13 



Family 



CHIRONOMID/E 



Midges. 



Although these insects are by far the smallest of all blood-sucking 

 flies, the pertinacity and blood-thirstiness of some species of midges is 

 such that, in the British Islands at any rate, they cause much more 

 discomfort and annoyance to human beings than the species of any 

 other family mentioned in this book ; and, during the spring and 

 summer months, in the evening hours when they are most active, their 

 presence often constitutes a serious drawback to life in the country. 

 Occasionally midges occur locally in such numbers as to amount to a 

 veritable plague. With reference to a species, at present un- 

 determined, which abounds in Scotland, Colonel Yerbury writes : 

 " This insect is a great pest in the Highlands ; it collects in large 

 numbers on one's knickerbocker stockings, and the bites cause the 

 skin to look as if covered with a severe rash." It should be pointed out 

 that the majority of the species of midges are perfectly harmless. The 

 British blood-sucking forms belong to the genus Ceratopogon {sens, lat.), 

 which is distributed throughout the world, and of which we have some 

 fifty indigenous species. Only a few of these, however, are known to 

 suck blood, and the habit is confined to the female sex. As in the 

 gnats or mosquitoes (Culicida^), the wings when at rest are carried flat, 

 closed one over the other like the blades of a pair of scissors ; in 

 many species (as in the two selected for illustration) they are minutely 

 hairy, and they are often speckled with greyish brown blotches. The 

 sexes can be distinguished owing to the possession by the males of 

 tufted antennae and a more elongated shape. As a general rule the 

 larvae of naked-winged species of Ceratopogon are aquatic, those of 

 hairy-winged species terrestrial. The eggs of aquatic species are laid 

 in floating alga;, in star-shaped clusters containing from one hundred 

 to one hundred and fifty. The larva; of these species are whitish 

 worm-like creatures, with long narrow heads ; they live in the masses 

 of Confervse floating on the surface of stagnant pools and ditches, and 

 progress with a serpentine motion. The larvae of the hair\'-winged 



