Rosy Apple Aphid
Rosy Apple Aphid (Dysaphis plantaginea), and its equivalent the pear bedstraw aphid (Dysaphis pyri), are two of the most damaging top fruit pests. The aphid migrates between plantain and apple or pear trees and attacks all commercially-grown varieties. Symptoms include rosette leaf distortion at the green cluster to pink bud growth stage and later at the end of blossom and early fruitlet development. A spray of an approved aphicide such as Tau-fluvalinate should be applied as soon as infestation is detected and early enough to reach the parasite before it is blocked by cover from distorted mature leaves.
Heavy infestations of the Pear Sucker (Cacopsylla pyri) cause extensive damage to the flower stalks and leaves as the adult and larvae feed on the plant sap. Honeydew excreted by the pest acts as a substrate for sooty mould, which is followed by leaf curl, fall and necrosis. The insect secretions cause spots on the fruits which lower their commercial value. Insect predators, such as anthocoris and orius species have been used successfully as biological controls for the Pear Sucker alongside chemical control measures in integrated pest management programmes.
Apple Codling Moth
The Codling Moth (Cydia pomonella) is a key pest, even at low population densities, in both apple and pear orchards. Adults emerge in May to July laying eggs on leaf and fruit surfaces. The larvae hatch after a week and cut into the fruit leaving an entrance hole.
Control measures are implemented once monitoring - using pheromone traps - shows five or more moths per trap, per week between May and June. The threshold is lowered as the fruit softens and becomes more susceptible.
As well as chemical controls like Acetamiprid + Novaluron, biological measures are available such as spraying with a granulovirus or a sex pheromone to disrupt the mating process.