A pair of crescent-shaped markings on the second segment
behind the head distinguish navel orangeworm larvae
© Jack Kelly Clark, UC IPM
Photo courtesy of Jack Kelly Clark, UC IPM
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Navel orangeworm
Have you seen this citrus pest?
What is navel orangeworm?
Navel orangeworm (Amyelois transitella) is an exotic pest
that feeds on a variety of fruit and nuts, including citrus.
While the insect is a serious pest of some nut crops like
almonds and pistachios, it also grazes on citrus fruit,
causing surface scarring that allows decay-causing
organisms to enter the fruit. This reduces fruit quality
and causes fruit drop, reducing economic return.
Navel orangeworm is not known to occur in Australia.
What does navel orangeworm look like?
Adults
• A dult moths are about 9–11 mm long and greyish-
brown.
• T heir wings have silver-grey markings.
• T he moths have short, dark projections from the
front of the head.
Adult moth of navel orangeworm
Photo courtesy of Jack Kelly Clark, UC IPM
Larvae
• T he larvae are white to pink with a dark reddish-
brown head.
Tomorrow’s Queensland:
strong, green, smart, healthy and fair
• They have a distinctive pair of crescent-shaped
markings on the second segment behind the head.
• Larvae are tiny when they first hatch, but as they
develop they can grow up to 13–19 mm long.
Pupae
• P upae are about 7–12 mm long and dark brown.
Eggs
• N avel orangeworm eggs are tiny, oval and flattened,
with ridge-like marks.
• I nitially, eggs are white, but turn pink, then reddish-
brown before hatching.
• T hey are laid in the navel end of injured oranges.
What symptoms does navel orangeworm
cause on plants?
Check for caterpillar frass near wounds in the fruit.
Navel orangeworm larvae scavenge in splits and wounds
of citrus fruit (such as naval oranges) and feed in or
near the core. The larvae can overwinter in rotting or
mummified fruit left on trees.
Navel orangeworm leaves copious webbing and frass in fruit
and nuts it infests. Pupa (circled) and larvae (right) shown
Photo courtesy of Jack Kelly Clark, UC IPM
Which plants are affected?
Navel orangeworm feeds on a variety of fruit and nuts.
It is a serious pest of nut crops such as English walnuts,
pistachios and almonds, but also feeds on citrus, dates,
figs, apples, pears and stone fruit.
Where does navel orangeworm occur?
Navel orangeworms occur in the United States and Canada.
How does navel orangeworm spread?
Long-distance spread occurs by movement of plant
material infested with the larvae and pupae. The
Australian Government closely regulates approved
imports of host plants (whole or parts) and monitors
for illegal plant movement.
How can I protect my farm from navel
orangeworm?
There are simple steps you can take to protect your farm:
• Be aware of navel orangeworms.
• Do not illegally import fruit.
• Keep your farm clean. Use good hygiene practices
to manage discarded fruit under trees. Remove
damaged or mummified fruit from trees.
• Check your crop. Make sure you and your farm
workers are familiar with the signs of navel
orangeworm infested fruit.
• Regularly check your orchard and report any unusual
or unfamiliar pests.
Have you seen navel orangeworm?
In Queensland, navel orangeworm is prohibited
matter under the Biosecurity Act 2014. If you
believe that you may have detected navel
orangeworm, you must report it immediately to
Biosecurity Queensland. You must also take all
reasonable steps to minimise the risks of spreading
the pest or making the situation worse. Do not
move any damaged fruit off your property—this can
spread the pest.
Be on the lookout for navel orangeworm and
report them immediately to Biosecurity
Queensland.
Call Biosecurity Queensland on 13 25 23 or the National
Exotic Plant Pest Hotline on 1800 084 881.
Further information
For more information, call Biosecurity Queensland on
13 25 23 or visit www.biosecurity.qld.gov.au or the
UC IPM website at www.ipm.ucdavis.edu
Disclaimer: The material in this publication was prepared from
the most recent information available at the time of publication.
It is intended as a guide only. 2
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http:www.ipm.ucdavis.eduwww.biosecurity.qld.gov.au
