Microbial alternatives for sustainable insecticide use, a Canadian perspective

Abstract

This perspective examines the potential of microbial biological control agents (MBCAs) as sustainable tools for managing agricultural insect pests, set against the backdrop of growing pesticide use and climate-driven shifts in pest pressures. We highlight how Canada’s unique combination of supportive policies, dedicated research funding, and clear regulatory frameworks has enabled MBCAs to become an integral part of national pest management strategies. By focusing on regulatory innovation, market trends, and the biological and technological factors shaping MBCA adoption, we outline why Canada’s experience offers valuable insights for other countries seeking to reduce reliance on synthetic insecticides. We propose practical directions to expand the global use of MBCAs, emphasizing the importance of harmonized regulations, stronger data infrastructure, and coordinated public-private initiatives. This perspective aims to contribute to the broader discourse on sustainable pest management by showcasing how lessons from Canada can inform more resilient, climate-adapted agricultural systems worldwide.

Sustainability Statement.

This perspective highlights how advancing the use of microbial biological control agents (MBCAs) can directly contribute to global sustainability efforts. By illustrating Canada’s experience, it demonstrates pathways to bolster food security (SDG 2) through resilient, eco-friendly pest management. It also emphasizes reducing dependency on synthetic pesticides (SDG 12), adapting to climate-driven shifts in pest populations (SDG 13), and fostering international cooperation to accelerate sustainable solutions (SDG 17). In doing so, it frames MBCAs not only as agricultural tools but as strategic components for achieving broader environmental and development goals.

Current projections indicate a troubling rise in global surface temperatures over the next decade, which is expected to have profound impacts, including shifts in the population dynamics and geographic distribution of agriculturally significant insect pests (IPPC Secretariat 2021, WMO 2023). As a result, pest pressures will change, with downstream effects on global food security. For example, staple grain crops such as wheat, rice, and maize, which together accounted for nearly 90% of global cereal production in 2021, are forecast to suffer increased losses due to insect pest damage (Curtis et al. 2018, FAO 2022). Although individual insect pests may respond differently to ongoing climate warming, estimates suggest that crop losses are likely to rise for about half of the 31 major global insect pests studied (Lehmann et al. 2020, Plante et al. 2024).

As of 2021, data from 211 countries show that about 3.77 Mt of pesticide products were used worldwide in agriculture, including roughly 0.82 Mt of insecticides (Fig. 1) (FAO 2023). Agriculture’s heavy reliance on synthetic pesticides has been well documented (Tudi et al. 2021, Ahvo et al. 2023, Metcalfe et al. 2024). Projections suggest global use could increase 2.5 times between 2000 and 2050 (Tilman et al. 2001), supported so far by a 1.35-fold rise in application volumes by 2020 (FAO 2023). Efforts to reduce these risks face significant obstacles. Producers often express concern that reducing pesticide applications may lead to diminished yields or heightened production costs. There is also apprehension that increased regulatory pressures could compound these effects, resulting in higher prices for agricultural products (Damalas and Eleftherohorinos 2011).

Figure 1.

Pesticide and insecticide usage in the last 20 years and annual percentage growth rate. Pesticide and insecticide usage data were obtained from the FAOSTAT Pesticides Use domain, which provides statistics on the agricultural application of major pesticide groups (https://www.fao.org/faostat/en/#data/RP). The dataset was filtered to include records labeled as Pesticides (total) or Insecticides (total) and restricted to entries categorized under Agricultural Use for the years 2000 to 2021. Usage values, reported in metric tonnes, are shown as the total sum across all countries with available data for each year. Annual percentage growth rate (APGR) was calculated based on year-to-year changes. For each year, the APGR was determined by comparing the current year's value to that of the previous year and expressing the result as a percentage. This approach captures the relative increase or decrease in usage on an annual basis. The data plotted in this figure is provided as Supplementary Table S1.

