REPORT OF THE STATE ENTOMOLOGIST I912 75 



QUEEN BLOW FLY 

 Phormia regina Meign. 



A study of the queen blow fly was undertaken for the purpose of 

 obtaining data which could be used as a basis for estimating the 

 period a human body had lain exposed to the elements in midsum- 

 mer. We found so little definite in available literature concerning 

 the biology of the blow fly, and especially the duration of the various 

 stages, that it was necessary to work out the life history before 

 attempting a moderately accurate estimate of the age of certain 

 maggots taken from the corpse. It was supposed at the inception 

 of the work that the so-called common blow fly, C a 1 1 i p h o r a 

 erythrocephala Meign. was the more prevalent species at 

 Nassau, the place where these investigations were conducted. Our 

 experiments resulted in rearing only the above named species, 

 kindly determined by Mr C. W. Johnson of the Boston Society of 

 Natural History, and a flesh fly, which latter will be discussed 

 subsequently. There seems to be comparatively little known con- 

 cerning this blow fly. Mr G. N. Hough records this species as 

 very common everywhere in this country, though it appears to be 

 rare in Europe. Aldrich lists it from such widely separated local- 

 ities as New Jersey, Montreal and New Mexico. It is worthy of 

 note in this connection that Mr J. H. Paine reared this species in 

 larger numbers from city garbage in Boston, Mass., than either 

 the common house fly or the bluebottle fly, Lucilia sericata, 

 though it should be noted that Phormia was present in fewer lots 

 and that by far the most came from one lot, concerning which there 

 seems to be no special record except that no house flies were 

 obtained and the material was collected in August. 



Methods. The head of a recently killed calf was procured about 

 6 p. m. August 1st, and on account of the low temperature pre- 

 vailing for that season, no ova were deposited upon the head that 

 evening. It was exposed throughout the next day which was mod- 

 erately cool, in a place protected from larger animals, and at 

 5 p. m. there were hundreds of eggs about the mouth and in the 

 hair at the base of the horns. Several flies were observed in the 

 immediate vicinity. This was the source of the material upon 

 which the following notes are based, since flying insects were ex- 

 cluded after this primary infestation. Observations were made and 

 material collected about y a. m. and 6 p. m. during most of the 



