| I have found that ALL of the common insects (for me), scale, mealies, mites (3 kinds so far), and aphids are eliminated, eggs and all, by the use of a Neem Oil spray. You must cover the plant surfaces 100%. You MUST also reduce the light and heat. I will be out this morning doing my entire GH, mostly as precautionary, though I did find a couple of scale on a new plant, and a mealie bug on another new plant. These plants both got mechanical removal of the bugs, and this may have been enough, but since I plan to treat my GH once a month, and am a couple of months over due, I am going forward with this even tho I have a cold or maybe even a mild case of the flew. Yesterday, I added more shade cloth over the GH, and will turn down the cooler a bit when I start. This seems to have the best safty to effectiveness ration of any thing I have used, for both people and plants. If you don't reduce the light and heat, you will get mottled leaves, with the color returning very slowly over a long time. I have seen a pre-mixed version of neem oil at Home Depot, and most nurseries carry a concentrate. My ordhids are ready for watering, so they will be getting a fair amount in their pots too, but this does not seem to harm them. By the way, I had someone's plant to treat that had the worst case of red mites you can imagin. A week or two after treatment, I found one nymph on the plant. So, really bad cases probably need a second spraying a couple of weeks later.
For slugs and snails, use diatomaceous earth (DE). Get it at a pool supply, and don't breath the dust, or you'll get something akin to sillicosis. I completely eliminated a bad slug problem I brought with me from Calif. overnight with this stuff. Up to that point, I was collecting slugs in dishes of beer, 20 or 30 every morning. I kept up the beer for awhile, but never collected another slug after dusting the floor with DE.
By the way, aphids transmit virus between plants, so get rid of them pronto. Cynthia  |