BRITISH BLOOD-SUCKI\-G FLIES
they apparently always have the lateral light patches very distinct, and coverinothree
segments.
The female bisigriatiis, particularly the darker form with the side-marcrins
practically absent, is one of the commonest of the species of Tabanns m this
country, though, except locally, it seems to be much less common on the
Continent. It is a woodland species, and is widespread in the south and
midlands irom May to August.
It is apparently to the males of this species that the remarks of Jones (19-^
p. 41) apply. He speaks of having, in the Xew Forest " on several occasions
in 1921, tound the males of Tabanus tropiais sitting on damp mud bv the
margins ot partially dned-up puddles," but adds that most specimens captured
m this position proved to be females (see also under T. solstitialis, p. 95).
Goite (1935, p. 106) has taken the males in large numbers in Tune-July over
water in the Xew Forest.
At Chantilly. not far from Paris, in 1914, Surcouf (1921, p. i8\ found
F I G . 27.—T. bisignaius Jaenn. 2. Head.
sevent3--six larvae of this species among a layer of fallen oak-leaves carpeting
the bottom of a shallow pond not more than a few centimetres deep In
captivity some of these larvae, which like those of other Tabanidae are carnivorous
and extremely voracious, devoured several Chironomid larvae bloodworms
"), and seemed to prefer them to Copepods, which are able to escape
more easily. In June, 1930, Mr. H. St.-J. K. Donisthorpe found several
iabanid pupae in a swan's nest at Windsor, and both sexes of T. bisignahis
were bred out.
Until recently the light form of this species was held to be the T tropicus
of Linnaeus, the commoner dark form being known as " tropicus bisignatus
Jaenn. , under which name it still appears in Continental works (e g Krober
1925, pp. 57, 72, and Seguy, 1926, p. 153). Collin (1932, p. 39), and late^
^oite (1935, P- 106), have put forward the view that the true T. tropicus
Linn. IS a diiferent, quite distinct species (see below, p. 96) The form
previously known as " T. tropicus " is thus left without a name, and Goife has
revived a suggestion of Verrall's (1909, p. 403) that it may be the Tabanu,
paga?ius of Fabricius, who described the species from " Henly " England
BRACHYCERA—TABANIDAE 93
Should this view be generally accepted the older name paganus will, of course,
take precedence. The typical paganus would be the form with light sidemargins,
the " T. tropicus " of Verrall, while the common dark form would
become T. paganus Fabr. var. bisignatus Jaenn.*
Tabanus montanus Meigen
(Fig. 28 and Plate 24)
In the male of this species the sides of the abdomen are always more or
less tawny; in the female such tawny markings may be absent. The
absence of a small tuft of black hair
on the crown of the head, behind
the ocellar tubercule is a useful distinguishing
mark in the male. This
sex shows an area of enlarged facets
in the upper part of the eye, but the
size of the larger facets varies somewhat
in different specimens, and the
line of demarcation between large
and small facets is not always very
conspicuous. Yxo.2Z.-T. montanus Head.
Brauer (1880, p. 144) describes the eye of the male in life as " green, with
three purple bands and red lower margin bordering the face," while of the female
he writes : " Eyes emerald green, with three linear carmine-red bands, the
middle one of which often does not reach the hinder margin of the eye ; upper
and lower margin emerald green." According to Colonel Yerbury, in notes
on specimens in the British Museum, the bands may be either one or three in
different individuals, and may be yellow, dark orange, chocolate or brown.
The specimens of this species in the Museum range in size from 12 to
14-5 mm. in the male, and from 12 to 15 mm. in the female.
In 1906, when the first " Illustrations of British Bloodsucking Flies " appeared,
Austen (1906, p. 39), wrote : " So far as regards the British fauna,
Th. montanus would appear to be essentially a Scotch and Irish species, since
the Museum collection includes no specimens from England or Wales." In
1935, however, Audcent (^1935, p. 90) was able to state that this species had
been recorded from Cheshire, Derbyshire, Glamorgan, Hampshire, and
Devonshire, and from Scottish and Irish localities, and to remark on its probable
occurrence in Northern England. This at once elicited a reply from Fordham
(193S, P- 114)1 ^^'ho gave several localities in Yorkshire and Lancashire, so
that the species is now shown to be widespread, if local, all over the British
Isles, except perhaps in the south-eastern counties.
As its name implies, this species is usually met with in mountainous or hilly
districts, where it appears to be common, at least locally, but it seems not to be
confined to such localities. Haines (1932, p. 40) took a number of specimens
* I have been unable to trace the type of T. paganus Fabr. Dr. Schröder tells me that it w.is
probably in the Kiel Museum, but if so, it has been destroyed by pests.
.••••js. t i f^