OBSERVATIONS ON THE CH^TOTAXY OF 

 CALLIPHORINAE.* 



By Phineas W. Whiting. 

 LUCILIA. 



In his "Synopsis of the CalHphorinse (Diptera) of the 

 United States" (Zool. Bull. 1899, Vol. 11, No. 6), Garry de 

 Neuville Hough defines our species of Lucilia as follows: 



"Two postacrosticals. Front of male linear, of female one-third as wide as the 

 head; abdomen unicolorous. cazsar L. 



"Front of male not linear, at narrowest part about one-eighth as wide as the head; 

 front of female about one-fourth as wide as the head; abdomen not unicolor- 

 ous, first segment and hind margins of second and third blackish, contrasting 

 strongly with the remainder pilatei nov. sp. [Hough] 



"Three postacrostalis. Palpi black; front of male very narrow, that of female 

 about one-third as wide as the head; abdomen with two stout marginal 

 macrochsetas on the second abdominal segment. syl varum Meig. 



"Palpi yellow; front of male varies from one-eighth to one-sixth as wide as the 

 head, that of female about one-third as wide as the head; second abdominal 

 segment without marginal macrochastse. sericata Meig." 



Moreover, he says, "The chastotaxy is invariable for each 

 species except for an occasional evident deformity, and it 

 differs in the different species only in the number of achrostical 

 bristles." 



Observations w^ere made on this subfamily during the past 

 season and especial attention was given to the matter of cheeto- 

 taxy in Lucilia. Thus some estimate may be obtained of 

 the extent of deformity as it occurs in nature. Female flies 

 of this genus, moreover, were obtained alive and set in cages 

 containing fish, in order that their offspring might be obtained 

 for the purpose of studying the range of variation in the progeny 

 of the separate females. Each family probably represents 

 the offspring of several males as copulation is frequent. The 

 bristles studied comprise only the achrosticals and the dorso- 

 centrals posterior to the transverse suture of the thorax, with 

 the exception that in L. sylvarum the marginal bristles on the 

 second abdominal segment were recorded as they showed 

 considerable divergence from the normal condition recorded by 

 Hough and are regarded as a specific character. 



*Contributions from the Entomological Laboratory of the Bussey Institution, 

 Harvard University, No. 67. 



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