丹皮酚对马铃薯块茎蛾雌虫产卵选择及幼虫的忌避作用研究

为探讨丹皮酚对马铃薯块茎蛾Phthorimaea operculella(Zeller)行为的影响,采用室内生物测定法,研究了丹皮酚对马铃薯块茎蛾雌虫产卵选择及初孵幼虫、老熟幼虫的忌避作用.结果表明,丹皮酚对马铃薯块茎蛾雌虫产卵、初孵幼虫、老熟幼虫均有显著忌避作用:选择性产卵实验中,5 mg/mL丹皮酚溶液的忌避指数为-0.63;非选择性产卵实验中,5 mg/mL和1 mg/mL丹皮酚溶液的产卵忌避率分别为-89.0％和-46.6％,且前者对马铃薯块茎蛾产卵有抑制作用;5 mg/mL及1 mg/mL丹皮酚溶液对马铃薯块茎蛾初孵幼虫均有极显著忌避作用,5 mg/mL丹皮酚溶液的忌避作用在0.5 h内可保持100％的忌避率,之后随时间延长而逐渐减弱;丹皮酚:沙(1 mg:2 g)对马铃薯块茎蛾老熟幼虫有显著忌避作用.本研究为丹皮酚作为一种有潜力的植物源忌避剂用于马铃薯仓贮期马铃薯块茎蛾虫害的防治提供理论依据.     

山东茶褐蓑蛾生物学特性及防治

茶褐蓑蛾MahasenacolonSonan是茶树的主要害虫之一。该虫在山东茶区每年发生 1代 ,以 7龄幼虫越冬。作者于 1 997年起对其幼虫、蛹、成虫及天敌进行了初步研究 ,统计出害虫在各龄期的分布规律 ,并提出了针对性的防治方法。     

蕾鹿蛾生物学特性及防治

蕾鹿蛾是黑荆树的一种重要害虫。该虫在福建南平一年发生3代,以幼虫越冬,翌年4月下旬开始化蛹本文描述了该虫的形态特征,记述了它的生活史、生活习性、天敌种类,提出了防治方法。     

葡萄花翅小卷蛾抗药性研究进展

葡萄花翅小卷蛾是葡萄上的重要害虫,具有多食性、多化性等生物学特点,抗逆能力极强。该虫起源于欧洲,现已入侵全球多个国家。葡萄花翅小卷蛾主要以幼虫取食葡萄花序、幼果和成熟果实,给葡萄生产造成重大损失;其危害有利于真菌的侵入,导致灰霉病、白粉病等病害大量发生,从而造成葡萄腐烂。由于该虫入侵风险极高,已被我国列为重要的进境检疫性有害生物。国外对葡萄花翅小卷蛾的防治主要采用化学杀虫剂,由于长期大量且不合理地使用化学杀虫剂,葡萄花翅小卷蛾已对多种不同类型的杀虫剂产生了抗药性。本研究总结了葡萄花翅小卷蛾的抗性测定方法、抗性现状及其抗性机理,同时结合国外葡萄花翅小卷蛾抗性和防治相关研究,提出该虫抗性治理策略,并对我国预防该虫的入侵提出建议。     

肉桂双瓣卷蛾为害对樟树叶片挥发物的影响

采用顶空固相微萃取(SPME)及气相色谱-质谱联用仪(GC-MS)技术分析肉桂双瓣卷蛾为害前后的樟树叶片挥发物变化。结果表明,健康和虫伤的樟树叶片中均含有26种相同的挥发物成份,但是肉桂双瓣卷蛾为害后挥发物的相对含量发生显著变化。肉桂双瓣卷蛾危害后,叶片中的黄樟素含量显著增高,健康叶片中黄樟素仅占0.6%,而虫伤叶片中为2.7%;但是反-水合倍半香桧烯、顺-橙花叔醇、反-橙花叔醇及α-红没药烯含量均显著降低,健康叶中分别含1.9%、4.5%、11.6%和1.2%,而虫伤叶片中分别占0.6%、2.1%、7.0%和0.7%。挥发物组分含量变化可能在调控害虫取食、天敌对猎物的搜寻等行为过程中发挥作用。本研究为探索植物挥发物对害虫及天敌行为的影响奠定基础,为了解寄主-昆虫-天敌三层营养关系的相互作用、利用天然活性化合物防治害虫提供理论依据。     

