椰子织蛾种群繁殖特征

本文研究了椰子织蛾Opisina arenosella Walker种群繁殖的特征。2015年每月从儋州市野外采集椰子织蛾,收集当天羽化的成虫,记录成虫的产卵前期、单雌产卵量、卵的孵化率、初孵幼虫数以及成虫寿命。结果表明:1月份的气温最低,雌成虫的产卵前期最长,为(3.00±0.21)d;5、6月气温最高,产卵前期次之;其他月份的产卵前期较短。11月份椰子织蛾的单雌产卵量最高,为(231.07±19.55)粒;3、4、7、8、9、10月份的产卵量次之;1、2、5、6、12月份的单雌产卵量最低。1月份(低温)椰子织蛾卵的孵化率最低,为(2.70±2.01)%;2—12月份椰子织蛾卵的孵化率差异不显著。1月份的初孵幼虫数最少,为(4.17±2.94)头;5、6月份的较少,分别为(54.04±8.18)、(52.31±10.81)头;3月份的最多,为(87.89±14.94)头。低温使成虫的寿命延长;各月雌成虫的寿命短于雄成虫的寿命;5、6月份雄成虫的平均寿命分别为(7.08±0.68)、(7.67±0.84)d,雌成虫的平均寿命分别为(6.50±0.34)、(6.22±0.36)d,低于其他月份雌雄成虫的寿命。5、6月的高温会抑制种群的数量,是药剂防治的最佳时间。该研究为椰子织蛾的防治、预测预报等提供基础科学依据。     

葱兰夜蛾幼虫肠道细菌群落结构与多样性分析

为明确葱兰夜蛾Brithys crini(Fabricius,1775)幼虫肠道细菌的群落结构和多样性,利用IonS5TMXL高通量测序平台对肠道细菌16S rDNA基因V3-V4变异区进行测序,应用Cutadapt、Uparse等软件整理、统计样品序列数和OUT数,分析肠道细菌的物种组成、丰度和多样性。4个虫体肠道样本测序拼接后,共得273 453条序列和在97%相似度下平均每个样本可聚类为512个OTU数目,总共注释到23门57纲86目168科347属,优势菌群为变形菌门Proteobacteria和厚壁菌门Firmicute。葱兰夜蛾肠道细菌Simpson指数、Shannon指数和Chao1指数分别为0.93~0.98,5.67~6.82和439.57~584.12。结果表明葱兰夜蛾幼虫肠道细菌多样性比较丰富,个体间微生物群落结构和多样性有差异。     

牛腹腔丝虫对3种伊蚊的感染试验

用牛腹腔指状丝虫和唇乳突丝虫的微丝蚴感染埃及伊蚊、白纹伊蚊和东乡伊蚊,观察了蚊虫的感染情况及牛腹腔丝虫Ⅲ期蚴的形态。结果,这两种丝虫的微丝蚴在3种伊蚊体内都能发育成熟,各蚊种的感染率不同,埃及伊蚊和白纹伊蚊分别为40%和30%以上,东乡伊蚊近70%;Ⅲ期蚴的表面结构不因蚊种而异。以不同蚊体内发育而成的Ⅲ期蚴感染小鼠,均可致小鼠出现与马、羊脑脊髓丝虫病相似的瘫痪或转圈运动等神经症状。由此认为,埃及伊蚊和白纹伊蚊也可能为脑脊髓丝虫病的传播媒介。     

松实小卷蛾和松梢螟的防治研究

通过对松实小卷蛾、松梢螟在不同时期发生规律的观察和多种药剂,混剂的系列防治试验,结果表明,1.4月中下旬和5月下旬分别为松实小卷蛾和松梢螟的初孵幼虫盛期,是防治的最佳时期。2.在4月中下旬一次和4月中下旬,5月下旬二次采用20％氯氰菊酯(20毫升/亩)、40％氧化乐果(75毫升/亩)或其混剂(氯氰10毫升+氧化乐果40毫升/亩)对二种害虫的防治效果达80～90％。     

旋毛虫各隔离种雌虫体外产新生幼虫能力的研究

本试验对旋毛虫各隔离种雌虫体外产新生幼虫能力进行了研究.结果显示,猪旋毛虫和旋毛形线虫(Trichinellaspiralis)雌虫体外培养24小时,平均产新生幼虫数分别为66.00±7.34和76.20±7.57,而犬旋毛虫和本地毛形线虫(Trichinellanatiua)分别是28.80±4.30和22.00±3.22,前者在雌虫体外产幼虫能力上明显高于后者.研究结果表明,黑龙江猪旋毛虫相当于旋毛形线虫,犬旋毛虫相当于本地毛形线虫.     

