Abstract

Sericultural practices in Japan underwent a scientization process during the nineteenth and early twentieth centuries. Within this context, nineteenth-century silk cocoon cultivators endeavoured to control indoor climates to better direct insect development; they also formed new strategies to prevent the spread of disease from one generation to the next. As sericulture gained popularity, various political, economic, and scientific interests converged as experts, bureaucrats, and industry leaders confronted a need to organize a multiplying number of cocoon-spinners strains. I trace how sericulturists and scientists sought to ‘improve’ cocoons used to manufacture silk threads, and relatedly, how they made practical use of cocoon spinners’ hereditary information discerned through scientific breeding experiments. I focus upon the cultivation of cocoons to show how efforts to coax greater uniformity among these objects had been especially encouraged by government and industry and led to standardizing practices and national sericultural infrastructure. This analytic perspective anchored to the cocoon additionally clarifies how improvement activities helped spur research opportunities for university-based genetic researchers distanced from industry. Scientific interest in mutations of these metamorphosing insects during the 1920s and 1930s became dually oriented toward a growing international field of genetics and Japanese sericulture. Subsequently, efforts to raise awareness about the need for organizing, exchanging, and preserving the genetic matter and information contained in mutants paved a new path that invited scientists to view cocoon-spinners as a resource for biological research.