We investigated colour discrimination and learning in adult males of the nocturnal cotton bollworm moth, Helicoverpa armigera, under a dim light condition. The naive moths preferred blue and discriminated the innately preferred blue from several shades of grey, indicating that the moths have colour vision. After being trained for 2 days to take nectar at a yellow disc, an innately non-preferred colour, moths learned to select yellow over blue. The choice distribution between yellow and blue changed significantly from that of naive moths. However, the dual-choice distribution of the trained moths was not significantly biased to yellow: the preference for blue is robust. We also tried to train moths to grey, which was not successful. The limited ability to learn colours suggests that H. armigera may not strongly rely on colours when searching for flowers in the field, although they have the basic property of colour vision.
The authors declare no competing or financial interests.
Designed the experiments: A.S., K.A. and M.K. Performed the experiments: A.S. Analysed the data: A.S. Wrote the paper: A.S. and K.A., with suggestions from M.K.
This work was supported by a National Agriculture and Food Research Organization (NARO) grant for SIP ‘Technologies for creating next generation agriculture, forestry, and fisheries’, and by a Japan Society for the Promotion of Science (JSPS) Kakenhi for Scientific Research A (26251036 to K.A.).
- Received August 9, 2016.
- Accepted October 2, 2016.
- © 2016. Published by The Company of Biologists Ltd