Citrus fruit borer

Have you seen citrus fruit borer symptoms?

Be on the lookout for symptoms and report them to Biosecurity Queensland.

Early detection and reporting are the key elements in controlling the pest.

Call us 13 25 23

General information

The caterpillar of the citrus fruit moth (Citripestis sagittiferella) is known as the citrus fruit borer. The borer is a serious threat to our citrus industry because it burrows into the fruit rind, and eventually the fruit flesh, causing internal rot and fruit drop. Besides decreasing productivity and market value due to scarring of fruit and fruit becoming inedible, market access could also be affected.

Citrus fruit borer (Citripestis sagittiferella) is not known to occur in Australia. It is prohibited matter in Queensland under the Biosecurity Act 2014.

Overview

Symptoms

The borers leave minute holes in the fruit rind, and cavities under the fruit surface. These holes might be associated with caterpillar frass or gumming.

Internal fruit rots introduced by borers can lead to fruit drop.

Appearance

Adults

Adult moths are about 10 mm long, grey-brown with yellow to grey-brown forewings and transparent hind wings. They are strong nocturnal flyers.

Caterpillars

After the eggs hatch, the caterpillars bore into citrus peel, then tunnel into the pith and citrus flesh. Initially, the caterpillars are orange to dark reddish-brown with a dark brown head, and can grow up to 20 mm long.

When mature, the caterpillars fall to the ground on silken threads and pupate in the soil. Pupation takes about 10 days.

Eggs

The eggs are laid in clusters on the underside of citrus fruit.

Hosts

Citrus fruit borers feed on plants in the family Rutaceae, particularly citrus.

Distribution

Citrus fruit borer is known to occur in Thailand, Malaysia, Singapore and western Indonesia. It is not currently known to occur in Australia.

Spread of pest

Long-distance spread occurs by movement of infested citrus fruit or soil containing pupae. Long-distance dispersal by strong winds may also be possible.

Citrus fruit borer could be introduced into Australia through illegal importation of fruit or soil. The Australian Quarantine and Inspection Service closely regulates approved plant imports and monitors for illegal plant movement.

Management and quarantine

Inspect fallen fruit from citrus trees for minute holes and cavities under the fruit surface, with caterpillar frass or gumming.

Cut open fruit to look for citrus fruit borer caterpillars and damage caused by caterpillars.

If detected, report immediately to Biosecurity Queensland.

There are simple steps you can take to protect your farm:

  • Be aware of the citrus fruit borer threat.
  • To avoid introducing citrus fruit borer onto your property, establish new plantings with reputable pest- and disease-free nursery stock. On receipt of any new plants, check that they are free from pest and disease. If citrus fruit borer is detected, isolate the nursery stock from healthy plants until official checks are completed.
  • Make sure that you and your farm workers are familiar with all life cycle stages of the citrus fruit borer and the fruit damage it causes. Regularly check your orchard and report any unusual or unfamiliar symptoms.
Reference and acknowledgement

Citrus fruit borer fact sheet (PDF, 372.3KB)

Andrew Beattie (University of Western Sydney), David Astridge (Department of Agriculture, Fisheries and Forestry, Queensland) and Ceri Pearce (Biosecurity Queensland, Department of Agriculture and Fisheries).

Last updated 30 May 2016