What plants are affected?
Palm leaf beetle are known to attack and damage young coconut and other palm species.
What do I look for?
- Chewed large areas of palm leaflets turn brown.
- When the leaf opens, these brown areas shrivel and curl, producing a characteristic scorched appearance.
 Linear chewing marks made by adult beetle |  Brown areas of death tissue cells in unopened leaves |  Twisted fronds with scorched appearance |
How does the pest survive and spread?
- Female palm leaf beetles lay eggs in small batches in grooves chewed into the surface of young leaflets of the palm.
- Female palm leaf beetles lay eggs daily during their lifetime (between 2-3 months)
- After hatching, larvae move into the unopened spear leaf or ‘heart’ of palm where they develop, only leaving after reaching full maturity, 5-6 weeks later.
- The larvae and adult beetles feed on tissues of unopened palm leaves.
- The adults are slow-moving. Flight activity occur mostly during twilight and night-time. Adults have been reported to only fly a few hundred meters in one flight.
What damage can this pest cause?
- Leaf damage reduces the leaf’s ability to photosynthesize, resulting in stunting of the palm and reduced nut production.
- Successive severe defoliations weakens the palm, making it more vulnerable to drought and disorders that can lead to plant death.
Status in Western Australia
Brontispa longissima is a quarantine pest in Western Australia. It is a declared pest under section 22(2) of the Biosecurity and Agriculture Management Act 2007.
The restricted distribution of palm leaf beetle in Western Australia is supported by general and specific surveillance, and specific import requirements to prevent its spread. A person who finds or suspects the presence of palm leaf beetle in plantations, nurseries or urban areas must report it to DPIRD.
What do I do if I find it?
It is important that any suspect palm leaf beetle occurrence outside of Broome is reported. Early detection and eradication will help protect Western Australia’s horticulture and nursery industries. If you find or suspect plants infested with palm leaf beetle, please make a reportusing MyPestGuide® or contact the Pest and Disease Information Service (PaDIS) to report this pest.
Report your observations
 | MyPestGuide® Reporter Pest and Disease Information Service |