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1. Executive Summary
Until recently, very little has been known about the insect fauna associated with rambutans in Australia. With the expansion of the rambutan industry it has become evident that several insect species are significant pests of the crop and require the development of integrated control strategies. Pest damage results in market rejection of the fruit; yield decline and the loss of income to the grower.

The current commercial practice for controlling pests of rambutan relies exclusively on calendar based spraying of broad-spectrum insecticides. The most common insecticide groups currently being used by industry are organophosphates and organochlorins, which are toxic to the environment and human health.

The rambutan industries of north Queensland and the Northern Territory along with the Department of Primary Industries and Fisheries (DPI&F) – Queensland, have identified the development of integrated pest management (IPM) as a number one priority in industry strategic plans. This project was given greater priority because of the recent reviews and restrictions placed on the use of endosulfan and chlorpyrifos by the Australian Pesticides Veterinary Medicines Authority (APVMA).

This project has successfully achieved all of its aims in starting the development of IPM in Australian rambutans. This was achieved by conducting insect fauna surveys to help identify the major pest and beneficial insect spectrum unique to the Australian environment and developing monitoring strategies to reduce the frequency with which costly and environmentally threatening insecticides are used.

Growers were educated to identify and monitor the major pest and beneficial insects and only apply pesticides as required. Environmentally safe insecticides suitable for sustainable pest management were screened and the most effective treatments have been selected for minor use registration to replace endosulfan and chlorpyrifos.

1.1 Achievements
The project adoption by industry should result in a reduction in the use of toxic insecticides and the overall frequency of insecticide applications. This will be achieved by the use of a monitoring strategy and pest monitoring tools.

The major achievements of this project have been to:

• Identify major pests and beneficial insects unique to Australian rambutan orchards
• Identify the seasonal pest pressures over the growing season in Qld and NT
• Develop monitoring strategies for the major pests of economic importance
• Develop insect identification and monitoring tools to assist grower adoption.
• Screen insecticides that have a safe environmental profile and unique mode of action to cover the pest spectrum and assist with insecticide resistance management.
• Seek minor use registration of insecticides for industry use.

This was followed by Coleoptera and Hymonoptera (5 species each), Acarina (4 species), Diptera and Orthoptera (2 species each) and one species of Thysonoptera.

Twenty-two phytophagous insects, mites and three ant species were collected and identified in the Northern Territory (table 2). In the Northern Territory Hemiptera were the most represented order (10 species) followed by Lepidoptera (8 species), Coleoptera and Hymonoptera (3 species), Orthoptera (2 species) and Acarina and Thysonoptera (1 species each).

Identify the seasonal pest pressures over the growing season in Qld and NT
Seasonality data was collected on all pests of north Queensland and the Northern Territory (table 3-4); Pest populations were recorded over a three-year growing season at five locations in the coastal tropics of north Queensland. Historical data was used over a five-year period for the Northern Territory. Fortnightly pest and beneficial incidence and population records were recorded as well as the type and level of pest damage.

Develop monitoring strategies for the major pests of economic importance
The data collected on seasonal pest pressures was used in developing a monitoring strategy for the rambutan industry detailing the time of year individual pests of economic importance are most active, and when monitoring is critical during the crop cycle. Preliminary and conservative economic threshold levels were also developed for the major pests of economic importance.

Development of insect identification and monitoring tools to assist grower adoption of results
An integrated pest monitoring kit (poster, book and software) has been developed and released at a series of workshops in north Queensland and the Northern Territory. The kit was developed based on the seasonality for the major pests of economic importance for both Queensland and the Northern Territory. The poster and book details the major pests responsible for plant damage as well as their biology and control. They also show where to monitor pest insects within the crop cycle and when the insects are most active throughout the growing season. Insect population analysis software has also been developed to compliment the poster and book and provide growers with a decision tool on when to apply pest management strategies. Two workshops were held in the Northern Territory for 25 growers and three workshops were held in Queensland (Mossman, Innisfail and Tully) for 85 growers on insect identification and monitoring procedures.

Screen insecticides that have a safe environmental profile and unique modes of action to cover the pest spectrum.
Insecticide screening has been completed against the major pest complex of phytophagous insects in rambutan. A total of 16 insecticides were screened to cover the pest spectrum.

Eight insecticides where selected because of their good environmental profiles and unique modes of action and suitability for managing insecticide resistance.