Many practices tied to sustainable agriculture have been shown to improve plant resistance to insect pests more effectively than using insecticides alone. These include maintaining a healthy soil microbial community (Blundell et al. 2020), applying well-planned crop rotations (Howard et al. 2020), and incorporating cover crops that support natural enemies of pests (Rowen et al. 2022). Together, these examples highlight the value of integrated and sustainable approaches to pest management. Alongside these practices, Microbial Biological Control Agents (MBCAs) have emerged as key tools for advancing sustainable farming (Zehra et al. 2021, Elnahal et al. 2022, Chaudhari et al. 2024). They have strong potential to take up a larger share of the pesticide market and to lessen the negative impacts of synthetic insecticides (Elnahal et al. 2022). Farmers have applied entomopathogens in various forms since the late 1800s (van Lenteren and Godfray 2005), and they are now part of many agricultural systems worldwide (Lahlali et al. 2022). Although biopesticides made up only about 0.2% of the global pesticide market in 2000, this share grew to around 2.5% by 2006 (Thakore 2006), and recent reports suggest they now account for roughly 10% (Marrone 2024).

This perspective highlights how the continued growth of the synthetic insecticide market, together with rising concerns about their impacts on ecosystems and human health, underscores both the urgency and the opportunity to explore MBCAs as practical, environmentally responsible alternatives. Our analysis emphasizes Canada's long-standing leadership in this area, through clear regulatory frameworks, sustained investment in research, and the development of extensive datasets—all of which have supported the safe and effective integration of MBCAs into agriculture. By considering both historical milestones and current market trends, we outline a realistic pathway toward more resilient agricultural systems that combine effective pest control with environmental stewardship and strong regulatory oversight.

Prospects and challenges of entomopathogens commercialization

MBCAs offer valuable advantages over synthetic insecticides, largely due to their high host specificity and generally lower risks to human health and the environment (Shapiro-Ilan et al. 2012, Bamisile et al. 2021). They control insect pests by triggering various harmful effects, including direct mortality (Ho et al. 2020), feeding deterrence (Rashid and Chung 2017), and interference with reproduction (Hurst and Jiggins 2000).

Despite these benefits, several practical and biological factors continue to limit their wider use. Compared to chemical pesticides, MBCAs often show slower action, less consistent performance across environments, and more demanding application requirements (Jaronski 2010, Bonaterra et al. 2012). Additionally, as living agents, they can degrade before reaching targets if not properly formulated (Leggett et al. 2011). Resistance is also a concern; for example, resistance to Bt toxins has been documented in 27 insect species (Siegwart et al. 2015). Furthermore, environmental conditions heavily influence MBCA effectiveness, leading to variable results between lab, greenhouse, and field settings (Reddy et al. 2014, Rangel et al. 2015). This highlights the need for more research on the conditions that support MBCA success and on how to adapt tailored strategies to local climates.

Innovations in delivery methods could help address some of these challenges. Technologies such as drone spraying (Hiremath et al. 2024), electrostatic application (Zhou et al. 2024), and hydrogel carriers (Tay et al. 2020) may improve targeting and coverage, while being compatible with existing pesticide infrastructure. Newer approaches under study include using pests themselves to carry pathogens (Harris and Parnas 2020), deploying managed pollinators (Kevan et al. 2020), or attracting natural predators with semiochemicals to spread microbes (Sharma et al. 2019, 2020). However, these strategies require deeper understanding of complex ecological interactions (Cullen et al. 2021).

Beyond application and formulation, advancing MBCA effectiveness also depends on discovering and optimizing new species and strains. Most genetic research so far has focused on fungal agents (Wang and Wang 2017, Wang et al. 2021), leading to improved transformation systems in fungi like B. bassiana and M. brunneum that enable targeted studies and enhancements (Chen et al. 2017, Davis Kyle et al. 2020). These efforts have already reduced lethal dose requirements and improved pathogenicity (Yang et al. 2014, Du et al. 2022). Ongoing advances in genomic technologies are deepening our understanding of infection mechanisms, paving the way for more precise and effective MBCA engineering.

