Abstract
The action spectrum for breaking diapause in the oak silkworm, Antheraea pernyi Guer., and the codling moth, Laspeyresia pomonella (L.), was determined from 400 to 700 nm with a wedge-interference spectrograph. Insects were exposed to ten hours of white light, followed by six hours of spectral light each day for 45 days. The portion of the spectrum between 400 and 500 nm was found to be the most effective in terminating diapause. Diapause was broken for both insects with energy levels as low as 0.02 muw/cm(2).