culicoides truncorum sp. n.
The wing markings of this species will serve to distinguish it without much
difficulty from all others of the genus known in Britain except C. simulator.
As in C. fascipejinis and related species the wing is mainly greyish, with a
rather large whitish spot on the front margin before the radial cells and a smaller
one beyond them ; it differs from these species in having (in both sexes) illdefined
paler areas on the margin round the tip, between the tips of the veins ;
these pale areas are not large and are most easily seen when the wing is viewed
obliquely against a dark background ; the dark spot over the radial cells is
much less obvious than in C. fascipennis. The thorax is rather light dull
brownish in colour, clothed with dark hair, and entirely without markings ;
the legs are almost uniformly pale yellowish-brown. The wing in both sexes
IS clothed with hair on most of its surface, but the basal cell is bare, as usual.
The wing-length in the male is about 1 7 mm., in the female about 2-0 mm. For
description of genitalia see p. 139.
C. truncorimi is apparently an uncommon insect in Britain ; few specimens
have been obtained, and most of these have been reared from larvae The
records are as follows CAMBS. : Snailwell, vi. 07, 3 3 ? in British Museum,
includmg type c? (others in Mr. Collin's collection), reared from moist debris
collected from a very large hollow (not a water-hole) in a chestnut tree ( / E
Collin). HERTS.: Letchworth, vi. 17, I and vii. 18, I on window!
HANTS : Brockenhurst, v. 06, I C?, I ? reared from beech wood {D. Sharp).
The above records suggest that this species breeds normally in damp rotten