Smallholder farmers' knowledge,perceptions and management of pea weevil in north and north-western Ethiopia

Pea weevil (Bruchus pisorum L.) is one of the most serious insect pests of field pea (Pisum sativum L.) in Ethiopia. A survey of 400 farmers was conducted in four main pea-growing districts in north and north-western Ethiopia. The objectives were to assess farmers' knowledge and perceptions of pea weevil, to examine their current pest management practices and to identify challenges to pea weevil control, so that participatory integrated pest management for smallholder farmers in Ethiopia can be developed. The results revealed that most (71%) of the farmers surveyed had knowledge about pea weevil and were able to identify damaged seeds based on common visible symptoms of weevil infestation. However, most farmers did not know that pea weevil attacks plants in the field, but rather considered it a storage pest. The results also showed that farmers' cultural practices influence the incidence and spread of pea weevil and that most farmers did not check seed for pea weevil symptoms before planting. Only a minority of farmers (19%) harvested peas early and some harvested late, unintentionally promoting infestation and carryover of weevils. In addition, most farmers (74%) were not aware of the source and means of weevil spread on their farm and some did not clean up fallen and shattered peas during harvesting and threshing. The majority (63%) of the farmers surveyed relied on chemical insecticides, namely actellic dust and phostoxin, to treat harvested peas in storage. However, the results revealed a knowledge gap in that farmers were well aware of the problem of pea weevil, but lacked knowledge of cultural practices affecting pea weevil and of problems in the use of pesticides. This highlights the need for farmer training and for development of participatory integrated pest management methods for pea weevil.     

Factors determining adoption of integrated pest management by vegetable growers in Nakhon Ratchasima Province,Thailand

Widespread use of highly toxic pesticides primarily for agricultural purpose has generated increasing concerns about the negative impact of pesticides on human health and the environment. Integrated pest management (IPM) usually seeks to minimize the use of pesticides and can be utilized to solve pest problems while minimizing risks to people and the environment. A total of 220 vegetable farmers in Nakhon Ratchasima Province of Thailand was interviewed with the objective of investigating the factors determining their adoption or non-adoption of IPM practices. The findings demonstrated that farmers had different uncompromising reasons for determining the use of IPM for their insect pest management. Higher costs of insecticides (91%), adverse effects of insecticides on human health and the environment (80%), and a greater risk of insect pests developing resistance to insecticides (28%) were the primary reasons for the adoption of IPM by vegetable growers in the study area. The reasons for the rejection of IPM practice were unsuitability of IPM for a large farm (52%), implementation difficulties (80%) and a greater belief in synthetic insecticides and their efficacy for target pest control (39%). A comparison between the IPM and the non-IPM farmers showed a significant difference (P < 0.01) in farmers' knowledge of pest management, which influenced IPM adoption or non-adoption. The IPM farmers had greater knowledge about identifying natural enemies and their beneficial role in controlling insect pests, about plant extracts and their efficacy in controlling insect pests and about sticky traps and their efficacy in monitoring natural enemies and controlling insect pests. For example, 24% of IPM farmers had knowledge of natural enemies whereas it was only 4% for the non-IPM farmers. A logistic regression model was fitted which showed that lower cost of pest management, better knowledge on IPM after training and availability of extension services were the factors which influenced farmers' adoption of IPM practice. The non-IPM farmers rejected adoption of IPM due to the common belief that natural enemies would not be effective in controlling insect pests and yields of vegetables would not be increased by practicing IPM.     

Control of invasive Liriomyza leafminer species and compliance with food safety standards by small scale snow pea farmers in Kenya

The Kenyan horticultural industry faces a new challenge following invasion by the quarantine Liriomyza leafminer species Liriomyza huidobrensis, Liriomyza sativae and Liriomyza trifolii which have recently become pests of economic importance. Controlling Liriomyza leafminers poses serious difficulties due to their biology and quarantine status. This paper examines farmers’ awareness of the pests and difficulties faced in controlling them. (1) A questionnaire survey showed that snow pea farmers in Kenya rely mainly on pesticides for control of invasive Liriomyza leafminers; (2) Sixty five percent of respondents perceived pesticides to be ineffective; (3) As a result, 74% of respondents increased the frequency of pesticide applications, 61% increased dose rates and 58% used broad-spectrum insecticides to avert damage by the pests; (4) Snow pea farmers who signed contracts with exporters and whose production practices were monitored for compliance with Good Agricultural Practices (GlobalGAP) used fewer control strategies; (5) These findings imply that the pest status of Liriomyza leafminers is likely to increase and snow pea production will significantly decrease in Central areas of Kenya unless an integrated leafminer management strategy is developed and farmers educated on methods of identifying them in their early stages of attack and use appropriate chemicals and application methods.     

