斜纹夜蛾生长发育与温度的关系

以白菜为食物，在全温度范围内测定斜纹夜蛾（Ｓｐｏｄｏｐｔｅｒａｌｉｔｕｒａ）的生长发育温度参数．分别测定了斜纹夜蛾卵，１～６龄幼虫，蛹发育及成虫产卵的起点温、最适温、最高温及有效积温．结果表明１～６龄幼虫及成虫的死亡速率与温度有正相关关系．卵及蛹的死亡速率与温度有负相关关系．卵，１～６龄幼虫，及蛹的存活有一最适温区，温度愈高，成虫的产卵量愈小．建立了各龄幼虫日取食白菜叶量与温度的关系     

1×10~9 PIB/g SpltNPV·15%虫酰肼悬浮剂对甘蓝斜纹夜蛾的田间防效

用1×109PIB/g斜纹夜蛾核型多角体病毒·15%,虫酰肼悬浮剂进行了甘蓝斜纹夜蛾的田间药效试验。结果表明:供试药剂对甘蓝斜纹夜蛾具有良好的防治效果,田间制剂用量1 500 g/hm2时,药后3天对甘蓝斜纹夜蛾幼虫的防效达到80%,以上,且持效期达14 d,显著优于对照药剂1×109PIB/g斜纹夜蛾核型多角体病毒可湿性粉剂1 500 g/hm2的防效和持效期,说明1×109PIB/g斜纹夜蛾核型多角体病毒·15%,虫酰肼悬浮剂在防治甘蓝斜纹夜蛾上具体良好的推广应用前景。     

中华卵索线虫Ovomermis sinensis对蔬菜害虫的人工感染和菜田释放试验

1996—1997年,在福州,用中华卵索线虫Ovomermis sinensis(Chen et al)侵染期幼虫对当地主要蔬菜害虫,菜青虫、斜纹夜蛾和甜菜夜蛾等幼虫,在室内做人工感染试验。在室温20—28℃,寄生线虫与宿主昆虫的比例为为80:1的情况下,线虫对菜青虫、斜纹夜蛾和甜菜夜蛾幼虫的寄生率分别为50％,94％,92％。在当地土壤中无中华卵索线虫的空心菜田,设三个小区,每小区15m~2,各移植斜纹夜蛾2—3龄幼虫150头于菜株上,A区用12540条线虫侵染期幼虫混在2460克湿沙中,撤施于植株根部土面;B区用同样数量的线虫混在8公斤水中,喷洒在菜株上;C区为不释放线虫的对照区。于释放线虫后的第4天和第7天,从各小区随机回收斜纹夜蛾幼虫20头和30头,在室内单头饲养,检查线虫的寄生率和寄生强度。结果:第4天调查寄生效果相近,寄生率分别为61.1％,60％。第7天调查寄生率分别为76.7％,70％。而对照区的虫体中均未见有线虫寄生,寄生率为0。差别显著。在元白菜上释放中华卵索线虫侵染期幼虫,莱青虫的寄生率为6.6％。     

加拿大一枝黄花天敌——白条银纹夜蛾的寄主专性研究

实验室条件下, 以白条银纹夜蛾(Argyrogramma albostriata)二代4 龄幼虫为实验对象, 选择52 科104种植物对其进行寄主专性测定, 观察幼虫的取食选择和存活时间。结果显示, 该虫幼虫仅取食小飞蓬、钻叶紫菀、马兰、一年蓬和加拿大一枝黄花5 种植物的叶片, 其他植物叶片均无咬痕, 直至饥饿死亡。分别用以上5 种植物的新鲜叶片饲喂白条银纹夜蛾幼虫, 观察其生活史, 得到以下几点结论。1) 饲喂小飞蓬、钻叶紫菀、马兰和加拿大一枝黄花的昆虫幼虫期存活率较高, 大量死亡发生在成虫期; 饲喂一年蓬的幼虫在幼虫期存活率较低, 仅极少量能存活到成虫期。2) 饲喂不同植物对该虫幼虫各龄期长度影响不同。3) 饲喂小飞蓬、钻叶紫菀、马兰和加拿大一枝黄花的昆虫化蛹率、羽化率、平均寿命和蛹重均显著高于取食一年蓬的幼虫。由此得出, 白条银纹夜蛾为寡食性昆虫, 其食料植物多为菊科外来杂草, 可在小飞蓬、钻叶紫菀、马兰和加拿大一枝黄花上正常完成生活史, 饲喂一年蓬抑制该虫生长。     

