About citrus longhorn beetle
This beetle is one of the most destructive pests of fruit trees, especially citrus. It's native to lowland China and other parts of Asia. It has invaded parts of Europe, including Italy, Turkey, France, Germany, and Croatia.
Global distribution of the citrus longhorn beetle
Why this is a problem for New Zealand
The citrus longhorn beetle feeds on over 100 different host plants, in particular orchard species, like apples and pears. The damage done in orchards can cause serious economic losses, including a decrease in the amount of fruit grown.
The beetle also feeds on many trees found in our urban landscapes, such as alders and plane trees.
The larvae tunnel under the bark, weakening the trees and making them susceptible to disease and wind damage. Young trees are less able to withstand the beetle's damage.
How it could get here
The eggs, larvae, and pupae (the dormant stage before adulthood) could arrive on nursery stock, wood products, or wooden packaging.
Biosecurity New Zealand has strict measures in place to limit the chances of the beetle making it through the border. The measures include putting imported nursery stock in quarantine for at least 3 months. All wooden packaging is treated for pests.
How to identify
The beetle
Both males and females are black and shiny with white to blue spots.
- Males are about 21mm long
- Females are about 37mm long
Left: Female citrus longhorn beetle. Source: Wikimedia commons Right: Top and bottom view of citrus longhorn beetle. Source: Wikimedia commons
Description of other life stages
Eggs are found singly under bark and are about 6mm long.
The larva (maggot) is:
- cylindrical
- about 56mm long
- 10mm wide (at its widest)
- without obvious legs
- pale yellowish white with a dark head.
Pupae
- have long coiled antennae
- have legs
- are found under bark.
Source: Public Domain USDA
What to do if you see the beetle
If you think you've found citrus longhorn beetle:
- photograph it
- capture it (if you can)
- call 0800 80 99 66
Note: This information is a summary of the citrus longhorn beetle's global distribution and potential impacts to New Zealand.
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