Delivering Integrated Pest and Pollinator Management (IPPM)

A theoretical framework to improve the adoption of green Integrated Pest Management tactics

Sustainable agriculture relies on implementing effective, eco-friendly crop protection strategies. However, the adoption of these green tactics by growers is limited by their high costs resulting from the insufficient integration of various components of Integrated Pest Management (IPM). In response, we propose a framework within IPM termed Multi-Dimensional Management of Multiple Pests (3MP). Within this framework, a spatial dimension considers the interactive effects of soil-crop-pest-natural enemy networks on pest prevalence, while a time dimension addresses pest interactions over the crop season. The 3MP framework aims to bolster the adoption of green IPM tactics, thereby extending environmental benefits beyond crop protection.

Adverse effects of the fungal biopesticide Beauveria bassiana on a predatory social wasp

Biopesticides are considered eco-friendly alternatives to synthetic agrochemicals. However, their impact on non-target organisms is still poorly understood. Social wasps, in particular, are a largely neglected group when it comes to risk assessment of plant protection products, despite the relevant ecological and economic services provided by these insects. In the present study, we evaluated the impact of a common biopesticide, the entomopathogenic fungus Beauveria bassiana, on the paper wasp Polistes dominula. We adopted a holistic approach in ecotoxicology by focusing not only on the detrimental effects on isolated individuals, but also on the whole colony. Both adult wasps belonging to different castes and immature larvae were topically exposed to a field-realistic concentration of fungal spores from the commercial strain of B. bassiana ATCC 74040 to assess the impact of the biopesticide on their survival, behavior and physiology. Our results showed that the fungus causes a number of adverse effects on P. dominula, that include increased mortality, altered locomotion and feeding rate, selective ejection of exposed larvae from nests, reduced oviposition rate and ovary development in foundresses, and colony failure. Our findings provide new insights on the often-neglected sublethal effects of pollutants that can jeopardize not only individual beneficial insects, but also the delicate social balance of their colonies and their valuable ecosystem services, highlighting that the natural origin of plant-protection products does not always guarantee environmental safety.

Variation in the physiological response of adult worker bees of different ages (Apis mellifera L.) to pyraclostrobin stress

The social division of labor within the honeybee colony is closely related to the age of the bees, and the age structure is essential to the development and survival of the colony. Differences in tolerance to pesticides and other external stresses among worker bees of different ages may be related to their social division of labor and corresponding physiological states. Pyraclostrobin was widely used to control the fungal diseases of nectar and pollen plants, though it was not friend to honey bees and other pollinators. This work aimed to determine the effects of field recommended concentrations of pyraclostrobin on the activities of protective and detoxifying enzymes, on the expression of genes involved in nutrient metabolism, and immune response in worker bees of different ages determined to investigate the physiological and biochemical differences in sensitivity to pyraclostrobin among different age of worker bees. The result demonstrates that the tolerance of adult worker bees to pyraclostrobin was negatively correlated with their age, and the significantly reduced survival rate of forager bees (21 day-old) with continued fungicide exposure. The activities of protective enzymes (CAT and SOD) and detoxifying enzymes (CarE, GSTs and CYP450) in different ages of adult worker bees were significantly altered, indicating the physiological response and the regulatory capacity of worker bees of different ages to fungicide stress was variation. Compared with 1 and 8 day-old worker bees, the expression of nutrient-related genes (ilp1 and ilp2) and immunity-related genes (apidaecin and defensin1) in forager bees (21 day-old) was gradually downregulated with increasing pyraclostrobin concentrations. Moreover, the expression of vitellogenin and hymenoptaecin in forager bees (21 day-old) was also decreased in high concentration treatment groups (250 and 313 mg/L). The present study confirmed the findings of the chronic toxicity of pyraclostrobin on the physiology and biochemistry of worker bees of different ages, especially to forager bees (21 day-old). These results would provide important physiological and biochemical insight for better understanding the potential risks of pyraclostrobin on honeybees and other non-target pollinators.

Plant protection and biotremology: fundamental and applied aspects

There is overwhelming evidence that synthetic pesticides have a negative impact on the environment and human health, emphasizing the need for novel and sustainable methods for plant protection. A growing body of literature reports that plants interact through substrate-borne vibrations with arthropod pests and mutualistic arthropods that provide biological control and pollination services. Here, we propose a new theoretical framework that integrates insights from biological control, the ecology of fear, and plant-borne vibrations, to address plant-insect interactions and explore new, sustainable opportunities to improve plant health and productivity.

Complex Effects of a Land-Use Gradient on Pollinators and Natural Enemies: Natural Habitats Mitigate the Effects of Aphid Infestation on Pollination Services

Pollinators and natural enemies are essential ecosystem service providers influenced by land-use and by interactions between them. However, the understanding of the combined impacts of these factors on pollinator and natural enemy activities and their ultimate effects on plant productivity remains limited. We investigated the effects of local and landscape vegetation characteristics and the presence of herbivorous pests on pollination and biological control services and their combined influence on phytometer seed set. The study was conducted in a Mediterranean agro-ecosystem, encompassing ten shrubland plots spanning a land-use gradient. Within each plot, we placed caged and uncaged potted phytometer plants that were either aphid-infested or aphid-free. We quantified insect flower visitation, aphid predation and parasitism rates, and fruit and seed set. We found scale-dependent responses of pollinators and natural enemies to land-use characteristics. Flower species richness had a positive impact on aphid parasitism rates but a negative effect on pollinator activity. Notably, we found a more pronounced positive effect of natural areas on pollinator activity in aphid-infested compared to aphid-free plants, indicating a potentially critical role of natural habitats in mitigating the adverse effects of aphid infestation on pollination services. These results highlight the complex and interactive effects of land-use on pollinators and natural enemies, with significant implications for plant productivity.

