Aphids, the horror of every plant lover. However, often one cannot avoid getting them. Once the weather is a little instable; temperature jumping up and down and periods of extreme rain mixed with periods of heat and dry wind very quickly lead to infestations of aphids. These insects suck the moisture right out of the phloem, effectively robbing the growing tips of the plant of their water. In extreme cases this may lead to the death of a plant.
What many people do not realize, is that most aphids do not fly into your plants. They may actually not even walk into the plant. They are often carried to the best spots in your plant. Ants will farm aphids, protect them and bring them to the best places in plants to suck fluids. In return, the aphids produce honeydew. This they excrete from their abdomen, ensuring the protection of the ants. By stopping the ants from getting into your trees, you drasticallly reduce the risk of serious aphid infections.
Stopping ants is easier than it may seem, if you have your trees on a stand. Ants do not typically swim to go where they need to go. By placing the feet of your bonsai stand in a small plastic tray, and placing this small tray in a larger tray, filled with water, you create a barrier which will easily stop the ants from walking around on your trees. And what is even better: It will stop a lot of crawling insects from entering your tree. The smaller tray is just meant to keep the feet of your stand dry. If you are not worried about them getting wet, you can of course place them directly in the water.