Jacob wrote: "There is one species in particular that is very efficient at farming mealybugs on a plant, from soil level upwards. These ants move soil particles up the stems of plants, caking loosely but effectively around the most vulnerable parts of the plant: growth nodes on dicots and the tender meristem region of monocots." Thanks for that information, Jacob. For the first time ever in my own garden here in Maryland I'm seeing what you have described on potted plants. And I had never heard of this before. I spotted the soil clusters on some New Guinea impatiens Also, this year mealybugs are common on garden plants such as fuchsia, coleus and salvias. Until this year I had thought of mealybugs as pests of indoor plants but not significant pests of outdoor plants. Jim McKenney -----Original Message----- From: pbs-bounces@lists.ibiblio.org [mailto:pbs-bounces@lists.ibiblio.org] On Behalf Of Jacob Knecht Sent: Monday, August 02, 2010 3:05 PM To: Pacific Bulb Society Subject: Re: [pbs] ants Ants have never been neutral in any horticultural setting I've ever worked in. As Lou mentioned, perhaps the worst thing they do is transport mealybugs from one root mass to another. This happens VERY quickly in Hawai'i. It dry leeward areas especially, but also in very wet ones, absence of root mealies is exceptional. There, the longer a plant lives in a pot and the more pot bound it is, the more mealies it is bound to have. It is my impression that at least outdoors in California, root mealies are generally not too big of a problem with most plants, except for cacti, succulent and bulb collectors! I have seen many a rare amaryllid looking sick and stunted. Also on O'ahu there are some non-native ants that remove media so fast from potted plants that it causes serious problems and death of plants (as mentioned by Roy). I have had potted houseplants collapse within three days of the ants' excavating media out through the drainage holes! I solved this by applying a line of boric acid chalk to the perimeter of a terracotta drainage saucer. If kept dry thee ants will not cross the line. There is one species in particular that is very efficient at farming mealybugs on a plant, from soil level upwards. These ants move soil particles up the stems of plants, caking loosely but effectively around the most vulnerable parts of the plant: growth nodes on dicots and the tender meristem region of monocots. Underneath these coverings the mealies are brought in and go to work faster than if exposed to the elements. They can seriously weaken or kill some monocots within a very short time frame. I found that I must be diligent and check all plants at least once a week for this. The ants have killed seedling amaryllids and understorey Dypsis palms this way. Spraying the plant with high pressure water only temporarily removes these structures, and I have seen the ants rebuild completely them in 24 hours! Like humans, (many) ant species are super successful organisms. They are tenacious and will pretty much always get what they want. They can easily spell the end of a collection (at least in Hawai'i) if left unchecked. Also root mealies can spread virus. Jacob