This daisy is covered with blackfly a close relation of the greenfly. Greenfly can do damage to a plant by weakening it and helping to spread disease.
The importance of getting rid of greenfly depends upon the plant. For example, a daisy like this doesn’t seem to be that affected by infestations and it is often fine to leave it to nature’s control.
This hoverfly is an excellent predator of greenfly and blackfly, it can munch through a large quantity of greenfly.
However, if you have prize roses or want to grow cut flowers then you will want to get rid of the greenfly.
Insecticide’s from Amazon
Organic Method of Killing Greenfly
This greenfly killer is based on a fatty acid solution which kills greenfly on contact. The important thing is the spray needs to come into contact with the greenfly. But, it can provide an excellent alternative to chemical pesticides.