Relative toxicity of insecticides to the crucifer pests Plutella xylostella and Myzus persicae and their natural enemies

The widespread and intensive use of conventional pesticides, particularly insecticides, presents a major risk to natural enemies of target pests, as well as to the environment in general. The aim of this study was to investigate the differential intrinsic toxicity of insecticides to two key pests of crucifers, Plutella xylostella and Myzus persicae and their respective hymenopteran parasitoids, Cotesia vestalis and Aphidius colemani. Such knowledge can help inform effective integration of insecticides and biological control in IPM systems. Three insecticides generally regarded as being compatible with natural enemies (abamectin, spinosad and indoxacarb) and one compound regarded as harmful to natural enemies (lambda-cyhalothrin) were examined. A comparative measure of the intrinsic toxicity of fresh deposits of insecticides on Chinese cabbage leaf discs was determined for both pest and parasitoids species after exposure to insecticide for 24 h and 120 h, and after 24 h exposure to insecticide plus 96 h on untreated leaf discs. Differences in the susceptibility of pests and parasitoids to different insecticides were marked for P. xylostella and C. vestalis, LC₅₀ values being significantly lower for the pest species. Such differences were not observed for M. persicae and A. colemani. There was a direct relationship between dose, exposure time and toxicity for all insecticides tested. All insecticides tested showed lower toxicity to both parasitoids compared with P. xylostella, which suggests that for this pest species side-effects on parasitoids can be minimised through IPM practices that reduce exposure time to such non-target organisms.     

云南河口芒果主要病虫害发生规律调查及害虫天敌种类研究

通过对湿热地区云南河口县芒果园内的5种主要病虫害发生规律进行调查,根据调查情况对芒果白粉病、炭疽病,芒果横线尾夜蛾、芒果切叶象甲、桔小实蝇等5种发生程度较重的病虫害进行发生危害情况的相关分析,同时对云南河口地区芒果害虫天敌进行搜集、调查及鉴定,调查鉴定结果表明：共有天敌昆虫24种,其中寄生性天敌11种,分属于2目5科;捕食性天敌昆虫21种,分属于5目8科。调查结果对于生产上科学制定芒果病虫害防治措施具有重要的意义。     

Propagation and release of natural enemies for control of cotton insect and mite pests in the United States

The state of the art for controlling four primary pests or pest complexes by augmentative releases of predators and parasitoids in the United States is reviewed. The pests are (1) the bollworm, Helicoverpa zea (Boddie) and tobacco budworm, Heliothis virescens (F.), (2)_the boll weevil, Anthonomus grandis grandis (Boheman), (3) the pink bollworm, Pectinophora gossypiella (Saunders) and (4) plant bugs, specifically Lygus spp. Rearing of the predators and parasitoids and identification and the use of behaviour-modifying chemicals are described and discussed.     

Integrated pest management in field vegetable crops in northern Europe — with focus on two key pests

Improvements in (1) insecticide application, (2) supervised control, and (3) pest forecasting systems have each helped to reduce considerably the amounts of insecticides required to control fly, caterpillar and aphid infestations in vegetable crops in northern Europe. By growing plants that are partially resistant to certain major pests, it is now possible to apply even less insecticide than the dose recommended for the crop. In crops where only small amounts of insecticides are applied, natural predators should prevent large increases in pest insect populations and natural parasitoids should reduce the numbers of pest insects entering subsequent generations. The possible impact of introducing transgenic plants and the use of physical (crop covers), cultural (crop rotation, undersowing) and microbial (e.g. fungi, bacteria and nematodes) methods of control are also discussed. The withdrawal of certain insecticides, as a result of environmental and commercial pressures, means that some crops may soon be without appropriate insecticides for controlling one or more of the major pest species. Whether such systems will be sustainable, remains to be seen.     

