REGULATION OF FLIGHT CAPACITY AND CONTENTS OF ENERGY SUBSTANCES BY METHOPRENE IN THE MOTHS OF ORIENTAL ARMYWORM,MYTHIMNA SEPARATA*

Abstract The flight capacity and contents of energy substances in the moths of migratory Oriental armyworm, Mythimna separata (Walker)dosed with juvenile hormone analogue methoprene(JHM) were compared with the normal moth through day‐1 to day‐6 after the treatment. The flight capacity of JHM‐treated moths, as determined by a 12‐hours tethered‐flight test, was significantly lower than that of the controls, although it might differ with their age and sex. The moth's flight capacity between the treatments was insignificantly different from the first to 3rd day after the treatment but was significantly different from the 4th to 6th day either in the mean flight duration or in distance. Evaluation of the long fliers at the same stages between the treatments also supported this finding. Flight capacity of the JHM‐treated moths also differed with the sex. The JHM‐treated female did not fly less than the control from day‐1 to day‐3, but did significantly less from day‐4 to day‐6 after the treatment. The flight capacity of the JHM‐treated males, however, was not weaker than that of the control throughout the test period. Comparison of the levels of energy substances in the JHM‐treated adults and the controls showed that JHM may directly acted on metabolism of glyceride, which in turn affected flight capacity. Furthermore, higher levels of glyceride in the treated male adults raised their flight capacity to a stronger levels than the control in most of the days of tethered‐flight test period. Contents of glycogen, however, were insignificantly affected by JHM in both male and female adults. In might therefore be concluded that levels of JH is a critical factor regulationg migratory behavior in the army worm moth. In addition to affect metabolism of glyceride, other possible physiological roles that JH played in determining migrattory behavior are also discussed.     

Substances antiappétantes pour insectes phytophages présentes dans Angelica silvestris et Heracleum sphondylium

Eleven furocoumarins from Angelica silvestris and Heracleum sphondylium were tested for their antifeedant activity gainst two insect larvae: Mythimna unipuncta and the Colorado beetle Leptinotarsa decemlineata. Angular furocoumarins show a smaller effect that the corresponding linear homologues. The following order of activity is observed for substituents:

4-Methoxybenzofuran, a synthetic analogue shows also medium activity. But the most active component is a sesquiterpene: the known bisabolangelone.     

粘虫迁出与迁入种群的行为和生理特性比较

系统比较了田间粘虫Mythimnaseparata (Walker)迁出与迁入种群在飞行能力、 飞行肌干重、卵巢发育、交配以及保幼激素滴度等指标的差异。结果显示,迁出种群的飞行潜 力显著强于迁入种群,雌蛾中胸背纵肌平均干重（6.53 mg）也显著高于迁入种群（5.92 mg ）,但卵巢发育程度显著低于迁入种群;迁出种群的交配率和平均交配次数均显著低于迁入种 群;早期迁入的雌蛾卵巢发育级别和交配率相对较低,并随迁入时间的延长而增加。迁出与迁入 种群雌蛾的保幼激素滴度也存在显著差异,两者的JHⅡ滴度平均分别为4.63 ng/mg和8.69 ng/mg。这些结果说明,粘虫迁飞前后的行为、生理和生殖特性具有明显的变化,迁出种群具有较强的飞行潜力,生殖系统的发育受到暂时性抑制;而迁入种群飞行能力下降,卵巢发育级别 较高,交配率增加。同一世代早期迁入的雌蛾卵巢发育程度较低,表明粘虫迁飞是发生在成虫 发育的初期,迁飞过程中卵巢发育受到暂时性抑制,迁入以后便迅速发育并开始繁殖。粘虫迁 飞的行为和生理特性与“卵子发生 飞行拮抗综合症候(oogenesisi flight syndrome)”相符 。内分泌激素（保幼激素）在其迁飞与生殖的转换过程中起着重要的调控作用。     

粘虫性信息素分泌腺的超微结构

对粘虫Ｍｙｔｈｉｍｎａ ｓｅｐａｒａｔａ雌蛾性信息素分泌腺的位置及结构进行了光学显微镜、扫描电镜。透射电镜的观察，结果表明：粘虫性信息素分泌腺位于腹部末端第８－９节节间膜腹面。求偶时，伸出节间膜，为一白色的囊泡。腺体表面分布着饱满的锥状体。羽化后５天未交尾雌蛾，腺体细胞呈单层排列，中央细胞为柱状，细胞核为椭圆形。细胞与细胞间有明显的胞连接，细胞基底膜基褶较高，质膜上，分布着微绒毛，并与内表皮连接，内表皮之上含有多层几丁质，外角质层染色较深。细胞质中含有空泡，线粒体、脂质粒、糖原及粗面内质网。了解粘虫性信息素分泌腺的位置形态结构，对了解性信息素合成和释放的时辰节律，改进性信息素的提取、分离、鉴定是有意义的。     