Spinosad, emamectin benzoate, tebufenozide, thiamethoxam and Bacillus thuriengiensis var kurstaki where the most effective insecticide treatments against Conogethes punctiferalis and were not significantly different to the standard chlorpyrifos (P<0.05) three to four days after treatment. Beta-cyfluthrin was an effective alternative to endosulfan for controlling Amblypelta spp. and achieved 100% mortality five days after treatment and was not significantly different to the endosulfan standard. Beta-cyfluthrin also controlled Rhyparida sp and achieved 100% mortality after four days. Imidaclorprid was effective in controlling Planococcus citri and achieved 100% mortality after three days. Spinosad gave effective control against red-banded thrips at all the rates tested in the NT bioassays, achieving 100% mortality 24 h after spraying at the highest concentration of 1.6 % and 97% mortality at the lowest concentration of 0.2% formulated product.

The mineral oils DC Tron Plus® and Fuchs Universal Spray Oil® achieved 80% and 84 % mortality respectively at 2% oil concentrations and were considered partially effective. No chemical was particularly effective against two-spotted mites but Fuchs Universal Spray Oil® and Neemtech® gave greater than 70% mortality at the highest concentrations tested.

Minor use registration insecticides for industry use.
QFVG was approached to seek minor use registration on behalf of the rambutan industry.

Insecticides chosen for minor use registration included, Success® and Entrust® (spinosad), Proclaim® (emamectin benzoate) Mimic 700 WP® (tebufenozide), Bulldock Prime® (betacyfluthrin), Actara ® (thiamethoxam), Confidor® (imidaclorprid).

1.2 Future Directions
This project has started the development of IPM in rambutan in Australia by giving growers the ability to identify and monitor the major pests and beneficial insects and only apply insecticides as required. The insecticides selected for minor use registration cover the pest spectrum and are well suited to IPM because of their unique modes of action, which can be used in developing insecticide resistance management strategies. Conservative economic threshold levels (ETL’s) have been developed for the major pests in rambutan. These levels were developed based on field observation of pest damage over the life of the project as well as the known information on the pest’s biology, ecology and threshold levels set in other tree crops. At best the ETL’s developed in this project are only conservative guides until more detailed economic impact assessments can be carried out for each pest. As this project is only the beginning of IPM development in rambutan, a whole range of research areas can be investigated in the future in the following broad areas.

Economic impact assessments of the major pests in rambutan
A better understanding of the level of economic damage caused be the major pests as well as the impact of beneficial insects on pest populations will help develop more accurate ETL’s for future use by growers and can possibly result in further reducing the level of spray applications over the growing season.

Biological control – predators and parasitoides
Little information is known on many of the major pests natural enemies except for Cryptoleamus montrouzieri, which is an important and major predator of citrus mealybug (Plannococcus citri).

An understanding of which beneficial insects or complex of beneficials impact on individual pests populations, as well as identifying ways to naturally increase these populations in the orchard will also help reduce the frequency of pesticide applications over the growing season.

Biological control – entomopathogens
The use of naturally occurring insect pathogens (bacteria, fungi, viruses), which cause disease in pest populations, is another area of research, which has the potential to compliment the rambutan IPM strategy. This technology may be well suited to north Queensland where there are tropical warm temperatures, high rainfall and humidity over the growing season. Natural strains of Beauveria bassiana have been recorded infecting 60-70% of field populations of swarming leaf beetles (Rhyparida sp.) in north Queensland.

Pheromones and kairomones
The potential for using mating disruption or insecticide baiting strategies using pheromones and kairomones also have potential to be used in the development of a rambutan IPM strategy. A pheromone for yellow peach moth (Conogethes punctiferalis), a major pest in Queensland rambutans has been developed but has not been tested here in Australia.

A kairomone is also being developed and tested as insecticide bait for attracting and killing fruit piercing moths (Eudocima spp.) which can be tested in rambutans.

Cultural control
Various cultural practices could be investigated to conserve and enhance natural enemies of pests.

This could include border plantings of different plants to attract and encourage natural enemies into the orchard. Certain pollen and nectar producing plants encourage high populations of natural enemies, which could be used for this purpose. Inter-row plantings of some legumes, which attract beneficial insects, may also have the potential to promote good soil structure and increase nitrogen levels in the soil promoting increased tree health.

Crop hygiene
General crop hygiene promoting the removal of planting material infected with insect pests (e.g. fruit infected with caterpillar larvae) will reduce increasing pest populations over time and should be investigated as a control strategy.

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