几种药剂对桃蚜和两种瓢虫的毒力选择性研究

在室内分别测定了吡虫啉,吡虫啉＋增效剂,氰戊菊酯,硫丹、乐果和灭多威6种杀虫剂对桃蚜Myzus persicae Sulzer,七星瓢虫Coccinella septempunctata Linnaeus和龟纹瓢虫Propylea japonica(Thunbery)的毒力,比较了药剂在桃蚜和两种瓢虫之间的选择毒力比值（STR）,以及药剂之间选择性差异,研究了桃蚜对不同药剂相对适合度,结果表明：吡虫啉＋增效剂（SVI）和吡虫啉对桃蚜的毒力均很高,LC50分别是4628mg/L和0．9535mg/L,吡虫啉在七星瓢虫和桃蚜之间,龟纹瓢虫和桃蚜之间的STR值分别是37．6和13．0,吡虫啉＋增效剂的STR分别是9．84和7．75,硫丹的SR分别是54．0和7．28,都表现出显的毒力选择性,而氰戊菊酯,乐果和灭多威的STR值均很小（0．02－0．21）,不仅对桃蚜毒力低,而且对两种瓢虫也不安全,用吡虫啉和吡虫啉＋SV1的LC50浓度处理桃蚜,其存活个体的产仔率和单雌产仔量明显减少,与其它药剂处理相比,显降低了桃蚜的相对适合度,六种杀虫剂处理的桃蚜种群,其相对适合度大小排列为：乐果EC（0．92）＞氰戊菊酯EC（0．67）＞灭多威EC（0．66）＞硫丹EC（0．51）＞吡虫啉WP（0．40）＞吡虫啉＋增效剂（SV1）EC（0．18）,由此证明,吡虫啉不仅对桃蚜毒力高,对天敌瓢虫杀伤力小,而且对桃蚜种群有持续控制作用。     

温度对桃蚜和萝卜蚜种群增长的影响

测定了桃蚜Myzus persicae(Sulzer)、萝卜蚜Lipaphis erysimi (Kaltenbach)非全周期孤雌胎生型在13个恒温、3组自然变温下的发育、存活和生殖情况.结果表明:(1)温度对两种蚜虫的发育速率(以及桃蚜的翅型分化)、寿命和存活率;生殖力和生殖率都有直接的影响;(2)两种蚜虫能生存繁衍的温度广度基本一致,恒温下限到上限约相距23℃,但所对应的具体温度范围桃蚜的比萝卜蚜的约低3—4℃;(3)在较低的温度下,桃蚜的发育速率、若虫期存活率、生殖力和生殖率都比萝卜蚜的高,而在较高温度下则是萝卜蚜的比桃蚜的高;(4)两种蚜虫的内禀增长能力r_m均随温度升高呈二次抛物线变化,在16—24℃范围内两种蚜虫的r_m基本一致,低于16℃桃蚜的比萝卜蚜的高,高于24℃则萝卜蚜的比桃蚜的高;(5)在变温下两种蚜虫能适应的低温范围都比在恒温下明显要低.     

温度对桃蚜和萝卜蚜翅型分化的影响

采用恒温试验,自然变温试验和大田系绕调查相结合的研究方法,探讨了温度对桃蚜和萝卜蚜孤雌胎生型翅型分化的影响,结果表明低温有助于翅的发育,高温则对翅的发育有抑制作用,但低温对翅发育的促进作用在桃蚜中比在萝卜蚜中要强得多。在桃蚜中还证实母蚜体内的仔蚜胚胎期及仔蚜都可感受温度的作用从而对仔蚜的翅型分化产生影响。根据本文结果并综合文献中有关报道,作者认为在确定蚜虫翅型分化与环境因子的关系时,温度是一个不可忽略的重要因子。     

SO2 污染油菜对桃蚜的影响

ＳＯ_２污染油菜对桃蚜的影响龚佩瑜,吴坤君,李秀珍（中国科学院动物研究所北京１０００８０）ＳＯ２是我国大气污染的主要成分,它是一种对生物影响很大的污染物。ｓｏ。曾被用作熏蒸剂来防治害虫,但只有在浓度很高时才有效。更多的观察表明,ｓｏ：污染有利于蚜虫的?..     

