赤松毛虫越冬幼虫生化物质变化与抗寒性的关系

昆虫的抗寒性与其体内生化物质的种类、含量密切相关。测定了赤松毛虫(Dendrolimusspectabilis)越冬幼虫体内和血淋巴内抗寒物质含量的变化,结果表明,血淋巴内小分子碳水化合物总量1月份为10月份的3.8倍,其中以葡萄糖、海藻糖和山梨醇增加幅度较大,依次为10月份的10.08倍、2.84倍、7.44倍。3月份有较大幅度的下降,虫体内糖原含量下降了56.5%。越冬期苏氨酸、丝氨酸、谷氨酸、丙氨酸、胱氨酸增加幅度较大,分别比越冬前增加了493.8%、433.7%、474.2%、21.5%和47.1%,甘氨酸、天门冬氨酸、蛋氨酸、亮氨酸、酪氨酸、苯丙氨酸、组氨酸、精氨酸、脯氨酸含量则有较大幅度的降低。越冬幼虫体内脂肪含量下降,蛋白质含量上升。应用蛋白质垂直平板电泳法对糖蛋白进行电泳分析发现糖蛋白含量增加,为越冬前的300%。综合分析认为赤松毛虫越冬幼虫体内抗寒物质系统为小分子碳水化合物类(山梨醇、海藻糖、葡萄糖)-糖蛋白-氨基酸类(丙氨酸、苏氨酸、谷氨酸等)。该系统可随生态条件的改变而变化。

The biochemical mechanism of cold-hardiness in overwintering larva of Dend-rolimus spectabilis Butler(Lepidoptera: Lasiocampidae)

One of the most striking characteristics of overwintering insects is their capacity to accumulate high concentrations of low-molecular-weight polyols and sugars, and that can greatly affect the cold-hardiness of overwintering insects. Dendrolimus spectabilis is one of the most destructive pests attacking pine tree, it overwinters as larva in the cold winter in Shandong Province. In the present study, experiments were carried out to examine the relationship between the content of bio chemical substances and cold-hardiness of overwintering larva of D. spectabilis.Results showed that the content of low-molecular-weight carbohydrates in the larval haemolymph in January was about 3.8 times of that in October, especially the content of glucose, trehalose and sorbitol increased about 908%, 184%, and 644%, respectively, while the glocogen decreased about 56.5%.Compared with the larva before winter period, the content of threonine , serine, glutamicnine, alanine, cystine in the overwintering larva increased about 493.75%,433.70%,474.15%,21.45% and 47.08%, respectively. However,the content of glycine, asparticacid, methionine, leucine, phenylalanine, tyrosine, histidine,arginine,proline decreased remarkably. During the over-wintering period, the content of fat in over-wintering larva decreased, but the protein increased, and the diagrams of glyprotein electrophor-esis analysis showed that the content of glycoprotein increased about 200% than that in the larva before overwinter. The results in this paper indicated that the main antifreezes in the overwintering larva of D. spectabilis included low-molecular weight carbohydrates (sorbitol, trehalose, glucose)-glycoprotein-amino acid (alanine, threonine etc.).