Pests, Beneficials, Diseases and Disorders of Mangoes - Northern ...

Longicorn beetle
Acalolepta mixtus (Family Cerambycidae)
Description:
Eggs: Ovoid, white or light cream in colour.
Immatures: Larvae are white or light cream with a brown head, and
constrictions along the length of the body. Size: up to 40 mm in length.
Adults: Dark grey or brown with a mottled back and antennae which
may be at least as long as the body. Size: 20–30 mm in length.
Life Cycle: One generation per year. Eggs are laid into cracks and
crevices in branches or trunks that have been damaged. Larvae feed
and tunnel under the bark or into the wood. Adults emerge from the
trees after pupating in the tunnels.
Similar to: The damage is similar to that caused by auger beetles
which produces smaller tunnels and finer sawdust.
Damage: Recently pruned or stressed trees are more vulnerable to
attack by longicorns. Affected trees have sap exudate on damaged
areas and the bark may appear loose or lifted. Often damage is not
noticed until the emergence holes of the adults are seen. Eventually
the affected branches die.
Critical Control Period: Late wet season and early dry season.
Monitoring: Inspect trees for symptoms of stress or damage. Look
for loose bark with lots of coarse sawdust underneath, for circular cut
outs of bark with emergence holes underneath and holes packed with
timber fibres. Symptoms are usually more obvious when they are
advanced, especially during the dry season.
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