Homemade Fogging Fumigator

Looper caterpillars invaded our tomatoes. This is an act of war, and so I needed a way to disperse toxic dust particles (Derris Dust) amongst the plants in a thorough and pervasive manner - though I should imagine the same technique could be used to fog with any dry powder. It certainly beats heck out of the little pepperpot holes on the end of the derris tub. Here's a shot of it being tested; it's more impressive when a lot of powder is used and great billowing clouds come out.

We have an air compressor system in the workshop, so I dragged an air hose outside to provide the puff at 80 psi. On the end of the hose went the air gun fitted with a ball inflator needle. That pokes into a piece of plastic tube on a 13mm (1/2 inch in old money) barbed T joiner from my hydroponics plumbing box. Into the upright of the T goes a piece of 6mm i/d stiff PVC pipe, wrapped with tape to fit. This only goes half way up the T. Blasting air through the needle causes entrapped air to be sucked up the 6mm tubing and blown out of the open end of the T, together with any dust it may have sucked up. Cool, eh?

Derris dust is organic, but so is hemlock so only use it when no cold-blooded things you want to see alive are around, mask up, and don't muck about with it. Testing of the fogger was done with plain flour.