生物源农药在苹果蠹蛾防治中的应用

苹果蠹蛾是世界性检疫害虫,对我国苹果优势产区构成了巨大威胁。长期依赖化学防治使该虫抗性问题变得十分严峻。为了保障食品安全,以环境友好的生物源农药替代化学农药已成为当前苹果蠹蛾防治的热点。本文对国内外现有的生物源农药,如寄生蜂、不育昆虫、颗粒体病毒、病原线虫、Bt、病原真菌、微孢子虫、性信息素、斑蝥素、多杀菌素等,在苹果蠹蛾防治中的最新应用及其存在的问题进行论述,讨论了生物源农药凭借其种类多、来源广且在用药时期上选择性强等特点,在该虫综合治理中的重要地位及面临的挑战。     

竹笋禾夜蛾生物学特性及其防治

竹笋禾夜蛾是福建省竹林的主要害虫,该虫在福建一年发生1代,以卵越冬,翌年2月中旬开始孵化,幼虫6龄,幼虫期51—80天,蛹期17—29天。每雌一生产卵84—467粒．成虫寿命6—17天。该虫的综合防治应以林业防治为主,9月份开始林地除草灭虫;3月初以化学农药喷杂革治虫,4月初出笋后对笋喷药2次;成虫羽化盛期点灯诱蛾等坊治措施,可以有效地控制虫害。     

控制害虫的新设想——不育基因的生物工程

害虫防治的重要性和艰巨性害虫给农作物和人类健康所造成的危害是巨大的。在长期生产实践中,人们已经发展了各种方法来控制害虫,其中包括农业防治、化学药剂防治、生物防治(应用微生物杀虫剂和天敌昆虫)、物理防治和遗传防治等防治和技术。但是这些方法的使用都有一定的局限性和副作用,有的甚至造成了严重后果。例如作为目前生产中占主导地位的化学药剂防治,已给人类带来了很大麻烦,害虫对化学农药产生抗性,导致农药的     

用马铃薯人工饲养马铃薯块茎蛾的方法

介绍一种马铃薯块茎蛾Phthorimaeaoperculella的室内人工饲养方法。在人工养虫室内用 1 0 %的蜂蜜水喂养成虫 ,用滤纸收集卵块 ,幼虫在薯块上饲养 ,化蛹于牛皮纸卷成的纸筒中 ,饲养结果发现马铃薯块茎蛾完成 1代大约需要 35～ 4 6d ,室内连续饲养块茎蛾 3代 ,卵的孵化率、幼虫化蛹率、成虫羽化率均在 90 %以上。     

害虫的生物防除

昆虫天敌对于昆虫的发生常有抑制的作用,科学工作者根据这一原理,利用害虫的天敌去防治害虫,其方法称为害虫生物防除法. 昆虫的天敌很多,包括病原微生物(病毒、细菌、真菌和原生动物)线虫、壁虱目动物,昆虫(捕食性昆虫及寄生性昆虫)和脊椎动物.除此以外,还可包括一些高等植物.昆虫的天敌,虽然有上述的几大类,但并非全部都能够用来防治害虫,利用得最普遍的是捕食性昆虫和寄生性昆虫,其次是病原微生物和脊椎动物,至于线虫和壁虱目动物,只是偶有利用.     

The potential of the fungus, Muscodor albus, as a microbial control agent of potato tuber moth (Lepidoptera: Gelechiidae) in stored potatoes

Potato tuber moth (PTM), Phthorimaea operculella, is a serious pest of stored potato in most countries where potatoes are grown. Entomopathogens offer promise as alternatives to broad spectrum insecticides for management of this pest. The fungus Muscodor albus, which produces a mixture of antimicrobial volatile organic chemicals, was tested for its insecticidal activity against PTM. Adults and neonate larvae were exposed to volatiles generated by 15 or 30 g of M. albus rye grain culture plus water for 72 h in hermetically sealed 28.3 L chambers at 24 degrees C. Mean percent mortalities in adult moths exposed to 0, 15, and 30 g of fungal formulation were 0.9, 84.6, and 90.6%, respectively. Development to the pupal stage of PTM that were exposed as neonate larvae to 15 or 30 of M. albus culture was reduced by 61.8 and 72.8%, respectively, relative to controls.     

