芫花活性成分抑制鳞翅目幼虫取食的机理

就芫花及其有效成分β-谷甾醇对斜纹夜蛾及卫矛尺蠖取食的抑制作用进行了研究.结果表明:斜纹夜蛾和卫矛尺蠖4龄幼虫连续4天取食涂有10%芫花乙醇粗提物(YAE)的食物后,其中肠淀粉酶、酯酶、蛋白酶的活力指数均显著高于对照;连续4天取食0.1%β-谷甾醇后,淀粉酶活力指数也显著高于对照,酯酶与蛋白酶的活力与对照持平.10%芫花乙醇粗提液处理斜纹夜蛾4龄幼虫4天,其谷胱甘肽-S-转移酶活性呈先升后降趋势,至第4天,活力绝对值虽高于对照组,但差异不显著.斜纹夜蛾4龄幼虫连续3代取食涂有芫花乙醇粗提物的食物后,其谷胱甘肽-S-转移酶活性呈先升后降的趋势,至F2代,与对照组的差异已不显著;以同样方法饲养5龄幼虫,其酶活性亦呈先升后降趋势,但每代处理与对照组的差异均不显著.芫花活性物质既抑制试虫取食,使其"收入"减少,又促进消化酶及解毒酶超量分泌,造成"支出"增加,最终导致虫体逐渐衰竭死亡.     

无瓣海桑主要害虫绿黄枯叶蛾的取食行为研究

绿黄枯叶蛾Trabala vishnou Lefebure是红树林植物无瓣海桑Sonneratia apetala Buch-Ham的重要害虫,为制定科学的防治指标和防治策略,对该虫的取食行为和取食量进行了初步的研究。结果表明:绿黄枯叶蛾幼虫喜食无瓣海桑、尾巨桉,拒食秋茄、桐花树;幼虫5龄,1～3龄幼虫具有聚集性,4龄幼虫开始分散取食;1～2龄幼虫取食量少,3～5龄取食量占整个幼虫期取食量的98.12%,其中5龄幼虫的取食量占整个幼虫期取食量的74.52%;幼虫期平均取食无辨海桑叶片178.94 cm2/头,确定防治指标为9.8头/千叶。     

芫花活性物质对昆虫取食和生长的影响

室内生测表明不同浓度芫花乙醇粗提物（YAE）处理叶饲养卫矛尽Hu24h后，导致试虫食量减少，体重下降，且浓度与效果呈正相关，如10％芫花处理组食叶量比CK减少53.78％（重量计），虫重比原来下降14.81%，而K体重增加19.51%。β－谷甾醇对试虫食叶量影响虽不明显，但1.0%,0.5%,0.1%处理仍可使虫体显著下降。YAE的拒食中浓度为2.76％β－谷甾醇为0.34%。YAE及β－谷甾醇 对4龄斜纹夜蛾的抑制取食及生长的作用均不及卫矛尺Hu显著。     

油茶斜纹夜蛾、黄刺蛾的生活习性与防治方法

一、斜纹夜蛾 1.危害情况 危害荷花、睡莲、大丽花、木槿、月季、百合、仙客来、菊花、山茶、葛兰等约200余种.初孵幼虫取食叶肉,2龄后分散危害,4龄后进入暴食期,将整株叶片吃光,影响植物正常生长,严重时可至植株死亡.     

松褐天牛肿腿蜂对松褐天牛低龄幼虫控制作用的研究

研究测定了松褐天牛肿腿蜂对松褐天牛1～3龄幼虫的控制作用,采用林间和室内罩网相结合的方法研究了2组松褐天牛肿腿蜂对松褐天牛幼虫的寄生情况.结果显示:在室内试验条件下,松褐天牛肿腿蜂产卵之前的刺蛰、补充营养取食能直接造成松褐天牛1～3龄幼虫死亡,对1、2及3龄幼虫的平均致死率分别为95.66％、85.91％、57.88％,并可产卵寄生2、3龄幼虫;林间释放2组松褐天牛肿腿蜂后,在刺蛰和补充营养取食后能有效寄生寄主的肿腿蜂雌蜂数量比例变化较大,有效肿腿蜂率最高为14.9％,最低为2.3％.松褐天牛肿腿蜂寄生行为不受寄主聚集程度的影响,但刚羽化出茧肿腿蜂雌蜂的寄生效率比经饲喂后的雌蜂高近5倍.从肿腿蜂单一个体来看,每头雌蜂补充营养取食和产卵寄生致死的松褐天牛幼虫数为2.1～7.7头.松褐天牛肿腿蜂雌蜂的补充营养习性及刺蛰、取食致死寄主行为在防治中有很重要的作用,表明该种肿腿蜂是防治松褐天牛的重要天敌,在生物防治松褐天牛幼龄幼虫上具有良好的应用前景.     