Pollination crisis Down-Under: Has Australasia dodged the bullet?

Since mid-1990s, concerns have increased about a human-induced "pollination crisis." Threats have been identified to animals that act as plant pollinators, plants pollinated by these animals, and consequently human well-being. Threatening processes include loss of natural habitat, climate change, pesticide use, pathogen spread, and introduced species. However, concern has mostly been during last 10-15 years and from Europe and North America, with Australasia, known as Down-Under, receiving little attention. So perhaps Australasia has "dodged the bullet"? We systematically reviewed the published literature relating to the "pollination crisis" via Web of Science, focusing on issues amenable to this approach. Across these issues, we found a steep increase in publications over the last few decades and a major geographic bias towards Europe and North America, with relatively little attention in Australasia. While publications from Australasia are underrepresented, factors responsible elsewhere for causing the "pollination crisis" commonly occur in Australasia, so this lack of coverage probably reflects a lack of awareness rather than the absence of a problem. In other words, Australasia has not "dodged the bullet" and should take immediate action to address and mitigate its own "pollination crisis." Sensible steps would include increased taxonomic work on suspected plant pollinators, protection for pollinator populations threatened with extinction, establishing long-term monitoring of plant-pollinator relationships, incorporating pollination into sustainable agriculture, restricting the use of various pesticides, adopting an Integrated Pest and Pollinator Management approach, and developing partnerships with First Nations peoples for research, conservation and management of plants and their pollinators. Appropriate Government policy, funding and regulation could help.

Meta-Analysis of Herbicide Non-Target Effects on Pest Natural Enemies

A critical component of integrated pest management is minimizing disruption of biological control by reducing the use of pesticides with significant non-target effects on natural enemies. Insecticide non-target effects testing for natural enemies has become increasingly common, but research examining the non-target effects of herbicides on natural enemies is scarce, and recommendations regarding herbicide selectivity are non-existent. We used meta-analysis to summarize laboratory bioassays testing non-target effects of herbicides on arthropod natural enemies and identify patterns in taxon susceptibility and active ingredient toxicity. Data were extracted from 78 papers representing 801 total observations. Herbicides increased natural enemy mortality and decreased longevity, reproduction, and predation. Mesostigmatan mites and hemipterans were the most sensitive to herbicides, and spiders, neuropterans, and hymenopterans were the least sensitive. Mortality was higher in juvenile predators versus parasitoids but did not differ between adults; parasitoid juveniles are likely better protected within the host. In terms of acute mortality, metribuzin, glufosinate, and oxyfluorfen were the most harmful herbicides. Only nicosulfuron, rimsulfuron, pendimethalin, phenmedipham, atrazine, and urea did not increase natural enemy mortality. The large effect size of glufosinate is particularly concerning, as it is the most likely replacement herbicide for glyphosate in many crops. Many active ingredients remain under-studied. Our analysis indicates that herbicides have a strong potential to disrupt biological control in cropping systems.

Pollinator-dependent crops significantly contribute to diets and reduce household nutrient deficiencies in sub-Saharan Africa

Recent literature highlights the potential of animal pollinator-dependent (PD) crops in enhancing food and nutrition security, although there is a lack of detailed household-level estimates. In this study, we investigate the nutrient composition, productivity, and contribution of PD and pollinator-independent (PI) crops to household nutrition in four sub-Saharan African (SSA) countries. We also evaluate the impact of reallocating resources from PI crops to PD crops on nutrient deficiencies, utilizing nationally representative panel data from three waves and over 30,000 household-year observations. Our findings reveal that PD crops exhibit higher micronutrient content per unit, albeit with lower macronutrient content compared to PI crops. PI crops have higher yield of calories per hectare while PD crops have higher vitamin A yield per hectare. However, protein and iron yield for PD and PI crops varies across countries. PI crops predominantly contribute to macronutrients and iron, while PD crops significantly contribute to vitamin A production. Our econometric results demonstrate that increasing the cultivation of PD crops relative to PI crops reduces the prevalence of nutrient deficiencies and increases crop income without compromising macronutrients production. This suggests that greater investment in PD crop production can be an integral approach to achieving nutrition security in SSA.

Trait-based approaches to predicting biological control success: challenges and prospects

Identifying traits that are associated with success of introduced natural enemies in establishing and controlling pest insects has occupied researchers and biological control practitioners for decades. Unfortunately, consistent general relationships have been difficult to detect, preventing a priori ranking of candidate biological control agents based on their traits. We summarise previous efforts and propose a series of potential explanations for the lack of clear patterns. We argue that the quality of current datasets is insufficient to detect complex trait-efficacy relationships and suggest several measures by which current limitations may be overcome. We conclude that efforts to address this elusive issue have not yet been exhausted and that further explorations are likely to be worthwhile.

