Scoping study - management options for mealybug in persimmon (PR11000)

This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

Citrus mealybug, longtailed mealybug and citrophilous mealybug were important pests in persimmon. These insects and the sooty mould associated with them reduced plant vigour and contaminate fruit. The project reviewed worldwide research, with the following aims:

To collate information on mealybug in Australian persimmon.

To identify control techniques not available to, or utilised by, the Australian persimmon industry at the time, prioritised according to their potential for adoption.

To identify future research and development required to manage mealybugs in persimmon appropriately, especially for access to export markets, using the control techniques identified during the review process.

The findings, documented in this report, provided the basis for decisions on future research.

Information at the time was collated in the areas of biology, distribution, life-cycle and seasonal activity of the three pest species, as well as methods employed for their control. Growers were heavily reliant on a limited number of mostly broad spectrum insecticides. This had hindered the development of an integrated pest management (IPM) system for persimmon.

Control techniques with potential for control of mealybug in Australian persimmon and areas requiring further R&D were documented. The following were categorised as high priority:

• Increase the number of IPM-compatible insecticides available to growers for control of mealybug and other persimmon pests, and phase out broad spectrum chemistry. This would allow natural enemies to suppress mealybug populations and insecticide resistance to be managed.
• Trial adjuvants: these chemicals could increase insecticide efficacy through enhanced coverage and penetration of the mealybugs’ waxy coating.
• Determine the most effective timing of insecticide applications for maximum efficacy. For instance, contact insecticides must be timed to coincide with the exposed and dispersing crawlers and young stages undergoing moults.
• Develop an effective monitoring system for mealybug in persimmon, utilising pheromone lures as well as other methods such as targeted visual assessments, based on a better understanding of the biology, behaviour and seasonal activity of the pest species.
• Obtain registrations or permits for effective chemical controls for ants. These insects could protect mealybugs and other honeydew-producing pests from natural enemies and contribute to their spread.
• Trial postharvest disinfestation techniques such as hot water immersion, cold storage and oils as a postharvest dip.

It was recommended that future research should be focused on these priority areas. These elements formed the basis of an IPM system for mealybug in persimmon, incorporating a range of complementary control methods and informed by efficient monitoring.