049-When Good Bugs Eat Bad Bugs: The Business of Beneficial Insects

| Care, Podcast

This week’s guest is Suzanne Wainwright-Evans, the Bug Lady of Bug Lady Consulting. To say that Suzanne – an entomologist and expert on biocontrol who I’ve known for many years and interviewed multiple times – is a wealth of information… well, that would be a true understatement.

Our conversation is so jam-packed with pest management gold, that I’ve expanded this to a two-part series. Once you’ve finished here, check out Part Two.


Suzanne Wainright-Evans and Joe Lamp'l

Suzanne Wainright-Evans and I talk bugs from Bug Lady Headquarters.


Suzanne travels internationally as a self-proclaimed “fixer of insect problems.” She consults for greenhouses, nurseries, theme parks, aquaponics operations, medical cannabis – basically anyone who grows plants and, often, for large growers. Her work focuses on biocontrol (biological control). Biocontrol is all about putting a pest’s natural enemies to work to fight that pest – encouraging nature to take its course.

Suzanne’s work also incorporates the use of pesticides but only after a thoughtful process of elimination and investigation.

If you are a regular reader of my podcast show notes, you know that I always encourage you to listen to the podcast recording in addition to reading, as there are always interesting and fun conversational aspects that can’t be fully conveyed in the show notes.

This week, I’m just going to start right off with that suggestion.

Certainly, continue reading and refer back to the show notes later for details too – but Suzanne provides so much information on pest management during our conversation that sharing it all in show notes would result in page after page of text.

Below, I will cover much of what we discuss, but this podcast recording, more than most, will touch on so many more nuances and topics that may speak to your personal gardening situation. Don’t miss it, and check out the link to Suzanne’s website at the end of the show notes in the Links & Resources section.

Are you ready? This podcast will open up a new world to you. Hold on – here we go:

Bugs Are Everywhere

Did you know it is easier to manage pests outdoors than indoors – like in a greenhouse environment? Suzanne explains that the walls of a greenhouse actually make management more challenging, as those walls exclude beneficial insects from getting in to fight pest issues.

Outdoors, there are native beneficials already at work in the ecosystem. As pests move in on garden plants (which they inevitably do), they are hunted and can be kept in check by beneficials.

What are pests and beneficials? Bugs. There are pest bugs and beneficial bugs, but they are all bugs.

This is the classic good guy vs. bad guy situation. Except in this case, the good guys eat the bad guys. When you see a bug on your plant, you may be looking at a good guy. So, take pause before you take action.

Plants were designed to sacrifice some of their foliage to being eaten. If you spray or treat what you think is a bug problem (or in an effort to be proactive), you will likely harm the beneficial insects that would naturally take care of the problem without any treatment being necessary. Let Mother Nature do her work first.

As Suzanne says: “This is an ecology. A chew here and there isn’t going to hurt anything.”


Braconid wasp cocoons on a tomato hornworm

Braconid wasp cocoons ride on their pest victim – the tomato hornworm. (photo: Suzanne Wainwright-Evans)


Most pest management products sold are broad-spectrum products. Broad spectrum means that they kill indiscriminately. Bug armageddon. Since the very word “bug” has a negative connotation, many gardeners reach for the “bug killer” a few times a year, apply it around their garden and sleep soundly thinking they have done the right thing.

The commercial grower industry used to take that approach. Suzanne had some surprising things to say on that front. She has been working with commercial growers for years and can attest to a dramatic change in pest management industry-wide.

Putting Bugs to Work

Many commercial growers have moved away from the use of pesticides in their operations. They have come to realize that biocontrol is easier and more economical than pesticide application. These operations are turning first to the use of beneficial insects to manage pest problems.

When Suzanne comes onsite to consult, the approach she and the on-site staff take is thoughtful and measured. The first task is to determine whether or not there actually is a pest problem versus an inconsequential population. If there is a problem, they work carefully to identify the pest or pests causing the problem. Many insects look very much alike and actually mimic other insects, so identification can be a challenge.

Next, Suzanne and facility staff determine if pest treatment can be localized or should be applied throughout the crop. Insecticidal soaps or horticultural oils may solve the issue, but if they don’t, biocontrol agents (good bugs) are brought in and put to work. Only after all of this research and care do pesticides become a treatment consideration.

Many of these large-scale operations have become keenly aware of the long-term consequences of pesticide use, so they turn to pesticides as their last option.

