【摘要】 5种地老虎越冬幼虫室内抗寒力测定结果表明:大地老虎、黄地老虎、三叉地老虎和警纹地老虎在-8℃±2下的致死中时间(LT₅₀)分别为28,30,33与36天,而小地老虎在0°C下的LT₅₀仅为8天.在室内经降温锻炼,可以提高上述大地老虎等4种越冬幼虫的抗寒力,但对小地老虎幼虫无效.降温锻炼后,前四种幼虫的过冷却点,分别从-9.9℃±2.8,-12.6℃±3.0,-7.6℃±2.0与-17.7℃±3.7下降到-16.0℃±3.7,-17.5℃±4.0,-17.4℃±5.7与-25.2℃±2.8.生化分析结果表明,小地老虎幼虫与其它4种地老虎幼虫相比,不能随着温度的下降而调节代谢机制,积累抗寒物质,在我国大部分地区,只能通过迁飞来回避低温的伤害.更多还原

【Abstract】 Four constant temperatures were used to investigate the role of low tempera-tures in triggering or modulating cold hardiness in cutworm larvae of Agrotis ypsiion,A.tokionis,A.segetum,A.trifurca and A.exclamationis.The lethal times for 50% mortalities（LT₅0）under treated low temperatures,supercooling points（SCP）and severalcryprotectants of these larvae were determined.The LT₅0 of A.ypsilon at 0℃,was 8 days.However,the LT₅0 of A.tokionis,A.segetum,A.Trifurca and A.exclamationis were 28,30,33,and 36 days respectively.The SCPof A.tokionis,A.trifurca,A.segetum and A.exclamationis were -15.98℃ -17.5"C,-17.41℃and -25.2℃ respectively,but the SCP of A.ypsilon only being -6.4℃,during the period ofacclimation.Except the larvae of A.ypsilon,other four species were easily adapted to low tempera-tures.High concentrations of sugars（especially glycogen and trehalose）,amino acids（es-pecially alanine and serine）and glycoproteines were induced by low temperatures.更多还原