印楝素乳油对小菜蛾种群的控制作用

通过室内外系统试验探讨了印楝素乳油对小菜蛾Plutella xylostella种群的控制作用。结果表明,其控制作用主要表现在对成虫产卵的显忌避作用。对幼虫的拒食作用以及对生长发育的影响和减少幼虫危害为等方面,印楝素乳油0.005mL/59.0%,使小菜蛾种群趋势指数（I值）降为2.4干扰作用控制指数（IIPC）为0.1079,采用状态空间分析法就印楝素乳油施用后小菜蛾种群数量动态的模拟分析亦表明,其显的控制作用表现在种群发展初期对成虫的忌避作用。     

印楝素乳油x对-小菜蛾种群的控制作用

通过室内外系统试验探讨了印楝素乳油对小菜蛾Plutella xylostella种群的控制作用.结果表明,其控制作用主要表现在对成虫产卵的显著忌避作用、对幼虫的拒食作用以及对生长发育的影响和减少幼虫危害力等方面.印楝素乳油0.005 mL/L处理对成虫的忌避率为78.3%,对幼虫的选择性和非选择性拒食率分别为71.8%和62.9%,幼虫总取食量是对照的59.0%,使小菜蛾种群趋势指数(I值)降为2.4,干扰作用控制指数(1lpc)为0.1079.采用状态空间分析法就印楝素乳油施用后小菜蛾种群数量动态的模拟分析亦表明,其显著的控制作用表现在种群发展初期对成虫的忌避作用.     

印楝素乳油对荔枝蒂蛀虫种群的控制作用

利用生命表的方法和干扰作用控制指数评价了印楝素乳油对荔枝蒂蛀虫Conopomorpha sinensisBradley种群的控制作用,结果表明:0.3%印楝素乳油对荔枝蒂蛀虫成虫显著的产卵忌避作用是其对该种群控制的主要机理。在室内,0.3%印楝素乳油在6 mL/L和3 mL/L的浓度处理下,对荔枝蒂蛀虫成虫产卵的忌避率分别为89.3%和86.3%。田间的试验结果表明,在印楝素乳油浓度为6 mL/L和和3 mL/L的处理区中,荔枝蒂蛀虫的种群趋势指数分别为1.23和1.45,显著低于对照区的种群趋势指数11.60,干扰作用控制指数分别为0.106和0.112。这2个浓度的印楝素乳油对荔枝蒂蛀虫种群的控制效果分别可达89.4%和87.5%。     

植物提取物和药剂对蔬菜蚜虫种群的联合控制作用

研究白蝴蝶(Syngonium podophyllum)乙醇提取物、苍耳(Xanthium sibiricum)乙醇提取物、机油乳剂和0.3%印楝素乳油对桃蚜(Myzus persicae)和萝卜蚜(Lipaphis erysimi)的控制效果.室内四因子(1/2实施)二次正交回归旋转组合设计测试对有翅蚜的忌避作用,结果表明,对有翅桃蚜的主要忌避作用物为苍耳乙醇提取物,当苍耳提取物与白蝴蝶乙醇提取物混用,以及机油乳剂和印楝素混用时,对桃蚜有翅蚜的忌避效果提高;而对萝卜蚜有翅蚜的忌避作用主要受苍耳提取物和白蝴蝶提取物的影响.这些干扰作用均是非线性的.田间试验结果,单独使用白蝴蝶提取物对有翅成蚜有较强的驱避作用;对萝卜蚜自然种群的干扰控制作用以4种植物提取物和药剂混配效果最好,达95.7%;对桃蚜自然种群干扰控制效果最好的则是白蝴蝶提取物,控制效果达87%;同时,白蝴蝶提取物与印楝素乳油混配以及苍耳提取物与印楝素乳油混配,对两种蚜虫的控制效果均达80%以上.     

印楝素乳油对黄曲条跳甲种群控制作用评价

在生命表方法分析的基础上。建立了害虫累积为害量指标,用以描述和比较某一时间段内害虫动态持续为害力大小．应用该指标分析印楝素乳油对黄曲条跳甲(Phyllotreta striolata(F.))种群控制作用,结果表明,对成虫显著的忌避作用是其对种群控制的主要机理．印楝素0．50ml·L^-1对成虫的忌避率为83．75％,种群趋势指数I值降为0．3354,干扰作用控制指数为0．0863．采用田间试验获得的结果,避免了室内测定的空间限制,因而是评价异源植物次生化合物对害虫忌避作用的主要依据．该指标在以害虫控制为目标的动态研究中具有较好的应用前景．     

