Ohgushi, R., Mori, T., Itayama, T., & Yamaguchi, T. 1964 On the altitudinal variation of age distribution and development of ovaries of overwintering arrowhead scale, Prontaspis yanonensis Kuwana at Mt. Unzen, Nagasaki Prefecture.. Japanese Journal of Applied Entomology and Zoology 8(1): 24-25.

Notes: Altitudinal distribution and variation of such biological characters as age distribution, mortality in each stage and the development of ovaries of adult females of overwintering populations of arrowhead scale, Prontaspis yanonensis collected from nine stations. The altitudinal distribution of arrowhead scale ranged from the seashore to 280m above sea level. On the upper part of this range, it was observed that the population density of arrowhead scale became lower and other scales such as Pinaspis strachani and Lepidosaphes gloverii appeared instead.