臭椿皮蛾生物学特性及防治试验

臭椿皮蛾,主要危害臭椿叶片,老熟幼虫每头每昼夜能取食臭椿叶2片,取食叶片面积68.25cm2,叶重达1.5g;特别是将苗木、幼树常常吃成残枝秃梗。成虫为吸果夜蛾,夜间能危害吮吸梨、苹果、柑橘等果实,造成腐烂和落果。     

芒果成果期虫害的防治

芒果幼果的主要害虫有食果蛾和蛀果蛾。它们将卵产在果皮、果柄上,孵化出的幼虫在果内取食,引起芒果枯缩、落果。芒果果实成熟期主要害虫有柑桔小食蝇和吸果夜蛾。小食蝇将卵产在将近成熟的芒果果皮内,孵化出的幼虫在果内取食,引起烂果、落果。吸果夜蛾以锐利的口器吸芒果果汁,引起芒果腐烂。其防治方法有:①在芒果落花后,果实有碗豆大时,便要开始喷施敌敌     

芫花杀虫活性组份的浸提、分离与生物测定

以卫矛尺蠖和斜纹夜蛾为试虫,以取食量及虫体增重为指标,用选择性和非选择性取食法测定乙醚等7种溶剂浸提芫花茎皮粉5 d后的浸提液.结果表明:乙醚、甲醇、氯仿及乙酸乙酯是最好的几种溶剂,乙醇次之,石油醚最差;芫花乙醇粗提液减压浓缩--石油醚多次萃取,是获得柱层析物质的必要步骤.柱层析各组份生测一致显示,活性组份存在于极性小的第4,5组份及极性大的第13组份,通过小柱纯化及薄层层析检测与标准化合物对照,认为β-谷甾醇是第4,5组份中主要的物质,生测表明,它能显著减少试虫取食量及体重增长,乙醇浸泡1,3,5 d与活性强弱关系不大.20%芫花乙醇粗提物在室内贮藏一年,不会使活性下降.     

幼虫取食不同寄主树种的云斑白条天牛成虫种群分化

【目的】基于幼虫取食不同寄主树种云斑白条天牛的成虫补充营养行为、形态特征及遗传特性的比较,探讨不同寄主对成虫行为的影响及其机制。【方法】比较幼虫取食毛白杨和美国红木岑2种寄主树种的云斑白条天牛成虫外形特征及雄性生殖器结构差异,利用选择性取食试验,观测这2类云斑白条天牛成虫对美国红木岑、野蔷薇、美国山核桃、日本珊瑚树及毛白杨5种寄主植物嫩枝的取食行为及交配行为,最后基于COI基因分析二者间遗传多样性差异及系统发育关系。【结果】1)幼虫取食美国红木岑的云斑白条天牛和幼虫取食毛白杨的云斑白条天牛外部特征存在明显差异。幼虫取食美国红木岑的云斑白条天牛雄虫腹部末端窄,呈钝角内凹状,毛稀疏,雌虫腹部末端呈弧形内凹,底部中央缺刻不明显,而幼虫取食毛白杨的云斑白条天牛雄虫腹部末端宽,呈弧形内凹状,密被毛,雌虫腹部末端呈平截状,底部中央具有明显缺刻;两者生殖器差异不明显; 2)幼虫取食美国红木岑的云斑白条天牛成虫仅取食美国红木岑嫩枝,而幼虫取食毛白杨的云斑白条天牛可取食野蔷薇、美国山核桃和日本珊瑚树3种植物嫩枝,偏好顺序为野蔷薇美国山核桃日本珊瑚树; 3) 2个种群的天牛雌、雄成虫之间可相互交配,平均交配次数较同类群间存在差异但不显著(P0.05); 4) 2个不同寄主源的天牛种群存在明显遗传分化,分化指数Fst=0.814(P0.001),变异分化主要来源于种群间(83.19%)。【结论】幼虫的取食经历(取食不同寄主植物)和生境异质性可能对云斑白条天牛成虫补充营养行为及种群遗传分化产生显著影响。     

二株莱氏野村菌对斜纹贪夜蛾幼虫的致病性(英文)

二株莱氏野村菌分别分离自日本的淡剑贪夜蛾和大豆夜蛾 ,将他们接种于斜纹贪夜蛾的幼虫 ,并饲以人工饲料 .共设置 5个分生孢子悬浮液的浓度梯度 ,即 10 7,10 6 ,10 5,10 4 ,10 3孢子 /毫升 .对斜纹贪夜蛾幼虫的毒力试验结果表明 :分离自淡剑贪夜蛾菌株的LC50为 5 38,分离自大豆夜蛾菌株的LC50为 5 71,10 7孢子 /毫升浓度分生孢子悬浮液的致病死亡率分别为 89 5%和 84 2 %     