植物提取物和药剂对蔬菜蚜虫实验和自然种群的联合控制作用

研究白蝴蝶（Syngonium podophyllum ）乙醇提取物、苍耳（Xanthium sibiricum ）乙醇提取物、机油乳剂和0.3%印楝素乳油对桃蚜（Myzus persicae）和萝卜蚜（Lipaphis erysimi）的控制效果.室内四因子（1/2实施）二次正交回归旋转组合设计测试对有翅蚜的忌避作用,结果表明,对有翅桃蚜的主要忌避作用物为苍耳乙醇提取物,当苍耳提取物与白蝴蝶乙醇提取物混用,以及机油乳剂和印楝素混用时,对桃蚜有翅蚜的忌避效果提高;而对萝卜蚜有翅蚜的忌避作用主要受苍耳提取物和白蝴蝶提取物的影响.这些干扰作用均是非线性的.田间试验结果,单独使用白蝴蝶提取物对有翅成蚜有较强的驱避作用;对萝卜蚜自然种群的干扰控制作用以4种植物提取物和药剂混配效果最好,达95.7%;对桃蚜自然种群干扰控制效果最好的则是白蝴蝶提取物,控制效果达87%;同时,白蝴蝶提取物与印楝素乳油混配以及苍耳提取物与印楝素乳油混配,对两种蚜虫的控制效果均达80%以上.     

植物保护剂保卫德对小菜蛾种群控制效应评价

室内外试验表明,植物保护剂保卫德（BIOACT－T35）对小菜蛾种群具有较好的控制效应,其显的控制机理主要表现在对成虫产卵的忌避作用和对幼虫的拒食作用。保卫德10．00ml／L处理对成虫的忌避率为81．43％,对幼虫的选择和非选择性拒食率为96．32％和93．17％,小菜蛾种群趋势指数I值由对照的18．2840降为1．9492,干扰作用控制指数为0．1066。     

印楝素乳油对斜纹夜蛾的生物活性及田间防效研究

在室内测定了印楝素乳油对斜纹夜蛾(Spodopteralitura)的生物活性,并进行了田间防治试验.结果表明,印楝素乳油对斜纹夜蛾具有多种生物活性,主要表现在对幼虫的拒食作用、生长发育的抑制作用和一定的毒杀活性,以及对成虫产卵的忌避作用.经印楝素处理后,幼虫平均发育历期延长、幼虫体重、蛹重、化蛹率和蛹羽化率显著低于对照,印楝素乳油12μl·L^-1浓度处理3龄幼虫5和7d后的体重分别是对照组的36.8%和14.5%,而幼虫平均发育历期比对照组延长6d左右,化蛹率和蛹羽化率分别是27.79%和37.23%,显著低于对照组85.66%和82.11%.印楝素对低龄幼虫有一定的毒杀活性,而对高龄幼虫活性则很低.田间防治试验表明,印楝素乳油对斜纹夜蛾种群有良好的控制作用,施药7d后其防治效果要优于化学农药10%除尽悬浮剂.     

植物提取物和药剂对瓜蚜控制作用的室内和田间效果评价

测试机油乳剂、0 .3%印楝素乳油和苍耳XanthiumsibiricumPetr .etWidd .提取物、白蝴蝶SyngoniumpodophyllumSchott提取物对瓜蚜AphisgossypiiGlover的控制效果。室内实验结果 ,几种药剂和植物提取物对一龄若蚜存活影响的大小次序是 :0 .3%印楝素乳油 (2 0 0 0× ) >机油乳剂 (4 0 0× ) >白蝴蝶提取物 (0 .0 4gDW·ml- 1) >苍耳提取物 (0 .0 4 gDW·ml- 1) ;机油乳剂与植物提取物的不同组合中 ,以机油乳剂单独使用对有翅成蚜忌避效果较好 ;田间试验结果 ,以四种药剂和植物提取物混配 ,对有翅成蚜的驱避作用和种群增长的控制效果最为理想 ,种群增长量只有对照的 2 5 .9%。     

番茄抽提物对小菜蛾的忌避,拒食及抑制产卵作用

在自然变温条件下,研究了番茄抽提物对小菜蛾成虫的忌避、幼虫的拒食作用及成虫繁殖力的影响。试验表明：番茄抽提物对小菜蛾成虫具有很强的忌避作用;用番茄抽提物处理过的包菜叶饲喂小菜蛾幼虫,其拒食率达５３％;番茄提物对小菜蛾成虫产卵也有明显抑制作用,产卵量下降６０％;番茄与包菜间种能明显地抑制小菜蛾种群数量的增长。其种群可下降５０％以上。     