甘肃武威市凉州玉米产区截形叶螨对3种杀螨剂的敏感性测定

截形叶螨(Tetranychus truncatus Ehara)是我国玉米生产上的一种重要的害螨。目前对截形叶螨的防治主要依赖化学农药。本研究通过室内浸液法测定截形叶螨成螨、若螨对3种不同作用机制的杀螨剂乙唑螨腈、联苯肼酯和螺螨酯的敏感性。结果表明,乙唑螨腈的毒力最强,对雌成螨和若螨24 h的LC50分别为0.033 mg/L、0.070 mg/L;联苯肼酯的毒力最低,对雌成螨和若螨24 h的LC50分别为0.685 mg/L、0.210 mg/L。3种杀螨剂对产卵量的影响均显著。乙唑螨腈可作为田间防治截形叶螨的最佳备选药剂。     

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.     

Managing storage pests of maize: Farmers' knowledge,perceptions and practices in western Kenya

Insect pests are a key constraint to effective utilization of cereal crops in sub-Saharan Africa (SSA), with damage caused by these pests in the stores of particular concern. Although a number of approaches have been advanced for control of storage pests of maize, uptake remains a challenge, with effectiveness of some approaches being questionable. We conducted a survey in western Kenya among 330 respondents using face to face interviews and focus group discussions to evaluate farmers' practices, knowledge and perceptions of storage pests of maize, and their current practices in managing such pests as a basis for development of efficient integrated pest management (IPM) approaches for the pests. Majority of the respondents stored maize in traditional granaries, with less than 10% of them using modern improved facilities, mainly due to inability to afford these. Majority of the respondents also cited attack of their stored grains by a number of insect pests, causing about 40% grain losses. The larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), sawtoothed grain beetle, Oryzaephilus surinamensis (L) (Coleoptera: Silvanidae), and maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), were perceived as the most common and damaging pests. Farmers' perceptions of pests were positively and significantly influenced by level of education and farming experience, indicating that education and experience build farmers' understanding of storage pests. Storing maize in unshelled form seemed to result in less pest attack, although majority of the respondents stored their maize in shelled form. Moreover, local maize varieties were perceived to be resistant to pests. The farmers applied various control methods, with sun-drying being the most popular practice. Usage of pesticides was minimal, mainly due to high costs, lack of information, and unavailability of appropriate and effective products. There were also other cultural methods applied, such as use of smoke and insecticidal plants. The respondents decried lack of training and extension services on storage pests and their management, underscoring the need to develop extension services. The underlying mechanisms of the perceived pest resistance in local varieties of maize and cultural pest management methods need to be established for exploitation in development of effective IPM approaches. There is also need to address the challenges hindering uptake of modern storage and control approaches.     

Pest management challenges for smallholder vegetable farmers in Zimbabwe

Smallholder vegetable production is expanding rapidly in Zimbabwe both for local sale in urban markets and for export. Pest management practices of 12 small-scale vegetable farmers in two areas of Zimbabwe were surveyed over a five-month period to gather information on crops, pests, diseases and crop protection methods. A range of serious pests and diseases affects non-indigenous vegetables such as Brassicas, tomatoes, onions and cucurbits. Although farmers use some cultural control methods and occasionally botanical pesticides, pest control is predominantly by the use of conventional synthetic pesticides. These are usually applied through lever operated knapsack sprayers although some less orthodox application methods are occasionally used. Results are variable and there are concerns about risks to sprayer operators, consumers and the environment (including natural enemies) due to shortcomings in protective clothing, large deviations from recommended doses and excessive run-off to the soil. Field trials were carried out to evaluate a modified sprayer lance which directs the spray upwards rather than downwards in an attempt to place more of the spray under the leaves where most of the arthropod pests are found. The ‘V lance’ as it is called improved the uniformity of spray coverage on the upper and lower leaf surfaces and is expected to improve efficacy of spraying and/or offer the opportunity to reduce doses or spray frequencies. Farmers who tested the device reported good results and gave constructive feedback for future improvements. The smallholder vegetable sector requires support in the form of improved access to existing pest management information (in an appropriate form) and focused research targeted at the knowledge gaps which currently impede implementation of sustainable IPM.     