Spatial and temporal dynamics of potato tuberworm (Lepidoptera: Gelechiidae) infestation in field-stored potatoes

The potato tuberworm, Phthorimaea operculella (Zeller), is a major pest of potatoes in fields and traditional storage. A common method of nonrefrigerated storage is to pile potatoes in straw-covered heaps in the field. Tubers may be stored up to 3-4 mo in this manner, until the next harvest. We studied the dynamics of potato tuber moth infestation associated with such field storage in a 12-wk experiment in Israel. We set up six potato heaps, and sampled them for potato tuber moth at different locations at weekly intervals. Potato tuber moth infestation was significantly higher at the perimeter of the heaps than at their center, but it did not differ between bottom, mid-height, and top of the heaps. The proportion of potato tuber moth-infested potato tubers increased from 10 to 65% over the course of the experiment, and the mean number of potato tuber moth larvae per tuber increased from 0.25 to 2.50. Potato tuberworm populations increased sharply after 3, 6, and 9 wk of study, possibly corresponding to successive generations that developed within the heaps. This interpretation is supported by calculations of potato tuberworm generation length based on temperature data. Catches in pheromone traps that were placed near the heaps were not correlated (spatially and temporally) with potato tuberworm densities within heaps, hinting that migration among heaps did not considerably affect within-heap population dynamics. Potato tuberworm levels were not correlated with ambient temperatures, perhaps because of the warm, humid, and constant microclimate within the heaps. We discuss the significance of our findings for control efforts of the potato tuberworm.     

Experimental mixtures of Phthorimaea operculella granulovirus isolates provide high biological efficacy on both Phthorimaea operculella and Tecia solanivora (Lepidoptera: Gelechiidae)

The Guatemalan potato moth Tecia solanivora (Povolny) recently invaded part of South America, colonizing zones where Phthorimaea operculella (Zeller), another potato moth species belonging to the same group, was previously established. T. solanivora is now the major insect pest of potato in this area encompassing Venezuela, Colombia and Ecuador. P. operculella granulovirus (PhopGV) (Betabaculovirus) is a biocontrol agent to be considered for the simultaneous management of these two potato pests, instead of classical chemical insecticides. In a previous work, five PhopGV isolates were isolated in Colombia from T. solanivora and were tested against larvae of the same species showing variable efficacies. Infections with mixtures of different genotypes of Baculoviruses had been carried out in a wide range of species and several showed interesting results. In the present study, the effect of sequential passages of PhopGV in P. operculella and T. solanivora larvae was analyzed through biological assays. Three different mixtures containing a Peruvian PhopGV isolate (Peru) adapted to P. operculella and a Colombian PhopGV isolate (VG003) adapted to T. solanivora were tested. A preliminary analysis of the correlation between the genotypic marker egt gene and the level of pathogenicity after a variable number of replication cycles was made. Mixtures of virus isolates showed a higher efficacy in both hosts compared to individual PhopGV isolates. This higher pathogenicity was maintained through passages. In P. operculella the mixtures were between 2.8 and 23.6-fold (from 7.15 OB/mm(2) to 0.10 OB/mm(2)) more pathogenic than isolate Peru applied alone. In T. solanivora they were between 2.3 and 4.9-fold (from 12.29 OB/mm(2) to 1.25 OB/mm(2)) more pathogenic than isolate VG003 alone. Viral biopesticide containing a mixture of selected genotypes active against each hosts seemed suitable for the development of a biopesticide aimed to simultaneously control P. operculella and T. solanivora.     

