HEREDITY OF BRISTLES IN THE COMMON 

 GREENBOTTLE FLY, LUCILIA SERICATA 

 MEIG. A STUDY OF FACTORS GOVERN- 

 ING DISTRIBUTION 1 



PHINEAS W. WHITING 

 Bussey Institution 



In a previous paper 2 I have given data showing that 

 variation in the number of posterior dorso-central and 

 acrostichal bristles of the common greenbottle fly, Lucilia 

 sericata Meig., is determined by hereditary factors. 

 Since the publication of that paper further evidence, 

 bearing upon the nature of the hereditary factors in- 

 volved, has been obtained. 



Two general conclusions from the work may be stated 

 as follows: 



1. Reduction in bristles tends to affect the males more 

 than the females, while additional bristles are found more 

 often in the females. 



2. Distribution as well as number of bristles is heredi- 

 tary. 



On account of very high mortality in these flies it has 

 been impossible to make selections as might seem desir- 

 able. The results, however, furnish considerable evi- 

 dence for the foregoing conclusions, and throw light, I 

 believe, on the nature of factors governing distribution, 

 such as spotting factors, for example. 



Fig. 1 shows the mesonotum of Lucilia sericata with 

 chaetotaxy normal. The bristles considered in my work 

 are those lettered A, B, C, the post-acrostichals, and A', 

 B', C, the post-dorso-centrals. 



ttaivertity, Xo' 7 t ° mologlcal Laborator > of the y 



2 Whiting, P. W., "Observations on the Chaetotaxy of Calliphorinse," 

 Annals of the Entomological Society of America, VI, 2. 



339 