However, despite scientific progress, many countries still regulate MBCAs under frameworks originally designed for synthetic pesticides (Sundh and Goettel 2013). This imposes data requirements and assessment criteria poorly suited to biologicals, slowing approvals and complicating commercialization (Chandler et al. 2011, Busschers et al. 2023). Even where products are registered, inconsistent tracking systems make it hard to assess real-world use and impact. As a result, clear, tailored regulations and robust monitoring are essential to fully integrate MBCAs into sustainable pest management.

Canada as a pioneer for biological pest control

Canada has long been recognized as a global leader in developing and implementing entomopathogenic organisms for biological pest control. This leadership spans diverse contexts, including agriculture (Kabaluk et al. 2007), forest management (Nealis et al. 2001), and even human vector control (CSRD 2016). Canada's early commitment dates back to the 1950s, when substantial government investment established the Laboratory of Insect Pathology in Ontario and the Laurentian Forestry Centre in Québec (van Frankenhuyzen 2000). Initially focused on finding pathogen-based alternatives for managing forest insect pests, these institutions pioneered research on Bt (Angus 1954, 1956) and led to the development and registration of a Bt-based product for large-scale forest applications, the first of its kind globally (McConnell and Richards 1959, Lavallée et al. 2016). By 2000, nearly all synthetic insecticides in Canadian forestry had been replaced, with over 8.5 million hectares treated (van Frankenhuyzen 2000, Lavallée et al. 2016).

This legacy continues in modern agriculture, where Canada’s use of biological insecticides remains substantial. As of 2021, ∼2960 Mt of biological insecticides were applied, compared to 4800 Mt of synthetic insecticides, reflecting a meaningful shift toward more sustainable pest management (Fig. 2) (PMRA 2023). This transition is further underscored by a 53.7% increase in biopesticide sales from 2020 to 2021. Spinosad accounts for the majority of this volume (>1 Mt), while other MBCAs each contribute <0.5 Mt, illustrating both Canada's commitment to integrating biological control and the complexities inherent in the current market composition.

Figure 2.

Pesticides intended usage and composition in Canada. All data shown in this figure were obtained from the Pest Control Products Sales Report 2021, published by the Pest Management Regulatory Agency (PMRA) (https://publications.gc.ca/collections/collection_2024/sc-hc/H111-3-2021-eng.pdf).

The Canadian MBCA industry has historically featured a mix of large multinationals focused on transgenic crops and smaller companies involved in developing or distributing microbial products (Dupont 1998). To date, 23 companies have registered entomopathogenic products in Canada, totaling 109 insecticidal products derived from three fungal, three bacterial, and one microsporidian species (Fig. 3). This diversity of commercial options supports projections of increasing MBCA use and aligns with Canada’s pledge under the 2022 Kunming-Montreal Global Biodiversity Framework to reduce pesticide risks by at least 50% by 2030 (Bailey et al. 2010, Health Canada 2023).

Figure 3.

Canadian microbial biological control agents (MBCAs) registered by company and main active ingredients registered. MBCA-based product registrations were retrieved from the PMRA's Pesticide Product Information Database (https://pest-control.canada.ca/pesticide-registry/en/product-search.html) (March 31, 2024). All products were screened based on active registration status. Furthermore, MBCAs with intended agricultural usage were screened for both active and historical registrations. The data plotted in this figure is provided as Supplementary Table S2.

Canada also stands out for its regulatory approach. All MBCAs intended for pest control are governed by the Pest Control Products Act and overseen by the PMRA (Mason et al. 2013). Unlike many countries that use the same frameworks for synthetic insecticides, Canada’s process accounts for biological-specific characteristics such as host range, pathogenicity, and environmental persistence. Reviews typically take about 12 months, faster than for chemical pesticides, and similar regulatory models have since been adopted by Brazil and the EU (European Commission Directorate-General for Health 2020). Canada’s joint reviews with the U.S. EPA further streamline transnational registrations, facilitating market access and reducing barriers for developers (Mason et al. 2013).