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.     

Selective control of mite and collembolan pests of pastures and grain crops in Australia

Control of invertebrate pests in broad-acre agriculture largely relies on the application of broad-spectrum pesticides, however resistance problems and environmental concerns are driving a search for alternatives including more selective products. Here we explore the feasibility of using novel chemical groupings in the control of problematic pests that attack germinating pastures and grain crops in Australia. A modified laboratory bioassay is described for testing the response of several invertebrate pests to pesticides that have contact and systemic/translaminar properties. Two contact pesticides (fenitrothion and gamma-cyhalothrin) and three pesticides with strong systemic/translaminar properties (lambda-cyhalothrin, abamectin and diafenthiuron) showed promise for control of the collembolan Sminthurus viridis and four mite pests (Halotydeus destructor, Balaustium medicagoense, Penthaleus falcatus and Bryobia sp.). No single pesticide emerged as the most efficacious against all these pests, highlighting the need for correct pest identification before making control recommendations. Incorporating these new chemical options into pest control programs may help to control emerging pests and counter pesticide resistance issues. Selective pesticides in particular are likely to be compatible with integrated control programs that promote the establishment and maintenance of beneficial natural enemies.     

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.     

Current and Potential Role of Transgenic Crops in U.S. Agriculture

SUMMARY

Transgenic crop cultivars with resistance to insects, pathogens, and herbicides offer growers powerful new pest management tools. We reviewed the observed and potential farm-level impacts of transgenic cultivars, including those with regulatory approval and commercial availability as well as those still being researched and developed. Direct grower benefits, such as yield and production increases and decreased management costs, have led to rapid and extensive adoption of Bt corn and cotton, herbicide-resistant cotton, soybean, and canola, and virus-resistant papaya. Other transgenic crops, including Bt sweet corn and potato, and herbicide-resistant sugar beet and corn, have not been adopted despite strong agronomic and pest management performance, largely because growers fear there will be no market for their harvests. Despite inconsistent adoption of transgenic cultivars, demonstrated benefits of the technology encourage ongoing efforts to incorporate pest management traits into a wider variety of crops, including broccoli, tomato, lettuce, grape, citrus, pineapple, raspberry, peanut, wheat, barley, and rice. Potential impacts of these upcoming transgenic cultivars range from a decrease in weed management costs for lettuce and tomato growers, to the defense of stone fruit, grape, and citrus against devastating new pests.     

Large-scale sugarcane farmers' knowledge and perceptions of Eldana saccharina Walker (Lepidoptera: Pyralidae), push–pull and integrated pest management

A push–pull strategy for controlling Eldana saccharina Walker is being promoted as part of an area-wide integrated pest management (AW-IPM) programme in the South African sugar industry. Understanding farmers' perceptions of pests and pest management can improve rates of adoption of pest management strategies, in particular for knowledge-intensive practices such as AW-IPM. Fifty-three large-scale sugarcane farmers were interviewed using a semi-structured questionnaire. Respondents recognised the threat which E. saccharina posed, and 83% had heard of push–pull and IPM. Ecozone delineations played a more important role in adoption decisions than demographic and general enterprise factors such as farmer age, experience and land tenure, supporting the suggestion that experiential learning activities with small, local groups of farmers are suitable for introducing new pest management strategies. Notwithstanding good basic knowledge of E. saccharina, push–pull and IPM which farmers demonstrated, there is still a need for more detailed and practical knowledge on the implementation of push–pull at farm level. This knowledge should be made available to farmers in a hands-on manner with an emphasis on locally-oriented field days and model farms. Eldana saccharina may not be a priority for all farmers in the region where surveys were conducted. However, farmers should not be allowed to become complacent about this pest, as its range is increasing. These results will be used to formulate future push–pull and AW-IPM dissemination activities amongst large-scale sugarcane farmers in South Africa.     