Implementing IPM in crop management simultaneously improves the health of managed bees and enhances the diversity of wild pollinator communities

Impacts of insecticide use on the health of wild and managed pollinators have been difficult to accurately quantify in the field. Existing designs tend to focus on single crops, even though highly mobile bees routinely forage across crop boundaries. We created fields of pollinator-dependent watermelon surrounded by corn, regionally important crops in the Midwestern US. These fields were paired at multiple sites in 2017-2020 with the only difference being pest management regimes: a standard set of conventional management (CM) practices vs. an integrated pest management (IPM) system that uses scouting and pest thresholds to determine if/when insecticides are used. Between these two systems we compared the performance (e.g., growth, survival) of managed pollinators-honey bees (Apis mellifera), bumble bees (Bombus impatiens)-along with the abundance and diversity of wild pollinators. Compared to CM fields, IPM led to higher growth and lower mortality of managed bees, while also increasing the abundance (+ 147%) and richness (+ 128%) of wild pollinator species, and lower concentrations of neonicotinoids in the hive material of both managed bees. By replicating realistic changes to pest management, this experiment provides one of the first demonstrations whereby tangible improvements to pollinator health and crop visitation result from IPM implementation in agriculture.

Dynamic Economic Thresholds for Insecticide Applications Against Agricultural Pests: Importance of Pest and Natural Enemy Migration

In Integrated Pest Management programs, insecticides are applied to agricultural crops when pest densities exceed a predetermined economic threshold. Under conditions of high natural enemy density, however, the economic threshold can be increased, allowing for fewer insecticide applications. These adjustments, called 'dynamic thresholds', allow farmers to exploit existing biological control interactions without economic loss. Further, the ability of natural enemies to disperse from, and subsequently immigrate into, insecticide-sprayed areas can affect their biological control potential. We develop a theoretical approach to incorporate both pest and natural enemy movement across field borders into dynamic thresholds and explore how these affect insecticide applications and farmer incomes. Our model follows a pest and its specialist natural enemy over one growing season. An insecticide that targets the pest also induces mortality of the natural enemy, both via direct toxicity and reduced resource pest densities. Pest and natural enemy populations recover after spraying through within-field reproduction and by immigration from neighboring unsprayed areas. The number of insecticide applications and per-season farmer revenues are calculated for economic thresholds that are either fixed (ignoring natural enemy densities) or dynamic (incorporating them). The model predicts that using dynamic thresholds always leads to reduced insecticide application. The benefit of dynamic thresholds in reducing insecticide use is highest when natural enemies rapidly recolonize sprayed areas, and when insecticide efficacy is low. We discuss real-life situations in which monitoring of natural enemies would substantially reduce insecticide use and other scenarios where the presence of beneficial organisms may lead to threshold modifications.

Conservation Biological Control as an Important Tool in the Neotropical Region

The history and recent developments of conservation biological control (CBC) in the context of industrialized and small-scale agriculture are discussed from theoretical framework available in the Neotropical region. A historical perspective is presented in terms of the transition of the way pests have been controlled since ancestral times, while some of these techniques persist in some areas cultivated on a small-scale agriculture. The context of industrialized agriculture sets the stage for the transition from chemical pesticides promoted in the green revolution to the more modern concept of IPM and finds in conservation biological an important strategy in relation to more sustainable pest management options meeting new consumer demands for cleaner products and services. However, it also noted that conservation, considered within a more integrative approach, establishes its foundations on an overall increase in floral biodiversity, that is, transversal to both small-scale and industrialized areas. In the latter case, we present examples where industrialized agriculture is implementing valuable efforts in the direction of conservation and new technologies are envisioned within more sustainable plant production systems and organizational commitment having that conservation biological control has become instrumental to environmental management plans. In addition, a metanalysis on the principal organisms associated with conservation efforts is presented. Here, we found that hymenopteran parasitoids resulted in the most studied group, followed by predators, where arachnids constitute a well-represented group, while predatory vertebrates are neglected in terms of reports on CBC. Our final remarks describe new avenues of research needed and highlight the need of cooperation networks to propose research, public outreach, and adoption as strategic to educate costumers and participants on the importance of conservation as main tool in sustainable pest management.

Evolutionarily inspired solutions to the crop pollination crisis

The global decline in insect diversity threatens pollination services, potentially impacting crop production and food security. Here, we argue that this looming pollination crisis is generally approached from an ecological standpoint, and that consideration of evolutionary principles offers a novel perspective. First, we outline that wild plant species have overcome 'pollination crises' throughout evolutionary history, and show how associated principles can be applied to crop pollination. We then highlight technological advances that can be used to adapt crop flowers for optimal pollination by local wild pollinators, especially by increasing generalization in pollination systems. Thus, synergies among fundamental evolutionary research, genetic engineering, and agro-ecological science provide a promising template for addressing a potential pollination crisis, complementing much-needed strategies focused on pollinator conservation.

A Review of Cultural Practices for Botrytis Bunch Rot Management in New Zealand Vineyards

Botrytis bunch rot of grapes (BBR) causes substantial crop and wine quality issues globally. Past and present foundations for BBR control are based upon synthetic fungicides and varying forms of canopy management. Many authors regard the continued dependence on fungicides as unsustainable and have urged greater deployment of cultural, biological and nutritional strategies. However, in contrast to organic wine production, the uptake of alternative strategies in conventional vineyards has been slow based on cost and perceived reliability issues. This review summarises research from many different wine growing regions in New Zealand with the aim of demonstrating how traditional and newly developed cultural control practices have cost-effectively reduced BBR. In addition to reviewing traditional cultural practices (e.g., leaf removal), mechanical tools are described that remove floral trash and mechanically shake the vines. Multi-omics has improved our knowledge of the underlying changes to grape berries after mechanical shaking. Exogenous applications of calcium may correct calcium deficiencies in the berry skin and reduce BBR but the outcome varies between cultivar and regions. Nitrogen aids in grapevine defence against BBR but remains a complex and difficult nutrient to manage. The sustainable growth of organics and The European Green Deal will stimulate researchers to evaluate new combinations of non-chemical BBR strategies in the next decade.

