20 BULLETIN 597, U. S. DEPARTMENT OF AGRICULTURE. 



Questioning the fate of pupae if buried, a lot consisting of larvae 

 that had moved near to the surface before pupating were replaced in 

 moist loam to a depth of 5 inches. The adults had no difficulty 

 in penetrating this soil, as 29 emerged normally from 32 pupae. 

 A lot of 15 larvae buried 4 inches under black loam and fresh horse 

 manure produced 14 pupae, many of which were located near the 

 surface. Lachnosterna larvae were present and during their develop- 

 ment kept the soil well pulverized. Of the 14 pupae, 8 produced 

 normal adults. 



The experiments cited in Table III, with the exception of the 

 lot of puparia eaten by a field mouse, show that the greater emer- 

 gence percentage occurred when larvae were placed upon grass sod. 

 By this method sufficient moisture was supplied, and at the same time 

 the movement of the larvae to the roots of the grass protected the 

 pupae from excessive heat. In one lot 32 adults emerged from 35 

 pupae, and in another, under similar conditions, 38 adults emerged 

 from 42 pupae. 



It is also noted from other experiments that excessive moisture 

 or dryness is less favorable for the metamorphosis. 



EFFECT OF HEAT ON LARVAE AND PUP^. 



Doubtless numerous larvae and pupae are subjected to heat, in 

 barren places, when dropping from work horses driven upon the 

 roads. This may not be confined to the heat of the sun, for horses 

 standing in stalls may drop larvae which are placed with the manure 

 in piles that generate heat. The results of some tests are given in 

 Table IV. 



