Influence of Food Plants on the Hibernating Physiology of the Cabbage Moth Mamestra Brassicae

• Katrin Jogar, Luule Metspalu, Kylli Hiiesaar, Anne Luik And Aare Kuusik
• Institute of Agricultural and Environmental Sciences, Estonian Agricultural University, 64 Kreutzwaldi St., 51014 Tartu, Estonia
• The Third International Conference onIPM Role in Integrated Crop management and Impacts on Environment and Agricultural Products. 26-29 November 2005, Giza, Egypt.

Abstract

To determine the influence of food plants on diapause intensity, larvae of the cabbage moth Mamestra brassicae were reared either on white cabbage (Brassica oleracea var. capitata f. alba), swede (Brassica napus var. napobrassica), collard (Brassica oleracea var. acephala), or onion (Allium cepa) at 20?C under 12 h light: 12 h dark (short daylength). There was a significant effect of host plant on larval survival and pupal mass, with the performance being lowest on onion. Pupae in the onion treatment also had a higher respiration rate and lost greater mass per day than those reared on collards. Furthermore, adults in the onion treatment emerged sooner than those on collards. We found no difference in the supercooling points of pupae reared on the different host plants. The results suggest that the difference in diapause intensity would, at least in part, account for the higher levels of overwintering mortality of pupae from larvae reared on non-cruciferous hosts under field conditions.