What Are “Modes of Action” Or MoA?

First, what does “Modes of Action” mean?

Simply, this is the way in which the pesticide, herbicide, aracnicide, fungicide, etc. works. Each chemical typically using one way in which it kills your garden’s pest.  It may be making the insect sterile, incapable of molting, suficating, starving to death, unable to control their nerves (neurotoxin), etc.

What makes it even better is there are different ways in which it can stay with the plant.  It can be a surfactant or leaf polish, when it only stays on the surface of the leaf. It can enter the plant but only stay in one area. Or it can stay in the plant and travel around ( a true systemic).

Second, what does “Modes of Action” mean to ME?

This is the most important question.  Understanding modes of action is extremely crucial to fighting spider mites as well as other pests that have multiple generations per crop.  If you don’t destroy your pest infestation the first time, they will adapt and beat you.

Take Spinosad for example, a common active ingredient in the fight against spider mites. This is an insecticide that works by killing on contact or ingestion.  Also it kills by by causing uncontrollable muscle contractions and eventually paralysis.

If you continue using this same mode of action time after time, generation after generation. Remember no matter how  through you think you are you WILL miss a couple of eggs or worse yet live mites.  Eventually, your friendly, local spider mite is going to grow immune to your spinosad. If you do it long enough there will be no killing spider mites in your neck of the woods with Spinosad for a very very long time.

But if you were to toss in a different chemical, not more harsh just with a different mode of action, you might have a winning plan.  You could switch to Forbid 4F, which uses a form of “Lipid biosynthesis inhibition”, presumably that means, slows or stops the ability to make fats.

Switching the product used every application gives the enemy, the spider mite, no time to

build up a tolerance.  Usually it is suggested to use 3 products with 3 different modes of action.  When you have this regiment down you will win the war agaist pests in your garden.

In addition to your chemicals, it is highly recommended that you get an organic leaf shine product such as Dyna-Gro Pure Neem Oil.

Finally, How do i learn more about Modes of Action?

There was not many sources of good quality information until now.  Sporadically, we will be writing informative article about each major chemical, as well as it’s mode of action.  Recently, we discussed the most primitive modes of action. Ingestion. Yep, being eating. Our, Top 5 Predator Insects for Indoor Gardens, highlights the best predators for removing pests from your garden the ULTIMATELY organic way.