【作者】 陈永杰；

【导师】 孙绪艮；

【作者基本信息】 山东农业大学 ， 森林保护学， 2004， 硕士

【摘要】 桑螟(Diaphania pyloalis Walker),属鳞翅目(Lepidoptera),螟蛾科(Pyralidae)。是桑园的主要害虫之一。其分布广泛,国内各蚕区均有发生,山东以临沂、泰安两地发生较重。为准确预测来年的虫口密度及其生长发育规律,确立防治措施提供依据,本文对其抗寒性和有效积温进行了研究。1 桑螟越冬幼虫的死亡率桑螟越冬幼虫的死亡率以枯枝落叶中最高,为87.62%;树缝的阴面和阳面都在75%左右,居中;室内越冬幼虫死亡率最低,为55%。死亡率的变化与环境温度的变化密切相关,越冬结束时的寒流对桑螟越冬幼虫的死亡率有较大影响。2 越冬幼虫过冷却点和冰点 桑螟越冬幼虫从9月份到翌年4月份的过冷却点分别为-7.16℃、-9.36℃、-11.32℃、-18.38℃、-18.88℃、-19.69℃、-15.46℃、-8.24℃。冰点分别为-5.62℃、-7.46℃、-8.52℃、-9.77℃、-10.74℃、-11.78℃、-9.35℃、-5.44℃。 过冷却点和冰点的变化与温度的变化一致,相对于环境温度的变化有一定的滞后性。过冷却点比冰点的变化幅度更大。3 越冬幼虫体内含水量的变化采用60℃恒温烘干法测定越冬幼虫体内水分含量。从9月份到翌年4月份,虫体含水率分别为:72.59%、70.03%、68.36%、67.92%、67.57%、66.90%、68.76%、69.79%。表明在越冬期间,越冬幼虫体内含水量与当月的外界环境温度变化呈正相关,相对于温度的变化表现出一定的滞后性。4 越冬幼虫体内小分子碳水化合物含量的变化 从越冬初期到越冬期,桑螟幼虫体内小分子碳水化合物含量均有所上升,其中海藻糖、果糖、甘露醇、葡萄糖、山梨醇的含量分别上升了53%、66%、52%、28%、21%。小分子碳水化合物的总量由54.22mg/g上升到78.64mg/g,增加45%。而幼虫血淋巴内的碳水化合物含量变化不同,其中,海藻糖、果糖、甘露醇、山梨醇的含量分别增加了62%、714.3%、315%、346%。而乳糖和葡萄糖的含量分别减少了98%和34%;小分子碳水化合物<WP=7>的总量由36.02mg/g上升到45.89mg/g,上升27.4%。海藻糖、果糖、甘露醇、山梨醇为桑螟幼虫的重要抗寒物质。5 越冬幼虫体内氨基酸含量变化血淋巴中的丝氨酸,丙氨酸,酪氨酸,赖氨酸,精氨酸5种氨基酸含量随着越冬期的到来而升高,随着越冬结束而降低,越冬前期到越冬期,分别增加了84.75%,783.06%,110.41%,26.07%,23.56%。越冬后期含量分别减少了85.21%,76.42%,51.79%,21.56%,28.4%。虫体中丙氨酸和丝氨酸的含量变化也符合这一趋势。 6 越冬幼虫体内甘油和蛋白质含量的变化虫体内甘油的含量对桑螟越冬幼虫的抗寒能力的提高具有重要作用。从越冬初期进入越冬期,虫体内甘油含量由3.85 mg/ml(9月份)上升到10.82 mg/ml(1月份),增加181%;越冬幼虫虫体蛋白质含量由越冬前期(10月份)的33.61%减少到越冬期(1月份)的23.49%;而血淋巴蛋白质含量由越冬前期(9月份)的3.184 mg/ml上升到越冬期(1月份)的6.089 mg/ml,增加91.23%。虫体和血淋巴中的蛋白质可能通过某些途径转化,血淋巴中的甘油和蛋白质含量对桑螟幼虫抗寒性的提高有重要作用。7 越冬幼虫体内脂肪含量变化从越冬初期进入越冬期后,越冬幼虫体内游离脂肪由22.51%减少到20.73%,越冬期后,增加到22.39%;在越冬期间幼虫体内的结合脂肪含量由 5.16%上升到8.24%,越冬期后减少到5.81%。8越冬幼虫抗寒物质系统的确定根据越冬期间的生化物质的变化规律认为,桑螟越冬幼虫以“小分子碳水化合物(海藻糖、甘露醇、山梨醇)—氨基酸(丝氨酸,丙氨酸,酪氨酸,赖氨酸,精氨酸)—甘油—蛋白质-结合脂肪”组成抗寒物质系统。9 卵及各龄期幼虫有效积温的测定 分别测定了卵及各龄幼虫的发育起点温度(C)和有效积温(K)。比较直线回归法和最小变异系数法的测定值,认为通过最小变异系数法测定的C和K值更接近于实际,卵期的C和K值分别为8.7℃和88.20日度;幼<WP=8>虫各龄期的C值分别为:8.74℃、10.99℃、9.48℃、9.77℃、10.31℃;K值分别为:37.45日度、26.87日度、39.38日度、40.76日度、48.57日度。整个幼虫期的C和K值分别为9.88℃和192.75日度。更多还原

