Chemical control of stored product insects with fumigants and residual treatments

Integrated pest management (IPM) programs that eliminate infestations and prevent economic damage in raw commodities, food storage facilities, and milling and processing plants typically involve chemicals. They are preferred because they are often the cheapest and most efficient strategies available. When evaluating pesticides, it is important to recognize the biological and environmental factors that can affect pesticide efficacy so the insecticide can be effectively used in control programs. We illustrate these concepts with data from research studies with cyfluthrin, a pyrethroid insecticide used as a residual surface treatment, and with data from developmental research with new fumigants. These chemical pesticides and others like them could have specific applications and strategies in an IPM program for post harvest pests well into the 21st Century.     

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.     

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.     

Networking of integrated pest management: A powerful approach to address common challenges in agriculture

Integrated pest management (IPM) is facing both external and internal challenges. External challenges include increasing needs to manage pests (pathogens, animal pests and weeds) due to climate change, evolution of pesticide resistance as well as virulence matching host resistance. The complexity of designing effective pest management strategies, which rely less heavily on the use of conventional pesticides, is another external challenge. Internal challenges include organizational aspects such as decreasing trend in budget allocated to IPM research, increasing scarcity of human expertise, lack of knowledge transfer into practice and the communication gap both at country level and between countries, and lack of multi-, inter- and transdisciplinary IPM research. There is an increasing awareness that trans-national networking is one means to overcome such challenges and to address common priorities in agriculture. A large number of stakeholders (researchers, policy makers, growers and industries) are involved in the sector of crop protection, which needs to be coordinated through effective communications and dynamic collaboration to make any IPM strategy successful. Here we discuss a decade-long IPM networking experiences in Europe emphasizing how IPM research, implementation and adoption in Europe may benefit from a broader level networking.     

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.     

Bottlenecks in IPM

Integrated pest management (IPM) continues to have different meanings for different people. It is not the intention to define the term in this paper nor to explore the concept in depth, except to note that there appears to be almost constant redefinition and shifting of semantic boundaries whenever it is expedient to do so — often more in response to political fashion than crop pest reality. Rather, the intention is to consider constraints to the implementation of IPM, or to use the analogy of the title “bottlenecks”. Recognition of a bottleneck depends very much on different perception, whether of the politician, industrialist, scientist or farmer. In some instances, especially those originating from a pest crisis, different perceptions can converge and radical changes in control practise can come about, especially for indigenous crops. Problems arise if changes in pest control practice are sought in situations where there is no immediate crisis. If there is no convergent perception of the need for IPM then is it even right to raise the question of whether a bottleneck exists? This question becomes more pressing with increased emphasis on agricultural sustainability, “organic” forms of agriculture where IPM may be counter-indicated and, in a different context, the cultivation of introduced and/or novel crops including those genetically modified. In such situations the hegemony of the pest specialist is likely to decline with any shared perception being formed around the crop, the cropping system, and increasingly the surrounding landscape.     

The metal silo: An effective grain storage technology for reducing post-harvest insect and pathogen losses in maize while improving smallholder farmers’ food security in developing countries

Traditional storage practices in developing countries cannot guarantee protection against major storage pests of staple food crops like maize, leading to 20-30% grain losses, particularly due to post-harvest insect pests and grain pathogens. As a result, smallholder farmers end up selling their grain soon after harvest, only to buy it back at an expensive price just a few months after harvest, falling in a poverty trap. The potential impact on poverty reduction and greater livelihood security will not be realized, however, if farmers are unable to store grains and sell surplus production at attractive prices. Apart from causing quantitative losses, pests in stored grain are also linked to aflatoxin contamination and poisoning. To address this problem, a metal silo was developed as a valid option and proven effective in protecting stored grains from attack by storage insect pests. A metal silo is a cylindrical structure, constructed from a galvanized iron sheet and hermetically sealed, killing any insect pests that may be present. The impact of metal silo technology in Africa, Asia and Latin America includes, improving food security, empowering smallholder farmers, enhancing income opportunities and job creation, and safeguarding the agro-ecosystems. The metal silo can be fabricated in different sizes, 100 kg-3000 kg holding capacity by trained local artisans, with the corresponding prices of $35 to $375. The use of metal silo, therefore, should be encouraged in order to prevent storage losses and enhance food security in developing countries.     

Perspectives of integrated pest management

Integrated pest management (IPM) programmes require joint interdisciplinary scientific efforts to assemble sound information about: (1) the ecological basis of the pest problem; (2) factors in the agroecosystem that can be manipulated to make the crop environment unfavourable for pests; (3) pest and natural enemy population trends to determine if and when pesticide treatments are necessary; and (4) the benefits and risks of the IPM strategy for agriculture and society. The IPM technology is complex and this is partly why implementation of IPM has been slow. Projections are that if IPM is adopted by agriculture, pesticide use could be reduced by 35–50% from present use levels. Concurrently there would be a reduction in environmental and social problems caused by pesticides.     

Cropping Systems and Integrated Pest Management: Examples from Selected Crops

SUMMARY

Cropping systems have been central to managing associated pests for centuries. This treatment focuses on the history, concepts, and the integration of available Integrated Pest Management (IPM) tools/strategies into cropping systems. Pest assessments/diagnoses, IPM-decision-making aids, and examples of pest management in selected crops/cropping systems (wheat, soybean, corn, cotton, potato, and strawberry) as well as emerging opportunities and challenges are discussed. The evolving philosophy of IPM and the recently renewed emphasis on ecologically based pest management address the fact that significant levels of predation and/or parasitism are desirable insofar as they promote diversity and sustainability of agroecosystems. Thus, cropping systems are beginning to focus on soil and crop health as well as specific IPM and production goals. Although extensive efforts have been directed toward modeling the many interactions between crops, associated pests and the environment, the general implementation of a systems approach to integrated crop and pest management remains to be accomplished.     

