T
108 BRITISH BLOOD-SUCKING FLIES BRACHYCERA -TABANIDAE 109
the male ot cordiger the present species is distinguished hv having the antennae
cinnamon-coloured, instead of black at the base, and from the male oiglaucopis
by Its dull frontal triangle, ^>rrall also states that " the black hairs on the
upper part of the side-cheeks near the base of the antennae distinguish T.
viacuhcornis m both sexes from all its allies."
This species is on the wing in June and July, and is very common in the
south ot England, though Goife (1931, p. 86) regards it as " not nearly so
abundant, nor so widely spread as T. broviiusr \>rrall (1909, p. 413) recorded
It from Perthshire (Rannoch), apparently the only record beyond the^ Midlands,
and Goffe (1931, p. 86) mentioned that maculicornis had not yet appeared in
the taunal lists of either Cornwall or the Isle of Wight ; Thornley (1933, P- 62),
ILG. 42.—T. maculicorriis ZfiXX. Head.
however, points out that it is
recorded in the Victoria County
History of Cornwall (1906) from
Middle Lynter, i. vi. 1900.
On the Continent )7iaculicor?tis
occurs in north and central
Europe (" from Scandinavia to the
Tyrol " according to A-'errall).
Males of this species were taken
by Jones (1922, p. 40) and Goffe
(1935, P- 105) notes that the habits
are similar to those of T. bromius
Lundbeck (1907, p. 132) found a larva of this species " in boggy soil," and
Its pupation period was nineteen days, while Stammer (1924, p. 123), during
September and October found larvae " m rotting vegetation removed from the
River Ryck and piled in heaps on its banks." The latter author does not
beheve that the heaps represent the original habitat of the larvae. " Owing
to the character of the stream," he writes, " which resembles a canal with
steep banks and deep water, it is scarcely to be supposed that the larvae came
from the Ryck itself; and that they did so is also rendered unlikely by the fact
that I did not find any of the larvae in heaps situated upon a dry and somewhat
more elevated spot. On the other hand, I succeeded in obtaining several
additional specimens from the moss covering the wet low-lying meadows. I
am therefore inclined to assume that the larvae were originally living in this moss,
and that they then migrated into the heaps of vegetable matter and iiourished
there in consequence of the very abundant fauna. Larvae of Anthomyiidae
Chironomidae, Psychodidae, Ephydridae, Stratiomyiidae, Cecidomyiidae, and
beetles, besides mites and other creatures developed therein."
Tabanus bromius Linnaeus
(Fig. 43 and Plate 33)
This species, at least in the south of England, is the commonest British
Tabanus. The large, conspicuous, and sharply defined yellowish spots on
the abdomen give it quite a distinctive appearance, which can be confused only
with glaucopis, a species at once recognised by its isolated upper callus and
shining frontal triangle. Except for a more noticeable amount of pale coloration
at the sides of the base of the abdomen in the male, the two sexes are closely
similar. While the form of T. bromius shown in pi. 33 would seem to be not
uncommon in this country, and to be the form normally met with on the
Continent, in England it is more usual to find the reddish abdominal side
coloration more distinct.
The eyes in the male have an upper area of conspicuously enlarged facets,
and in both sexes have a single purple band. Brauer (1880, p. 188) describes
the eyes of the female as " sometimes lighter, sometimes darker green, shimmering
red . . . with one purple band." Goffe (1932 p. 16) records the capture
of two females of this species with the eye-band scarcely visible.
In the Museum collection the males vary in length from 13-5 to 15-5 mm.
and the females from 13 to 16 mm.
In England T. bromius is on the wing from June to August, and Goffe
(1931, p. 81) says it " seems to occur in every suitable situation in almost every
southern county." Like aiitumnalis, T. bromius is a southern species, and
is rare beyond the Midlands,
and unknown in Scotland. It
is found throughout Europe,
and eastward to Afghanistan.
Goffe (193s, p. 103) notes
that the males of broviius are
"undoubtedly the most difficult
to capture " when visiting
water, and corroborates the
experience of Jones (1922,
p. 40) of the swiftness of their
1 ^ J I descent and ret urn. FIG. 4S.—T. bromius Linn. 2.
Head.
Lundbeck (1907, p. 128) mentions the finding of a larva of this species in a
lake—a somewhat curious experience in view of the statements by various other
authors mentioned below—while the late Mr. Holland of the Oxford University
Museum, found a pupa in sand at St. Helens, Isle of \\'ight, on July 7th, 1899
(Verrall, 1909, p. 410).
Beling (1875) writes : " The larvae live by choice in the turf-clad soil of
meadows, grass-plots, the green strips round the edges of fields, and similar
places. They are frequently turned up and brought to light by the activities
of moles, and during the spring and summer of 1874 I often found them, and
later the pupae also, in fresh mole-hills, especially in meadows. As a rule the
duration of the pupal stage is between a fortnight and three weeks, and the
jxM'fect insects make their appearance from the second half of the month of
June onwards. The larvae feed by sucking out earthworms, the larvae and
pupae of other insects, and their own kind if all else be lacking, but in case of
need they can apparently subsist on nothing but earth, in which I have kept
them for months at a time until they pupated." Mr. Goffe (in correspondence)
writes : " I think the main reason for T. bromius being so widely spread is
that the larvae can feed in almost anything from earth to water."