南方根结线虫侵染对乌桕癞皮夜蛾幼虫生长发育和食物利用的影响

为明确南方根结线虫（Meloidogyne incognita）侵染对癞皮夜蛾（Gadirtha fusca）幼虫的影响是否因龄期而异,本研究以南方根结线虫侵染乌桕（Triadica sebifera）,选用该植株叶片饲喂癞皮夜蛾大龄幼虫,以未受南方根结线虫侵染植株的叶片作为对照,比较不同龄期幼虫生长指标和食物利用指标的差异。结果表明：随着幼虫龄期的增加,癞皮夜蛾幼虫体质量、取食量及发育历期呈上升趋势;相对生长率呈下降趋势;食物利用率和食物转化率先上升后下降,而近似消化率则呈先下降后略微上升的趋势。线虫侵染处理后,与对照相比,癞皮夜蛾4龄幼虫的相对生长率、食物利用率和食物转化率显著提高;5龄、6龄幼虫的虫体质量和5龄幼虫的相对生长率以及6龄幼虫的取食量、近似消化率、化蛹率显著降低。南方根结线虫侵染对癞皮夜蛾幼虫生长及食物利用的影响因发育阶段而异,主要通过抑制两个末龄龄期幼虫的生长发育及化蛹,从而间接减轻癞皮夜蛾对乌桕的危害。     

斜纹夜蛾前胸腺的生长发育研究

 通过解剖观察4龄至蛹期斜纹夜蛾前胸腺,对其形态特点和生长发育规律进行了研究,主要结果如下：发现斜纹夜蛾前胸腺由53个左右的圆形或椭圆型细胞成串组成,Y型,成对,外围包裹一层透明鞘膜,位于胸部第一气门的气管丛内;在斜纹夜蛾4龄到蛹期的发育过程中,前胸腺不发生有丝分裂,细胞数量基本恒定;前胸腺细胞直径在幼虫发育期间不断增大,斜纹夜蛾幼虫在4龄第1天的前胸腺直径为(28.80±0.47) μm,而到了6龄末期,则增加到(92.22±2.43) μm;幼虫期的斜纹夜蛾前胸腺细胞直径和虫体体质量呈显著相关,r=0.826,P=0.000,拟合曲线方程为Y=82.1X ^0.263;此外,幼虫期的斜纹夜蛾前胸腺细胞直径和虫体体长也呈现出显著相关,r=0.886,P=0.000,拟合曲线方程： Y=e^{(4.781-1.863/Z)}。     

S1NPV对斜纹夜蛾幼虫的侵染阈值

斜纹夜蛾核型多角体病毒对斜纹夜蛾幼虫的侵染阈值因温度和虫龄而异，早龄愈大，温度愈高，则侵染阈值也大。在２０－４０℃内，３龄幼虫的侵染阈值为９０９０．９－６６６６６６．７ＰＩＢ头，５龄幼 虫为１３１５７８．９－７１４２８５．７ＰＩＢｓ／头。温度升高，各龄幼虫的侵染阈值差异逐渐减小，接种量为２×１０＾６ＰＩＢｓ／头左右及高于２×１０＾７ＰＩＢｓ／头时，Ｓ１ＮＰＶ自身似有一定的协生作用和拮抗作用。     

二点委夜蛾幼虫防治药剂的筛选及活性影响因素初步分析

二点委夜蛾是近年来严重危害夏玉米的一种新害虫,筛选有效的化学药剂对于其田间防治有重要的指导意义。本文采用浸虫法测定了12种常规杀虫剂对采自田间的二点委夜蛾5龄幼虫和室内饲养的4龄幼虫的触杀效果。供试药剂中40%辛硫磷乳油、480 g·L-1毒死蜱乳油及4.5%高效氯氰菊酯微乳剂对二点委夜蛾4龄和5龄幼虫的触杀效果相对较好,其他杀虫剂触杀效果较差。40%辛硫磷乳油、480 g·L-1毒死蜱乳油、4.5%高效氯氰菊酯微乳剂对二点委夜蛾4龄幼虫72 h的LC50值分别为0.244、0.308和0.406 mg·L-1,相对毒力指数分别是30%乙酰甲胺磷乳油的5.9、4.7和3.6倍。杀虫剂对二点委夜蛾幼虫的触杀活性与活性测定方法、杀虫剂种类、剂型、当地用药情况以及幼虫的龄期等因素有关。建议生产上优先选用辛硫磷乳油、毒死蜱乳油和高效氯氰菊酯微乳剂在二点委夜蛾低龄幼虫期进行喷雾、灌根或毒土防治。     