Effects of integrated pest management, biological control and prophylactic use of insecticides on the management and sustainability of soybean

This study aimed to evaluate the prophylactic use of insecticides (PUI) in comparison with integrated pest management (IPM) and biological control (BC) strategies. Five replicated experiments were carried out independently in two Brazilian soybean-producing states, Goiás and Paraná, where those pest-control strategies were evaluated during two consecutive growing seasons. The evaluated treatments were integrated pest management (IPM); prophylactic use of insecticides (PUI), a practice that has been increasingly adopted by soybean growers in Brazil as well as in other Latin American countries; biological control (BC) and the control (C), which involved no pest treatment. Although the pest infestation rates in the BC and IPM treatments were higher than that in the PUI treatment, crop productivity, in general, was similar among these treatments and differed only from the control with no pest treatment. These results indicate that the prophylactic use of insecticides on soybeans does not result in higher productivity in the field and that this practice merely requires larger amounts of pesticides, which can impair the sustainability of the soybean crop. Therefore, the use of IPM still remains the best alternative for pest management in soybean fields.     

Cabbage development and associated lepidopterous pest complex in the southern USA

The cabbage variety ‘Greenback’ was grown using similar cultural practices at three locations across the southern USA during a 2-year period. Leaf production, plant development and lepidopterous pest populations were monitored and correlated to heat units as degree-days. Results indicate that significant quadratic and linear relations exist between leaf production and degree-days and that a robust linear model can be used to describe leaf production across the southern region of the USA. Pest populations differed in abundance and species composition among locations and between years. Findings indicate that the greatest variability in population abundance may be due to pest immigration from alternate hosts; therefore, pest management strategies may be most reliably based on weekly or twice-weekly scouting of fields, rather than expending efforts on trying to predict populations from models based on heat units and previous population abundance in individual fields.     

Current status of IPM in apple orchards

Apple integrated pest management (IPM) research and the development of apple IPM programs through transfer technology activities of Extension and Advisory personnel and Crop Consultants has been intense and continuous for over 20 years, and current apple IPM programs vary largely from one country to another and even in different regions within a country. Factors that account for these differences include the number of major and minor pests, available technology, commitment to IPM approach, and financial and personnel support for IPM research, demonstration, and implementation. This short review discusses the basic approaches for managing arthropod pests and pathogens included in current apple IPM programs.     

Synergisms in Science: Climate Change and Integrated Pest Management Through the Lens of Communication—2019 Student Debates

Every year, the Student Debates Subcommittee (SDS) of the Student Affairs Committee (SAC) for the annual Entomological Society of America (ESA) meeting organizes the Student Debates. This year, the SAC selected topics based on their synergistic effect or ability to ignite exponential positive change when addressed as a whole. For the 2019 Student Debates, the SAC SDS identified these topic areas for teams to debate and unbiased introduction speakers to address: 1) how to better communicate science to engage the public, particularly in the area of integrated pest management (IPM), 2) the influential impacts of climate change on agriculturally and medically relevant insect pests, and 3) sustainable agriculture techniques that promote the use of IPM to promote food security. Three unbiased introduction speakers gave a foundation for our audience to understand each debate topic, while each of six debate teams provided a strong case to support their stance or perspective on a topic. Debate teams submitted for a competitive spot for the annual ESA Student Debates and trained for the better part of a year to showcase their talents in presenting logical arguments for a particular topic. Both the debate teams and unbiased introduction speakers provided their insight toward a better understanding of the complexities of each topic and established a foundation to delve further into the topics of science advocacy and communication, climate change, and the many facets of integrated pest management.     

Crop protection services in Southern Africa

Despite the considerable progress made in different farming systems in Southern Africa, effective crop protection services remain a major constraint in their agricultural production systems. Factors responsible for these limitations include the following: the low government priorities still accorded crop protection services; the scarcity or complete lack of trained experienced professional and technical crop protection personnel; the fact that techniques for pest and disease control either are not available to small-scale farmers, or, where available, are not appropriate to the local situation; the inadequacy or lack of cooperation and communication between scientists, extension workers and farmers. A rigorous research, extension and training programme with an efficient infrastructure is advocated. In order to set priorities for appropriate integrated pest management (IPM), a standardized survey of pests of important food crops as well as losses suffered by small-scale farmers in each country of the region is imperative. The crop protection services can also be strengthened through the establishment of a Southern African Development Coordination Conference (SADCC) Crop Protection Collaborative Network to coordinate crop protection activities, as described below.     

An Australian approach to IPM in cotton: integrating new technologies to minimise insecticide dependence

Insect pests represent a severe limitation for cotton production in many regions of the world. Key pests include several Heliothine moths, which are well adapted to exploit cropping systems associated with cotton and often evolve resistance to pesticides. While many components of IPM have been implemented, the main intervention for the management of key pests continues to be insecticides. This reliance on pesticides brings significant environmental liabilities of off-target drift, chemical residues and resistance. IPM must be founded on a thorough understanding of the ecology of pest and beneficial species and their interaction with the crop. The emerging era of insect resistant transgenic cottons offers real prospects to provide a foundation for more sustainable, economically acceptable IPM with the integration of a range of non-chemical tactics and much less reliance on pesticides.     

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.     

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.     

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.     

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.