【Abstract】 Diaphania pyloalis Walker is one of the main pests in the mulberry field. It distributes widely, especially in Tai’an and Linyi, Shandong province. In order to predict its quantity and development rule and prevent it from erupting, its cold-hardiness and effective accumulation temperature was studied in the paper.1 Death rate of the over-wintering larvae The death rate of over-wintering larvae is the highest in the dead woods and scatters, which is 87.62%; the lowest indoors which is 55%; the middle in crevice which is about 75%.The death rate ties up with the environment temperature. The chilliness flow at the end of the over-wintering period affects the death rate greatly. 2 Super cooling point and freezing point of the over-wintering larvae From September to next April, the super cooling point(SCP) is -7.16℃、-9.36℃、-11.32℃、-18.38℃、-18.88℃、-19.69℃、-15.46℃、-8.24℃ respectively and the freezing point is -5.62℃、-7.46℃、-8.52℃、-9.77℃、-10.74℃、-11.78℃、-9.35℃、-5.44℃ respectively. SCP and freezing point have the same trend with the variation of environment temperature. But SCP changes greater than the freezing point. <WP=10>3 The variation of water content of the body of over-wintering larvae Water content of the larvae’s body was measured by drying at 60℃ unvaryingly. From September to next April, water content of the body is 72.59%、70.03%、68.36%、67.92%、67.57%、66.90%、68.76%、69.79% respectively. It shows that water content of the body have the same trend with the variation of environment temperature. But fall behind the latter. 4 Content of low-molecular carbohydrate in the over-wintering larvae From non-over-wintering period to over-wintering period, content of every low-molecular carbohydrate in the over-wintering larva’s body rises. trehalose, lactose, fructose, mannitol, glucose and sorbitol raises 53%、66%、52%、28%、21% respectively. The whole contents of low-molecular carbohydrate in the over-wintering larva’s body rise from 54.22mg/g to 78.64mg/g, about 45%. But content of low-molecular carbohydrate in the over-wintering larva’s blood changes differently. trehalose, fructose, mannitol and sorbitol raises 62%、714.3%、315%、346% respectively, on the other hand, lactose and glucose reduces 98% and 34%.The whole content of low-molecular carbohydrate in the over-wintering larva’s blood rises from 36.02mg/g to 45.89mg/g. Trehalose, fructose, mannitol and sorbitol is important substances of cold hardiness.5 Content of amino acid in the over-wintering larvaeContent of SER, ALA, TYR, LYS and ARG in the larva’s blood rises during the period of over-wintering and decreases at the end of over-wintering period. They raises 84.75%, 783.06%, 110.41%, 26.07%, 23.56% respectively and decreases 85.21%, 76.42%, 51.79%, <WP=11>21.56%, 28.4% respectively. Content of SER and ALA in the larva’s body has the same trend.6 Content of glycerin and protein in the larvae Content of glycerin and protein in the larvae has great effect on the improvement of the larva’s cold hardiness. During the over-wintering period, content of glycerin in the larvae rises from 3.85 mg/ml to 10.82 mg/ml, about 181%. The content of protein in the larva’s body decreases from 33.61% to 23.49%, but the content of protein in the larva’s blood rises from 3.184 mg/ml to 6.089 mg/ml, increasing 91.23%, protein in larva’s body and blood maybe changes from each other, content of glycerin and protein in the larva’s blood maybe have something on the cold hardiness of larvae.7 Content of fat in the over-wintering larvae During the over-wintering period, the content of dissociative fat in the larvae decreases from 22.51% to 20.73%, but the content of combined fat increases from 5.16% to 8.24%.After the period, the content of dissociative fat increases to 22.39% and the content of combined fat decreases to 5.81%.8 The system of cold hardiness substance in the over-wintering larvae Based on the variation of chemical substance in the over-wintering larva’s body, we consider that th更多还原