斜纹夜蛾NPV染病幼虫发育与温度的关系

在不同温度下，以不同剂量的ＳｌＮＰＶ饲食斜纹夜蛾ＳｐｏｄｏｐｔｅｒａｌｉｔｕｒａＦ．幼虫．结果表明，１～６龄染病幼虫的发育起点温分别是１８．７９，１６．２９，１４．１９，１０．８７，８．３９，７．０３℃；１～４龄染病幼虫的发育最适温分别是３２．８５，３３．４８，３４．２２，３１．７５℃．１～６龄染病幼虫的取食最适温分别是２６．５，２５．５７，２７．９０，２７．８２，２９．０１，２８．８５℃．建立了１～６龄染病幼虫取食白菜量的温度依赖模型，死亡速率模型，以及依赖于温度和ＳｌＮＰＶ饲食量的发育速率模型     

SINPV对斜纹夜蛾幼虫的侵染阈值

斜纹夜蛾核型多角体病毒（ＳＩＮＰＶ）对斜纹夜蛾幼虫的侵染阈值因温度和虫龄而异，虫龄愈大，温度愈高，则侵染阈值也愈大．在２０～４０℃内，３龄幼虫的侵染阈值为９０９０．９～６６６６６６．７ＰＩＢｓ／头，５龄幼虫为１３１５７８．９～７１４２８５．７ＰＩＢｓ／头．随温度升高，各龄幼虫的侵染阈值差异逐渐减少，接种量为２×１０６ＰＩＢｓ／头左右及高于２×１０７ＰＩＢｓ／头时，ＳＩＮＰＶ自身似有一定的协生作用和拮抗作用．作为病原体侵染阈值、致病性及寄主抗病性的指标，侵染阈值优于ＬＤ５０和ＬＣ５０，为解决病原体密度阈值的获取提供了一定的基础．     

Nickel accumulation and its effects on the survival rate of Spodoptera litura Fabricius under continuous nickel stress

The artificial diets mixed with various concentrations of nickel were offered to the larvae of the phytophagous insect Spodoptera litura Fabricius for 3 generations. Nickel accumulations in the 6th instar larvae, pupae and newly emerged adults of the corresponding generations of S. litura were investigated by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), and the effects of nickel accumulations on the survival rate of S. litura were also evaluated by individual rearing. The results showed that nickel accumulated in the 6th instar larvae, pupae and adults of S. litura, and the accu- mulated nickel in all the tested developmental stages within a generation increased with the increase of the nickel doses in the treated diets and showed significant dose-dependent relationship with the nickel doses in the artificial diets. The results also indicated that the nickel accumulations in the 6th instar larvae, pupae, and newly emerged adults from the 3rd generation were higher than those from the 2nd generation, which were also higher than those from the 1st generation. Nickel concentrations in pupae and adults were significantly lower than those in larvae, which indicated that the excessive nickel might be excreted during metamorphosis. Furthermore, larval survival rate, pupation rate and eclosion rate of S. litura in the tested three generations all decreased with the increase of the nickel doses in the treated diets.     

Metallothionein expression induced by nickel accumulation in the midgut of Spodoptera litura Fabricius larvae exposed to nickel

Metallothionein expression induced by nickel accumulation in the midgut of Spodoptera litura Fabri- cius larvae was investigated by exposing S. litura larvae to the artificial diets amended with different doses of nickel for 3 generations. Nickel accumulations in the midgut of 6th instar larvae were detected by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), and the induced metal- lothionein expression in the midgut of 5th and 6th instar larvae in 120 h were quantified using cad- mium-hemoglobin total saturation methods. The accumulated nickel in the midgut of the 6th instar larvae within a generation increased with the increase of the nickel doses in the treated diets and showed significant dose-dependence with the nickel doses in diets. Metallothioneins induced by nickel accumulated in the larval midgut also increased with nickel doses in diets and with the increasing stressing time in a generation. Results also suggested that the metallothionein expression was differ- ent with the time of S. litura larvae stressed by nickel.     