Rediscovering wild food to diversify production across Australia's agricultural landscapes

Conventional agriculture currently relies on the intensive and expansive growth of a small number of monocultures, this is both risky for food security and is causing substantial environmental degradation. Crops are typically grown far from their native origins, enduring climates, pests, and diseases that they have little evolutionary adaptation to. As a result, farming practices involve modifying the environment to suit the crop, often via practices including vegetation clearing, drainage, irrigation, tilling, and the application of fertilizers, pesticides, and herbicides. One avenue for improvement, however, is the diversification of monoculture agricultural systems with traditional foods native to the area. Native foods benefit from evolutionary history, enabling adaptation to local environmental conditions, reducing the need for environmental modifications and external inputs. Traditional use of native foods in Australia has a rich history, yet the commercial production of native foods remains small compared with conventional crops, such as wheat, barley and sugarcane. Identifying what native crops can grow where would be a first step in scoping potential native food industries and supporting farmers seeking to diversify their cropping. In this study, I modeled the potentially suitable distributions of 177 native food and forage species across Australia, given their climate and soil preferences. The coastal areas of Queensland's wet tropics, south-east Queensland, New South Wales, and Victoria were predicted to support the greatest diversity of native food and forage species (as high 80–120 species). These areas also correspond to the nation's most agriculturally intensive areas, including much of the Murray-Darling Basin, suggesting high potential for the diversification of existing intensive monocultures. Native crops with the most expansive potential distribution include Acacia trees, Maloga bean, bush plum, Emu apple, native millet, and bush tomatoes, with these crops largely being tolerant of vast areas of semi-arid conditions. In addition to greater food security, if diverse native cropping results in greater ecosystem service provisioning, through carbon storage, reduced water usage, reduced nutrient runoff, or greater habitat provision, then payment for ecosystem service schemes could also provide supplemental farm income.

Toward evidence-based decision support systems to optimize pollination and yields in highbush blueberry

Highbush blueberry (Vaccinium spp.) is a globally important fruit crop that depends on insect-mediated pollination to produce quality fruit and commercially viable yields. Pollination success in blueberry is complex and impacted by multiple interacting factors including flower density, bee diversity and abundance, and weather conditions. Other factors, including floral traits, bee traits, and economics also contribute to pollination success at the farm level but are less well understood. As blueberry production continues to expand globally, decision-aid technologies are needed to optimize and enhance the sustainability of pollination strategies. The objective of this review is to highlight our current knowledge about blueberry pollination, where current research efforts are focused, and where future research should be directed to successfully implement a comprehensive blueberry pollination decision-making framework for modern production systems. Important knowledge gaps remain, including how to integrate wild and managed pollinators to optimize pollination, and how to provide predictable and stable crop pollination across variable environmental conditions. In addition, continued advances in pesticide stewardship are required to optimize pollinator health and crop outcomes. Integration of on- and off-farm data, statistical models, and software tools could distill complex scientific information into decision-aid systems that support sustainable, evidence-based pollination decisions at the farm level. Utility of these tools will require multi-disciplinary research and strategic deployment through effective extension and information-sharing networks of growers, beekeepers, and extension/crop advisors.

Integrated Pest Management (IPM) and One Health - a call for action to integrate

One Health (OH) has gained considerable prominence since the beginning of the 21^st century, among others, driven by the recent epidemics and the increasing importance of zoonotic diseases. Yet, despite the holistic and multidimensional nature of OH, to date, most emphasis has been on the interactions between animal and human health, with considerably less attention to environmental and plant health. However, there is growing evidence that the challenges of climate change, growing food and nutritional insecurity, and biodiversity loss can best be addressed within the context of the OH framework. Conceptionally, Integrated Pest Management (IPM) could perfectly fit into such an approach, but historically, IPM has been practiced very much in a compartmentalized manner. New approaches such as Regenerative Agriculture and Sustainable Intensification offer solutions to how to successfully embed IPM into a OH framework.

Laboratory Risk Assessment of Three Entomopathogenic Fungi Used for Pest Control toward Social Bee Pollinators

The use of fungal-based biopesticides to reduce pest damage and protect crop quality is often considered a low-risk control strategy. Nevertheless, risk assessment of mycopesticides is still needed since pests and beneficial insects, such as pollinators, co-exist in the same agroecosystem where mass use of this strategy occurs. In this context, we evaluated the effect of five concentrations of three commercial entomopathogenic fungi, Beauveria bassiana, Metarhizium anisopliae, and Cordyceps fumosorosea, by direct contact and ingestion, on the tropical stingless bees Scaptotrigona depilis and Tetragonisca angustula, temperate bee species, the honey bee Apis mellifera, and the bumble bee Bombus terrestris, at the individual level. Furthermore, we studied the potential of two infection routes, either by direct contact or ingestion. In general, all three fungi caused considerable mortalities in the four bee species, which differed in their response to the different fungal species. Scaptotrigona depilis and B. terrestris were more susceptible to B. bassiana than the other fungi when exposed topically, and B. terrestris and A. mellifera were more susceptible to M. anisopliae when exposed orally. Interestingly, increased positive concentration responses were not observed for all fungal species and application methods. For example, B. terrestris mortalities were similar at the lowest and highest fungal concentrations for both exposure methods. This study demonstrates that under laboratory conditions, the three fungal species can potentially reduce the survival of social bees at the individual level. However, further colony and field studies are needed to elucidate the susceptibility of these fungi towards social bees to fully assess the ecological risks.

