Technical Series, No. 22. 



U. S. DEPARTMENT OF AGRICULTURE. 

 bxjrkj^xj oi^^ entom:olog-y. 



L. 0. HOWARD, Entomologist and Chief of Bureau. 



THE STRUCTURE OF CERTAIN DIPTEROUS 



LARA7E WITH PARTICULAR REFERENCE 



TO THOSE IN HUMAN FOODS. 



BY 

 NATHAN BANKS, 



Assistant. 



Issued Januaky 10, 1912. 



WASIIINGl'ON: 



GOVERNMENT PRINTING OFFICE, 



1912. 



