19 IS] Leaf Eating Crane- Fly 79 



Duration of Pupal Period. — In the breeding-cages, the period 

 of pupation varied from six to ten days. Mueggenberg, quoted 

 by Alexander (loc. cit., p. 106) states that for Liogma glabrata 

 the pupal period persists for 11 to 12 days, and it will be prob- 

 ably found that in individual cases the period is as long for our 

 species under natural conditions in the field. 



Emergence of Adult. — The pupal skin spHts in T-shaped 

 fashion on the dorsal region of the thorax. The adult thorax 

 and head are the first to appear followed by the wings. After a 

 series of efforts, punctuated by periods of quiescence, in which 

 the prevailing movement is a straining forward of the free parts 

 of the body, the legs are unsheathed from their closely-investing 

 cases and the adult emerges. At first, it is of a pale-green color 

 which gradually gives place to the yellow and black of the 

 mature animal. 



The process of emerging occupies one and a half to two 

 hours, and after it is completed, the adult rests for a short time 

 until the cuticle hardens and the wings expand. A tiny drop 

 of green fluid is voided from the alimentary canal soon after 

 the exit is made. 



The pupal skin is never at any time completely uncovered 

 and when sloughed off by the adult, still retains the adhering 

 last larval skin. In some cases where the pup£e had been gently 

 withdrawn from the last larval skin and placed on the floor 

 of the breeding-cages, the adults experienced great difficulty in 

 emerging, and a few, indeed, did not succeed in liberating 

 themselves at all. It is evident, therefore, that the fast adher- 

 ence of the last larval skin to the leaf-surface and its close 

 investment of the pupa, serves a useful function in facihtating 

 the successful emergence of the adult. 



PROPORTION OF SEXES. ' 



From 108 adults reared from larvae collected in the field, 91 

 were females and the remaining 17 males. Thus the percentages 

 of females and males reared were respectively 84.2% and 15.8%. 



On June 1, 96 individuals were captured by sweeping the 

 food-plant, T. grandis, at Westholme, when the males were 

 found to be in the ascendant in the proportion of 60.2% to 

 39.8%. On this date many were taken in copula. 