广西南宁地区龙眼害虫群落结构及其动态研究

根据龙眼害虫群落内部物种的组成和数量，采用群落的几个参数进行分析和探讨群落内部的演替规律。结果表明，为害龙眼的害虫有３１科６７属７６种。优势种有１３种。每年３－９月是主要害虫发生为害高峰期。是生产中防治的重要。多样性指数以５、６月份最高。２月份最低。害虫生物学特性、树龄、气候条件和生态环境等都是影响害虫群落结构的主要因子。     

2种瓜实蝇寄生蜂的研究进展

瓜实蝇(Bactrocera cucurbitae Coquillett)是危害多种蔬菜和水果的重要害虫,化学防治效果成效甚微,生物防治有望成为最有潜力的防治技术。本文主要对瓜实蝇的寄生性天敌阿里山潜蝇茧蜂(Fopius arisanus Sonan)和弗氏短背茧蜂(Psyttalia fletcheri Silvestri)的生物学特性、影响寄生蜂存活和雌雄性比的主要因素、寄主范围及寄主选择性、扩繁技术及其对实蝇的防治效果等方面进行综述,为2种蜂在瓜实蝇生物防治中的应用提供参考。     

Farmers’ knowledge and perceptions of pests in agroforestry with particular reference to Alnus species in Kabale district, Uganda

Ugandan farmers were interviewed in order to investigate their knowledge, perceptions and ability to manage pests in agroforestry generally and on Alnus species particularly. Farmers’ ability to recognise pest problems on Alnus species was significantly influenced by their length of experience in cultivating the species, but not their age, sex or formal education. Most farmers (77%) were aware of pest problems on Alnus species. However, identification of pest problems was based largely on damage type rather than causal agents. Whereas farmers had good knowledge of vertebrate pests of Alnus, insects and diseases that infest the tree species were unknown to most farmers. Apis mellifera damage on Alnus was the most frequently described damage, but its cause was either unknown or misdiagnosed. Most farmers did not control insect and disease infestations on Alnus because they did not know the causal agents and/or appropriate control measures. Farmers were generally more knowledgeable on insect and disease infestations on crops than on multipurpose tree species (MPTS) and most of them (98%) perceived that crops suffer more damage from such pests than do MPTS. However, farmers’ ability to manage insect pests and diseases seemed weak on both crops and MPTS. Most farmers suggested the use of pesticides to combat pests, but they mentioned only one insecticide, permethrin and one fungicide, mancozeb. More alarming were the suggestions by a few farmers on the use of mancozeb against aphids, and permethrin to combat crop wilt and dieback. Farmers need to be educated about diagnosis, basic ecology and management strategies for both crop and tree pests to ensure sustainable pest control in agroforestry.     

Current control methods for diamondback moth and other brassica insect pests and the prospects for improved management with lepidopteran-resistant Bt vegetable brassicas in Asia and Africa

The diamondback moth (DBM), Plutella xylostella (L.), remains a major pest of brassica crops worldwide. DBM has been estimated globally to cost US$ 1 billion in direct losses and control costs. Chemical control of this pest remains difficult due to the rapid development of resistance to insecticides and to their effect on natural enemies. These problems are especially severe in South Asia and Africa where lack of knowledge, limited access to newer and safer insecticides, and a favourable climate result in DBM remaining a serious year-round pest which substantially increases the cost and uncertainty of crop production. Despite these problems, application of synthetic insecticides remains overwhelmingly the most common control strategy. Biologically-based efforts to control DBM in Africa and Asia have focused strongly on parasitoid introductions. However, despite the identification and deployment of promising parasitoids in many regions, these efforts have had limited impact, often because farmers continue early-season spraying of broad-spectrum insecticides that are lethal to parasitoids and thus exacerbate DBM outbreaks. A significant driver for this pattern of insecticide use is the presence of aphids and other pests whose appearance initiates inappropriate spraying. Despite often extensive training of producers in farmer field schools, many growers seem loath to discard calendar or prophylactic spraying of insecticides. The introduction of an IPM technology that could replace the use of broad-spectrum insecticides for DBM and other key Lepidoptera is crucial if the benefits of parasitoid introduction are to be fully realised. The deployment of DBM-resistant brassicas expressing proteins from Bacillus thuringiensis could help to break this cycle of insecticide misuse and crop loss, but their deployment should be part of an integrated pest management (IPM) package, which recognises the constraints of farmers while addressing the requirement to control other Lepidoptera, aphids and other secondary pests.     

