Paul,
Thanks for the link it made a very interesting read and it does show that there can be alot more to the average aphid.
After reading through this post i'm going to have to admit that the chances are i probably saw what i wanted to see and didn't truly think other possibilities through, and i do think jaguarondi's theory is probably closer to the mark.
It's been a very informative post for me
Snowyriver, Jason, Charlieb, Jenny w, Paul, jaguarondi and Adam thanks for all of your views on this.
Gray.