There is a revolution taking place in people’s gardens.
The demand for Organic products; mistrust of chemical companies; the longing for a simpler time; near complete chemical resistance in some pests; and an adjusted sense of what constitutes garden productivity have all played a role in the major increase in demand for biological controls like beneficial insects.
So what is stopping you, and many others from jumping on this bandwagon? For most, it comes down to the time they spend in the garden. Many only notice pests when it is a problem instead of noticing when they first appear in small numbers, or anticipating (based on previous years) when they will appear. If people wait until they see a problem, using good bugs not only will frustrate them (as conditions will worsen before getting better) but it will also cost more money than some chemical pesticides. 
When people consider the cost in dollars between using beneficial insects vs chemical sprays they are failing to truly measure “cost.” This, I call the Stupid Threshold, since it really shouldn’t exist. The “cost” of using chemicals is beyond dollars. It will harm the environment; you will then have to rely on chemicals (as it would have killed the good bugs); your plants actually suffer from the chemicals (chemical companies don’t tell you that); and in some cases you are eating it. The other hang-up in using beneficial insects, is that people don’t understand bugs – “How do I get them? What sort of package is it in? Won’t they just fly or crawl into my neighbours yard? What bugs do I have and what bugs do I need?” Unlike the “stupid threshold”, there is nothing stupid about these questions. Buying beneficial insects is a new concept for many, and the education that goes along with it is immense. So, let’s work on that.
Step #1
Prepare your garden; Prepare for battle!
As a home gardener, you spend much of the winter planning your spring garden chores, dreaming up ambitious goals or images of what your space will look like by June and in September. Your garden, under a blanket of snow or the darkness of rain appears to be a blank canvas. However, just as your bulbs are sitting in-wait for an opportunity to spring-forth, so are the pests.
Many of the pests, and predators…. In fact, nearly all micro-fauna, is overwintering somewhere nearby. Should you allow nature to have a free-for-all in your garden, you will see that the pests arrive first, over populate, and then slowly make way for the predators who appear, eat, over populate and prepare again for winter. The predators always wait for pest pressure to peak, so that they never run out of food. Always trust nature – it has a plan. It just might be hard to watch those roses overcome by aphids while you wait for nature to catch up.
In this natural model, your young plants will be fed upon, and sometimes killed by pests. To make matters worse, chemical residues, the overall reduction in micro-fauna from human interference as well as the reduction of wild areas, all contribute to a reduction in the predators upon which you rely.
So Step #1, is about returning a balance (and getting the upper hand) in the season to come. So while you gaze longingly over your winter garden through your window, know that part of your planning is with beneficial insects.
What you need: Stratiolaelaps scimitus and amblyseius fallacis. These are one-time purchases. Never again (if you don’t apply chemicals) will you need to buy them. This is preparing for battle. Both Stratio and Fallacis (common names) will overwinter in most North American “USDA Zones.” They eat most “pests”. So even when they have eaten most of the overwintering spider mite or aphids, pupating thrips, grubs, wireworms russet mites…etc, they will turn to pollen, other eggs or mites, nematodes, bits of detritus, and other things to keep themselves alive. This is the most essential thing you can do for the health of your garden. In both cases, you can buy these products in a pseudo-soil (like vermiculite). Simply open the container and sprinkle the contents as per directions on the container. For example, stratiolaelaps may come in a 1 litre container with 25,000 mites (all life cycles). That means 1 ml has 25 mites. Directions may say something like “distribute 1 ml, per square meter.” The vermiculite product of fallacis is adults only, but you may find Fallacis on Leaves, which is far superior, as it has the full range of life-cycles (eggs, larva, adults and both sexes..etc) and food for them to eat enroute to your garden. In this case, simply distribute the leaves amongst your plants according to the label.
above: Dalotia, stratiolaelaps and fallacis
Stratiolaelaps will live exclusively in the soil (although current studies are proving they can and will feed above ground at night). They will control a variety of pests (pupating thrips, overwintering spider mites, black vine root weevil, fungus gnats, and more), and there is anecdotal evidence suggesting they will control a huge number of other pests, such as varroa and pollen mites, foliar nematodes, chafer beetle, and wireworm to name a few.