辣木人工林的主要害虫种类及其空间分布

对广东省梅州市梅江区西阳镇林林试验样地进行调查，初步掌握了辣木人工林为害害虫的 主要种类、发生规律以及空间分布。结果表明：辣木人工林主要害虫种类有含夜蛾 Prodenia litura、小 菜蛾 Plutella xylostella、赤斑白条天牛 Batocera rufomaculata、花蓟马 Frankliniella intonsa、稻管蓟马 Haplothrips aculeatus、斜纹夜蛾 Spodoptera litura 和茶蚜 Toxoptera aurantii 共 7 种；夜蛾与小菜蛾的发生 危害程度已达到重度危害水平，而花蓟马、稻管蓟马与茶蚜则达到中度危害水平，斜纹夜蛾与赤斑白条 天牛的危害程度则为轻度；主要害虫幼虫种群的发生为害高峰时间为 9 月，1 月 -3 月幼虫种群几乎不发 生为害，其余月份幼虫种群虫口密度较低；夜蛾、小菜蛾、花蓟马、稻管蓟马、茶蚜与斜纹夜蛾的幼虫 空间分布均呈均匀分布，而赤斑白条天牛幼虫呈聚集分布，聚集发生的原因是林间外界环境因子与其自 身生物学特性共同相互作用引起的。     

Antifeedant activity of Momordica dioica fruit pulp extracts on Spodoptera litura

The hexane extract and ethyl acetate soluble fraction of methanolic extract of the fruit pulp of Momordica dioica exhibited moderate and concentration dependent antifeedant activity against Spodoptera litura.     

Bioactivities of caffeic acid methyl ester (methyl-(E)-3-(3,4-dihydroxyphenyl)prop-2-enoate): a hydroxycinnamic acid derivative from Solanum melongena L. fruits

Feeding deterrent and growth inhibitory effects of caffeic acid methyl ester (CME) isolated from the fruit extract of eggplant, Solanum melongena L. along with two known phenolic acids, caffeic acid (CA) and chlorogenic acid (CG) and azadirachtin (taken as active control), were evaluated against Spodoptera litura Fab. and Achaea janata L. (Lep., Noctuidae). The structure of CME was determined on the basis of extensive spectroscopic (UV, FTIR, ¹H, and ¹³C NMR) data analysis. CME has exhibited strong feeding deterrent activity against S. litura and A. janata larvae with ED₅₀ values of 52.02 and 41.02 μg/cm² leaf area, respectively. CA and CG were relatively less effective compounds when compared with CME. The results also revealed that the isolated compound CME caused marked larval growth inhibition in S. litura and A. janata larvae after 7 days of feeding on a treated diet. The effect on growth of larvae was concomitant with the reduced feeding and digestibility of ingested food. So the activities of digestive proteases within the midgut of larvae were examined using specific substrates to understand the digestive physiology in the larval guts. The bulk of the activity was associated with serine proteases comprising trypsin-, chymotrypsin-, and elastase-like enzymes, which decreased in diets containing CME, whereas, interestingly increased with CG. From the results, we conclude that CME isolated from S. melongena fruit extract shows feeding deterrent and larval development inhibitory activities that may prove useful in the management of S. litura and A. janata larvae.     

Chemical constituents of the aerial part of Derris elliptica

A new coumaronochromone, 6,4'-dihydroxy-7,5' -dimethoxy-coumaronochromone (1), together with eleven known flavonoids (2-12) were isolated from the ethanol extract of the aerial part of Derris elliptica. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 2, 4, 7, 8 and 9 exhibited moderate insecticidal activities against larvae of Aedes albopictus. All compounds showed strong cytotoxic activities against Spodoptera litura (SL) and Trichoplusia ni BTI-Tn-5B1-4 (Hi-5) cells comparison to positive control of rotenone.     

四种植物提取物对斜纹夜蛾卵的毒杀效果

以斜纹夜蛾卵为研究对象．对雷公藤Tripter gium wilfordii茎、皂荚Gleditsia sinensis Lam．刺、苦参Sophora flavescens和博落茴Macleya cordata等4种植物材料的正已烷及乙酸乙酯提取物的杀卵活性进行了测定。结果表明：博落茴的乙酸乙酯提取物对斜纹夜蛾卵有较好的杀伤力,校正未孵化率高达95．63%;雷公藤的乙酸乙酯提取物和苦参的正已烷提取物对斜纹夜蛾卵的孵化也有明显的抑制作用。     

Zur Wirkung der Nahrungspflanze auf die Entwicklung und Vermeharung der Baumwolleule,Spodoptera littoralis (Boisd.) (Lep.,Noctuidae)

