This blog was written off an interview with Suzanne Wainwright-Evans, owner of Buglady Consulting.
Overview:
- A day in the life of a biocontrol expert
- How do biocontrol products compare to traditional chemical pesticides?
- What are some key considerations when adopting biocontrol products?
- What determines compatibility between biological and chemical products?
- What are “designer pesticides”?
- Beneficial insects and chemical tolerance
- What determines compatibility between biocontrol products?
- What challenges is the biocontrol industry facing?
Biological control, or “biocontrol“, involves using beneficial organisms or biopesticides to manage unwanted pests. Beneficial organisms include predatory mites, beneficial insects, and beneficial nematodes, while biopesticides encompass microbial products (bacteria, virus or fungi-based), semiochemicals and natural products like soaps and oils. Increasingly, growers are turning to biocontrol to supplement or replace traditional chemical pesticides. However, this shift requires an understanding of how different products interact.
Effective pest management depends on compatibility—whether between biological controls themselves or between biological and chemical controls. Achieving this synergy is critical to the success of a pest control program, underscoring the need for expert guidance.
Can microbials coexist with beneficial insects? Are there chemical products that are compatible with otherwise biological programs?
To explore these questions, we spoke with Suzanne Wainwright-Evans, a US-based agricultural advisor and owner of Buglady Consulting. With over 30 years of experience, Suzanne has worked with commercial growers to implement biocontrol solutions that blend science, economics, and practicality.
Suzanne’s passion for entomology started early. Her childhood was spent mostly outdoors, hunting for bugs. “I was one of those free-range kids,” she recalls. “My mom would just let me out the door.” In high school, Suzanne was part of a school ecology club aptly named “Save What’s Left,” where students would rehome native plants and animals from land about to be bulldozed for housing development. “During Florida’s rapid expansion in the 1980s, it was heartbreaking to see what big agriculture and human development were doing to the environment,” Suzanne reflects. “I wanted to be part of the solution.”
After earning degrees in entomology and horticulture from the University of Florida, Suzanne started her career with Florikan, helping growers design effective biocontrol programs. Today, she travels widely, offering expertise to nurseries, greenhouses, and botanical gardens across the U.S.
A day in the life of a biocontrol expert
Suzanne’s workdays are split between workshops, consultations, and her home studio. She regularly flies out to teach at conferences or visit growers, where she assesses their pest management programs, identifies problems, and recommends tailored solutions.
Her approach emphasizes integrated pest management (IPM) principles: “I always start with cultural practices, nutrition, and softer products before resorting to chemical solutions,” Suzanne explains. She also factors in the economics of pest control: “Growers need affordable solutions to stay in business.”
In addition to consulting, Suzanne devotes a large chunk of time to insect photography in her home studio, blending her scientific expertise with a creative outlet.
How do biocontrol products compare to traditional chemical pesticides?
“The biggest driver for switching to biocontrol is resistance.” explains Suzanne. “If traditional chemistries worked as well as they did on day one, people would still be using them.”
Unlike with synthetic pesticides, so far we have not seen pests develop resistance to microbial biopesticides, such as those containing Beauveria, Cordyceps, and Metarhizium despite their repeated use. This is also the case with oils and soaps, which work by suffocation or desiccation. The chance of developing resistance is very unlikely. Beyond efficacy, biologicals are often better for the environment, safer for workers, and more sustainable over time.
What are some key considerations when adopting biocontrol products?
1. Economics
“The primary challenge isn’t the cost of the biocontrol products themselves but the expense of application methods and labour”. Drones and other innovations, such as Biobest’s Entomatic system, which applies beneficial insects at the same rate as spraying a pesticide, are helping to automate the process and make biocontrol more affordable. The crop type also plays a role—high-value crops can better absorb the costs.
2. Target pests
Understanding the pests that are affecting your crop and prioritizing them matters. For instance, if you have both mealybugs and western flower thrips occurring on the same crop, pest management will be more complex if you require chemical treatments to control the mealybug. Those treatments could negatively impact bioprotection treatments against the thrips.
3. Application
“Microbials are contact products, so you need good spray coverage!” This introduces the importance of using high-quality sprayers, among which there is a wide spectrum of quality. Without proper coverage, product efficacy will be significantly reduced. Even factors like particle size can have a major impact on whether a product works well.
Applying macrobials (insects, mites, nematodes) also needs special care and attention. Growers need to apply them in a timely manner, with even distribution and without damaging them.
4. Climate
Biocontrol options vary by region. In the United States, there are more biocontrol options for temperate pests, such as western flower thrips, cotton melon aphid, and green peach aphid. For tropical pests, such as mealybugs or tropical thrips, there are less biocontrol options available. This sometimes makes it more likely to recommend biocontrol in the cooler climates of the Pacific Northwest and chemistries in the tropical climates of Florida. “Biologicals are more dominant further north, and chemistries are more dominant down south. This is because most of the biocontrol technology is coming out of Europe and Canada, which have largely more temperate climates.”
