San Jose scale - monitoring

There are four methods of monitoring San Jose scale in apple orchards.

The first method provides information on the timing of scale population development and can be used in combination with day degrees to predict population events, such as crawler release. Monitoring of crawler release (method 2) provides a direct guide to when fruit are at risk from crawler dispersal and when fruit should be monitored to check infestation levels (method 3). Harvest monitoring gives a measure of the success of the control programme over the past summer and can be used to determine the need for scale control in the following season. Monitoring in the apple IFP and organic programmes includes the last two methods for use by growers and these are supported by timing information from researchers and consultants checking male flight and crawler release.

Shelter and other host plants around the perimeter or near to the orchard should also be checked for scale infestations as part of a shelter management programme.