Hi folks, A really strange one.. Ive noticed hundreds of ants on my courgette plants! Im really not sure what theyre doing, they seem to do no harm but does anybody have a clue why theyre there?
My first thought also. Inspect your plant closely, underneath the leaves and in the new leaf growth and on any buds. A fairly hard spray of water, not hard enough to damage the plant, directly on the aphids should be enough. you can also use insecticidal soap solution and 1 T. isopropyl alcohol to 1 pint of water. there are several methods and recipes/insectides to use on them. But what ever you do get rid of them, if they are there. they will spread disease from plant to plant, such as mosaic viruses. The ants can also become fearsome while protecting the aphids. i had a colony of black ants nursing some aphids on a sunflower.... they would literally jump on you if you touched the leaves of the plant. they were nasty. I had to destroy the sunflower to get rid of them.
The relationship between aphids and ants is mutualistic. Ants go to extraordinary lengths to maintain "their" aphid population. Herding their charges from one plant to another as the plant nutrients are depleted. Overwintering aphid eggs in their underground nests to transport them to host plants in the spring and preventing the aphids, as their population exceeds food supply, from flight to another territory by removing their wings. In some cases releasing an allelochemical to prevent aphid movement or wing development. The aphids in processing their plant nutrients excrete a sugary substance, honeydew. The ants can even stimulate the aphids to provide the sugary food with their antenna. Each benefits in the relationship, each fills the voids in the others lives. Truly an interesting relationship in the insect world. Jerry
wow thats amazing and quite accurate too! I looked carefully and there are clusters of aphids under some of the leaves and it seems the ants are tending them! I'll be finding a spray to get rid of them. I'm quite astounded by this!
If you spray with water, or insecticidal soap (enough), the aphid herding ants don't truely go away, they just move to a nicer neighborhood.
So long as theyre not causing any problems i dont mind, but disease spreading doesnt sound too good :-(
Glad that you were able to discover the reason behind all the ants. There are any number of methods to get rid of the aphids; however, if there are only a few leaves harbouring colonies, you could simply clip them off and destroy them, aphids and all. The ants may still clamber over your plant taking the last of the honeydew, but eventually their numbers would decrease noticeably.