What determines compatibility between biological and chemical products?
When determining whether a pesticide is compatible with a biocontrol agent, both the active ingredient and the formulation must be considered, as both influence compatibility. The active ingredient can often be researched for its direct impact on beneficials, with extensive studies conducted by biological control companies and researchers. However, these tests are typically short-term and may not assess long-term effects, feeding repellency, or impacts on fecundity.
Inerts in a product, even if not directly toxic, can also affect beneficials. For example, an oil-based carrier may have a suppressive effect on predatory mites.
To ensure compatibility, it is essential to consult a qualified expert who can help navigate product selection for your program.
What are “designer pesticides”?
Suzanne points out that on today’s market there are products that are far more targeted, designed to affect specific pest groups while minimizing harm to non-target organisms. These are sometimes referred to as “designer pesticides.” Examples of active ingredients in these products include bifenazate, cyflumetofen, and pymetrozine.
Biopesticides can also be highly targeted, but some are broad-spectrum. While biopesticides tend to be softer on biological control agents, this is not always the case. This is why it is crucial to understand the product you are using and how it may impact the beneficials in your program.
Beneficial insects and chemical tolerance
Different biocontrol agents vary in their tolerance to chemical residues. Lacewing larvae, which feed on a variety of pests, are more tolerant than many other beneficials, making them a versatile option if there are pesticide residue concerns.
In contrast, some predatory mites and parasitoids are highly sensitive to pesticide residues. When these beneficials encounter treated foliage, they may either die or abandon the plant entirely. This sensitivity underscores the importance of carefully selecting a beneficial depending on the spray history of a crop.
What determines compatibility between biocontrol products?
Compatibility depends on the product’s formulation. For example, Beauveria bassiana in its wettable powder form (e.g., Bioceres®) is compatible with predatory mites when mixed with water and sprayed. However, oil-based formulations are less compatible, as the oil carrier can harm predatory mites. Oil carriers in formulations can improve shelf life and adhesion but require careful timing; applying the product first and allowing it to dry before releasing beneficials can mitigate risks.
Examples of reliable combinations of products
- Compatible miticide + Phytoseiulus persimilis: A miticide that just targets spider mites without harming P. persimilis predatory mites, Cyflumetofen is an example of this.
- Bioceres® (Beauveria bassiana strain ANT-03, wettable powder) + Phytoseiulus persimilis: The B. bassiana targets western flower thrips, while the predatory mite handles spider mites. Add beneficial nematodes to the soil for WFT pupae and yellow sticky ribbon for adult mass trapping.
Examples of combinations to do your homework on
- Fungicides + Beauveria bassiana: While it may seem that fungicides can’t be mixed with products containing B. bassiana, many are surprisingly compatible. However, don’t guess—always check with the manufacturer of the products you plan to mix to ensure compatibility.
- Plant Growth Regulators (PGRs) + Aphidius colemani: One area that definitely needs more research is the impact of plant growth regulators (PGRs) on biocontrol agents. A 2013 study at NC State examined the effects of PGRs on the aphid parasitoid Aphidius colemani and found a negative impact. This is an important factor to consider when using PGRs and a biocontrol program.
- Overuse of Soaps and Oils: While effective against pests, they can harm crops if over-applied or used at too high of a rate. Growers must apply particularly risky essential oils like garlic, rosemary, and thyme in precise amounts to avoid phytotoxicity. Highly refined petroleum-based oils have shown a high level of safety. Additionally, once dry, growers can safely release beneficials .
What challenges is the biocontrol industry facing?
Similar to the black market for pesticides, there is also a black market for microbial pest control products. These counterfeit products often have much lower efficacy and can erode confidence in biocontrol as a reliable pest management strategy. Growers and agro-input dealers should only buy products that are registered by the national regulator, only buy from reputable sources. They should also check that key aspects of any product, such as active ingredient name, content and concentration, or packaging, such as unbroken seals, legitimate labels or markers (like holograms) are present and as expected.
Another major hurdle is the lack of clear guidance on how to use macro biocontrol agents. “Biocontrol products are not like chemical products where you just follow the label. When you get into the insects, mites, and nematodes, there is a lot of wiggle room on rates.” Always seek an advisor with legitimate experience to check compatibility if you are unsure. Try to find a “bug buddy” to discuss ideas and share insights. And lastly, the International Organization for Biological Control (IOBC) database is a great resource on compatibility details for products.
Biological control offers a sustainable and effective alternative to traditional pesticides, but one crucial factor in its success is understanding pesticide compatibility —between beneficial organisms, microbial products, and chemical solutions. Suzanne emphasizes key factors for success, including selecting the right formulations, understanding the ecology of beneficials, and incorporating designer pesticides when necessary. By adopting tailored solutions that balance science, practicality, and sustainability, growers can unlock the full potential of biocontrol in their pest management programs.
This blog contains hyperlinks to products offered by our partners Biobest and Anatis Bioprotection. Use our search tool to find similar products in your country that meet your specific needs.
