aphids on lupins

where can i buy something to kill or help treat the aphids attacking my lupins

Doug says you can go to your garden shed. Pull out a hose. Turn on the water. Put your finger over the end of the hose to force a strong jet of water out the end. Spray the lupins with the forceful jet of water to knock the aphids off the plants.

Problem solved.

Looking for chemicals to solve a simple problem like this is like using a nuclear device to heat up your swimming pool water.