and Life History of Psychoda sexpundata. 2§5 



warmer season than that in which 

 my observations were made. 



Systematic position of Psychoda 

 sexpundata. 



The long antennas of many similar 

 joints, and the slender flexible maxil- 

 lary palps, at once place Psychoda 

 among the Nemoccra. The absence 

 of ocelli, the short and fleshy mouth- 

 parts, the bead-like joints of the 

 antenna 3 , the prominent genital 

 forceps, and the structure of the 

 wings characterize the Psychodidae. 

 The pattern of the wing-veins suffi- 

 ciently indicates the genus Psychoda, 

 while the black tufts on the margin 

 of the wing distinguish the species 

 sexpundata. 



External features of the Larva 



(Fig. 1). 

 The body consists of a head and 

 eleven segments. Each of the first 

 three segments is imperfectly 

 divided into two annuli, and each 

 of the remaining ones into three. 

 The last segment is the only one 

 which is extensively modified. The 

 integument is covered with a thick 

 layer of chitin, which is in places 

 thickened into special protective 

 plates. In general there is a thin 

 membrane between the adjacent 

 segments, and a longitudinal thin 

 strip separating the dorsal from the 

 ventral armour. The cuticle of a 

 larva which has recently shed its 

 skin is white and transparent, and 

 such larvae can be easily studied 

 alive as transparent objects. As 

 time goes on, however, the cuticle 

 thickens, and a larva which has a 

 moult in prospect becomes com- 



ft 



A 



d 



G 



Fig. 1 ( x 20). 

 Dorsal view of larva. 