Mechanisms for flowering plants to benefit arthropod natural enemies of insect pests： Prospects for enhanced use in agriculture

Reduction of noncrop habitats, intensive use of pesticides and high levels of disturbance associated with intensive crop production simplify the farming landscape and bring about a sharp decline of biodiversity. This, in turn, weakens the biological control ecosystem service provided by arthropod natural enemies. Strategic use of flowering plants to enhance plant biodiversity in a well-targeted manner can provide natural enemies with food sources and shelter to improve biological control and reduce dependence on chemical pesticides. This article reviews the nutritional value of various types of plant-derived food for natural enemies, possible adverse effects on pest management, and the practical application of flowering plants in orchards, vegetables and field crops, agricultural systems where most research has taken place. Prospects for more effective use of flowering plants to maximize biological control of insect pests in agroecosystem are good but depend up on selection of optimal plant species based on information on the ecological mechanisms by which natural enemies are selectively favored over pest species.     

Determining the number of instars in potato tuber moth Phthorimaea operculella (Zeller) using density‐based DBSCAN clustering

The potato tuber moth (PTM), Phthorimaea operculella (Zeller), is an important pest of Solanaceae crops and especially devastating to potatoes. There is no significant difference in morphological characteristics of PTM from the first to third instar larvae; therefore, it is difficult to directly determine the number of instars of this pest based on morphology. In the present study, head capsule width and length and mandible width of 340 PTM individuals were measured. Density‐based spatial clustering of applications with noise (DBSCAN) clustering was used for instar grouping. The results of DBSCAN clustering were compared with those obtained using Gaussian mixture models and k‐means clustering; the results of the three clustering methods were verified using Brooks–Dyar rule, Crosby rule and linear regression model. The clusters obtained using the three methods were the same and comprised four PTM instars with three morphological characteristics. Moreover, the results of the three methods fit the Brooks–Dyar rule, Crosby rule, frequency analysis and logarithmic regression model well. Head capsule width was the best morphological characteristic for determining the number of instars of PTM, and this characteristic may be used for determining PTM instars in the field. These results show that the DBSCAN clustering method is a promising tool for the identification of insect instars.     

Population dynamics of the potato tuber moth on processing tomatoes in Israel

The potato tuber moth (PTM),Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is a major pest of processing tomatoes,Lycopersicon esculentum Mill. (Solanaceae), in Israel. The larvae penetrate the tomato fruit through the stem end and present a serious threat to crop quality. Foliage and fruit samples were taken in nine commercial tomato fields located in Israel's three main tomato growing areas, two of which are potato growing areas as well. PTM was not found where potatoes were absent. Potato harvest in nearby fields was found to be the most significant factor affecting seasonal trends in PTM population density in tomatoes. All four larval instars were found in foliage on all sampling dates. Significantly higher proportions of first instars were found during the population density increase which followed potato harvest. Damaged fruits did not contain first instar larvae, indicating that PTM never undergoes complete development within tomato fruit. Fruit damage levels at harvest were positively correlated to the peak mean population densities on foliage and the date they were observed. In tomato fields not adjacent to potatoes, infestation was first observed at the edge of the field. Both before and after the potato harvest in nearby fields, population density at the edge of the field was significantly higher than at the center. In tomato fields adjacent to potatoes, no significant differences were found between population densities at the edge and center before the potatoes were harvested. After the potato harvest, population density at the center of tomato fields was higher than at the edge. Deceased, October 1988     

Can microbial-based insecticides replace chemical pesticides in agricultural production?

Extensive use of chemical insecticides to control insect pests in agriculture has improved yields and production of high-quality food products. However, chemical insecticides have been shown to be harmful also to beneficial insects and many other organisms like vertebrates. Thus, there is a need to replace those chemical insecticides by other control methods in order to protect the environment. Insect pest pathogens, like bacteria, viruses or fungi, are interesting alternatives for production of microbial-based insecticides to replace the use of chemical products in agriculture. Organic farming, which does not use chemical pesticides for pest control, relies on integrated pest management techniques and in the use of microbial-based insecticides for pest control. Microbial-based insecticides require precise formulation and extensive monitoring of insect pests, since they are highly specific for certain insect pests and in general are more effective for larval young instars. Here, we analyse the possibility of using microbial-based insecticides to replace chemical pesticides in agricultural production.     

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.