The Influence of Fatty Acids on Cold Hardiness of Eogystia Hippophaecolus Larvae

BACKGROUND: Larvae of the Cossidae family moth Eogystia hippophaecolus bore into and overwinter in the roots of sea buckthorn, which damages this plant in China. OBJECTIVE: The primary aims of the current study were to investigate the effects of fatty acids on cold hardness in overwintering larvae. MATERIALS AND METHODS: The supercooling point (SCP), low temperature mortality and fatty acid composition of different overwintering larvae were assessed. RESULTS: E. hippophaecolus larvae could survive for a long time at temperatures far below the SCP. Saturated fatty acids became less abundant as overwintering proceeded, while unsaturated fatty acids did the opposite. C10:0, C16:1, C16:0, C18:0, C20:0, C20:5, C22:0 and C24:0 fatty acids showed significant seasonal variation during the overwintering period. CONCLUSION: E. hippophaecolus is "freezing-tolerant" and cold hardiness is enhanced by increasing fatty acid unsaturation and degrading medium- and long-chain fatty acids and eicosapentaenoic acid.