广西芒果病虫害发生情况和防治现状调查与分析

为准确了解当前广西芒果病虫害的防治现状及存在的问题,本研究通过网络平台、会议交流、实地调查等形式进行调研并统计分析,以期为芒果病虫害的绿色防控提供基础数据。广西芒果产区经营方式主要以家庭农场经营为主,占70.83%;种植品种主要包括‘台农’、‘桂7’、‘金煌’、‘热农1号’、‘贵妃’、‘桂10’和‘金兴’等,且71.58%的果园同时种有2个或2个以上品种。总体上芒果病害的发生为害程度较虫害严重,以芒果细菌性黑斑病和炭疽病最为严重。芒果病虫害使用最普遍的防治方法为施用化学药剂,且98.95%的种植户单次用药选择2种或2种以上混配使用,其中单次选用2~3种药剂混配的占55.32%。对于选择药剂的方式,不同种植年限的种植户不同,总体上,44.34%的种植户依靠自己经验或邻居介绍,36.79%依靠农药店推荐,18.87%按农技人员指导用药。药剂成本的投入在200~1000元/667 m ²不等,但是药剂投入与产量并没有成正比关系。     

吉林省玉米穗期害虫种类及发生情况分析

吉林省是玉米生产大省,为明确吉林省玉米穗期害虫种类、分布及发生情况,2013～2016年对吉林省9个地市,42个县(市/区),累计409个地点的玉米穗期害虫进行系统调查,为玉米穗期害虫的监测预警和制定合理防治策略提供科学依据。调查发现,吉林省玉米穗期有27种有害生物,隶属于3个纲,7个目,18个科。亚洲玉米螟、双斑长跗萤叶甲、叶螨和蚜虫的有虫田率均在80%以上,百株虫量和危害级别较高,是吉林省玉米的主要害虫。美洲黍潜叶蝇、古毒蛾、大青叶蝉、梨剑纹夜蛾、赤角盲蝽、白星花金龟等有虫田率在20%以下,且百株虫量<1头,尚未玉米生产造成威胁。此外,迁飞性害虫黏虫也是玉米穗期重要害虫,棉铃虫是潜在的玉米穗期重要害虫。     

Population dynamics of arthropods associated with early-season tomato plants as influenced by soil surface microenvironment

Two field studies were conducted in the San Joaquin Valley (SJV) of California in order to describe the association of arthropods and possible virus diseases with the plant canopy of early-season, bush-trained, fresh-market tomato (Lycopersicon esculentum L. cv. Shady Lady) over three soil surface microenvironments. The experimental treatments were based on alterations to planting bed surfaces, as follow: 1) soil covered with silver metalized, light-reflective plastic mulch; 2) soil covered with biological mulch consisting of killed, chopped, cool-season cover crop residues [mixture of triticale (X Triticosecale Wittm.), rye (Secale cereale L. cv. Merced), and common vetch (Vicia sativa L.)]; or 3) bare soil (not covered) – the SJV standard tomato production practice. In both studies, the predominant arthropods encountered in all treatments were the aphid species Aphis craccivora Koch, Macrosiphum euphorbiae Thomas, and Myzus persicae Sulzer; the western flower thrips (Frankliniella occidentalis Pergande), and the false chinch bug (Nysius raphanus Howard). These are all considered to be pests of cultivated tomato plants. Spiders were the most prevalent arthropod predator group recovered from foliage samples. All monitored arthropods, except spiders, were most abundant in tomato plants grown over the conventional, bare soil surface, and least abundant (P < 0.05) in plants grown over the silver plastic mulch. Spider numbers were highest in plant foliage over the biological mulch. Other arthropods commonly found on tomato plants in the SJV, including leafhoppers, whiteflies, various caterpillars, and predaceous taxa, were not commonly nor consistently encountered. This was likely due to the early-season timeframe of these studies. Similarly, foliar virus disease symptoms, which were originally targeted for monitoring, were virtually nonexistent. The only arthropod pest species encountered which consistently caused economically important damage to tomato fruit was N. raphanus. In both experiments, tomato fruits grown over the reflective plastic mulch had significantly less (69.5% and 39.7%, respectively) damage due to this pest than those over bare soil. The biological mulch gave inconsistent, intermediate damage reductions. Results from these two field studies showed that reflective plastic bed mulch suppressed populations of a variety of tomato canopy-associated arthropod taxa in early-season plantings, as compared to conventional, bare-soil beds. The biological bed mulch results were more inconsistent, but gave indications that killed cover crop residues, as well as the light-reflective plastic, may be of value in integrated pest management programs for fresh-market tomato production.     