Toward global integration of MBCAs

Canada’s success with MBCAs not only highlights local innovation but also offers a practical model for integrating these solutions into global agriculture. Decades of dedicated research, development, and careful regulation have shown how sustainable pest management can be implemented alongside environmental goals. Canada’s approach, marked by strong government support, adaptable but rigorous regulation, and extensive data collection, illustrates what is possible when biological alternatives are prioritized. As climate change and sustainability concerns grow, similar standards could help other countries transition to more effective and environmentally friendly pest control. Maintaining clear data records and consistent terminology will also be essential to assess long-term impacts and guide future MBCA integration. To help replicate this success internationally, we propose a strategic framework comprising four clear recommendations to overcome current barriers and expand MBCA use (Fig. 4):

Figure 4.

Strategic framework to overcome barriers currently limiting the incorporation and implementation of MBCAs.

• Regulatory Harmonization: Building on Canada’s example, countries should develop clear standards for MBCA registration that are separate from those for synthetic insecticides. Joint regulatory efforts, like those between Canada and the United States, can speed up approvals, reduce administrative hurdles, and give smaller companies faster access to broader markets.

• Enhanced Governmental Support: As Canada has done since the 1950s, governments should fund specialized research on insect-pathogen systems. This investment would drive discovery, encourage the shift from chemicals to biologicals, and support tailored solutions for regional pest issues through dedicated research facilities.

• Global Data and Standardization: Creating an international database to track MBCA use, and outcomes would improve transparency and enable better global assessments. Backed by organizations such as the FAO and WCO, this effort could also standardize terminology and usage metrics, setting clear benchmarks for the MBCA sector.

• Public-Private Collaboration: Partnerships between government agencies and private companies can accelerate development and commercialization. Public funding can strategically leverage private investment, helping bring innovative MBCA products to market. Canada’s Sustainable Agriculture Research Initiative, which funds projects like our LeafHope program (https://www.edelabcriv.ca/leafhope) aiming the developing of new and efficient MBCAs, is one example of how this can work.

By adopting elements like those suggested above, the global community can better address the challenges of pest management in a warming world. This transition not only supports more sustainable agriculture but also aligns with broader environmental goals such as those in the United Nations’ Sustainable Development Goals. A widespread commitment to MBCA adoption could be a key step in securing both agricultural productivity and ecosystem health for the future.

A vision for the future: embracing MBCAs

The dual pressures of climate change and the long-standing overuse of synthetic pesticides underscore the urgent need for more sustainable pest management solutions. As demonstrated by Canada’s experience, integrating MBCAs through supportive policies, targeted research investment, and tailored regulations is not only feasible but effective. MBCAs offer a pathway to reduce environmental impacts while maintaining agricultural productivity, directly contributing to global sustainability and climate adaptation goals. Looking ahead, broader international efforts to harmonize regulations, build robust data infrastructure, and foster public–private collaboration could accelerate the shift to microbial-based pest management worldwide. By learning from models like Canada’s and adapting them to local needs, countries can strengthen food security and ecosystem resilience in the face of mounting global challenges.

Author contributions

Joshua Molligan (Conceptualization [lead], Data curation [lead], Formal Analysis [lead], Visualization [lead], Writing – original draft [lead]), and Edel Pérez-López (Conceptualization [equal], Funding acquisition [lead], Project administration [equal], Resources [equal], Writing – original draft [supporting], Writing – review & editing [supporting])

Conflict of interest

None declared.

Funding

This work was supported by the RQRAD, MAPAQ, and FRQNT through the Programme de recherche en partenariat—Agriculture durable—Volet II—2e concours, application number 337847, and by NSERC through the Alliance-SARI Program, Grant ALLRP 588519-23.

Data availability

No new data was generated in this study. However, the data used to generate Figs 1 and 2 are provided in Supplementary Tables S1 and S2.