Fallacis is a field mite that prefers spider mite. However, it will take cover in the ground or in hedges and detritus to over winter. It is a fast moving general predator that will roam over all surface areas, preventing the build-up of pest populations. It will feed on most soft bodied plant pests and is ideal for control of microscopic pests like russet mites, cyclamen mites and other eriophyid mites.
Another step 1 product is Dalotia coriaria (Rove beetle), while you may have to purchase this every year, it is an excellent first step as it prefers cool temperatures and is an excellent hunter both above and below ground. While it prefers aphids, it will eat a variety of prey. Also in a pseudo-soil, sprinkle it in your garden according to the label. It eats many of the same things as above, and will eat a lot, but they will spread out or leave, as opposed to the other two that stick around.
With Step #1, your garden is given a head-start and a more balanced battle field.
Step #2
Step two is about Protection. Step 1 gives you a head start, but you’re not out of the clear. 
Certain weather patterns, annual patterns and fluctuations can all result in an explosion of pest pressure. There are three ways to apply step two:
1. Scout: regularly check your garden closely…under leaves, in all nooks and crannies. When you find a pest, react: Begin step two;
2. Record keeping and anticipation: Note in a journal when you see pests arrive throughout the year. Ahead of that time in future years, purchase and apply the step 2 predators in a rate that will keep the pests from establishing. This takes the most organization and detailed note taking on your part;
3. Prevention: buy a small amount of step two beneficial insects and apply them to your garden at regular intervals (3-6) weeks to maintain a steady pressure of good bugs, to keep the bad bugs at bay. (most commercial applications use weekly applications, but they are working with a monetary threshold).
above: Flip a leaf and see what you find. Here are whitefly and their eggs.
Of course, the best method for step two, is a combination of the above. If you love your garden, and love gardening, the note-taking and scouting is not a chore, and the inexpensive prevention purchases are the ideal for peace-of-mind.
What you need:
above: encarsia, aphidoletes, cucumeris, brown lacewing
Aphidoletes aphidimyza: This predatory midge will fly to your hidden aphids (attracted by honeydew secretions) and lay several hundreds of eggs directly on the aphids. Each hatched larva can eat up to 30 aphids (but kill hundreds more) before pupating in the soil and recycling. They will cycle all season, but regular applications keep their numbers optimal. These come in a container kept at room temperature. When the adults are seen flying around in the container, release them at dusk by opening the lid in the garden. Or get a slow release hanging container. Hang it on a branch and they will emerge as they go.
Encarsia formosa: This parasitizing wasp targets whitefly. The steady release of these will prevent an explosion of whitefly in your garden. They come as eggs on a card. Hang the card in your garden and the adults will emerge and start hunting.
Micromus variegatus: (brown lacewing). Unlike green lacewing, the brown version’s adult stage is also a hunter, and a voracious one! Buy the adults and let them fly. Although they are known as an aphid hunter, they will attack most pests. While they may fly away, check the undersides of your leaves as they likely left some eggs. They hide and won’t fly far but they are notoriously hard to scout. Brown Lacewings are sold as adults. Open the lid and they will fly to their food. (They can smell them.)
Neoseulus Cucumeris: Another predatory mite, but this one feeds primarily on thrips and remain above ground. It is known to eat other prey as well, but the ability to completely control thrips will save your beautiful blooms. It’s a must for a garden producing flowers. This comes in a pseudo-soil. Sprinkle it in your garden according to the label.
above: Don, founder of Applied Bio-Nomics, sprinkles product in a greenhouse.
