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

Red shouldered leaf beetle
Monolepta australis (Family Chrysomelidae)
Description:
Eggs: Unknown (not normally seen).
Immatures: White/cream in colour and up to 12 mm in length (not
normally seen).
Adults: Yellow with a red spot on the base of each wing cover and a
red mark across the top of the shoulders. Size: 4–8 mm in length.
Life Cycle: Eggs are laid into the soil. Larvae hatch in about 12 days
and feed on the roots of grasses. They take about 3 months to mature.
Larvae pupate in the soil, adult emergence takes place after the first
rains at the onset of the wet season. There are usually two or three
generations per year.
Similar to: A range of solitary beetles.
Damage: Leaves, flowers and fruit of native trees and horticultural
tree crops may be affected. Large swarms of this beetle can cause
defoliation leaving behind a vein network (skeletonising) which dries
out or turns brown. They can also strip the bark from small branches
which causes loss of vigour, poor fruit set and reduced fruit quality.
Critical Control period: Late wet season to flowering.
Other comments: Large swarms can develop between December
and April. When conditions are optimal small numbers of beetles can
survive throughout the dry season by sheltering under the leaves and
bark of trees, especially in humid areas. Swarms generally occur in
one or two trees on the outer edge of the orchard and within several
hours or a few days may increase dramatically in numbers. They may
occur in hot-spots and sometimes only a few trees on the edge of the
orchard may be defoliated.
Monitoring: Monitor new leaves in the early morning and evening,
particularly during late wet season to flowering.
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