Coddling moth, black spot, and powdery mildew

(Cydia pomonella, Venturia
inaequalis, Podosphaera leucotricha)

Boundary Control Pest

A brown branch A brown and beige moth sitting on a tree branch.

Codling Moth, Black Spot and Powdery Mildew are organisms that damage apple and pear crops. Codling Moth (right) is a small, speckled, grey moth, hosted by apple, pear and walnut trees. It burrows into fruit, leaving a small hole that results in the fruit being rejected for sale. Black Spot is a fungus that grows on the leaves and fruit of apple and pear trees, spreading from spores released from leaf material on the ground to nearby trees. Any sign of Black Spot results in reject fruit. Powdery Mildew is a fungus that affects the tips of the growing shoots of apple trees. It affects the growth of the tree, reducing production through smaller and lesser fruit.

Reasons for the Strategy

Purple spots with yellow centres on green leaves, black spot.

Codling Moth, Black Spot (left) and Powdery Mildew can significantly decrease the value of pipfruit crops and impact on orchard production if not controlled. During downturns in the pipfruit industry, some growers have left their orchards unmanaged. This poses a risk to neighbouring growers, as an increase in pest levels in the unmanaged orchards will result in higher pest control costs. Neighbouring growers will need to use more pesticides at a time when the industry is trying to reduce their use. Pipfruit growers controlling Codling Moth, Black Spot and Powdery Mildew should reasonably expect not to have their orchards infected by pests from a nearby unmanaged orchard. Assurance that this will not happen can only be provided by a Strategy that empowers the Management Agency to be able to require the occupier of a unmanaged orchard to carry out appropriate control of the organisms within 500 metres of a neighbouring pipfruit orchard. Appropriate control may include chemical or non-chemical methods. The 500 metre distance is based on advice from HortResearch on the travelling limit for the large majority of these organisms.

Codling Moth, Black Spot and Powdery Mildew are assessed at “7” on the infestation curve. Extensive areas of suitable habitat, and the potential for them to cause significant adverse effects, mean the benefits of boundary control far outweigh the costs.


To prevent Codling Moth, Black Spot, and Powdery Mildew (right) spreading from host plants where these organisms are not controlled, to pipfruit orchards where these organisms are controlled, in the Tasman-Nelson region during the term of this Strategy.

Alternative Measures

The alternative option of “do nothing” or relying on voluntary control will not achieve the objective of the prevention of the spread of Codling Moth, Black Spot and Powdery Mildew from unmanaged pipfruit orchards. Requiring a greater level of control, instead of just boundary control, is not appropriate given the widespread distribution of these organisms, and the limited distribution of pipfruit orchards.

Strategy Rule for Codling Moth, Black Spot and Powdery Mildew

A white powder on a green leaf.

An occupier of a pipfruit orchard within 500 metres of another pipfruit orchard shall control Codling Moth, Black Spot and Powdery Mildew to recognised industry standards. Where there are individual trees outside of a pipfruit orchard that host these pests, then the property owner will allow an adjacent orchardist, or an agreed third party, access to control these pests to recognised industry standards. Where the adjacent non-orchard property wishes organic controls to be used, the orchardist will use control measures recognised by certifying organic agencies. A breach of Strategy Rule 7.4.5 is an offence under Section 154(r) of the Biosecurity Act 1993.

Explanation of Strategy Rule

The Management Agency will limit its intervention to enforce compliance of the rule to occasions when a reasonable complaint is received. This would require a pipfruit grower to show that their orchard is clear, or being cleared of Codling Moth, Black Spot and Powdery Mildew, and that they could be caused economic harm by the lack of control of these organisms in another orchard less than 500 metres away.

Biosecurity Act Requirement

No person shall knowingly sell, propagate, breed, release, or commercially display Codling Moth, Black Spot and Powdery Mildew, under Sections 52 and 53 of the Act.