Red blue beetle table grape disinfestation research (TG13002)

What was it all about?

This project investigated management strategies for reducing the risk of accidental contamination of Australian table grape exports to new markets in China, Japan and South Korea. Live insects in a consignment would be a major quarantine issue and represent a significant potential threat to these emerging markets.

Initially, the red and blue beetle (Dicranolaius bellulus Guérin-Méneville) was the target insect for this research, but as the project got underway it could not be found in large enough numbers to conduct disinfestation trials. Alternative pest species to focus on were identified: long tailed mealy bugs (Pseudococcus longispinus) and lady bird beetles (Chilocorus sp.).

The survival of these two pest insect species was tested in conditions similar to those experienced during export shipping to China and other Asian countries (transit temperatures for table grapes are generally around 1°C, with sulphur dioxide generating sheets used primarily to control fruit rot, and transit times of two to four weeks or more).

Under the conditions described, two weeks storage at 1°C resulted in 100 per cent mortality of long tailed mealy bugs and lady bird beetles placed in cartons of export grade Thompson seedless grapes. This indicates that these insects would not survive in consignments of table grapes exported by sea from Australia to China, given storage and transport of grapes to China takes around four to five weeks.

Further trials to test other insects of concern to export markets for table grape consignments were recommended, with the project Effect of sulphur dioxide and cold on survival of insects during storage of table grapes (TG15003) continuing the work.