214 The Philippine Journal of Science isis 



they become hardened and prepared for flight. The fly does not 

 spend any time preening itself as is the case with some of the 

 Muscidse at this stage. The time prior to flight is spent, how- 

 ever, in a clearing process. This begins with a copious dis- 

 charge of meconium within three to five minutes after emerging. 

 At first the defecation is performed at least five times per minute, 

 then once per minute for a period of twelve minutes. At the 

 end of this time the excretions become more watery in char- 

 acter. In the meantime the fly walks about in a restless man- 

 ner, constantly vibrating the balancers and flapping its wings, 

 while the distended abdomen becomes reduced to more normal 

 proportions. 



The meconium, which is deposited in large quantities, is in 

 color pale brown, rapidly changing to amber, then becomes clear. 

 The primary, heavier excretion appears decidedly oily in nature, 

 when examined with the microscope. 



In from fourteen to twenty minutes, voluntary flight takes 

 place. This is at first tentative, the insect alighting upon the 

 floor about a meter distant. After a minute of rest, flight is 

 resumed, the fly escaping through the open window. 



The puparium left behind shows certain points of cleavage 

 which prove to be very constant. There is a dorsal slit on the 

 median line of the thorax which extends nearly the length of the 

 notum. Another slit extends midway across the orbital region 

 through the gena to the wing pouches. A third slit extends 

 between the two wing envelopes, and a slight one behind the 

 prothoracic spiracular tubercle. 



In the 32 emergences recorded, the males preceded the females 

 by an average of half a day. The males spent from three to 

 seven days in the pupal stage, averaging five and one-half days, 

 while this period required four to nine days with an average of 

 six days in the female flies. 



GENERAL DESCRIPTION OF THE IMAGO 



MALE 



The male is very distinct from the female, being smaller and 

 having a larger head and different color markings. 



The distinctly clavate palpi are shorter than in the female, 

 only two-thirds as long as the labium ; they are dirty white and 

 fringed with moderately long black hairs. 



The abdominal color markings take the form of a T of pale 

 cadmium yellow in a field of burnt sienna, bordered with pale 

 clay yellow. The area of the large facets of the eyes is colored 