新疆苹果蠹蛾幼虫期及蛹期的寄生蜂调查初报

经3年在新疆伊犁的调查，发现苹果蠹蛾幼虫和蛹的5种寄生蜂，包括1种重寄生蜂。它们是光点瘤姬蜂，蠹蛾玛姬蜂，红足微茧蜂，四齿革腹茧蜂和凹腹双短刺金小峰。     

14株苏云金芽孢杆菌伴胞晶体蛋白对猪蛔虫第3期幼虫的毒性比较

14株苏云金芽孢杆菌经培养提取伴胞晶体蛋白并测定其蛋白含量。感染性蛔虫卵经胃感染小鼠 ,3d后宰杀并从小鼠肝脏内分离蛔虫第 3期幼虫 (L 3)。设置空白对照 ,将不同剂量的 Bt伴胞晶体蛋白与 L 3置于培养孔在 37℃的二氧化碳培养箱中 (含 5 % CO2 )培养 ,间隔 12 h检查幼虫活性 ,计算死亡率、校正死亡率及半数致死量。L D50 随着作用时间的延长而逐渐减小。14株细菌伴胞晶体蛋白对 L 3的毒力差异很大。 0 17株对 L 3的杀虫作用快速而持久、毒力最强 ,其 L D50 是所有 14个菌株中最小的 ,作用 12、2 4和 36 h时分别为 1.135 7、0 .2 32 2和 0 .15 32 g/ L。     

甘蓝田四种鳞翅目幼虫的生物学特性及其田间株内分布

作者研究了不同层次甘蓝叶片对四种鳞翅目幼虫(菜粉蝶、小菜蛾、甜菜夜蛾和斜纹夜蛾)生长发育和取食特性的影响。随着叶片成熟度提高(内层→外层),四种幼虫的存活率和生物量积累均逐渐下降,发育历期和总取食量均逐渐增加,但在低、高龄幼虫之间存在一定差异。在田间,低龄幼虫株内分布通常与其卵的株内分布相一致,而高龄幼虫均集中分布在植株中部以内叶片上;甜菜夜蛾和斜纹夜蛾低龄幼虫表现明显的趋边性,高龄幼虫却表现明显的趋中性。作者讨论了叶片营养状况、害虫自身的生物学特性和其它环境因素对四种幼虫田间株内分布的综合影响。     

5,7,4-三羟基黄酮等生物源化合物对菜青虫幼虫生长发育的影响

为了研究生物源化合物对菜青虫幼虫Pieris rapae（L.）生长发育的影响,选用5,7,4＇-三羟基黄酮、槲皮素、芦丁、5-甲氧基水杨酸和曲酸5种化合物,以触杀和摄食毒力法进行了生物活性测定.结果表明,5,7,4＇-三羟基黄酮和槲皮素对菜青虫幼虫生长发育具有明显的影响,浸渍法处理后72 h,两种化合物对试虫致死LC50值分别为0.226和0.951g/L;叶片药膜法处理后72 h,LC50值分别为0.062和2.420 g/L.结果还表明,采用叶片药膜法,当5,7,4＇-三羟基黄酮的浓度高于0.200g/L时,所有试虫均不能正常化蛹;采用浸渍法,用5,7,4＇-三羟基黄酮、槲皮素、芦丁、5-甲氧基水杨酸和曲酸处理的菜青虫5龄幼虫体重与对照相比增长量明显降低.离体试验结果显示,5,7,4＇-三羟基黄酮和槲皮素对菜青虫酚氧化酶（phenoloxidase,EC.1.14.18.1）具有明显的抑制作用,抑制中浓度（IC50）分别为25.65和43.94mg/L.     

Effects of Mixed Grazing of First- and Second-year Calves on Trichostrongylid Infections in Lithuania

The objective of this study was to examine whether susceptible calves grazing together with second-year resistant heifers are less exposed to trichostrongylid infection than are calves grazing on their own. Two groups of animals representing each age category were turned out onto pasture on 24 May 1997 and grazed at comparable stocking rates. The grazing of calves and heifers together was compared to groups of each age category grazing separately. The results indicated that herbage larval counts were significantly reduced in the second part of the grazing season on the plot grazed by the mixed group compared to the plot grazed by the first-season calves only. The mixed grazing strategy protected the young calves and no clinical signs were observed in this group, while most of the calves that grazed alone exhibited clinical signs. The availability of herbage was reduced towards the end of the season, with subsequent competition for the grass forcing all the animals to graze the tufts around the faecal pats, where the quality of the grass is poor and the numbers of infective larvae are high. The effect of this was visible in the form of increased parasite burdens in the calves that were grazed together with the heifers, confirmed by increased blood serum pepsinogen concentrations and reduced daily weight gains in the second part of the grazing season. The lower numbers of infective larvae on the pasture were probably achieved through the heifers ingesting many of the larvae but subsequently depositing relatively few eggs, since they had acquired some degree of resistance against trichostrongylid infections during their first grazing season. Thus they did not suffer any parasitological ill-effects during mixed grazing with first-season calves.