斜纹夜蛾幼虫不同组织对Zn2+积累作用的比较研究

 通过在人工饲料中添加不同质量分数的Zn²⁺,研究了植食性昆虫斜纹夜蛾Spodoptera litura Fabricius连续3代幼虫取食含不同质量分数Zn²⁺饲料后,第1和第3代6龄幼虫不同组织对Zn²⁺的积累作用。结果表明,经连续3个世代的胁迫,Zn²⁺在第1、3代斜纹夜蛾6龄幼虫脂肪体、表皮和中肠中的积累量随幼虫饲料中Zn²⁺ 质量分数及胁迫时间的增加而升高;中肠对Zn²⁺的积累作用最强,表皮次之,脂肪体最低。     

斜纹夜蛾杆状病毒流行病模拟模型研究

根据斜纹夜蛾生物生态学及其杆状病毒病流行的一般规律，建立了斜纹夜蛾杆状病毒流行病的微分方程模拟模型，模拟系统由１８个微分方程组成，可以模拟易感的和染病的１～６龄幼虫、蛹、成虫，卵的种群动态．模拟模型包含４个分室，即易感种群过程，染病种群过程，病毒在作物上的积累过程，易感种群和染病种群的相互转化过程．系统中纳入了作物生长对病毒数量的稀释效应，以及病毒数量的自然衰减作用．模型参数须由试验测定得到．给出了杆状病毒病的有关试验参数     

咪唑类化合物对天蚕幼虫生长发育的影响

本文报告了咪唑类化合物——金鹿三眠素对天蚕幼虫生长发育的影响。三龄0～48小时喂饲浸渍过500～2000ppm三眠素溶液的白栎鲜叶后,三眠蚕诱导率最高可达94.56％;诱导所得三眠蚕三、四龄历期明显延长,四龄起蚕体重和四龄末丝腺鲜重重于正常四眠蚕(对照),而三龄至结茧的总历期和熟蚕体重、丝腺鲜重则反之;仍为四眠蚕的三、五龄历期和三龄至结茧的总历期多长于对照、四龄起蚕和熟蚕体重大多重于对照。四龄0～48小时喂饲浸渍过500～2000ppm三眠素溶液白栎鲜叶后,极大多数仍为四眠蚕,三眠蚕诱导率最高仅为9.88％;其中四眠蚕四、五龄历期和四龄至结茧的总历期大多长于对照;诱导所得三眠蚕的四龄历期明显长于对照,但总历期反之。三眠蚕四龄期丝腺鲜重增长明显快于正常四眠蚕,但最终鲜重不及正常四眠蚕。     

Effects of herbivore-induced rice volatiles on the host selection behavior of brown planthopper, Nilaparvata lugens

It has been suggested that herbivore would react to volatiles produced by herbivore infested plant due to potential change, either positive or negative, in the acceptability of the host plant. This hypothesis was tested for the brown planthopper (BPH) in the laboratory. Sixteen components of the headspace volatiles from rice seedlings with different treatments were collected with SPME and Tenax-TA trap and analyzed with GC and GC-MS. Significant differences in volatile emissions were observed for rice plants with different treatments. Undamaged control plants, mechanically damaged plants and the plants infested by BPH for 1 or 2 d emitted much lower amounts of volatiles compared to the plants infested by BPH for 3 or 5 d. The plants infested by BPH for 3 or 5 d emitted several volatiles that were not detected in undamaged control plants, mechanically damaged plants or the plants infested by BPH for 1 or 2 d. Spodoptera litura infested plants released much higher amounts of volatiles than those in all other treatments, and the contents of several green leaf volatiles, methyl salicylate and terpenoids increased dramatically. In dual-choice flight tunnel experiments, adult BPH females showed no significant preference between the untreated healthy plants and mechanically damaged plants or the plants infested by BPH adult females. However, rice plants damaged by S. litura had a clearly repellent effects on BPH adult females compared to healthy undamaged plants, mechanically damaged plants or the plants infested by BPH.