雷公藤总生物碱对粘虫幼虫神经系统酶活性及神经递质含量的影响

【目的】明确雷公藤Tripterygium wilfordii Hook. f.生物碱对粘虫Mythimna separata (Walker)神经系统的影响,为阐明其杀虫作用机制提供依据。【方法】采用载毒叶片法测定粘虫5龄幼虫经雷公藤总生物碱处理后体内乙酰胆碱酯酶（AChE）、Na⁺, K⁺-ATPase、Ca²⁺, Mg²⁺-ATPase、谷丙转氨酶（GPT）和谷氨酸脱羧酶（GAD）等重要神经系统酶活性及乙酰胆碱（ACh）、谷氨酸（Glu）和γ-氨基丁酸（GABA）等神经递质的含量。【结果】雷公藤总生物碱处理对粘虫5龄幼虫AChE无明显影响,麻醉期处理粘虫幼虫体内ACh相对含量与同期对照无显著差异。处理粘虫幼虫在轻度麻醉期、深度麻醉期和复苏期体内GABA和Glu含量显著升高,GABA含量分别升高了89.86%, 49.28%和20.29%,Glu含量分别升高了24.55%, 23.33%和8.13%。处理粘虫幼虫GPT活性明显受到抑制,而GAD活性无明显变化。处理明显抑制粘虫幼虫头部Na⁺, K⁺-ATPase和Ca²⁺, Mg²⁺-ATPase活性,但对中肠两种ATPase活性影响不大。【结论】研究结果有助于了解雷公藤生物碱对昆虫神经系统的影响,也为进一步阐明其作用靶标奠定了基础。     

粘虫中肠α-淀粉酶活性的敏感性研究

研究了不同酶反应缓冲体系、pH值、氯离子浓度以及噁唑哒嗪对5龄2日粘虫 Pseudaletia separata Walker 中肠α－淀粉酶活性的影响。结果表明,乙酸-乙酸钠缓冲体系（pH 5.8）和磷酸氢二钠-磷酸二氢钠缓冲体系（pH 8.0）有利于增强α-淀粉酶活性,比活力最高分别达到4.49和4.97。在乙酸-乙酸钠缓冲体系（pH 5.8）中,5、10、20、40和80 mmol/L氯离子浓度引起α-淀粉酶活性呈现先减弱后增强的变化规律,而在磷酸氢二钠-磷酸二氢钠缓冲体系（pH 8.0）中仅呈现减弱的趋势。1.4 mmol/L噁唑哒嗪对α-淀粉酶活性的抑制率可达70%,但抑制程度随着反应体系中蛋白含量的增加而逐渐降低。     

粘虫成虫在气流场中飞行行为的观察研究

通过改进悬吊测飞技术、室内风洞和野外雷达相结合的观测方法,研究了粘虫在气流场中的飞行行为特征及其与气流的关系。直筒风洞自由飞行观测的结果表明,粘虫蛾对气流有明显行为反应,表现为头部迎风起飞和迎风飞行的特性;在3.0～5.5 m/s风速下,有92%～94% 的个体可一次逆风飞行通过2 m长的风洞;当风速≥6.0 m/s时,有71.9%的蛾子沿螺旋状的飞行轨迹逆风通过风洞。环形风洞悬吊飞行测试的结果表明,粘虫可逆风飞行的最大风速为7.2 m/s;在风速≤4 m/s条件下,90%以上个体头部迎风飞行或头部朝向与风向成一定的夹角,侧逆风飞行。 雷达观测发现粘虫在空中迁飞过程中具有成层现象,并有较强的秋季回迁定向行为,其头部总是朝向西南;迁飞的最终位移与风向及风速大小有关,迁飞位移速度是飞行速度与风速的矢量和。     

棉铃虫及粘虫肠中咽侧体静止激素样活性物质对咽侧体活性的影响

利用放射化学的方法分别检测了棉铃虫Helicoverpa armigera、粘虫Mythimna separata幼虫和成虫肠中咽侧体静止激素（allatostatin, AS）样的活性物质。发现在棉铃虫、粘虫幼虫和成虫肠中均存在的AS样活性物质,可以在体外抑制咽侧体（corpora allata, CA）的保幼激素（juvenile hormone, JH）的生物合成。生物测定的结果表明,粘虫幼虫肠中AS样活性物质的含量较棉铃虫的高;粘虫1个幼虫肠当量对CA的JH合成的抑制率达43%,而棉铃虫幼虫肠只有26%。无论是棉铃虫还是粘虫,雌成虫中肠对CA的抑制比雄成虫中肠的高,后肠对CA的JH合成的抑制明显的低于中肠对CA的抑制。中肠对CA的JH合成的抑制是可回复的。中肠粗提物经蛋白酶水解后对CA合成JH的抑制率降低,表明肠中AS样的活性物质是肽或蛋白质。     

粘虫飞行对生殖及寿命的影响

该文报道了粘虫Mythimna separata（Walker）成虫飞行后产卵、交配及寿命的研究结果。1日龄成虫飞行6 h、12 h、18 h、24 h后的产卵前期均显著短于对照的,其中飞行6 h、12 h的比对照的短2天以上,产卵量均比对照的高。对1～5日龄成虫分别飞行23.5 h后的研究结果表明,1日龄飞行的产卵前期和上述结果相一致。2～4日龄飞行的与对照的没有显著差异,但产卵量则随飞行日龄的延迟而逐渐减少。5日龄飞行的产卵前期显著延长,产卵量已不到对照的一半。所有经过飞行的成虫产卵高峰日比对照的早1天。不同日龄成虫飞行时间、距离与成虫产卵量的关系为：1～3日龄飞行时间、距离长的个体产卵量也高;但4～5日龄的成虫飞行时间与距离越长,其产卵量越少,表现出明显的卵子发生飞行拮抗症(oogenesis-flight syndrome)。除了5日龄飞行的成虫交配率有所下降以外,所有经过飞行的成虫产卵历期、交配率及寿命与对照的没有显著差异。最后,根据这些结果,对粘虫迁飞的起飞时期,迁飞在粘虫生殖、种群动态及成灾规律中的作用进行了讨论。