Biopesticides and insect pollinators: Detrimental effects, outdated guidelines, and future directions

As synthetic pesticides play a major role in pollinator decline worldwide, biopesticides have been gaining increased attention to develop more sustainable methods for pest management in agriculture. These biocontrol agents are usually considered as safe for non-target species, such as pollinators. Unfortunately, when it comes to non-target insects, only the acute or chronic effects on survival following exposure to biopesticides are tested. Although international boards have highlighted the need to include also behavioral and morphophysiological traits when assessing risks of plant protection products on pollinators, no substantial concerns have been raised about the risks associated with sublethal exposure to these substances. Here, we provide a comprehensive review of the studies investigating the potential adverse effects of biopesticides on different taxa of pollinators (bees, butterflies, moths, beetles, flies, and wasps). We highlight the fragmentary knowledge on this topic and the lack of a systematic investigation of these negative effects of biopesticides on insect pollinators. We show that all the major classes of biopesticides, besides their direct toxicity, can also cause a plethora of more subtle detrimental effects in both solitary and social species of pollinators. Although research in this field is growing, the current risk assesment approach does not suffice to properly assess all the potential side-effects that these agents of control may have on pollinating insects. Given the urgent need for a sustainable agriculture and wildlife protection, it appears compelling that these so far neglected detrimental effects should be thoroughly assessed before allegedly safe biopesticides can be used in the field and, in this view, we provide a perspective for future directions.

Synergies of integrated pest and pollinator management in avocado farming in East Africa: An ex-ante economic analysis

Using synthetic pesticides to manage pests can threaten pollination services, affecting the productivity of pollination-dependent crops such as avocado. The need to mitigate this negative externality has led to the emergence of the concept of integrated pest and pollinator management (IPPM) to achieve both pest and pollinator management, leading to complementary or synergistic benefits for yield and quality of the harvest. This paper aims to evaluate the potential economic and welfare impact of IPPM in avocado production systems in Kenya and Tanzania. We utilize both primary and secondary data and employed the economic surplus model. On average the potential economic gain from the adoption of IPPM is US$ 66 million annually in Kenya, with a benefit-cost ratio (BCR) of 13:1, while in Tanzania US$ 1.4 million per year, with a BCR of 34:1. The potential benefits from IPPM intervention gains are expected to reduce the number of poor people in Kenya and Tanzania by 10,464 and 1,255 people per year respectively. The findings conclude that policies that enhance the adoption of IPPM can fast-track economic development and therefore improve the livelihoods of various actors across the avocado value chain.

Exploring connections between pollinator health and human health

Despite recent advances in understanding the role of biodiversity in ecosystem-service provision, the links between the health of ecosystem-service providers and human health remain more uncertain. During the past decade, an increasing number of studies have argued for the positive impacts of healthy pollinator communities (defined as functionally and genetically diverse species assemblages that are sustained over time) on human health. Here, we begin with a systematic review of these impacts, finding only two studies that concomitantly quantified aspects of pollinator health and human health. Next, we identify relevant research relating to four pathways linking pollinator health and human health: nutrition, medicine provisioning, mental health and environmental quality. These benefits are obtained through improved pollination of nutritious crops and an estimated approximately 28 000 animal-pollinated medicinal plants; the provisioning of pollinator-derived products such as honey; the maintenance of green spaces and biocultural landscapes that improve mental health; and cleaner air, water and food resulting from pollinator-centred initiatives to reduce agrochemical use. We suggest that pollinator diversity could be a proxy for the benefits that landscapes provide to human health. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.

Pesticide risk to managed bees during blueberry pollination is primarily driven by off-farm exposures

When managed bee colonies are brought to farms for crop pollination, they can be exposed to pesticide residues. Quantifying the risk posed by these exposures can indicate which pesticides are of the greatest concern and helps focus efforts to reduce the most harmful exposures. To estimate the risk from pesticides to bees while they are pollinating blueberry fields, we sampled blueberry flowers, foraging bees, pollen collected by returning honey bee and bumble bee foragers at colonies, and wax from honey bee hives in blooming blueberry farms in southwest Michigan. We screened the samples for 261 active ingredients using a modified QuEChERS method. The most abundant pesticides were those applied by blueberry growers during blueberry bloom (e.g., fenbuconazole and methoxyfenozide). However, we also detected highly toxic pesticides not used in this crop during bloom (or other times of the season) including the insecticides chlorpyrifos, clothianidin, avermectin, thiamethoxam, and imidacloprid. Using LD₅₀ values for contact and oral exposure to honey bees and bumble bees, we calculated the Risk Quotient (RQ) for each individual pesticide and the average sample RQ for each farm. RQ values were considered in relation to the U.S. Environmental Protection Agency acute contact level of concern (LOC, 0.4), the European Food Safety Authority (EFSA) acute contact LOC (0.2) and the EFSA chronic oral LOC (0.03). Pollen samples were most likely to exceed LOC values, with the percent of samples above EFSA’s chronic oral LOC being 0% for flowers, 3.4% for whole honey bees, 0% for whole bumble bees, 72.4% for honey bee pollen in 2018, 45.4% of honey bee pollen in 2019, 46.7% of bumble bee pollen in 2019, and 3.5% of honey bee wax samples. Average pollen sample RQ values were above the EFSA chronic LOC in 92.9% of farms in 2018 and 42.9% of farms in 2019 for honey bee collected pollen, and 46.7% of farms for bumble bee collected pollen in 2019. Landscape analyses indicated that sample RQ was positively correlated with the abundance of apple and cherry orchards located within the flight range of the bees, though this varied between bee species and landscape scale. There was no correlation with abundance of blueberry production. Our results highlight the need to mitigate pesticide risk to bees across agricultural landscapes, in addition to focusing on the impact of applications on the farms where they are applied.