Are you wondering why Ladybugs aren’t listed? Check this out: Never Buy LadyBugs
Expect step two to last right through to September. However, with the long-hot days of summer you may run into other problems:
Step #3
Hot Spots: After doing steps one and two why should there ever be a need for step three?! You’re right for asking, but wrong for underestimating nature. Steps one and two can give you complete control all season, but we all know of troubled areas, or specific plants or streaks of weather that contribute to additional pest pressure. Most commonly, this additional pressure is caused by plant varieties that have been bred for a specific characteristic but had others ignored, like roses, which for hundreds of years were bred for colour and scent but not for pest resistance. If you’re reading this, you probably have aphids on your roses, spider mite on your citrus, or hedges and whitefly on your eggplant and tomatoes. So be prepared for hot spots!
What you need for hotspots:
Phytoselius persimilis and Stethorus punctillum for spider mite. Both eat only spider mite. Persimilis, a mite, has a three day life-cycle and will quickly overrun the spidermite. Buy it as adults in vermiculite or (better) buy them on leaves with all lifecycles and some food for them. Release similar to fallacis in step one. Stethorus is a beetle that will spread out via flight and lay eggs in spider mite areas. They both eat a huge number of spidermite. They are such successful predators that they will both eat themselves into starvation. When there are no spidermite, persimilis will leave the plant by collecting at the top and hoping for a favourable breeze. Stethorus will fly away.
above: Delphastus and Stethorus, for whitefly and spidermite (respectively)
Aphidoletes and micromus for aphids (higher concentration than step 2) This is similar to step 2 in application, but you are just over powering them. This is likely only needed if you have plants going to market, or are trying to save a food crop, otherwise, the cycling aphidoletes and lacewing from step 2 should suffice.
Encarsia formosa and delphastus catalinae for whitefly. This too, is a numbers game. Both could be used in step two at a lesser amount, so here we use them to overpower a problem. Encasia parisitizes white fly eggs at their third instar stage. Delphastus prefers eggs and will eat them early on. The whitefly won’t disappear but the eggs will, so this takes a few weeks to see the effect: it is better to prevent with stage two than to chase a whitefly hot spot. (many of the other beneficial insects listed will also prey on whitefly)
Neoseilius cucumeris (higher concentration) for thrips. Also a number game. If a farmer just cut a field on a windy day, you likely have millions of thrips floating into your garden. Get more cucumeris and set them free.
Remember: In some cases if you need to react in step 3, steps 1 and 2 were insufficient or you have chemical residue (maybe a neighbour sprayed their lawn), you have weak plants (healthy plants better resist pests….in fact, most pests are attracted to stressed plants), or you have a plant that is just difficult to work with genetically. In any case, step 3 can be expensive so avoid it as best you can.
So, to answer the questions at the beginning:
How do I buy bugs? – Find a supplier online with a simple google search and request the freshest, highest quality insects. (Freshness mean they search better, eat and reproduce quicker, so you need to buy less.) If you have high quality bugs that cost more you will need less of them. The result is you will save money buying less of the expensive ones.
What kinds of packages do they come in? – mostly containers with a soil-like substrate or as adults ready to fly, on on leaves and cards ready to be placed.
above: two products from Applied Bio-Nomics ltd. Stratiolaelaps and Aphidoletes (french label)
Won’t they just fly and crawl away? – release time matters. Release in shade, at dusk, and not when it’s windy. Then they will search for the closest available food. They will not leave your yard if it is organic and has food for them – but even if they do leave, they won’t go far and will likely come back as your yard becomes more attractive to them.
What bugs do I have and what bugs do I need? – I have listed the bugs you need. As for the bugs you have, use the internet to identify what you have found, or consult a specialist. They ones you should familiarize yourselves with are aphids, spider mite, and white fly and what their damage looks like and thrip and broad mite plant damage. 
Also look for scale, mealy bugs and ants. Ants protect aphids, so you sometimes need to control them as well. Knowing and identifying those potential problems gives you a good head-start.
Now there is no reason not to get started with beneficial insects. Finding a suitable supplier may be the biggest problem, so check out this list:
https://www.appliedbio-nomics.com/distributor-map/
PS: Don’t buy Ladybugs: They are collected from the wild at a detriment to the environment. They eat aphids, but don’t always control them, eating only enough aphids to reproduce, leaving aphids for their young to do the same. And they eat other bugs and may leave to find some other food.