温度对桃蚜、萝卜蚜体重及种群参数的影响

桃蚜Myrus perslcae、萝卜蚜Lipaphis crystml在能正常产仔的整个恒温范围内,成蚜和新产仔蚜体重随温度的变化都符合二次抛物线,但体重最高值出现较低的温度下．即体重变化主要表现为随温度升高而下降的趋势．在组建蚜虫的生命生殖力表时,以新产仔蚜体重对其在各温度下的生殖事进行校正。并未对计算所得的内禀增长能力rm值及其随温度的变化情况产生明显的影响,不仅没有提供新的信息。相反。这一方法使计算所得rm的值含义模糊。故建议不予采用。     

桃蚜、萝卜蚜的种内密度和种间竞争效应

在温室内不同密度条件下,研究了桃蚜和萝卜蚜在甘蓝上的种内密度效应和种间竞争作用。结果表明：单独饲养时,在5头／株和10头／株密度下,两种蚜虫种内密度效应均较弱;而在15头／株时,桃蚜和萝卜蚜的寿命和产蚜量都随之显降低,说明当两种蚜虫达到一定的拥挤程度时,种内密度对种群均产生一定的负效应。两种蚜虫共存时,单头产蚜量均比单独饲养时显下降,种问竞争作用明显。在10、15头／株密度下,桃蚜的竞争作用大于萝卜蚜,萝卜蚜的寿命和单头产蚜量都极显低于桃蚜。     

桃蚜提取液对南方小花蝽行为的影响

在室内(25±1℃,RH70%)条件下,研究了桃蚜Myzus persicae不同溶剂提取液对南方小花蝽0rius similis行为的反应.结果表明,桃蚜虫体用水研磨的浆液、用水或95%乙醇研磨提取的滤液,均含有很强的活性物质,而且用乙醇提取的滤液活性更强.其中桃蚜虫体用水研磨的浆液对南方小花蝽行为有很显著的影响.南方小花蝽对提取的活性物质均表现有明显的滞留和调转行为.     

微波辐射对桃蚜生长发育和繁殖的影响

【目的】研究筛选对桃蚜Myzus persicae有致死作用的安全微波频率和照射时长,以为探究新型物理防蚜技术,弥补化学防治上的缺陷提供参考依据。【方法】在暗箱中,应用微波发射仪分别发射1 375, 2 750, 5 500和11 000 MHz 4个不同频率的微波照射桃蚜1日龄无翅成蚜,每个频率的照射时长分别为15, 30, 60和120 s;照射后在人工气候箱中饲养,分别于照射后8, 24, 48和72 h观察其生长发育及繁殖状况,统计桃蚜死亡率、繁殖力(累计产蚜量)及子代有翅蚜率。【结果】4个不同频率的微波分别在4个不同照射时长下,对桃蚜1日龄无翅成蚜的死亡率、繁殖力和子代翅型分化都有不同程度的影响。照射后72 h, 5 500 MHz微波照射时间为15 s时对桃蚜1日龄无翅成蚜的致死作用最强,死亡率达到55.00%,在照射时间为30和120 s时可抑制子代桃蚜向有翅蚜的分化。2 750 MHz微波照射30和60 s时促进桃蚜1日龄成蚜繁殖,照射30 s时繁殖力最强,而照射15和120 s时却表现为抑制繁殖,且2 750 MHz微波照射30 s能抑制子代桃蚜向有翅蚜分化。【结论】...     

桃蚜脱皮对球孢白僵菌毒力的影响

室内测定了球孢白僵菌Beauveria bassiana BBSG8702菌株对桃蚜Myzus persicae 若蚜的毒力,并分析了若蚜脱皮与白僵菌有效侵染之间的关系。在21℃、1×10⁶/mL孢子浓度下, 1～4龄若蚜感菌后的累积死亡率分别为10.1%、2.1%、3.1%和40.2%,明显低于同样条件下成蚜的感菌死亡率(98.4%)。在若蚜各龄感菌死亡的个体中,1～4龄中分别有8.1%、50.0%、44.4%和98.0%的若蚜在死亡前发育到成蚜,且都能产下正常发育的后代。若蚜的感菌死亡率与接菌后到第一次脱皮的时间密切相关,脱皮早则感菌死亡率低,反之亦然。但试验中也发现有部分若蚜特别是低龄若蚜感菌后未完成第一次脱皮便死亡。观察了桃蚜在1、4龄早期感染球孢白僵菌后的发育、存活和生殖情况,结果表明：1、4龄早期若蚜接菌后第一次脱皮的时间早于未接菌若蚜,但提前幅度少于5%,在羽化为成蚜之前被致死的概率分别只有4.1%和0,在羽化为成蚜后8天内的生殖率与未接菌蚜虫的无明显差异。这些结果表明,若蚜的脱皮,尤其当蚜虫在低龄若蚜时受感染后的多次脱皮,可有效地摆脱球孢白僵菌分生孢子的侵染,降低该菌的毒力。     

