I think I have white fly on my lupins. One plant is badly infected and I got to spray it before it bloomed but now it has bloomed and I can see the whitefly on the other lupin I was wondering should I cut off all the blooms and spray again or should I just cut to the ground as I don’t think I am able to get all the flies as there is too much foliage. Or should I just leave the flies alone?
These are greenflies, they leave their white skins behind as they moult. This species only affects lupins but can do so very severely, large infestations causing flower stems to collapse. A spray of water reduces numbers but they build up again and a greenfly spray might be needed.