Establishment of legumes in grass swards: effects of pesticides on slugs,insects, legume seedling numbers and forage yield and quality*

Three legumes, red clover (Trifolium pratense L.), alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.), were planted with a minimum-tillage drill into eight grass fields, three in early spring, two in late spring and three in late summer, in Pennsylvania. The objective was to use pesticides at planting time to control slugs and insects which attack legume seedlings and ascertain whether pest control prevented seedling loss and increased yields of grass and legume dry matter (DM), in vitro DM digestibility and crude protein (CP). Methiocarb bait alone or in combination with carbofuran granules or spray applied at planting sometimes controlled the slugs Derocerus reticulatum (Müller), D. laeve (Müller) and Arion fasciatus Nilsson and improved establishment of seedling red clover and alfalfa but not birdsfoot trefoil. Increased yields of DM, digestible DM, CP and legume DM after treatment was greatest in late-spring sowings. Larvae of the clover root curculio, Sitona hispidulus (F.), attacked roots of legumes in the spring following the year of sowing. Late spring and summer sowings without pesticides sustained considerable seedling losses from pests, whereas seedlings from early spring sowings in untreated areas were injured less.     

Impact of integrated pest management of vegetables on pesticide use in subtropical Jammu,India

In a study at the subtropical vegetable-growing areas of the state of Jammu and Kashmir (J&K), a quasi-experimental research design with a non-equivalent control group was employed to examine the impact of an integrated pest management (IPM) program implemented from 2008 to 2010 on the adoption of non-chemical pest management practices, pesticide use by weight (active ingredient [a.i.]), pesticide use frequency, field use environment impact (FEIQ) and safe handling and application of pesticides by IPM-trained farmers. There was no significant change in adoption of non-chemical practices, other than pheromone traps used by okra (Abelmoschus esculentus (L.) Moench) growers. Growers reduced FEIQ by 17.9 per hectare from 2008 to 2010. Pesticide use (a.i.) did not decrease significantly, and frequency decreased significantly by 72.4% only in cauliflower (Brassica oleracea L. var. botrytis). The vegetable growers did not use protective equipment while handling and applying pesticides thus putting themselves at risk. Implementation of IPM thus needs to be reexamined to significantly reduce pesticide use by weight, treatment frequency and FEIQ.     

Integrated pest management of potato tuber moth in field and storage

Summary The potato tuber moth (PTM),Phthorimaea operculella (Zeller), is one of the most damaging pests of potatoes in field and storage. Tuber moth is active throughout the year in North Africa but is most active from late April to early August. Many cultural practices that are used by farmers to improve the yield and quality of potato can also limit the development of the potato tuber moth and minimise damage to tubers. As the farmers gain more experience with both agronomic practices and chemical insecticides, they are likely to rely more heavily on cultural practices and less on insecticides to manage PTM. Measures which could keep PTM damages in rustic and diffuse light stores to a minimum are discussed. Ideally, there is need to integrate pest management in potato fields and stores. PTM control in stores was found to be more effective if infestation in fields was kept to a minimum. Low infestation at harvest and rapid handling of the potatoes going into store established good initial storage conditions and decreased the likelihood of post-harvest losses. Biological insecticides in particular were more effective in preventing losses by insects in stores in cases where the initial level of infestation was relatively low.     

辽宁省玉米田农药使用现状、存在问题与建议

针对辽宁省玉米田农药使用情况进行深入调查,结果表明,当前辽宁省玉米田病虫草害防治以化学农药为主,用量最大的除草剂为莠去津,用量最大的杀虫剂是二嗪磷,用量最大的杀菌剂为福美双。在农药的使用过程中,存在农民对农药科学使用技术认知不足、用药技术落后、抗药性发展等问题。建议采取普及农药科学使用方法和安全使用准则、推广高效高质量施药机械、制定并实施合理的抗性治理对策应对玉米生产中病虫草的抗药性威胁,解决目前春玉米生产中农药不合理使用问题。     

Tracking the global dispersal of a cosmopolitan insect pest, the peach potato aphid

Background  

Global commerce and human transportation are responsible for the range expansion of various insect pests such as the plant sucking aphids. High resolution DNA markers provide the opportunity to examine the genetic structure of aphid populations, identify aphid genotypes and infer their evolutionary history and routes of expansion which is of value in developing management strategies. One of the most widespread aphid species is the peach-potato aphid Myzus persicae, which is considered as a serious pest on various crops in many parts of the world. The present study examined the genetic variation of this aphid at a world scale and then related this to distribution patterns. In particular, 197 aphid parthenogenetic lineages from around the world were analysed with six microsatellite loci.