微波辐射对桃蚜生长发育和繁殖的影响

【目的】研究筛选对桃蚜Myzus persicae有致死作用的安全微波频率和照射时长,以为探究新型物理防蚜技术,弥补化学防治上的缺陷提供参考依据。【方法】在暗箱中,应用微波发射仪分别发射1375, 2 750, 5 500和11 000 MHz 4个不同频率的微波照射桃蚜1日龄无翅成蚜,每个频率的照射时长分别为15, 30, 60和120 s;照射后在人工气候箱中饲养,分别于照射后8, 24, 48和72 h观察其生长发育及繁殖状况,统计桃蚜死亡率、繁殖力(累计产蚜量)及子代有翅蚜率。【结果】4个不同频率的微波分别在4个不同照射时长下,对桃蚜1日龄无翅成蚜的死亡率、繁殖力和子代翅型分化都有不同程度的影响。照射后72 h, 5 500 MHz微波照射时间为15 s时对桃蚜1日龄无翅成蚜的致死作用最强,死亡率达到55.00%,在照射时间为30和120 s时可抑制子代桃蚜向有翅蚜的分化。2 750 MHz微波照射30和60 s时促进桃蚜1日龄成蚜繁殖,照射30 s时繁殖力最强,而照射15和120 s时却表现为抑制繁殖,且2 750 MHz微波照射30 s能抑制子代桃蚜向有翅蚜分化。【结论】微波辐射能够影响桃蚜1日龄成蚜的存活、繁殖和子代翅型分化。本研究初步筛选出了对桃蚜1日龄无翅成蚜有致死作用的微波频率和照射时长。     

以化学纯饲料饲养北京的桃蚜

应用修改后的Dadd和Mitter(1966)全纯饲料配方配制成人工饲料饲养定居在北京温室烟草上的桃蚜 Myzus persicae可完成生活史井连续饲养3代。本文描述饲料配制、饲养和取食量测定的方法。这3代初羽化无翅孤雌胎生雌蚜的平均体重分别为:440±90.7μg,264±104.9μg和312±127.9μg。用放射性同位素稀释法测定取食量的结果得悉若虫期的总取食量每蚜约为1.74μg,相当于1.16μl。     

实夜蛾属二近缘种对寄主植物次生物质的反应:次生物质对幼虫生长和食物利用的影响

实夜蛾属(Heliothis)的棉铃虫(H. armigcra)和烟青虫(H. assulta)是近缘种,幼虫期取食多种相同的植物,其中含有不同的次生物质.本项工作是在人工饲料中分别加入0.5%的烟碱、番茄苷、棉子酚、丹宁酸等饲养早期六龄的幼虫,测定它们对生长和食物利用的影响.结果表明这些次生物质对两种幼虫有不同的作用:烟碱对棉铃虫没有明显影响,但对烟青虫的取食却有一定的刺激作用.丹宁酸、棉子酚、番茄苷可抑制两种幼虫的生长,而以番茄苷抑制烟青虫的生长最为显著.番茄苷主要通过抑制取食来影响幼虫的生长,而丹宁酸和棉子酚则具有降低消化率的作用.通过次生物质对这两种幼虫效应的比较可知,棉铃虫有较大的忍耐力.     

蚜虫报警信息素与类似物的合成及其对桃蚜定居行为的影响

蚜虫是主要的农业害虫之一,它对作物的危害除直接吸取液汁外,更严重的是传播多种植物病毒病(张广学等,1981)。杀虫剂的大量使用,使得蚜虫的抗药性增长很快,而且由于蚜虫迅速得毒和迅速传毒,所以杀虫剂很准保护作物免遭蚜虫传播非持久性病毒。因此近年来国内外开展了蚜虫行为控制剂的研究(Montgomery等,1978;Briggs等,1983;Gibson等:1984;Dawsow等,1988;张钟宁等,1988)。 [反]-β-法尼烯是许多蚜虫报警信息素的主要成分。它是蚜虫受到危害时,从腹管分泌出的以告警于其他蚜虫逃散的化合物。其分子结构于1972年被Bowers等人鉴定。Pickett等(1980)进一步报道了蚜虫报警信息素全成分的研究。本文将报道[反]-β-法尼烯及其类似物的合成及生测结果。     

STUDIES ON PLANT GROWTH-REGULATING SUBSTANCES

The cress-root test and the maize-root segment tests, both of which depend on the measurement of root-growth inhibition, have been used to assess the growth-regulating activity of a wide range of phenoxyalkanecarboxylic acids. The results are presented and compared with those obtained with the same compounds in other tests in which shoot tissues were employed. The results are also discussed in relation to current theories on mode of action and structure/activity relationship. These studies included the 'α-hydrogen' effect, the activity of stereoisomers and activity of homologues of seventeen series of ω-phenoxyalkanecarboxylic acids, considered in relation to their degradation within the tissues by β-oxidation. Earlier findings were largely confirmed. Compounds which had previously been shown to be active in shoot tests such as the wheat-cylinder, the pea-curvature and the pea-segment tests, were found to be active in the root-growth inhibition tests and, furthermore, the degree of activity was usually similar.
It is concluded that the two root tests investigated are of real value in assessing the activity of phenoxy acids in studies on the relationships between chemical structure and plant growth-regulating activity.     