Effect of some host plants on development and reproduction of Spodoptera littoralis (Boisd.) (Lep., Noctuidae) Investigations were performed to study the effect of some hostplants on development and reproduction capacity of the Egyptian cotton leaf-worm,Spodoptera littoralis (Boisd,), Larval and pupal weights, life span, average number of eggs laid per female and percent digestability for fifth instar larvae were measured. Cotton leafworm was able to complete its life cycle only when reared on eigher castor bean leaves, clover, sweet potato leaves, or the outer green cabbage leaves. Chlorophyl-free inner white cabbage leaves, maize, and grape vine are nutritionally insufficient to support growth and development of larvae and, in turn, cause increase in span of survived larvae and none of these larvae metamorph to pupae. It seems that there is a positive correlation between larval and pupal weights and average number of eggs laid per female; the greater the weight of larvae and pupae the higher the number of eggs laid. Castor bean leaves seem to be the most favorable host plant for rearing cotton leafworm in the laboratory. The differences and variations in the growth and development of cotton leafworm due to feeding on different host plants are discussed.     

Insecticide and antifeedant activity of different plant parts of Melia azedarach on Xanthogaleruca luteola

In laboratory choice and no-choice bioassays, treatment of elm leaves with extracts obtained from unripe fruits and green or senescent leaves of Melia azedarach at 1-10% concentration significantly deterred feeding by adults of the elm leaf beetle, Xanthogaleruca luteola. Also, in no-choice tests, adults fed on leaves treated with 2, 5 or 10% extract showed a dramatic increase in mortality rates. Extracts from the different plant structures were similarly active, and starvation as a consequence of their strong antifeedant activity could play a significant role in the high mortality values observed.     

Effects of herbicides on consumption,growth and food utilization by cotton leafwormSpodoptera littoralis (Boisd.) larvae

The deterrent effects of nine herbicides on feeding and growth of cotton leafworm,Spodoptera littoralis (Boisd.), larvae were investigated. Fourth-instar larvae were fed on castor-bean leaves treated with recommended field rates of selected herbicides. Nutritional indices were measured regularly throughout the feeding tests until pupation. The food consumed by larvae in most herbicide-treatments was below that of control. Fluazifop [500 active ingredient (AI)], bentazon (250 AI), ametryne (800, 1600 AI), flamprop (130 AI), and isoxynil (187.5 AI) treatments seemed to be the best feeding deterrents. Relative growth rates of larvae fed on leaves treated with bentazon (250 AI), ametryne (1600 AI), gluphosate (1440 AI), glufosinate (800 AI), and bromoxynil (120 AI) were significantly reduced compared to that in control. Likewise, both the efficiency of conversion of ingested food to body substance (ECI) and the efficiency of conversion of digested food to body substance (ECD) were reduced with herbicide treatments below that in control. Approximate digestibility (AD), however, was significantly increased with most herbicide treatments. Moreover, feeding on herbicide-treated leaves resulted in a significant reduction in both pupation and adult emergence compared to that in control.     

6种木本植物叶浸液对钉螺驱杀作用及其生殖器官解剖结构的影响

通过应用乌桕、夹竹桃、大叶冬青、珊瑚朴、薄壳山核桃、苦楝6种木本植物叶浸液对钉螺驱杀实验及其解剖结构的影响研究,结果表明：（1）薄壳山核桃、珊瑚朴叶浸提液较短时间对钉螺几乎没有毒杀作用,苦楝叶浸液对钉螺毒杀作用最明显,其依次是夹竹桃、乌桕、大叶冬青;随着时间的推移,6种叶浸液对钉螺毒杀作用均达100％。（2）不同树种叶浸提混合液对钉螺的毒害作用明显大于单种植物浸提液。钉螺分别在大叶冬青×薄壳山核桃、夹竹桃×苦楝、冬青×乌桕、珊瑚朴×乌桕4种叶浸提混合液处理下,从5-30min,冬青X薄壳山核桃处理组的钉螺逃逸率10％～12％。假死率88％。99％;夹竹桃×苦楝处理组的钉螺逃逸率始终是0％,假死率始终是100％;冬青×乌桕处理组的钉螺逃逸率0。2％,假死率98％。100％;珊瑚朴×乌桕处理组的钉螺逃逸率8％-24％,假死率76％-97％。（3）钉螺分别在珊瑚朴、薄壳山核桃、乌桕、夹竹桃、大叶冬青、苦楝6种叶浸提液处理24h后,6种处理的雄性螺的阴茎、雌性螺的卵巢解剖结构分别与对照相比,均无明显变化。因此,在建设血防林时,可以考虑利用像大叶冬青、乌桕、夹竹桃、苦楝等树种营造混交林,对钉螺的分布与驱散有一定的作用。