Suzanne is certainly not anti-pesticide. She is quick to note that, without pesticides, our world would still be suffering under high rates of malaria and other diseases, and we wouldn’t have access to some of the foods that are part of our daily lives. Suzanne is simply a proponent of being shrewd with pesticide use.


Indian wax scale

Scale pests, like this Indian Wax scale, can be challenging to combat in the garden. (photo: Suzanne Wainwright-Evans)


When applying any type of treatment spray at home, you have probably learned how difficult it can be to treat the whole plant – covering the underside of leaves and everywhere that pests attack. So imagine the challenge of full treatment in a large-growth operation.

Several years ago, Suzanne and her colleagues implemented a test. They mixed pink dye with water in a spray container and gave the solution to a nursery worker in charge of pesticide treatment. After he sprayed nursery plants with what he thought was a pesticide, Suzanne and her colleagues toured the facility. They found the spray container had a leak, leaving a trail of pink residue in its wake (remember, this dye represented a pesticide). They also found pools of pink dye on container rims and in small areas of plants, but much of the plant foliage was untouched.

In other words, the diligent and well-intentioned work of the nursery employee, resulted in spotty application and more mixture left on the floor and containers than on plant foliage. Spray application is challenging.

Enter the good bugs.

Bugs come and bugs go.

Commercial growers began to understand that releasing good bugs was a game-changer in managing the bad bugs. Growers purchase the beneficial insects from insectories. These are bugs which have been used and studied for decades and which have been raised in a lab environment so as not to be exposed to disease.

A common method of application is a sachet, made of paper, which slowly releases predatory mites into the grower facility. That thought might give you the creepy crawlies, but think of these bugs as a tiny pest-fighting army, marching out to eliminate your garden foes. These specific mites feed on many problem pests, including spider mites. That’s right, there are good and bad mites, too.

Did you know that almost every tomato plant grown in a greenhouse in Canada has been grown with beneficial insects? Bumblebees play a big role in greenhouse pollination for these growers, so the growers can’t spray pesticides – which would kill the bees. Instead, good bugs are brought in to protect the tomato plants without presenting a risk to the bees.


Bottled product beneficials

The use of beneficial insects has become commonplace in commercial growing operations. (photo: Suzanne Wainwright-Evans)


Right about now, you may be wondering why, if it has been so common in the growing world to use beneficial insects, you don’t see them on the plants you purchase.

Sadly, large plant retailers (who purchase from the commercial growers) fear that the consumer will reject any plant with a bug – any bug. Although many beneficial insects are too small even to be seen, retailers sometimes require growers to spray their plants with pesticide – to kill the beneficials. So efforts made to avoid pesticide use are offset by treatment applied before you purchase that plant for your garden.

Large retailers often demand that the commonly-used biocontrol sachets be removed from plants before those plants are made available for sale.

This is an education problem. We, as consumers, need to re-adjust our bug mindset. Collectively, we need to send a message to retailers that we are pro-beneficials, and we need to adjust our ingrained bug avoidance.

For example, those tiny orange-ish balls you sometimes see on plants and probably think are a sign of pest issues. If you were pro-beneficial, you would want those to come home with you.

Aphidius colemani wasps are a common beneficial used by large growers. These tiny wasps lay eggs inside aphids. The egg larvae eats the innards of the aphid. As it develops, the larvae then uses the shell of the now-dead aphid as a sort of cocoon – a protective case – while it goes through metamorphosis to develop into wasp form. This aphid shell cocoon – an aphid mummy – is the tiny orange ball you see on plant foliage.

No, the description of the process isn’t pretty, but if it means fewer aphids in my garden – I want some of that action. Three cheers for aphid mummies!


Aphidius Colemani and aphids

Aphidius Colemani wasps lay their eggs inside aphids and use the aphid shell as a cocoon. (photo: Suzanne Wainwright-Evans)


Remember – growers have to purchase Aphidius colemani wasps, and they can be expensive. If you had the option of bringing some home – as a free bonus – to reproduce and fight pests in your garden, why wouldn’t you?

Maybe you don’t like the word wasp? Wasps sting, right? That’s like saying ants sting. Some ants do sting – in particular, fire ants species. Those are very bad bugs. Yet, there are about 12,000 species of ant in this world – and only a small fraction of that number will sting, including the approximately 280 fire ants species. Most of those 12,000 ant species are very beneficial.

Nature is a wonderous thing with so much beautiful diversity. The Aphidius colemani may be classified as a wasp, but it is very different than our homogenized image of what a wasp is.

