Step 14: About insecticides...

The use of chemical insecticides is prohibited to natural farmer. But what about organic insecticides? These two words together means "we will kill insects but with an organic product which will be destroyed rapidly in the nature and it will not be toxic for the humans." As with any insecticide the problem is the "S" at the end of the word "insects". This short picture story will illustrate that other solutions are possible than directly use insecticide.

 Organic insecticides should be used only when all other solutions are inefficient or unknown.

  We planted a few month ago some Sesbania as windbreak. 

 Very soon, we observed that the leaves of Sesbania was the favorite food of a caterpillar, probably a Pieris sp, same family we can find eating the cabbage.

This caterpillar is exactly the same color as the leave of Sesbania and when it takes a rest on a leave it is not so easy to see it. Our first counter measure was hand-picking. Not so efficient as we can see on the picture of the tree!

But one day, we discovered a sort of golden shield bug, sucking directly the caterpillar. And now our Sesbania are recovering and new leaves appear. The predator controls the pest and kills only the pest, not all the insectS.

 The lessons of this are:

- The nature can solve any problem and there is always "something" to regulate any excess (we have to think about that regarding the species Homo sapiens...)

- If I used an insecticide, even organic, I killed the caterpillar and the bug. I bet that a few weeks after the caterpillar reappears but not the bug, because predators are less numerous than preys.

- Different scenarios are now possible, for example:

   #1 The bugs feed on caterpillars and multiply so much that the caterpillars disappear but soon after the bugs will also disappear (or find another prey).

   #2 The bugs are not enough and the caterpillars continue to feed on the Sesbania.

   #3 The caterpillars eat too much the Sesbania and desappear because no more food. The bugs disappear just after.

 In fact, if we do nothing to interfere with the nature, 3 sinusoidal curves of populations, - one for each actor, the Sesbania, the caterpillar and the bug - will establish and act as feedback for the 2 others: The Sesbania is growing and when there is enough leaves, the caterpillars have food (in fact the butterfly lays its eggs), can thrive and continue there own life cycle. With a little delay the bugs appear and control the population of caterpillars. If they are too much guzzler, they kill themselves!

 Always work with the nature, not again!