CHAPTER I. 



Family CHIRONOMID^. 

 Midges. 



Subfamily CERATOPOGONIN/E. 



Plate I., figs. 1-3. 



The Chironomida3, or true Midges, are slender gnat-like flies of 

 small or sometimes minute size ; they are distinguishable from 

 Mosquitoes (Culicidae), to which the larger and perfectly harmless 

 forms present a strong resemblance and for which they are often 

 mistaken, by, among other characters, the veins of the wings not 

 being clothed with scales, by the absence of the costal vein from 

 the hind margin of the wing, and by the habit of the perfect insects 

 of waving their front legs in the air when at rest. Although blood- 

 sucking Midges are among the most troublesome of all the flies 

 with which this volume is concerned, both on account of the 

 pertinacity of the insects themselves and of the irritating effects of 

 their bites, the blood-sucking habit is exceptional in the family 

 Chironomidae, and is confined to the females of a relatively small 

 number of species, all of which belong to the subfamily 

 Ceratopogonince. The blood-sucking Midges, which are represented 

 throughout the world, are by far the smallest of all blood-sucking 

 flies, their average length being from 1 to 2 mm. They are frequently 

 met with in swarms, and when not flying the ^vings are invariably 

 carried closed flat one over the other Uke the blades of a pair of 

 scissors, as in the Tsetse-flies. Little need be said here with 

 reference to structural characters : the antennae generally consist 

 in both sexes of fourteen joints, six or eight of which in the male 

 usually bear long hair, forming a plume ; the palpi are composed 

 of four or flve, rarely of three joints ; in the wings the second 

 longitudinal vein is wanting, the first and third veins are stouter 

 than the remainder and situate close to the anterior margin, 



B 



