Red banded mango caterpillar

Alert

Have you seen Red banded mango caterpillar?

Red banded mango caterpillar is a distinctive red and white striped caterpillar that burrows into mango fruit.

If you suspect you have found Red banded mango caterpillar in Queensland, outside of the far northern biosecurity zone 1 (PDF, 333KB), report it to Biosecurity Queensland on 13 25 23 or contact the Exotic Plant Pest Hotline on 1800 084 881.

Early detection and reporting are key elements in controlling Red banded mango caterpillar.

Red banded mango caterpillar (RBMC) is a pest of mango in tropical parts of Asia where it causes commercial crop losses between 10–52%. It is a serious threat to Australia's commercial mango industry.

Present on some Torres Strait islands and on the Australian mainland in the remote northern Cape York Peninsula area, it has been declared a far northern pest. Movement restrictions from the far northern biosecurity zones 1 and 2 are in place to prevent red banded mango caterpillar from spreading.

Other names

  • Mango fruit borer
  • Red banded borer
  • Mango seed borer
  • RBMC

Description

Eggs

  • Typical egg shape (0.45 x 0.7mm)
  • Milky white colour when laid, but change to a crimson colour after 2–3 days.

Larvae

  • Initially the larvae are very small, cream coloured with pink banding and a black head.
  • As the larvae grow they become plump, glossy, with brightly coloured dark red and white bands, and have a black 'collar' near the head.
  • Can grow to up to 2cm in length.
  • More than one larva can be present in a single mango fruit, and they may be different sizes.
  • The larvae change to a blue-green colour prior to pupation.

Pupae

  • The pupa is encased in a spun cocoon which may incorporate soil particles or bits of bark.
  • Cocoons are approximately 1–1.5cm long, turning a pale brown to dark brown colour as they age.

Adults

  • Adults moths are plain greyish/fawn coloured, but the wings may have a shining bluish tint.
  • The moth's body is brown with some pale yellowish markings on the head and thorax.
  • Approximately 12mm long.
  • When at rest, the moth holds its wings to give a triangular appearance.

Plant stage and plant parts affected

Red banded mango caterpillar are a problem during mango fruiting season and infest mango fruit. Even small (marble sized), green fruit can be infested. Fruit is the only part of the mango tree that is affected.

Plant damage

Red banded mango caterpillar tunnels through the skin and flesh and mainly feeds on the seed, causing fruit to spoil and fall early.

Damaged fruit may also be attacked by fruit flies or various decaying bacterial and fungal organisms.

May be confused with

Mango seed weevil, which is known to occur in Queensland, is a uniformly pale coloured, generally plump larva that infests the mango seed within fruit. Red banded mango caterpillar also infest mango seeds, but in contrast to mango seed weevil, red banded mango caterpillar have distinctive dark red and white bands.

Distribution

Found in India, Indonesia (Java and Sulawesi), Myanmar, Papua New Guinea and the Philippines. 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 known to occur near the northern tip of Cape York Peninsula, within the far northern biosecurity zone 1 (PDF, 333KB).

These detections do not pose an immediate threat to the mango industry and should not affect national or international trade from commercial mango production areas.

Hosts

Mango (Mangifera indica)

Life cycle

  • Eggs are typically laid on the fruit stalk (peduncle).
  • Marble-sized fruit are preferred for egg laying.
  • Eggs may be laid singly, but egg masses containing up to 14 eggs have been recorded.
  • Early-season moths may lay larger numbers of eggs than moths occurring later in the flowering season.
  • After 7–12 days the eggs hatch into larvae, which tunnel into the fruit flesh and then into the seed.
  • The larvae enter the fruit usually through 1 bore hole.
  • Larvae feed for 15–20 days, passing through 5 growth stages (instars) as they grow.
  • The first 2 instars feed on mango flesh, the later instars feed on the mango seed.
  • The larvae can produce a strand of silk which they can use to move to other fruit or to nearby fruit on other trees when they run out of food, or to drop down onto the tree bark or soil to pupate.
  • Pupation occurs under the bark of mango trees or in the soil and usually takes around 20 days. When mango fruiting season finishes, the pupation period can be extended, allowing the pupae to survive until the next fruiting season.
  • Adult moth emergence may be triggered by the onset of flowering.
  • Once the adult moth emerges, after mating, the female will commence egg-laying.
  • Adult female moths may live for 3–9 days.
  • The moths are mostly nocturnal, spending their time resting under leaves during the day.

