Over on The Back Forty blog, Robbyn asks, "Are Organic Pesticides Safe?
The short answer could be, "Yes. They degrade rapidly in the environment, and so pose no long term threat."
Another, equally valid, short answer could be, "No! So-called Organic Pesticides, like any other disruptive measure, break the links and cycles in the local ecosystem, so, in the long term, they simply aggravate the problem you're trying to solve, albeit slightly more safely than do conventional pesticides."
As anyone who has taken a more-than-cursory glimpse at our farm website will have figured, I place my self firmly in the latter camp. If I use a poison (of whatever nature) to kill off the aphids presently attacking my Broccoli1, then I disrupt the food supply for the Ladybugs that make a meal of Aphids. Consequently the Ladybug population is going to decline for want of food. Then, come Summer, when I get a real Aphid infestation, I'll surely want for more Ladybugs. But they won't be there, due to my interference. Much better to leave things largely alone.
If the Aphid attack gets too severe -- unlikely, as the weather forecast is for a bit of cold front in another day or so -- I will resort to blasting the Aphids off with the hose, where they will remain as prey to the Ladybugs, but not on my soon-to-seed Early Purple Broccoli.
Remember that the term "Pesticide" still contains the root "-cide": death. It is a paradox to me that so many growers are trying so hard to grow stuff -- to make plants live, so that we in turn can eat and live, live and be healthy -- but spend their time running around trying to kill everything else. Surely the answer to vibrant life, exuberant life-liness, cannot lie in death!
Keep in mind who benefits most from pesticide use!
"But What Is Lurgy?"
All this begs the question, "What is the meaning of the term 'organic'?" I think the "Certified Organic" labels are pretty-much3 a load of crap (depending where in the world you are to some extent.) The range of practise that can legitimately be called "organic" is so wide as to render a single blanket label meaningless. At one end of the spectrum, all a grower has to do is replace the existing fossil-fuel-based fertilisers and pesticides with equivalents acceptable under some-or-other certification regime. At the other end are more "hardcore" practices that shun all such artificial interventions, and aim to build up a vibrantly healthy ecology, especially in the soil, and then rely on the natural health of plants to cope with whatever comes along.
Whilst I consider that my own growing is pretty much towards the "hardcore" end of the spectrum4, I am not knocking the other choices. There have to be paths for "conventional" growers to transition to a more sustainable practise while coping with the realities of the supermarket-oriented supply chain, the bank-beholden, joyless, tractor-enchained existence of industrial agriculture. (I cannot find it in myself to call that "farming", and, evidently, many agro-industry growers I have met agree, shunning the label "farmer".)
I would propose a three-level organic certification scheme. Something along the lines of "Green Label Organic" for the conventional-using-alternative-chemicals approach, "Silver Label" for somewhere in-between, and "Gold Standard" for the hardcore non-interventionist approach. It would take some working out, some marketing to educate consumers about the differences, but would enable price-tiering to the benefit of all. Maybe. It all sounds a lot like working in an office to me, and part of a way of thinking about the world that is soon to pass.
Mike's Answer to Robbyn
So, to answer Robbyn (if you've made it this far!) I would give the Stinkbugs a Round Of Applause. Clap, clap, clap, clap, clap! around the bugs, leaves and all. Damage to the leaves is minimal; you get Squashed Stinkbug all over your hands, but that washes off easily enough; the bugs you don't squash will fly away or get knocked off your Tomatoes, and you'll give predators some time to get going. Worst case, the crop will take a knock, but look upon it as a long-term investment in your garden's health.
Longer term, the Big Deal -- what defines "organic" for me -- is to build up your soil. Lots of compost, even if its pretty rubbish compost; as long as you're adding lots and lots of organic matter to the soil, sooner or later things will improve. As the soil becomes healthier -- and plenty of fungal activity is a good sign -- the biodiversity of your garden will improve. Everything derives from the soil/Earth itself, all plant health, all the predators, and ultimately our own wellbeing.
Tolerate the pests. You cannot cultivate a healthy garden without them!
1Aphids! In July, no less. I thought the buggers were all in bed for the Winter!
2Trying to remain polite and maintain a "Family" rating, here.
3But not totally! And sometimes very necessary as a way to reassure buyers.
4Even though I have violated the principle myself, on occasion, before anybody calls me out for lying!