广东省玉米有害生物种类调查

在广东省6县18个乡镇开展玉米有害生物种类、为害及分布调查,基本摸清广东省玉米有害生物种类、为害及分布情况。结果显示,广东玉米有害生物种类48种,其中病害22种,病害以真菌为主,虫害及蜗牛26种,以鳞翅目害虫为主。发生为害表现为发生种类多,病虫草害种类及发生为害区域间差异大。     

吉林省玉米苗期害虫种类及发生趋势分析

2014~2016年对吉林省9个地市、44个县(市/区)、424个地点的玉米苗期害虫进行系统调查,分析新的耕作栽培制度和气候变暖条件下吉林省玉米苗期害虫种类、分布及发展趋势。结果表明,吉林省玉米苗期害虫有20余种,隶属5个目13个科,其中,鳞翅目和鞘翅目种类最多,共涉及8个科16种害虫,占害虫种类的70%以上;新发现吉林省玉米苗期害虫3种。蛴螬和金针虫是苗期主要害虫,平均有虫田率分别为24.90%和27.76%,有虫田率从西部到东部递减,中部平原区有虫田被害株率高于西部和东部地区。随着吉林省玉米长年连作和秸秆还田、免耕等新耕作方式推广,蛴螬和金针虫2种害虫的发生数量和危害程度呈逐年加重趋势;其余害虫有虫田率均在5.00%以下,未对玉米生产造成威胁。     

Effects of nitrogen fertilization on insect pests,their parasitoids,plant diseases and volatile organic compounds in Brassica napus

Nitrogen (N) availability is a key factor influencing the yield of Brassica napus L. Thus, mineral fertilization is widely used to improve the quality and quantity of seeds. In this study, we conducted field experiments to determine the impact of nitrogen fertilization on B. napus pests, their parasitoids and plant diseases. The results showed that N treatment had an impact on the abundance of pollen beetles (Meligethes aeneus Fab.) and cabbage seed weevils (Ceutorhynchus obstrictus Marsh.) as well as dark spot disease (Alternaria brassicae (Berk.) Sacc.). Since pest abundance was not correlated with the flower and silique numbers, the feeding and oviposition sites, plant smell bouquets were analysed to determine potentially attractive or repellent volatile organic compounds. We detected 19 different compounds among which acetic acid and several lipoxygenase pathway products were emitted at higher levels from N-treated plants. Emission of a few other terpenoid compounds was correlated with the pest abundance in field conditions. Abundance of parasitoids of both pests was related to the host availability rather than to the fertilization treatment. Therefore, we suggest that plant chemical cues play a minor role in localization of hosts in close proximity to parasitoid. Dark spot disease levels decreased with increasing N availability, possibly reflecting enhanced emissions of acetic acid, a known antifungal volatile. This study demonstrates the effects of N fertilization on bud and flower volatile bouquets, which might play a role in B. napus insect pest host selection and in resistance to fungal plant diseases. Further studies are necessary to investigate the behavioural responses of insects to the changed volatile bouquets.     

大豆地下害虫生物生态控制

针对大豆一般地下害虫为害特点、主要种类生活习性,采取相应的生物生态控制策略进行归纳总结,充分利用自然资源———植物源农药、昆虫病原微生物、天敌进行生物防治,利用生态措施对大豆地下害虫进行控制,为大豆生产实践提供参考。     

Important Threats in Potato Production and Integrated Pathogen/Pest Management

Since the 1970s climate in Europe warmed rapidly. Over the next years climate is expected to become gradually milder and more humid in northern Europe and hotter and drier in southern Europe. These changes are forecasted to be responsible for major changes in the distribution of plant and animal species, pathogen/pest prevalence and their biodiversity. On the other hand, some changes in variability and epidemiology of pathogens are affected by biological factors. In the first part of this paper an overview is given of pathogens and pests that are potentially affected by climate change and are or will become a significant threat in potato production. The second part of the paper deals with integrated crop protection of potato against various pathogens and pests, considered the best solution for these disease and pest problems. Management of persistent and recurrent diseases and pests of potato requires the integration of many control measures to achieve an efficient crop protection. The protection of potato has to start very early before planting.     

