Twowinged Insects 



733 



Photo by W. P. Dando, F.Z.S., Regent's Park. 



HOUSE-FLY (MALE AND FEMALE). 



The larvse of the house-fly live in refuse, so do not thrive 

 where cleanliness abounds. 



blood which remains in the s-pot; but this is a trouble- 

 some task when one has several hundred punctures in 

 the course of a day [like Prince Siror, in one of Bulwer 

 Lytton's stories, who fell " pierced by five hundred 

 spears"]. I took the trouble to dissect specimens, to 

 ascertain the way in which the little pests operate. The 

 mouth consists of a pair of thick fleshy lips, and two 

 triangular horny lancets, answering to the upper lip and 

 tongue of other insects. This is applied closely to the 

 skin, a puncture is made with the lancets, and the blood 

 then sucked through between these into the oesophagus, 

 the circular spot which results coinciding with the 

 shape of the lips. In the course of a few days the red spots dry up, and the skin in time 

 becomes blackened with the endless number of discoloured punctures that are crowded together. 

 The irritation they produce is more acutely felt by some persons than others. I once travelled 

 with a middle-aged Portuguese who was laid up for three weeks from the attacks of Pium, his 

 legs being swelled to an enormous size, and the punctures aggravated into spreading sores." 



However, the traveller in Amazonia has one consolation : the great rivers which traverse 

 the forests are of three different colours ; and the black-water rivers so called from the dark 

 colour of the water, owing apparently to the amount of vegetable matter which they hold in 

 solution are never infested with mosquitoes. Probably the character of the water renders it 

 unsuitable to them for breeding purposes. 



The CRANE-FLIES, or DADDY-LONG-LEGS, are also very injurious insects, but in a different 

 manner, for their subterranean maggots feed on and destroy the roots of grass in the same 

 way as the grubs of the Cockchafers. They are insects of considerable size, with slender bodies, 

 terminating in a short, horny point (the ovipositor) in the female, and with long, slender legs, 

 which are liable to break off at the least touch. The commonest species has a grey body and 

 transparent wings ; but there is a larger one with the wings prettily variegated with brown, 

 and a smaller one in which there are yellow markings towards the end of the body. 



The more typical FLIES have usually shorter and broader wings, and thicker, shorter, and 



more hairy legs, than those just mentioned ; and the antennae have usually only three or four 



joints, and are often furnished with a long, slender bristle at or before the end of the last joint. 



As in the case of the Gnats and Crane-flies, so as regards the more typical Flies, we have 



only space to notice a few of the more important families. 



Some of the (TAD-FLIES are no larger than house-flies, but others are as large as wasps or 

 larger, with broader wings, and of a black, grey, or yellowish colour ; they frequent fields, and 

 settle on cattle, or on our clothes or hands. Some have transparent and others dark-coloured 

 wings, but they are all capable of inflicting a severe puncture, often sufficient to draw blood, 

 even in the case of the smaller species. 



The prettiest of the gad-flies are the GOLDEN-EYED FLIES. 

 They are black, with the abdomen more or less marked with 

 yellow ; and black, or black and transparent, wings. The eyes 

 are of a beautiful golden green, dotted and lined with purple. 

 They are moderately stout insects, about the third of an inch 

 long, and are not uncommon. Another insect, known as the 

 BLOOD-SUCKING EAIN-FLY, has a rather long arid slender body 

 for a gad-fly, and is nearly half an inch long. It is of a 

 lighter or darker grey, with reddish markings on the sides of 

 the abdomen in the male. The wings are greyish brown with 



Photo ly\l. P. Dando, F.Z.S., Regents Part.: ' J 



BLUE-BOTTLE FLY, OK BLOW-FLY. whitish dots, and & white mark towards the tip. Both these 

 These flies deposit their eggs on meat, w hen ' flies are vei T troublesome, the latter chiefly on the edges of 

 it becomes "fly-biown." woods or near water, especially in rainy weather. 



