Exotic plant pests
Red banded mango caterpillar
Officers of Biosecurity
What is it and where does it occur?
Red-banded mango caterpillar (RBMC, Deanolis sublimbalis ) is a pest of mango in tropical parts of Asia where it causes commercial losses in the order of 10-15%. Whether it will have a similar impact in Australian commercial mango production is unknown; therefore it is taken seriously as an industry threat. RBMC tunnels through the skin and flesh, then feeds on the seed causing fruit spoiling and premature fruit drop.
RBMC is known to exist in India, Burma, the Philippines, Java and Sulawesi in Indonesia and Papua New Guinea. It may be more widely distributed in south-east Asia than records indicate. Since 1990 it has been detected on several Torres Strait Islands and is now known to occur at several locations near the nothern tip of Cape York Peninsula.
What does it look like?
Figure 1 (at left). Dark streak on mango skin
An obvious external sign of infestation is the presence of a liquid exudate from the mouth of a tunnel chewed by the caterpillar through the skin. It trickles down to the tip of the fruit and accumulates. Although almost clear when fresh, the liquid darkens and shows up as a dark streak on the skin leading to a dark spot at the fruit tip (Figure 1). Early signs of infestation may not be as easily seen and could include small darkened boreholes on the fruit caused by entering larvae.
Damaged fruits may be attacked secondarily by fruit flies or various decaying organisms and may fall from the tree prematurely.
Figure 2 (left). Larvae of red banded mango caterpillar
To inspect fruit for RBMC, cut it open to expose the inside of the seed. The larvae will most likely be seen tunnelling in the seed, but can also be present in the flesh. The larvae are plump, glossy and brightly banded in white and dark red and have a black collar near the head (Figure 2). More than one larvae can be present.
Eggs are laid by the fawn coloured adult moth on the peduncle (fruit stalk) and after 7-8 days hatch into larvae, which tunnel into the flesh and then into the seed. Larvae feed for 15-20 days before pupating in the soil for around 20 days, before emerging as the adult moth to continue egg laying. The biology and life history of RBMC is not completely understood.
What is DPI&F doing about it?
Due to the isolation of the detections on Cape York Peninsula and Torres Strait, it poses no immediate threat to the mango industry. The detections should also not affect national or international trade from commercial mango production areas. Staff from the DPI&F Northwatch program regularly survey Cape York Peninsula for RBMC and other mango pests.
A quarantine area has been established on Cape York Peninsula and Torres Strait north of 13° 45' S latitude (see Figure 3) to restrict spread of the pest. The Coen Information and Inspection Centre is enforcing controls on mango fruit and plant movement.
Figure 3. Mango caterpillar quarantine area in Queensland
Control of RBMC is difficult and is exacerbated by the lack of knowledge of its biology. It has not been successfully eradicated anywhere in the world. DPI&F and other agencies are collaborating on an international research project to clarify the biology of RBMC and develop control options.
What do I need to do about it?
If you grow mangoes, keep watch for this pest during the fruiting period and advise your local DPI&F plant health inspector of any suspected infestation. Mango growers do not currently need to apply any chemical controls for RBMC, because the pest is still remote from commercial plantations.
If you are travelling in Cape York Peninsula or live there, please observe quarantine conditions. Mango plants and fruit cannot be moved between properties in the quarantine area or out of the area (see Figure 3 above). If you are unsure about what to do, contact the Coen Information and Inspection Centre on 07 4060 1135.
Further information
If you think that you may have seen red-banded mango caterpillar, contact your nearest DPI&F plant health inspector or the DPI&F Call Centre on 13 25 23 (free call) for advice on what to do next. Non-Queensland residents: phone 07 3404 6999. E-mail the DPI&F Call Centre: callweb@dpi.qld.gov.au. DPI&F Internet site: www.dpi.qld.gov.au.
Acknowledgements
Images by courtesy of Dr John Ismay, DPI, Konedobu, Papua New Guinea, and some text from AQIS Leaflet No.51, Red-Banded Mango Caterpillar; reprinted with the permission of the Australian Quarantine and Inspection Service.
Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries and Fisheries Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.
Last reviewed 31 May 2005
