31 
Order IV. Diptera.  (Flies.) 
Plate XXIII (left side). 
The Two-winged Flies are of moderate or small | cis. They come into houses, and sing at night, 
size, and their metamorphoses are complete. Their | when their blood-sucking propensities make them 
bodies are sometimes long and slender, and some- | very troublesome. Their larve live in water, 
times short and broad. The head is divided from In the genus Culex, the proboscis is long, 
the thorax by a short stalk, and the thorax is fre- | and armed with sharp bristles in the female. The 
quently separated from the abdomen in the same | antennae are generally plumose, and the body and 
manner. The antenna may be long and slender, | legs are long. 
and bare or plumose; but they are more frequently Fig. a. Culex pipiens, the Common Gnat, is 
short and only three-jointed, the last joint forming | pale brown with darker markings, and is about half 
a scale to which a simple or tufted bristle is attached. | an inch Ieng. It is a great pest in damp neighbour- 
They have large palpi, a proboscis adapted for suck- | hoods, or in hot wet summers, but is not very 
ing; large eyes, and sometimes, but not always, ocelli. abundant in dry places, or in dry summers. The 
The legs are moderately long, or, especially the hind | mosquitoes which are so troublesome in hot coun- 
legs, very long. Only the fore wings are developed, | tries belong to the same genus. Volatile oils are 
the hind wings, which are called poisers, being | useful to prevent their attacks, as long as the scent 
rudimentary. remains; and if the bites are bathed immediately 
The eggs are laid on decaying substances, or | with sal ammoniac, the irritation is soothed, and 
in water, or upon other animals, and soon become | swelling prevented. 
soft footless and often even headless maggots, which Family Il. Tipulidae. The Crane Flies are 
afterwards change into motionless pupe, when the | slender insects with a retractile proboscis and droop- 
larva-skin is not thrown off, but contracts and | ing palpi. The antenne are bristly or filiform, many- 
thickens into the covering of the pupa. jointed, and sometimes bushy. The legs are very 
long. The larvae live in damp earth. 
Fig. b. Fachyrrhina pratensis has a_ shining 
black thorax, and the abdomen is black, with yellow 
spots on the sides. The larve live in the soil of 
meadows, and do much mischief by destroying the 
roots of grass, and the flies are also found in mea- 
dows at the end of summer. 
The species of 7zpu/a have long and slender legs, 
bodies and antenne, 
and prominent palpi. 
Tipula oleracea, which 
isone ofthe commonest, 
has a grey thorax lined 
with brown, a reddish 
brown abdomen, and 
pale brownish wings 
with the front edge red- 
dish. The larve live in 
the ground fromautumn 
to spring, change to 
pupe in June, and 
emerge as flies in a 
few weeks, when the 
pupz push themselves 
half out of the ground. 
There are some larger 
species with brown 
blotches on the wings. 
Family III. Cecidomyide, The Gall-gnats have 
a long slender body, and short, but comparatively 
broad wings, with but few nervures. The flies are 
usually small and very delicate, and the larve of 
some species produce excrescences called galls on 
plants, and others injure them in different ways. 
Cecidomyia destructor, the Hessian Fly, was 
thus named in America, because it was supposed to 
have been introduced into America during the War 
of Independance by the Hessian troops. Be this as 
it may, it has been known as a very destructive 
insect during certain seasons both in America and 























































































Metamorphoses of Gnat (Culex pipiens). 
The Diptera are extremely numerous, and are 
often of very small size. Some produce galls, and 
the larvae of many species live in water. 

: Section I. Nematocera. in many parts of Europe, for many years; and its 
The antennz are long, and have at least six | appearance in England has lately been ascertained, 
joints. though many think that it has always been with us, 
Family I. Culicida. Slender flies with 4 jointed | but has not caused sufficient damage in this country 
palpi, bushy or bristly antenna, and a long probos- | to attract attention before. 