REPELLENT AND OVIPOSITION DETERRENT ACTIVITIES OF THE ESSENTIAL OIL FROM MIKANIA MICRANTHA AND ITS COMPOUNDS ON PLUTELLA XYLOSTELLA

Abstract  Repellent and oviposition deterrent activities of the essential oil from Mikania micrantha and five volatile compounds including limonene, α-terpinene, linalool, β-caryophylene and verbenone on the diamondback moth (DBM), Plutella xylostella , was investigated in door and in net-house. The results showed that the essential oil of the M. micrantha had significant repellant effect (at flow 100–180 mL/min) and oviposition deterrent activity at dose 10–20 μL/seedling for the DBM. In five volatile compounds, α-terpinene, limonene and linalool had significant effect on repellent and oviposition deterrent of the DBM moths, but verbenone and β-caryophylene, no significantly effect was observed in repellent and oviposition deterrent.     

Insect growth regulating and antifeedant effects of neem extracts and azadirachtin on two aphid species of ornamental plants

Leaf disc choice test bioassay demonstrated that formulated neem seed extracts were highly deterrent and growth regulatory to rose aphid,Microsiphum rosae (L.) and Chrysanthemum aphid,Macrosiphoniella sanbornii (Gillete). Effective concentrations to produce 50% feeding deterrence was 0.80 and 0.84% respectively for 2nd instar nymphs irrespective of bioassay duration. The disruption of aphid feeding was related to the presence of azadirachtin concentration in the extract. The toxicity on contact from the leaf surface or via topical application due to azadirachtin was significantly different and topical treatment was at least 7 times more effective for both species. Thus growth regulatory effects of azadirachtin were influenced by the host plant and the stage of treatment. Field evaluation with formulated neem extracts revealed the effect to be more of growth regulatory nature thereby showing that azadirachtin is a physiological toxin for aphid species. Neem seed extracts reduced the population of aphid on respective host plants significantly, EC₅₀ values being 0.88 and 0.96% forM. rosae andM. sanbornii respectively.     

Behavioural responses of diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) to extracts derived from Melia azedarach and Azadirachta indica

The impact of three different doses of botanical insecticide derived from the syringa tree, Melia azedarach and the neem tree, Azadirachta indica was tested on the behaviour of the diamondback moth, Plutella xylostella (Linnaeus). Both botanical insecticides had a significant impact on larval behaviour. At higher doses the extracts showed feeding deterrent activity, with larvae preferring the untreated sides of cabbage leaves and consuming less of the treated half of cabbage leaves. The botanical insecticides had less of an effect on the oviposition behaviour of P. xylostella moths. In laboratory and glasshouse trials, significantly fewer eggs were oviposited on the plants that had been treated with syringa extracts. Therefore, the syringa extracts appear to have a repellent effect. In contrast, when exposed to the neem extracts the moths did not discriminate between control plants and treated plants. Behavioural observation indicated that, despite the lower number of eggs oviposited on cabbage treated with syringa extracts, the moths chose cabbage treated with the highest dose of syringa more often than they chose control cabbage plants. Similar observations were found in cabbage plants treated with neem, moths chose the medium dose more often than they chose the control. Oviposition and feeding deterrent properties are important factors in pest control, and results from this study indicate that botanical insecticides have the potential to be incorporated into control programmes for P. xylostella in South Africa.     

The effect of neem (Azadirachta indica A. Juss) oil on oviposition, development and reproductive potentials of Sesamia calamistis Hampson (Lepidoptera: Noctuidae) and Eldana saccharina Walker (Lepidoptera: Pyralidae)

Abstract 1 The effect of different treatments of neem oil (0, 0.075, 0.1 and 0.15 mL/plant) and their persistence (0, 5 and 10 days after application; DAA) on the oviposition behaviour and the bionomics of the noctuid Sesamia calamistis and the pyralid Eldana saccharina were tested in laboratory and greenhouse experiments. 2 For most variables, no difference was found between DAA, showing that the treatments had a long‐term effect, and pooled analyses across DAA were performed. Compared with the control (0 mL/plant), mean reductions due to neem in numbers of egg batch and eggs laid were 70 and 88% for S. calamistis and 50 and 49% for E. saccharina, respectively, but no differences were found among neem concentrations. 3 For both species, larval and pupal development time was shortest in the control and longest with the highest oil concentration. Immature survival, larval weight and fecundity were highest in the control and similar in the neem treatments. 4 No differences were found in sex ratios. Egg viability was highest in the control (approximately 87%) and lowest (72%) with the highest oil concentration. As a result of lower fecundity and longer developmental time, on average, the intrinsic rates of increase in the neem treatments were 30% lower than in the control. 5 In view of the low oviposition rates, immature survival, fecundity and egg viability in the neem treatments, and the relatively high persistence of neem oil, it can be expected that the reduction in densities of the two borers species in the field will be considerable.     

