J. E. M. Mellor 87 



higher and falls sooner and lower than that of a tightly packed one. The 

 maxinunn temperature in a loosely packed heap is reached about the 

 third day. 



13. The deeper portions of a tightly packed heap remain at a higher 

 temperature for a longer time and then fall suddenly. 



14. Creosote oil mixture should be sprayed " Incremenlalli/" and 

 not merely on the surface. 



15. It is doubtful whether 1 gallon to the ton of manure is sufficient 

 to prevent flics from emerging. Four gallons proved enough, but it was 

 not possible to carry out sufficient experiments to determine the precise 

 minimum quantity necessary to prohibit developement of flies. 



16. Incremental applications of creosote oil mixture and of borax 

 lower the general temperature of the heap. The temperature never rises 

 as high and takes much longer to fall as low. This is probably due to 

 fermentation being delayed. 



17. If a heap is sprayed on the surface with creosote oil mixture, 

 M. dotnestica larvae are able to live between the sprayed surface and the 

 intense heat below. The temperature 1 inch below the surface of the 

 manure, when that of the heap is near its maximum, is about 41° C. — a 

 temperature of which Howlett wrote "It is improbable that they 

 (larvae) could live long at anything over 41° C. (about 106° F.) " — see 

 Copeman (1916). 



18. It is useless to bury larvae-infested material at a depth of 4 feet 

 in clay, loam or sand, whether loose or rammed down, as the majority 

 of flies will emerge. 



19. About 90 per cent, of the larvae, so buried, climbed to within 

 1 foot of the surface before pupating. 



20. The following parasites were bred — from two pupae of Hydrotaea 

 denlijies two Ichneumons {Afrodectes tenebricosus Grav. $, A. exilis Hal. c^), 

 from a third pupa of H. dentipes a Figifid; from pupa of Lonchaea 

 vaginalis or R. radicum an Ichneunwn; fiom two Calliphora-like pupae 

 one and two Figitids respectively; and from three pupae of Eristalis 

 tenax 72 (10$, 62(5*), 24 and 8 (5 c?, 3$), Proclotrypids — Diapria cornea, 

 Fabre, were extracted dead. 



REFERENCES. 



BisHopp, r. C, Dove, W. E. and Parman, D. C. (1915). Notes on certain points of 



economic importance in the biologj' of the House-fly. Journ. Ecotioin. Enloinol. 



viii, pp. 54-71. 



Copeman, S. ]\I. (1913). Hibernation of House-Fhes. Reports to the Local Government 



Board on Public Health and Medical Subjects, New Series, No. 85, pp. 14-19. 



(1916). Prevention of Fly-Breeding in Horse Manure. The Lancet, June 10th, 



1916. 