STUDIES ON PLANT GROWTH-REGULATING SUBSTANCES

A study has been made of the growth-regulating activity of a number of phenoxy acids possessing halogen or methyl substituents in the 2:6- or 33- positions of the nucleus. The pea curvature, Avena cylinder elongation and tomato-leaf epinasty tests have been used for assessing biological activity. The results show that in general 3:s- is more closely associated with inactivity than 2:6- substitution. The introduction of a further halogen atom into the 4- position does not enhance activity in the 2:6- compounds but does so in the 3:s- derivatives. Although the 2:4:6-trichloro- and 2:4:6-tribromo-phenoxyacetic acids are almost inactive, a:4-dichloro-6-fluoro- and 2:4-dibromo-6-fluoro- phenoxyacetic acids are very highly active. When a methyl group is substituted into the side-chain of certain phenoxyacetic acids possessing 2:6- substituents, growth-promoting activity is increased. Some of these findings conflict with recent theories on mode of action of phenoxy acids which are discussed in relation to the present work.     

STUDIES ON PLANT GROWTH-REGULATING SUBSTANCES

Fifteen series of aryloxyacetic, α-aryloxy-propionic, -butyric and -isobutyric acids and the corresponding arylthio-analogues have been synthesized and their growth-regulating activity has been assessed in the tomato-leaf epinasty, wheat cylinder and the pea curvature tests. It is shown that in general arylthio-derivatives are less active than their aryloxy-analogues. Although for a cell elongation response the presence in the molecule of an a-hydrogen atom is usually necessary, three exceptions to this generalization have now been found. A lower activity in the 3:5-dichloro- compared with the 2:6-dichloro-compounds has been demonstrated. Evidence is presented to show that an ortho hydrogen atom in the nucleus is not an essential requirement for cell elongating activity as is postulated by other workers.     

STUDIES ON PLANT GROWTH-REGULATING SUBSTANCES

Three synthetic growth-regulating substances, α-(2-naphthoxy)-, α-(2:4-dichloro-phenoxy)- and α-(2:4:5-trichlorophenoxy)-propionic acids, have been resolved into their (+)- and (-)-forms. The physiological activity of these isomers and of the racemic compounds has been investigated using the pea curvature and Avena cylinder test methods of assessment.
The (+)-isomers in each case displayed high activity in both tests, whereas that exhibited by the (-)-isomers was negligible. The racemic compounds showed intermediate activity.
The mode of action of aryloxyalkylcarboxylic acids is discussed in the light of the results presented. These considerations suggest the possibility that the activity of the (+)-isomers might be antagonized by the presence of the corresponding inactive enantiomorphs. Our experiments show that such antagonism does in fact operate.     

STUDIES ON PLANT GROWTH-REGULATING SUBSTANCES

A number of polycyclic carboxylic acids have been prepared and their plant growth-regulating activity has been assessed in the wheat-cylinder, pea-curvature and pea-segment tests. The compounds were selected in relation to a theory on the mode of action of plant-growth substances which involves the association of three essential groupings in the molecule with specifically sited receptor centres within the plant cell. High activity was found only in those compounds possessing a > CHCOOH grouping adjacent to an aromatic ring. It is concluded that molecular size, stereochemical and electronic considerations may all operate in determining whether compounds of this type show activity. The results obtained together with those of other workers are discussed in relation to current theories on mode of action.     

食料因子对家白蚁初建群体的影响

家白蚁Coptotermes formosanus是一种分布广、为害严重的害虫。最初群体的建立,除了需要适宜的温、湿度条件外,还需要一定的物质基础——营养,才能正常生长、发育及稳定地繁衍后代。 为了了解食料在幼龄群体建立时的作用,我们作了以下试验:1)家白蚁分群时,把配对的原始成虫,置于完全没有营养的消毒的净砂内饲养,观察其生存及繁殖情况。2)饥饿几天后再加入食料。3)配对的原始成虫及时得到食料补充。实验证明过着社群生活