English: Ecological investigation on the rice leaf-minor, Agromyza oryzella : 7 The Sawing density of rice in the nurseries and the population density of leaf-minors
Japanese: 稲葉潜蠅の發生機構に關する生態學的研究 : 第 7 報苗代播種密度並びに様式と葉潜蠅の發生密度  )