生态恢复状态下天敌对小菜蛾的自然控制作用

通过组建不同防治措施下的小菜蛾自然种群生命表,结果表明,化学防治区小菜蛾自然种群趋势指数为52.52;在生态恢复区,天敌因子对目标害虫的自然控制作用得到恢复和增强,连续4个世代的小菜蛾种群趋势指数分别为16.9、7.16、3.71和4.02,其种群数量的发展得到有效地抑制.影响小菜蛾春季第一、第二、第三及第四代种群数量的重要因子分别为绒茧蜂寄生、4龄幼虫的捕食及其它、赤眼蜂寄生和绒茧蜂寄生,其相应的排除作用控制指数分别为1.39、1.56、1.74和1.54.从天敌与小菜蛾种群相互作用的过程来看,前者对后者的控制作用表现出明显的时滞效应,其种群数量的发展需要一个累积过程.能否采取积极的田间保护、增强措施,将是充分发挥天敌控害潜能的关键因素之一.     

The effect of NeemAzal-T/S®, a commercial neem product, on different developmental stages of the common greenhouse whitefly Trialeurodes vaporariorum Westwood (Hom., Aleyrodidae)

The effects of NeemAzal-T/S^®, a commercial neem product, on different life development stages of the common greenhouse whitefly Trialeurodes vaporariorum Westwood (Hom., Aleyrodidae) were tested in laboratory and greenhouse experiments. Treatment of eggs of T. vaporariorum did not affect either larval emergence or the time until larval emergence. However, the proportion of pupal formation (based on the numbers of emerged larvae) was significantly reduced after a treatment of the eggs 3, 5 and 7 days after oviposition, respectively. The proportion of emerged adults (based on the number of formed pupae) was only significantly reduced when eggs had been treated 5 and 7 days after oviposition. In all neem treatments the time until adult emergence was significantly delayed. A neem treatment of early larval instars of T. vaporariorum resulted in a significantly reduced proportion of pupal formation, but subsequent adult emergence (based on the number of formed pupae) was not affected. Treating early larval instars of T. vaporariorum significantly prolonged the time until adult emergence. A neem treatment of T. vaporariorum pupae significantly reduced the proportion of emerged adults but had no effect on the time until adult emergence. Exposing female whiteflies to fresh, 24-h-old and 72-h-old residues of NeemAzal-T/S^® had no effect on the mortality of the insects, though the number of eggs laid per female was significantly reduced in T. vaporariorum exposed to fresh neem residues. These findings are discussed within the context of integrated control of whiteflies in the greenhouse environment.     

温度对小菜蛾生长发育和繁殖影响的研究进展

小菜蛾是典型的世界性害虫。本文综述了国内外有关温度对小菜蛾生长发育、存活、繁殖和种群增长等生物学特性影响的研究概况,提出了开展变温条件下小菜蛾生物学特性研究的重要性,这将有助于进一步弄清小菜蛾种群在田间自然条件下种群消长规律的内在机理,为利用当地的气象资料推测小菜蛾在某一时间段内的发生动态,确定防治适期,科学有效地指导防治提供理论依据。     

Biological activity of volatile di-n-propyl disulfide from seeds of neem, Azadirachta indica (Meliaceae), to two species of stored grain pests, Sitophilus oryzae (L.) and Tribolium castaneum (Herbst)

Head space volatiles, including 73% di-n-propyl disulfide, were collected from freshly crushed neem seeds. This compound along with previously reported diallyl disulfide (di-2-propenyl disulfide) were toxic when applied topically or as a fumigant to Tribolium castaneum adults and 8-, 12-, and 16-d-old larvae, and Sitophilus oryzae adults. Di-n-propyl disulfide significantly decreased the growth rate and dietary utilization with moderate inhibition of food consumption in both insects. The total coefficient of deterrence for this compound ranged between 68.5 and 178.6, which suggests that it has medium to very good deterrent activity vis-à-vis the treatment concentration and instar. Di-n-propyl disulfide and diallyl disulfide presented a similar effect on efficiency of conversion of ingested food, which is reduced 3-fold; this implies that both compounds are physiological toxicants. Present studies clearly demonstrate that di-n-propyl disulfide could be a potent toxicant, fumigant, and feeding deterrent for stored grain pests, if a suitable formulation and application procedure are developed.