FLIES. 



413 



FIG. 517. Chironomus oceanus, male, head of female 

 beneath, enlarged. 



bers, producing a buzzing or humming noise like that of a distant waterfall, and audible 

 for a considerable distance. While at rest they usually raise their fore legs in the 

 air, and keep them in constant vibration. 

 Chironomus oceanus was observed by Dr. 

 Packard in multitudes living on floating 

 sea-weed and eel-grass in Salem Harbor. 

 According to Professor S. I. Smith, the 

 larvae of numerous species are not uncom- 

 mon in dredgings from very great depths 

 in Lake Superior, reaching nearly one 

 thousand feet below the surface. Aquatic 

 larvae may be frequently met with in stand- 

 ing water, often extremely delicate little 

 creatures, sometimes so very transparent 

 as to be hardly distinguishable from the 

 water in which they live. 



The species of Ceratopogon are usually 

 not aquatic. Some are very minute, and when able to bite are often very troublesome. 

 An extremely small species, called by fishermen midges, is common in the White 

 Mountains and neighboring regions, and together with the black fly, has called forth 

 many an imprecation from the luckless tourist. 



It will be hardly necessary to describe the family of CULICID^E, or Mosquitoes, as 

 they are familiar enough to all. They will be at once distinguished from all others 

 with long antennae by the presence of an elongate proboscis, slender and firm ; the 

 wings lack the vein on the posterior border, which is delicately fringed with hair ; in 

 many the whole surface of the wings is hairy. About one hundred and fifty species 

 have been described. 



The name mosquito is the Spanish and Portuguese diminutive of mosca, a fly, and 

 has been often applied to the Simulidae, but in general only species of this family are 

 known under this term. 



Almost every one has noticed in pools or cisterns of standing-water a delicate little 

 creature actively moving about with a jerking motion, and in many localities known 



under the name of ' wigglers.' They are mosquito 

 larvae, and feed upon decaying matter, voracious 

 little scavengers of what would otherwise often be 

 miasmatic substances. The eggs are deposited by 

 the female, with the aid of her hind feet, in delicate 

 little boat-shaped masses upon the surface of the 

 water. They are packed side by side with the smaller 

 end uppermost, forming a gently concave mass that 

 readily floats about. They hatch in a few days, when 

 the larvae escape from the lower end into the water ; 

 here they grow rapidly, at times moving quickly 



about, at other times resting quietly near the surface, and breathing through the stig- 

 matic tube at the tail. This tube has at its end a fringe of hairs, which serve to close 



O 



the opening when under water, and to suspend the larva from the surface when 

 breathing. The larvas in species of Culex swim with the head downward, while those 

 of Corethra and Anopheles move about with the head horizontal. 



. 518. Transformations of Culex 

 pipiens j a, larva; b, pupa. 



