Wednesday, June 8, 2016
Attracting Beneficial Insects to the Grden - by Rebecca Veenstra
Yep. In the natural world, as conceived of before human intervention, insects exist in a carefully orchestrated food chain that starts with microscopic little bugs and ends with birds and frogs and lizards and so on. The little microscopic bugs eat plant matter like leaves, fruits and roots. Then, they get eaten by slightly bigger bugs who are then eaten by bigger bugs, who are eaten by birds and frogs and lizards.
Insects are fairly discriminating about what other insects they eat though. Of course, big bugs like praying mantis will eat practically anything they can catch but lady bugs prefer aphids and small soft bodied bugs, green lacewings prefer mealy bugs and white flies but they will eat spider mites in a pinch and they`ve been known to snack on aphids and thrips too.
Many farmers, especially greenhouse growers, will order beneficial insects from suppliers that propagate and distribute them in their larvea state for release into the garden.
The thing about that strategy is that in order to receive the bugs in good health, often the supplier includes the prefered diet of the insect in the mailing package too. They can`t have you receiving dead, starved bugs. So, by ordering the good bugs... you get a bunch of the bad bugs.
The idea is that the predator bugs will diminish the population of the bad bugs to the point that the two species can exist in harmony in the garden with the good bugs continuously eating the bad bugs. If you end up with the right balance, then the plants show no damage from the bad bugs because the good bugs are keeping the population in check.
The question is, how did your friend`s garden get spider mites in the first place? Well, in the natural world, insects are attracted to certain plants that they either will consume themselves, or they are attracted to plants that feed the kinds of bugs they like to eat.
So, a lady bug may be attracted to rose bushes not because she likes roses, but because she knows that there are yummy little aphids snacking on the rose bush. A green lace wing might be attracted to bean plants because there are spider mites on them.
Your friend`s sweet happy marijuana plants attracted hungry spider mites from an adjacent field or garden where they were snacking on something less appealing than your friend`s lovely ladies.
Now, you are thinking this through as you pace in the grow room. Fretting because you know your girls are way sweeter and tastier than any plants in the surrounding yards. You know the bugs will come in droves if you don`t do something.
Ordering up a vile of predator bugs sounds like a decent plan but the idea of all those pesky bad bugs stowing away in the package diminishes any feeling of relief.
Your friend is on a seek and destroy mission with the armoury of sprays. You weigh the sensibility of this plan, thinking that if you kill the bad bugs... don`t you wipe out the good bugs too?
What if you learned what plants attracted the beneficial insects? Maybe you could grow some of those plants around your garden? Maybe they would help to balance the ecosystem of creepy crawlies and allow your girls to thrive.
So what plants attract what kinds of bugs?
Well, keeping in mind that predator bugs are attracted to plants that have bad bugs on them, you will have to utilize what at first seems like a bit of a backwards strategy. It`s kind of like ordering the good bugs with the bad.
Your marijuana plants will naturally attract the bad bugs. That`s a given. Now, what if you supplied a barrier of sweeter plants on the perimeter of your garden? Something you know the bad bugs will like, maybe not as much as your marijuana, but something attractive enough to their taste buds that they stop there first on their way to your girls.
Greenhouse farmers refer to these plants as banker plants. They allow the bad bugs to be consumed before they get to the intended crop. Many farmers will place bean plants along the fields to attract spider mites. Then they will introduce predator populations to those plants. That way the battle between spider mite and predator is fought on the bean plants and not the farmer`s plants. The result is that the farmer`s crop will show significantly less damage from spider mites because the predator bugs consume them before they make their way to the fields.
In large scale farming adding to the population of naturally occurring predators makes good sense. In your backyard though, things work on a less grand scale. In theory the beneficial insects will be naturally attracted to the plants that host the bad bugs.
The bad bugs that might invade your garden are out and about marauding for fresh plant matter, but the good bugs are just on their heels looking for an opportunity to chow down on them. So, if you plan and monitor carefully, you could potentially create a harmonious insect food chain that will allow those pretty ladies to reach maturity with out significant bug damage.
The insects that live in our climate that prey on bad bugs are: pirate bugs, green lace wings, lady bugs, praying mantis and predatory gall midges. Predatory gall midges look a little bit like the kind of bug that bites. I think I am personally guilty of squishing a few in my lifetime when they landed on me. They go by a fancy scientific name in most references about them, Feltiella acarisuga. Try and say that three times fast.The pirate bug looks a little bit like a fly or a beetle. I could see people squashing them by mistake too. The others are fairly easy to identify.
Their preferred diets are as follows:
Praying Mantis- This bug will consume anything it can catch-- even eachother. They have been known to eat small hummingbirds and butterflies. This means they will eat other beneficial insects too.
Ladybugs- These pretty little insects will eat aphids, spidermites and other soft bodied bugs.
Green lacewing- These lovely flying insects will eat thrips, whiteflies, spidermites, mealy bugs, and aphids.
Pirate bugs- Even though they look like they`d bite people they prefer to eat thrips, spider mites and aphids.
Predatory gall midge (feltiella acarisuga)- These bugs prefer spider mites to all other foods.
Having researched the plants that attract these insects, I have found that there are some common plants that all of these bugs are attracted to. Which means that the bad bugs are into these plants as well. But if you attract the bad bugs the good bugs will come. The trick is to keep the bad bugs off the intended crop.
One of the plants that attracts praying mantis, lady bugs, green lace wings, pirate bugs and gall midges is fennel. Fennel also is wonderful habitat for bees and swallowtail butterflies. In fact the butterflies prefer fennel to any other host plant. The most recommended cultivar of fennel is Florence Fennel. This plant will grow a sweet celery like bulb that you can eat at maturity. The other varieties of fennel may only grow a grass like herb and go to seed.
Dill and caraway are two other plants that attract the good bugs. Be careful planting them in areas where they can cross pollinate though if you intend to harvest the seeds for culinary purposes. If they cross pollinate the seeds will be flavorless. The same applies to fennel seeds and coriander seeds.
Coriander is another plant that attracts beneficial insects. Primarily it will draw in green lace wings and lady bugs.
Yarrow is a common plant in our climate zone. You have probably seen it growing wild in many places. The plant has many good medicinal properties for humans and it also attracts green lace wings, lady bugs, and praying mantis.
Dandelions, as much as we try to eliminate them from our lawns, are very good for humans; providing a food source as well as herbal medicine. In addition, they attract lady bugs and green lacewings.
Traditionally, merrigolds are planted to repel insects from the garden. Imagine how surprised I was when I learned that merrigolds successfully attract praying mantis and pirate bugs to the garden. Another plant that lures both pirate bugs and praying mantis is Angelica.
Lady bugs and green lace wings like Queen Annes lace and Tansy.
Strategically, a garden plan that takes into account and allows for the natural order of things to occur can be intimidating and require a lot of planning and monitoring. In the long run, if successful, such a plan can bring a great sense of well-being to a gardener.
The reassurance of knowing that the ecosystem is allowed to thrive while allowing for the harvest of untainted, truly organic crops can provide great peace of mind.
Sure, it`s easier to grab a bottle of insecticide spray--much easier than learning to identify and monitor populations of good and bad bugs. Yes, it does take time to cultivate the plants that attract the insects. There is a big learning curve and mother nature is anything but predictable. There are always opportunities for things to go not according to plan.
Remember though that those opportunities are chances to modify your approach, change up your plan. Eventually, with perseverance and education, you will become an expert on your environment and the ecosystem that thrives in your garden. You will learn to use the resources mother nature provides to both honor her and provide for yourself.