The impact of beekeeping on household income: evidence from north-western Ethiopia

The existing literature acknowledges the benefits of beekeeping as a livelihood diversification strategy and income source for farmers across the world. However, the impact of beekeeping on income at household level has rarely been quantified. Furthermore, the few existing studies provide conflicting evidence and the methods quantifying the impact of participating in beekeeping are not rigorous. In this study, we identify key determinants of such participation and quantify the impact of beekeeping on household income. We use a cross-sectional data set collected from 392 randomly selected households in north-western Ethiopia, employing the endogenous switching regression model with estimated treatment effects. Unlike the methods used by previous studies, the approach adopted here enabled the control of observed and unobserved heterogeneities that affect not only the decision to participate in beekeeping, but also income differences among households. The results show that there are important differences between beekeepers and non-beekeepers in terms of their skills and resource endowments. After these differences were controlled for, beekeeping participation was found to increase income by 3,418 Ethiopian Birr (ETB) per person, namely a 51% increase. Furthermore, it was estimated that households not participating in beekeeping could have increased their income by ETB 442 per person (an 11% increase) had they become beekeepers. These findings indicate that income gains from beekeeping participation are 22–44 percentage points higher than benefits reported by previous studies. Capitalising on the existing beekeeping policy, targeted beekeeping extension to farmers could contribute to closing gaps in skills and resource endowments and, hence, minimising differences in income.

Towards integrated pest and pollinator management in tropical crops

Biotic pollination and pest control are two critical insect-mediated ecosystem services that support crop production. Although management of both services is usually treated separately, the new paradigm of Integrated Pest and Pollinator Management (IPPM) suggests synergetic benefits by considering them together. We reviewed the management practices in two major tropical perennial crops: cocoa and coffee, to assess IPPM applications under the tropics. We found potential synergies and antagonisms among crop pest and pollination management, however, very few studies considered these interactions. Interestingly, we also found management practices focusing mainly on a single service mediated by insects although species can show multiple ecological functions as pests, natural enemies, or pollinators. The tropics represent a promising area for the implementation of IPPM and future research should address this concept to move towards a more sustainable agriculture.

Impacts of Wildflower Interventions on Beneficial Insects in Fruit Crops: A Review

Integrated pest management (IPM) has been practiced by the fruit industry for at least 30 years. Naturally occurring beneficial insects have been encouraged to thrive alongside introduced predatory insects. However, Conservation Biological Control (CBC) and augmented biocontrol through the release of large numbers of natural enemies is normally only widely adopted when a pest has become resistant to available conventional pesticides and control has begun to break down. In addition, the incorporation of wild pollinator management, essential to fruit production, has, in the past, not been a priority but is now increasingly recognized through integrated pest and pollinator management (IPPM). This review focuses on the impacts on pest regulation and pollination services in fruit crops through the delivery of natural enemies and pollinating insects by provisioning areas of fruiting crops with floral resources. Most of the studies in this review highlighted beneficial or benign impacts of floral resource prevision to fruit crops. However, placement in the landscape and spill-over of beneficial arthropods into the crop can be influential and limiting. This review also highlights the need for longer-term ecological studies to understand the impacts of changing arthropod communities over time and the opportunity to tailor wildflower mixes to specific crops for increased pest control and pollination benefits, ultimately impacting fruit growers bottom-line with less reliance on pesticides.

Towards Integrated Pest and Pollinator Management in Intensive Pear Cultivation: A Case Study from Belgium

Simple Summary

Over the past decades, Integrated Pest Management (IPM) strategies have been widely adopted in commercial fruit production in Europe, supporting natural pest control as an ecosystem service. At the same time, there has been a growing awareness of the importance of pollinating insects, leading to the concept of Integrated Pest and Pollinator Management (IPPM). Here we present the outcomes of a 4-year case study as a valuable illustration of an IPPM strategy in a commercial intensive pear orchard. We show how the added-value of local biodiversity measures can be visualized in front of growers, linking ecological measures to economic benefits. This scientifically-based as well as practice-oriented demonstrative case study supports the acceptance and adoption of IPPM principles in commercial intensive pear production cultivation.

Abstract

Recently, the concept of Integrated Pest Management (IPM) was further extended into Integrated Pest and Pollinator Management (IPPM). Implementation of IPPM strategies entails the combination of actions for pest and pollinator management providing complementary or synergistic benefits for yield and/or quality of the harvest. The aim of this study was to examine IPPM elements (i.e., mixed hedgerow, nesting boxes for mason bees, Osmia spp.) and demonstrate their impact in the practical context of modern commercial fruit cultivation in a 4-year case study in an intensive ‘Conference’ pear orchard. The outcomes of visual observations during transect walks and molecular analysis of pollen collected by mason bees, showed the importance of additional floral resources for the presence of mason bees and other pollinating insects in the orchard environment. Pear quality assessments indicated that insect-mediated pollination had a significant positive impact, with a tendency for higher quality pears in the close vicinity of Osmia nesting boxes. However, despite the fact that pear pollen was also detected in Osmia spp. nest cells, the amount and frequency of pear pollen collection for their nest built-up turned out to be rather low. In the same intensive pear orchard studied for pollination effects, we simultaneously demonstrate the impact of a mixed hedgerow to enhance integrated pest control.