Impacts

Mangoes are an important crop in Queensland. The Australian mango industry produces about 60,000 tonnes of fruit annually, providing a gross value of production (GVP) at the farm gate of about $180 million per year, of which 67% are grown in Queensland. (Sources: Australian Mangoes, Plant Health Australia)

Red banded mango caterpillar is a serious threat to commercial mango production. Reported crop losses range from 10–52% in India, 30–40% in Indonesia and Papua New Guinea, and 40–50% in the Philippines and South-East Asia.

If it established in a mango production area, it may mean producers cannot sell the fruit to other states and territories or other countries.

Home gardeners can also be severely impacted as the caterpillars infest mango fruit making it unsuitable to eat.

How it is spread

Red banded mango caterpillar could be spread by movement of infested fruit or mango pest carriers (mango plants and soil).

The far northern biosecurity zones 1 and 2 (PDF, 333KB) have been established to restrict the movement of red banded mango caterpillar and mango pest carriers to the rest of Queensland.

Where mango trees are present and not far apart, red banded mango caterpillar can spread slowly, from tree to tree. There are large distances between host mango trees on Cape York Peninsula which helps to limit natural spread of this pest from the remote areas where it is known to occur.

Monitoring and action

If you grow mangoes, look for this pest during the fruiting season.

To inspect fruit for red banded mango caterpillar, look for:

  • fruit that have external sap stains – although almost clear when fresh, the sap darkens to a dark streak on the skin leading to a dark spot at the fruit tip
  • sap stains that result from an entry or exit hole – the entry holes of very young larvae may not be visible, but larger larvae can produce visible entry or exit holes, sometimes with mango pulp and insect frass near the opening. Cut the fruit open to expose the inside of the tunnel in the flesh and the seed
  • evidence of the caterpillar – e.g. burrowing damage in the seed and insect frass. The larvae will most likely be seen tunnelling in the seed, but can also be present in the flesh.

If you find red banded mango caterpillar outside of the far northern biosecurity zone 1 (PDF, 333KB), then you must report it as soon as possible to Biosecurity Queensland on 13 25 23.

Find advice for the mango industry on how to monitor for exotic mango pests and diseases.

Control

This pest is difficult to control. There are currently no registered pesticides for red banded mango caterpillar in Queensland.

If you have a backyard mango tree in the infested area near the tip of Cape York Peninsula or on Torres Strait islands:

  • protect your good fruit from infestation by covering them with a bag or sleeve. This can also protect the fruit from other insect pests, flying foxes and birds
  • remove and destroy fruit that may contain larvae in the flesh or seed to reduce the number of the pests present. These fruit may have entry or exit holes associated with sap stains and contain larvae
  • annually prune new mango trees to keep the trees smaller and easy to manage.

Legal requirements

The far northern biosecurity zones (PDF, 333KB) have been established to prevent the spread of far northern pests like red banded mango caterpillar.

It is illegal to move:

  • a far northern pest such as red banded mango caterpillar
  • far northern pest carriers, such as mango fruit, mango plants, and soil or other growing mediums in which a mango plant has been grown
    • from far northern biosecurity zone 1 to a place outside of that zone
    • from far northern biosecurity zone 2 to a place outside that zone, unless it is into far northern biosecurity zone 1.

A biosecurity instrument permit is required to move these items.

You must observe movement restrictions if you are travelling to or around the Cape York Peninsula, or you live there.

For information about biosecurity instrument permits phone the Customer Service Centre on 13 25 23 (from interstate use (07) 3404 6999) or email qld.plantquarantine@daf.qld.gov.au.

Biosecurity Queensland inspectors at the Cape York Biosecurity Centre at Coen check vehicles moving south from Cape York Peninsula to ensure that pests or pest carriers are not moved from the zone.

By law, everyone has a general biosecurity obligation (GBO) to take all reasonable and practical steps to minimise the risk of spreading red banded mango caterpillar.

Further information