I live in the Puget Sound region of WA. Yesterday while tying up my raspberry plants - which are just beginning to flower - I noticed that red headed ants were all over the plants and eating the flower parts of the buds that were just opening. They were not bothering any of the buds but you could see the little discarded stamen on the leaves and they were eating right into what would become the berry. I did some searching and it seem these ants are not normally considered a crop pest and often heard aphids as we have seen in other areas of our yard. Can you offer any suggestions for control? I value all creatures but I also want a berry crop this year.
Thanks for contacting us at AntAsk and including the photos! We asked two ant experts, Lloyd Davis and James Trager, for some help with this and here is what he had to say:
"Ants don't eat the flowers off plants in that area. If the ants are attracted to the plants, it is likely they are there because of some kind of problem the plant has, which might be some kind of pest or pathogen that is attracting them. So killing the ants will have no effect on the plant's fruit production. So, in short don't kill them, but watch them closely and see what is really going on. Perhaps a local extension agent would be helpful if the plants prove to have some sort of ailment. Lloyd"
"Looking at the pictures, it seems to me the ants may be licking residual nectar from the calyces of the berry flowers. The actual stamens would naturally become deciduous after pollination, while the stigmas that are the female pollen-receiving organs are more persistent and are clearly visible, attached to the apparently completely undamaged, individual, developing druplets of this compound fruit that we call a berry. That's how a botanist might describe it. In plain English, as far as I can tell, the ants are doing no harm, and further, their presence around the ripening fruits could well deter real pests from damaging them. The ant is Formica obscuripes, very common in that area. James"
So both experts agree that the ants are not damaging your plants, but might rather provide a benefit. Basically, just to wait and keep observing your plants. No need to kill the ants! If things get worse, a pest might be involved. If berries develop, everything was going its normal way. Hope this will help you understand what is going on with your plants.
All the best,
Lloyd Davis (guest expert), Steffi Kautz and the AntAsk Team