24 BRITISPI BLOOD-SUCKING FLIES
The life-history of T. richiardii is of exceptional interest. The larvae and
pupae, like those of all other mosquitoes, live in water and breathe air, but
instead of rising to the surface to breathe they obtain their oxygen from the
roots of water-plants. The adaptations of the larvae for this purpose are
highly remarkable ; organs of attachment and piercing, which include a sawlike
structure, are developed from the valves at the tip of the breathing-tube,
and in addition to this, special air-storage-sacks are formed as appendages to the
tracheal trunks. The pupae also have their breathing horns specially modified
for piercing the plant rootlets, so that, like the larvae, they can remain in the
mud at the bottom of the water, only rising to the surface when the adult fly
is ready to hatch. There is probabl y only one generation in the year ; the flies
may be found from May to September, but are most abundant in July when
the main brood is hatched. The eggs are fastened together in the form of
rafts which float on the surface of the water ; the larvae when quite young
breathe at the surface, but soon descend and take up their positions on the
plant roots. The winter is passed in the larval state ; the young larvae remain
half-grown until the spring, when they complete their development.
Females of this species attack man readily, and where they are abundant
may be very troublesome ; they bite at night, and are rarely active till it is
almost or quite dark ; they not infrequently enter houses, and according to
Shute are likely to enter bedrooms during the night and to depart, gorged with
the blood of the occupants, before daybreak, with the result that other harmless
insects (such, perhaps, as Culex pipiens) are liable to become objects of
suspicion.
REFERENCES
EDWARDS, F. W. and JAMES, S. P. 1925. British Mosquitoes and their Control.
British Museum (Natural History). Economic Series No. 4A, 28 pp.
EDWARDS, F. W. 1920. The British Chaoborinae and Dixinae. Ent. Mo. Mag. (3),
6 1 , 264-270.
EDWARDS, F. W. 1921. A new species of Dixa from Sussex. Ent. Mo. Mag. (3),
7, 57-
EDWARDS, F. W. 1930. The British species of Chaoborus and Mochlonyx. Ent.
Mo. Mag. , 66, 163-165.
JoBLiNG, B. 1938. On two subspecies of Culex pipiens L. Trans. R. Ent. Soc.
London, 87, 193-216.
MARLATT, C. L . 1933. Report of Chief of Bureau of Entomology, Washington, D.C.
MARSHALL, J. F. and STALEY, J. 1937. Some notes regarding the morphological
and biological differentiation of Ct/Zex pipiens Linnaeus and Culex molestus
Forskal. Proc. R. Ent. Soc. (A), 12, 17-26.
MARSHALL, J. F. 1938. The British Mosquitoes. Briti.sh Museum (Nat. Hist.).
341 pp., 20 pis. [Gives full account with extensive bibliography.]
MARTINI, E. 1929-30. Culicidae. In Idndner's " Die Fliegen der Palaarkt.
Region."
PEUS, F. 1934. Zur Kenntnis der Larven und Puppen der Chaoborinae (Corethrinae
auct.) Arch. HydrobioL, 27, 641-668.
SHUTE, P. G. 1933. The life-history and habits of British Mosquitoes in relation
to their control by antilarval operations. J. Trop. Med. Hyg., 36, 83-88.
N E M A T O C E R A — C E R A T O P O G O N I D A E 25
Family
CERATOPOGONIDAE
(BITING MIDGES ; in North America known as PUNKLES or sometimes as
SANDFLIES.)
THE small flies which comprise this family were, until somewhat recently,
included with other non-biting flies in the larger family Chironomidae, the two
groups having many features in common ; the separation, however, is now
generally agreed upon and is both convenient and natural, the biting midges
having in fact rather more in common with the Simuliidae than with the
Chironomidae. As in the case of the Simuliidae, the females of all Ceratopogonidae
possess well-developed biting mouth-parts, including a pair of
toothed mandibles which work on the " scissors " principle ; such structures
are absent in the Chironomidae. The flies are all small or minute in size
usually of slender build, with the wings superposed over the back when at rest.
The males (which do not bite) resemble those of Culicidae and Chironomidae
and differ from those of Simuliidae in having bushy antennae. The wingvenation
is of a simplified type and on a rather uniform plan throughout the
family (as described briefly below under the genus Culicoides).
In Britain nearly 150 species of Ceratopogonidae are known to exist.
Fortunately the great majority of these do not use their mandibles for the
purpose of obtaining animal blood. Nearly half of them are known or believed
to subsist by capturing and devouring other small insects ; many more feed, so
far as known, mainly or solely upon flower juices. Of those which do suck
blood some members of the genus Forcipomyia attack only smooth, juicy
caterpillars, others pierce the wing-veins of butterflies, moths, lace-wing flies
or dragon-flies ; others, in America, attack stick insects ; one European species
of the genus Atrichopogon confines its diet to the blood of oil-beetles and
another species of the same genus in South India has been found sucking mealybugs.
Probably future research will reveal a still greater variety of feedinghabits
in the family. The habit of sucking the blood of mammals or birds has
only been definitely established as occurring in three genera of this family
Cuhcotdes, Lasiohelea, and Leptoconops (including the allied Holoconops) •
ot these only the first-named occurs in Britain.
The Ceratopogonidae are almost as diverse in their life-histories as in the
teedmg-habits of the adults, and there is great variation even among members
ot the same genus.
Genus CULICOIDES Latreille*
The members of this genus are distinguished from others of the family by
a number of small details of structure which are for the most part only appreciable
under a fairly high magnification. Of these the following are the most
important : (i) the presence near the front margin of the thorax of two small
For an account of the genitalia of the British species see Appendix A (p. 129).