20 



AMERICAN MUSEUM (HIDE LEAFLETS 



future fly, lie directed downward and backward in the median line, 

 forming a "keel" just beneath the thorax. The legs are bent at the 

 knee-joints and lie pressed against the thorax on each side, then they 

 turn backward and terminate in S-shaped curves under the fore part of 

 the abdomen. They are partly concealed by the wings, which hang, 

 cramped in their wing-cases, closely pressed against the body on each 

 side of the thorax. Arising from the anterior third of the thorax in 

 front of the attachment of the wings, are the respiratory tubes terminating 

 in funnel-like expansions which spread out on the surface of the water 

 when the pupa is in the ordinary position of rest. In respect to the posi- 

 tion of its respiratory openings, the pupa differs decidedly from its 



HEAD 



THORAX 



ABDOMEN 



PADDLES 



MOUTH PARTS 



HALTER 

 Wl NG CASE 



LEGS 



A NTEN NA 



FIG 14 THE YOUNG PUPA OF ANOPHELES 



The abdomen of the emerging pupa is straight or with a slight upward 

 curve. The strong downward abdominal flexure of the older pupa 

 becomes established a few horns later. .Magnification 12 diameters. 



predecessor, the larva, which has its siphon near the end of the abdo- 

 men. Like the larva, it is easily destroyed by anything which interferes 

 with its free access to the air. Curving backward from the head, above 

 the legs and in front of the wings, are the two antenna'. Below the 

 origin of the antenna- lie the two palps, with sharply S-shaped flexures. 

 The duration of the pupal stage is usually from two to four days, but 



it may, under unfavorable conditions of temperature, be 

 Duration of . ' . , , . , , , , , , 



Pi Life prolonged to weeks. Un the other nana, the threatening 



dangerof a drought or the presence of a disagreeable sub- 

 stance in the water, such as the phinotas oil used for destroying mos- 

 quitoes, may very much hasten the emergence of the fly. 



The pupa represents that period in the metamorphosis of the insect 