Other beneficial wasps eat caterpillars which commonly prey on tomatoes, broccoli, cabbage, etc. These wasps lay their egg inside the caterpillar. Once again, those wasp larvae eat and destroy the caterpillar – which means less damage to your plants but also one less bad bug to grow to adulthood, breed and leave new pest offspring as its legacy.

That is the true beauty of putting beneficial insects to work. Their activities provide swift but far-reaching assistance – a trickle-down effect through the bug generations in your garden.

Other Beneficial Controls In Use

Beneficial nematodes and microbial pesticides are other common biocontrols being employed by commercial growers.

What the heck is a nematode? Nematodes are microscopic worms at work in the soil – all soil. There are good, bad and indifferent nematodes. Root-knot nematodes are some of the bad guys. Indifferent nematodes are just doing their thing in the soil – not causing any damage but not fighting any of the bad guys either. Beneficial nematodes help manage flea larvae, cutworm larvae, armyworms, grubs, and other bad guys in the soil (but they don’t harm earthworms).

Many large grower operations mix beneficial nematodes with water and spray them on the soil of their plants.


Commercial nursery

Large growers also use “banker plants” to draw pests away from more valuable crops. Seen here, at left, are pepper banker plants. (photo: Suzanne Wainwright-Evans)


What are microbial pesticides? These are naturally-occurring bacteria, viruses and fungi that attack the bad bugs. Certain fungus spores, for example, land on certain insects. The spore will grow on the insect – eventually killing it. This activity happens every day in the natural ecosystem. Researchers identify these fungi in the environment, collect samples and grow them in a lab to be sprayed as a biocontrol.

When biocontrols can’t or don’t work, growers are making smarter choices with pesticide use. Development of pesticides available to commercial growers has come a long way, creating products that are much more pest-specific (not broad spectrum). When application is necessary, growers are using a more refined management approach – removing plants most affected by pests and spraying only those remaining plants within the problem area.

These are just a few more examples of how many commercial growers are taking significant steps to reduce pesticide runoff, protect beneficial insects and utilize biocontrols – of all types.

So, why aren’t we hearing more about this? Shouldn’t these efforts – which are significant strides toward protection of our environment and utilization of organic methods – be shouted from rooftops? I think so. Unfortunately, this isn’t perceived as a good “marketing” message.


Orius insidiosus for biocontrol

Orius insidiosus, seen here in its adult form, is an effective partner in the battle against thrips. (photo: Suzanne Wainwright-Evans)


During her 40-50 lectures each year, Suzanne is frequently asked where to purchase plants grown with biocontrols and how to support the growers making these efforts. Unfortunately, a consumer won’t be able to identify these plants or many of their growers. Some plants do carry a grower brand name – such as Monrovia – so choosing plants branded from a grower using biocontrol methods is one way to show support. However, plants don’t carry any type of biocontrol label, and since some retailers require the application of pesticide before plants go to market, the point may be moot.

On to the Home Garden

So, what does all of this mean for the home gardener? Hopefully, Suzanne and I have you all fired up about biocontrols. If that’s the case – hold that thought. Before you buy something or apply something with the best of intentions, check out Part Two of this series.

In Part Two of this series, Suzanne shares more beneficials you should watch for – and common beneficials you should be cautious of. We also discuss common “natural” pest management products that can exacerbate your pest problems. The world of biocontrol is largely misunderstood and easily misapplied.

You may be anxious to begin, but Suzanne’s fundamental message is to make smart choices. You will be better equipped to make those smart choices after hearing and reading next week’s podcast.

While you wait, may I make a suggestion? Reach out to your local retailers. Let them know that you are not afraid of bugs and that you would like to start seeing more of the good guys on their product. Those beneficials won’t make it through the gauntlet of commercialism unless we all speak up and make it known that we welcome them in our gardens.

Meanwhile, I encourage you to check out Suzanne’s website.

Links & Resources

Episode 050: Organic Pest Control: Beneficial Insects And Beyond 

GGW Episode 403 – Controlling Pests Organically

Bug Lady Consulting

Milorganite® – Our podcast episode sponsor and Brand Partner of


About Joe Lamp’l

Joe Lamp’l is the creator and “joe” behind joe gardener®. His lifetime passion and devotion to all things horticulture has led him to a long-time career as one of the country’s most recognized and trusted personalities in organic gardening and sustainability. That is most evident in his role as host and creator of Growing a Greener World®, a national green-living lifestyle series on PBS currently in production of its ninth season. When he’s not working in his large, raised bed vegetable garden, he’s likely planting or digging something up, or spending time with his family on their organic farm, just north of Atlanta, GA.

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