Eight-hundred and forty-eight tobacco (Protoparce sexta (Johan.)) and tomato (P. quinquemaculata (Haw.)) hornworm moths were irradiated individually with energy bands, nominally 33 Angstroms wide, centered at 3129, 3341, 3654, 4047, 4358, 4916, 5461, and 5780 A. Tests were made in a light-tight, air conditioned chamber. An analysis of variance was used to determine differences in responses to treatments. A significant difference in response to waveband treatments was found in each moth group. Generally, responses to the four shorter wavelengths were greater than to the four longer. When considering all moths or all trapped moths, best responses were to 3129 and 3341 Angstroms and second best were to 3654 and 4047 Angstroms. Reared moths were more responsive to treatments than trapped moths. Greatest response was obtained from the reared male tobacco hornworm moths. Tomato hornworm moths were less responsive to treatments than tobacco hornworm moths. The female tomato hornworm moths 1rJere numerically, least responsive. Numerically, more responses were elicited from first exposures than from those received later. / Master of Science