Skip to main content
GrowersHelp your business growResearch reports, publications, fact sheets and more Integrated pest management of citrus gall wasp and Fuller’s rose weevil (CT19009)
Ongoing project

Integrated pest management of citrus gall wasp and Fuller’s rose weevil (CT19009)

Key research provider: NSW Department of Primary Industries

What’s it all about?

This investment is improving the management of citrus gall wasp and Fuller’s rose weevil, two of the most significant insect pests of citrus in Australia. Through establishing a better understanding of the biology and ecology of the pests and providing more effective monitoring and management tools for growers, this project will contribute towards improving the productivity and quality of citrus grown in Australia.

For citrus gall wasp, an updated online management guide will be produced, with new information obtained from this project as well as an updated online timing tool for nationwide prediction of citrus gall wasp emergence. For Fuller’s rose weevil, options will be presented to industry for new monitoring approaches and alternative chemical options.

Specifically, the project is addressing the following areas…

Understanding the spread of citrus gall wasp in Southern Australia

Through a PhD study, the factors responsible for the increase in citrus gall wasp populations in southern Australia will be examined, allowing the industry to develop more robust and sustainable management strategies. Suspected reasons for the recent distribution expansion include changes in climates, movement of citrus seedlings and agronomic practices.

Updating the timing guide for citrus gall wasp emergence

An online timing guide was developed in project Development of national strategies to manage citrus gall wasp (CT15006) and is currently available for the prediction of the emergency of adult citrus gall wasps and eggs hatching in the Riverina, Sunraysia and Riverland. This project will expand the application range to Perth in Western Australia and Mundubbera in Queensland.

Developing novel monitoring tools to guide the timing of Fuller’s rose weevil control

Improved monitoring techniques are needed to time Fuller’s rose weevil control methods, as branch shaking is a labour intensive method and is difficult to standardise. This project will explore whether machine vision is a viable alternative monitoring method for integrated pest management with reduced maintenance compared to traps. 

Exploring cultural control of citrus gall wasp with lucerne borders and/or inter-rows

Anecdotal evidence suggests that the presence of lucerne will attract lucerne seed wasp which has several parasitoids that may attack citrus gall wasp. Conversely, citrus gall wasp parasitoids may attack lucerne seed wasp, which could prove useful in future rearing for biological control of citrus gall wasp. This project will explore this further.

Investigating commercially available entomopathogens for Fuller’s rose weevil control

Entomopathogenic nematodes and fungi are organisms that can infect and kill insects in the soil and can potentially be used as biological control agents for many insect pests. Some have demonstrated potential for Fuller’s rose weevil control – but this concept needs to be investigated further.

Screening soft chemical options for citrus gall wasp and Fuller’s rose weevil control

For sustainable management of these pets, alternative chemical options, preferably those that are relatively ‘soft’ on beneficials are urgently needed. There is a risk of potential loss of the chemicals that are currently registered for pest control. Alternative options need to be reviewed on their efficacy and impact on beneficials.

Since the last reporting period, the project team have completed two laboratory bioassays of new direct- and residual-contact chemicals for controlling CGW adults. The research identified four potential new chemicals, with two appearing to be particularly promising. Potted-tree bioassays on new systemic insecticides for controlling CGW larvae is underway for completion next spring.

Early stages of the machine vision investigation showed encouraging results for automated counting of FRW on beat sheets, along with the identification of specific light wavelengths to distinguish old and new CGW galls. Further imagery will be collected to refine the machine vision algorithms. CGW emergence data from WA and QLD and parasitism data from the lucerne interplanting site will be analysed in the coming months.

The project team are engaging with growers and industry to share results as research progresses.

Related levy funds

This program is a strategic levy investment in the Hort Innovation Citrus Fund