Flies and Hydrangea

My hydrangea attracts large flies. I've sprayed it with garden spray to no avail. This hydrangea has large white cone-like flowers and th eleaves are not shiny. Any advice?

 

It is most likely a paniculata and I have no idea why flies would be attracted to it...unless there is something else around the area that smells bad.

 

Thanks. No, nothing else around it. This happens every summer. The flies are attracted to the blooms. Prior to blooming, there are no flies.

 

Thanks. No, nothing else around it. This happens every summer. The flies are attracted to the blooms. Prior to blooming, there are no flies.