Issues affecting the use of pheromones and other semiochemicals in orchards

Pheromones represent one of the major components of ecologically based orchard pest management. This paper reviews recent progress and highlights outstanding issues. The greatest use of pheromones has been as lures for moth to traps, although identification of attractants for other insect groups is permitting diversification. Sex pheromone traps have been widely used for decision support, usually with thresholds for intervention using either broad-spectrum, or more recently, selective insecticides. Many of the issues associated with this type of application have been resolved, but new trapping systems need to ensure that lure longevity, trap efficiency, and other factors (e.g. interpretation, thresholds) are addressed. The use of kairomones (inter-specific cues) as lures in traps raises analogous issues. Attractants for beneficials (such as sex pheromones of wasp parasitoids) can offer additional benefits, including demonstrating the level of abundance or synchrony of the biological control agent with the target pest. Pheromones have also enjoyed considerable success for direct control of orchard pests, mainly through mating disruption. The technical and biological issues have been more challenging in direct control applications. There remain major knowledge gaps in the amount of pheromone required to achieve disruption, as well as the plume structure and behavioural mechanisms that operate with different types of formulations, blends and delivery systems. There has been a recent upsurge of interest in lure and kill tactic internationally. The challenges associated with direct control by mass trapping, lure and kill or lure and infect tactics need further research.     

Adaptation of approaches to pest control in low-input agriculture

Adaptation and acceptance of pest control in low-input agriculture will be largely influenced by the approach used to manage soil-borne pests. A single tactic approach, consisting of the routine application of a broad spectrum biocide or biocides to disinfest soil is not compatible with the goal of minimizing inputs and will not have wide-scale applicability in low-input production systems. An integrated pest management (IPM) approach can be compatible with low-input systems but is often difficult to implement due to inherent constraints associated with identifying and treating organisms in the soil. Additionally, IPM will require more intensive knowledge of biological interactions in the soil and the timely management of that information, which may not be practical in low input systems. A pro-active approach, in which the production system is designed to avoid the outbreak of pests, minimizes the use of inputs in crop production by reducing the need for intervention treatments. Traditionally, the impact of soil-borne pests is not considered until after the production system has been designed and implemented. Combining biologically based pest control methods with a production system designed to minimize their impacts offers the most sustainable approach for low-input agriculture.     

Farmers' knowledge and perception of grain legume pests and their management in the Eastern province of Kenya

Grain legumes play an important role in community livelihood and in the national economy in Kenya. Unfortunately, in many African countries, production doesn't satisfy the demand in grains due to various constrains. Understanding farmers practices and behavior in the management of grain legume pests is a crucial step in the development of sustainable management strategies. A total of 216 farmers were surveyed in eight districts of eastern Kenya to evaluate farmers' knowledge and perceptions of grain legume pests; to examine current pest management practices, and to identify other production constraints. Grain legumes are grown by a wide age-group of farmers, with both genders equally represented. Chemical control remains the main pest management strategy, and, to ensure pesticide effectiveness, farmers also use increased application rates, chemical alternation, frequent application and mixtures of chemicals. While farmers used other control measures, they showed only limited interest in biological control. The majority of the farmers had experience in grain legume farming and were able to identify the major pests, which were the legume flower thrips Megalurothrips sjostedti Trybom, the cowpea aphid Aphis craccivora Koch and the legume pod borer Maruca vitrata Fabricius. Our survey revealed that education and proximity to extension services contributed significantly to farmers' knowledge of grain legume pests, suggesting the need to provide continuous training and capacity building on integrated pest management in grain legume farming. The study also suggests integration of other pest management strategies such as the use of early maturing varieties, biopesticides and biofertilizer to reduce the use of chemical for sustainable pest management.     