Identities, concentrations, and sources of pesticide exposure in pollen collected by managed bees during blueberry pollination

Bees are critical for crop pollination, but there is limited information on levels and sources of pesticide exposure in commercial agriculture. We collected pollen from foraging honey bees and bumble bees returning to colonies placed in blooming blueberry fields with different management approaches (conventional, organic, unmanaged) and located across different landscape settings to determine how these factors affect pesticide exposure. We also identified the pollen and analyzed whether pesticide exposure was correlated with corbicular load composition. Across 188 samples collected in 2 years, we detected 80 of the 259 pesticide active ingredients (AIs) screened for using a modified QuEChERS method. Detections included 28 fungicides, 26 insecticides, and 21 herbicides. All samples contained pesticides (mean = 22 AIs per pollen sample), with pollen collected from bees on conventional fields having significantly higher average concentrations (2019 mean = 882.0 ppb) than those on unmanaged fields (2019 mean = 279.6 ppb). Pollen collected by honey bees had more AIs than pollen collected by bumble bees (mean = 35 vs. 19 AIs detected at each farm, respectively), whereas samples from bumble bees had higher average concentrations, likely reflecting differences in foraging behavior. Blueberry pollen was more common in pollen samples collected by bumble bees (25.9% per sample) than honey bees (1.8%), though pesticide concentrations were only correlated with blueberry pollen for honey bees. Pollen collected at farms with more blueberry in the surrounding landscape had higher pesticide concentrations, mostly AIs applied for control of blueberry pathogens and pests during bloom. However, for honey bees, the majority of AIs detected at each farm are not registered for use on blueberry at any time (55.2% of AIs detected), including several highly toxic insecticides. These AIs therefore came from outside the fields and farms they are expected to pollinate. For bumble bees, the majority of AIs detected in their pollen are registered for use on blueberry during bloom (56.9% of AIs detected), though far fewer AIs were sprayed at the focal farm (16.7%). Our results highlight the need for integrated farm and landscape-scale stewardship of pesticides to reduce exposure to pollinators during crop pollination.

Socioecological Factors and Farmer Perceptions Impacting Pesticide Use and Pollinator Conservation on Cucurbit Farms

While research suggests that pollinator decline is linked with agricultural practices, it is unclear whether farmers share this view and adapt management to promote pollinators based on their understanding of these threats. To address these issues, we surveyed farmers of pollinator-dependent cucurbit crops across four states in the Midwest, USA. We grouped farmers by their perceptions of pollinator declines and routes of pesticide exposure and used statistical models to evaluate if farmers manage pests and pollinators based on these perceptions. Out of 93 completed surveys, 39% of farmers believed pollinators were in decline. When grouped, 17% of farmers were classified as proponents, ranking (on a 1–5 Likert scale) the factors mediating pesticide exposure and pollinator declines as important or highly important. For comparison, 44 and 39% of farmers were classified as neutral or skeptical, respectively, of these same factors. Compared to the neutral and skeptic groups, proponents were on average younger, had fewer years farming but more years in family farming, and were more dependent on income from outside the farming system. Proponents also on average reported smaller farms, higher pest richness, more land in cucurbit production, and greater richness of crops that are not pollinator dependent, when compared to the neutrals and skeptics. We did not find pest and pollinator management to be related to farmer perceptions of pollinator decline or routes of pesticide exposure, but farmers classified as pollinator “proponents” were more likely to indicate participation in future pollinator habitat restoration programs. Rather, management strategies were better explained by on-farm environmental conditions (e.g., pest richness, farm size, number of pollinator dependent crops) and economic factors (e.g., sources of income). Generally, our research shows that farmers who perceive pollinator threats may not be using pollinator supportive practices. Thus, while some farmers believe in pollinator declines, there remains a need to connect this knowledge with on-farm practices.

Managing orchard groundcover to reduce pollinator foraging post-bloom

BACKGROUND

Agricultural insecticides are believed to play a role in global pollinator decline. In mass-flowering orchard crops, recommendations to reduce exposure of pollinators to insecticides include spraying at periods when bees aren't foraging, such as dusk and dawn and outside of crop flowering times. However, the presence of flowering weeds within orchards mean pollinators may still be found foraging throughout the growing season, increasing the likelihood that exposure will still occur. We hypothesized that removing these weeds within orchard groundcover may reduce pollinator foraging post-bloom and thus reduce exposure of this group to pesticides. We tested this hypothesis by using herbicide to remove flowering broadleaf weeds in the sod middles ('groundcover') between rows of a nectarine orchard in New Jersey, USA, and assessing the effect on pollinator visitation via three different methods.

RESULTS

Significantly lower abundance, richness, diversity, and evenness of pollinators were found in plots where herbicide treatment had removed the majority of flowering weeds, compared to untreated plots. This was the case for bees, and for pollinators overall, and was reflected in both visual observations and active sampling through sweep netting. Passive sampling with blue vane traps failed to detect a difference between treatments.

CONCLUSION

Groundcover management in orchards is often employed as part of integrated pest management programs to remove alternative host plants of insect pests. The findings of this study show that it is also effective in reducing post-bloom pollinator foraging in orchards, thus potentially preventing exposure of these beneficial organisms to harmful insecticides. © 2021 Society of Chemical Industry.

