The Walnut Husk Fly (Rhagoletis Juglandis Cression)1

Abstract

"An infestation of this trypetid [sic] in English walntus in southern California has undoubtedly existed for several years though the correct identity of the insect concerned was not known until the beginning of the 1928 season. It appears to be a potentially serous pest of English walnust causing the most injury to the later ripening thick-husked commercial varieties. The nature of the injury is described. Notes on life history studies are given with a brief discussion of possible control."