Blackfly and Greenfly (aphids) are very common sap sucking pests affecting nearly all types of plants. Colonies are visible around new buds or shoots in spring onwards. Leaves may twist or yellow, become puckered and distorted as they develop. Sticky honeydew, the sugary plants sap can be seen on leaves at the feeding areas of these aphids. Product solution: Use Provado Ultimate Bug killer Ready to Use or Concentrate or Provado Ultimate fruit and Vegetable Bug Killer Ready To Use or Concentrate or Sprayday Greenfly Killer, Organic Bug Free, Natria Bug Control.