Focused Identification of Germplasm Strategy (FIGS): polishing a rough diamond

Focused Identification of Germplasm Strategy (FIGS) has been advocated as an efficient approach to predict and harness variation in adaptive traits in genebanks or wild populations of plants. However, a weakness of the current FIGS approach is that it only utilizes a priori knowledge of one evolutionary factor: natural selection. Further optimization is needed to capture elusive traits, and this review shows that nonadaptive evolutionary processes (gene flow and genetic drift) should be incorporated to increase precision. Focusing on plant resistance to insect herbivores, we also note that historic selection pressures can be difficult to disentangle, and provide suggestions for successful mining based on eco-evolutionary theory. We conclude that with such refinement FIGS has high potential for enhancing breeding efforts and hence sustainable plant production.

The investigation of honey bee pesticide poisoning incidents in Czechia

Honey bees are major pollinators of crops with high economic value. Thus, bees are considered to be the most important nontarget organisms exposed to adverse effects of plant protection product use. The side effects of pesticides are one of the major factors often linked to colony losses. Fewer studies have researched acute poisoning incidents in comparison to the study of the sublethal effects of pesticides. Here, we compared pesticides in dead/dying bees from suspected poisoning incidents and the suspected crop source according to government protocols. Additionally, we analyzed live bees and bee bread collected from the brood comb to determine recent in-hive contamination. We used sites with no reports of poisoning for reference. Our analysis confirmed that not all of the suspected poisonings correlated with the suspected crop. The most important pesticides related to the poisoning incidents were highly toxic chlorpyrifos, deltamethrin, cypermethrin and imidacloprid and slightly toxic prochloraz and thiacloprid. Importantly, poisoning was associated with pesticide cocktail application. Almost all poisoning incidents were investigated in relation to rapeseed. Some sites were found to be heavily contaminated with several pesticides, including a reference site. However, other sites were moderately contaminated despite agricultural use, including rapeseed cultivation sites, which can influence the extent of pesticide use, including tank mixes and other factors. We suggest that the analysis of pesticides in bee bread and in bees from the brood comb is a useful addition to dead bee and suspected crop analysis in poisoning incidents to inform the extent of recent in-hive contamination.

The Promise of a Multi-Disciplinary, Mixed-Methods Approach to Inform Insect Pest Management: Evidence From Wyoming Alfalfa

Pest management strategies involve a complex set of considerations, circumstances, and decision-making. Existing research suggests that farmers are reflexive and reflective in their management choices yet continue to employ curative rather than preventative strategies, and opt for chemical over biological solutions. In this piece, we detail work from a two-year, multidisciplinary, mixed-methods study of insect pest management strategies in alfalfa in Wyoming, integrating data from four focus groups, a statewide survey, and biological sampling of production fields. We outline how these different sources of data together contribute to a more complete understanding of the challenges and strategies employed by farmers, and specifically on biological pest control. We applied this approach across alfalfa hay and seed crop systems. Relatively few farmers acknowledged biological control in focus groups or surveys, yet biological exploration yielded abundant parasitism of common pest alfalfa weevil. On the other hand, parasitism of seed alfalfa pest Lygus was far less common and patchy across fields. It is only in integrating quantitative and qualitative, biological and social data that we are able to generate a more complete portrait of the challenges and opportunities of working with farmers to embrace a preventative paradigm. In doing so, we offer insights on possible barriers to the adoption of preventative insect management strategies and provide a case study of integrating social science and biophysical techniques to better understand opportunities to expand biological pest control in cropping systems.

How Does Improve Farmers’ Attitudes toward Ecosystem Services to Support Sustainable Development of Agriculture? Based on Environmental Kuznets Curve Theory

Agroecosystems are complex socio-ecological systems that are managed by farmers to achieve desired outcomes, including economic income and environmental benefits contributed by ecosystem services (ES). Therefore, understanding farmers’ attitudes for ES will provide references for targeted agricultural environment management, which is critical to achieving the sustainable development of agriculture. The aim of this study is to identify the attitudes of farmers regarding ES, and to test whether and how annual household income and social demographic characteristics affect farmers’ attitudes toward ES. Using face-to-face interviews to collect data and the hypothesis of environmental Kuznets curve (EKC) to provide an analytical framework, the results reveal that, in general, the perceptions of farmers’ attitudes on ES are highly complex, caused by characteristics of the farmers. Furthermore, the inflection points of the U-shaped curves, where priorities change from increasing income to paying more attention to waste assimilation and biological pest control, are identified at 17,091 and 25,071RMB, respectively. Initiatives that aim to achieve sustainable agricultural development by strengthening ES provisions should be sensitive to farmers’perceptions. Therefore, it is necessary to strengthen farmers’ educational attainment, concentrate fragmented cultivation area and create reasonable incentives for preserving and restoring of ES and increasing farmers’ income together, which then can enhance the positive outcomes from income growth.

Beyond the Decline of Wild Bees: Optimizing Conservation Measures and Bringing Together the Actors

Wild bees are facing a global decline mostly induced by numerous human factors for the last decades. In parallel, public interest for their conservation increased considerably, namely through numerous scientific studies relayed in the media. In spite of this broad interest, a lack of knowledge and understanding of the subject is blatant and reveals a gap between awareness and understanding. While their decline is extensively studied, information on conservation measures is often scattered in the literature. We are now beyond the precautionary principle and experts are calling for effective actions to promote wild bee diversity and the enhancement of environment quality. In this review, we draw a general and up-to-date assessment of the conservation methods, as well as their efficiency and the current projects that try to fill the gaps and optimize the conservation measures. Targeting bees, we focused our attention on (i) the protection and restoration of wild bee habitats, (ii) the conservation measures in anthropogenic habitats, (iii) the implementation of human made tools, (iv) how to deal with invasive alien species, and finally (v) how to communicate efficiently and accurately. This review can be considered as a needed catalyst to implement concrete and qualitative conversation actions for bees.