Influence of low temperature and photoperiod on the substances in Locusta migratoria tibetensis

In order to investigate the adaption of Locusta migratoria tibetensis to the. environment, this paper adopted the experiments with full light exposure (24L/OD), total. darkness (OL/24D), and low temperature (5 °C) to study the effects of low temperature and illumination stress on the cold-resistant substances of L. migratoria tibetensis. The results showed that the fat content of L. migratoria tibetensis reached 11.8%, which was the highest under the condition of full light exposure (24L/OD) without low temperature stress. The fat content of body in low temperature and darkness treatment (OL/24D) was 4.7%, which was the lowest. The trehalose, mannitol and sorbitol contents of locust after low temperature stress were significantly higher than that of locust without the same stress. Glycogen content of locust treated by full light exposure without low temperature 'stress was the highest (6.40 mg . g-1). Besides, low temperature and darkness treatment stimulated the accumulation of alanine, glutamic acid, lysine