我国茶园蜘蛛生态学研究进展

我国茶园中的蜘蛛资源十分丰富,是控制茶树害虫种群的重要天敌类群。茶园蜘蛛生态学研究是与茶园以蛛治虫的研究相应发展的。本文从蜘蛛类群与茶园主要害虫的种群动态关系、群落多样性、栽培和管理方式等对群落多样性的影响、生态因素对蜘蛛的影响、捕食行为生态学和化学生态学等方面简述了近年来我国茶园蜘蛛生态学研究的新进展,并提出了蜘蛛化学生态学是未来茶园害虫防治的重要研究和发展方向。     

Farmers’ knowledge, perceptions and management of vegetable pests and diseases in Botswana

Vegetable farmers’ knowledge and perceptions of pests, diseases and pest management practices were investigated by interviewing 112 growers in Botswana between April and June 2004. Most of the farmers grew brassicae crops, Swiss chard and tomato, and considered arthropod pest problems as the major constraint to vegetable production. Bagrada hilaris Burm., Plutella xylostella L. and Brevicoryne barassicae L. were the most serious pests on brassicas, with red spidermites (Tetranychus spp.) being the most serious pests on tomato. Ninety-eight percent of farmers relied heavily on the use of synthetic pesticides to control these pests. Their decision to apply pesticides was mostly on noticing the presence of a pest or disease. An integrated pest management programme is needed to reduce over reliance on pesticides.     

Wildlife pests of California agriculture: Regional variability and subsequent impacts on management

Numerous wildlife species are known pests of California agriculture. Effective management of these pests is required to maximize agricultural production, yet it is unclear how the importance of various wildlife pest species and associated management strategies may vary regionally throughout California. Accounting for these regional differences should yield management programs that are specifically tailored to the regions constituents and should be considered when managing wildlife pests at a more localized level. Therefore, we developed a survey to provide quantitative data on regional differences in research and management needs to better guide future research efforts in developing more effective, practical, and appropriate methods for managing wildlife pests. We found that coyotes were a more common pest in the mountain region, ground squirrels were a greater concern in the central and desert valley region, while birds were most commonly listed as pests by individuals working in multiple regions of California. Coyote damage varied regionally, with livestock depredation the greatest concern throughout most of California, although damage to irrigation tubing and sprinklers was of equal concern in the central and desert valley region. For bird pests, exclusionary devices were the most common and most effective methods of control in the coastal region. Frightening devices were the most commonly used method for bird control in all other regions, although the efficacy associated with frightening devices was considered far lower than their level of use, suggesting that better management options are needed for bird control in these regions. For all wildlife pests, nonlethal control options (e.g., exclusionary devices, habitat modification) were generally preferred in the coastal region while lethal removal options ranked higher in the central and desert valley region (e.g., baiting, burrow fumigation). Efficacy was considered the most important attribute of a control method for all regions, while Integrated Pest Management programs were considered the most effective method for controlling wildlife pests in all regions except for the central and desert valley region. Collectively, the importance of wildlife pests and the perception of associated control methods varied throughout California and reflects the need to consider these regional differences in order to optimize damage management strategies at the regional level.     

The David Rosen lecture: biological control in citrus

David Rosen was a scientist, professor, administrator, philosopher, organizer, family man, and friend to many. He made numerous and remarkable contributions to biological control in citrus. Much of his research was on the biosystematics of Aphytis parasitoids, but he also held strong convictions about the importance of biological control in citrus integrated pest management (IPM), and carried out research on genetic improvement of parasitoids. David was the first incumbent of the Vigevani Chair of Agriculture and Professor of Entomology at the Faculty of Agricultural, Food and Environmental Quality Sciences at the Rehovot campus of the Hebrew University of Jerusalem. David served as an organizer of the XIV International Plant Protection Congress in Jerusalem, Israel, and his imprint on the congress was evident despite his absence. In addition to reviewing David's scientific contributions, I present an overview of the challenges facing biological control in the USA, including many that concerned David: increased scrutiny from regulatory agencies regarding the effects of natural enemies on nontarget species, loss of taxonomic experts, concerns about the accidental introduction of plant pathogens with the importation of natural enemies of insect vectors, and challenges to the tradition of international cooperation. If the increased demand for biological control is to be met in 21st century agricultural IPM programs, several scientific, social, and legal issues must be resolved.