I love the concept that because Bacillus thuringiensis is 'organic' it is somehow wholesome, environmentally friendly and thoroughly OK. Kind of like 'natural remedies' for human diseases somehow not being 'drugs' - when the active principles are really chemicals and drugs just like any that the FDA approves. Bacillus thuringiensis has a broad host range and produces very potent toxins which kill all sorts of insects, beneficial and otherwise. It has many effects on the environment - just a bit different to using 'chemicals'. Best, John John T Lonsdale PhD 407 Edgewood Drive, Exton, Pennsylvania 19341, USA Home: 610 594 9232 Cell: 484 678 9856 Fax: 315 571 9232 Visit "Edgewood" - The Lonsdale Garden at http://www.edgewoodgardens.net/ USDA Zone 6b -----Original Message----- From: firstname.lastname@example.org [mailto:email@example.com] On Behalf Of Alberto Castillo Sent: Monday, March 21, 2011 4:02 PM To: Pacific Bulb Society Subject: Re: [pbs] Fungus Gnats Fungus gnats normally appear in peat based mixes. Why not to try a larger portion of mineral origin ingredients? They would never appear in them.