Exotic Pest Alert: Multicoloured Asian
lady beetle
February 2015, Primefact 1389, 1st edition
Plant Biosecurity & Product Integrity Orange
Multicoloured Asian lady beetle
(Harmonia axyridis) is an exotic plant pest
If found it must be reported promptly to the
Exotic Plant Pest Hotline 1800 084 881
Multicoloured Asian lady beetle
Multicoloured Asian lady beetle (MALB) is also
called harlequin ladybird because it is brightly
coloured and has a highly variable appearance.
MALB is not a plant pest. MALB is a generalist
predator of insects especially aphids and other
soft bodied insects including other lady beetles.
Figure 1 Orange, red and black colour forms of
multicoloured Asian lady beetle
Overseas MALB is a nuisance as it aggregates in
large numbers before overwintering in buildings
and other structures.
MALB is a hitchhiking pest that can arrive on
cargo and containers from Asia and
North America.
Description
Adult MALB are highly variable in colour and
pattern. The hard shiny wing case colour may be
orange, red or black (Figure 1). Orange and red
forms may be patterned with anything from zero
to twenty one spots (Figure 2) or may display a
grid like black pattern.
Figure 2 Zero to many spots on multicoloured
Asian lady beetle
Black forms usually have two or four large orange
or red spots (Figure 1, right). Other forms can
have bars or stripes or be black with large
patches of pale colour.
The head of the MALB is usually white with four
black spots, which range from small spots to
large patches that may blend together to look like
a black M or W (Figure 3, arrow).
Figure 3 Distinctive black M or W shape on the
head of multicoloured Asian lady beetle
Exotic Pest Alert: Multicoloured Asian lady beetle
Damage
MALB is considered a household pest as it
aggregates on homes and other structures in
autumn while seeking a place to overwinter.
When disturbed or crushed MALB will emit an
orange liquid that can stain carpet and other soft
furnishings. MALB can taint wine if present in
bunches after harvest. Some people may
develop an allergic rhinoconjunctivitis to MALB.
Spread
Figure 4 Square shoulders (top arrow) and
flattened rear end (bottom arrow) of multicoloured
Asian lady beetle
One of the best ways to identify MALB in any
colour form is by the overall body shape. MALB
has very squared “shoulders” that almost come to
a right-angled point (top arrow) and a flattened
flared rear end (bottom arrow) (Figure 4). Adult
MALB is 5 to 8 mm long and 4 to 6.5 mm wide.
Adult MALB fly readily between plants seeking
aphid populations to eat.
Distribution
MALB is native to China, Japan, Korea, Mongolia
and eastern Russia. MALB has spread to North
and South America, Europe and parts of Africa.
MALB is not present in Australia but it has been
intercepted at the border.
Reporting
If you suspect multicoloured Asian lady beetle:
Call the Exotic Plant Pest Hotline on
1800 084 881
Take photos (not samples) to report and
minimise the risk of spreading this pest
Email clear photos with a brief explanation
and contact details to
[email protected]
Figure 5 Larva of multicoloured Asian lady beetle
Larvae of MALB look like a tiny crocodile and are
mostly black with orange or yellow markings
(Figure 5).
Lifecycle
The lifecycle of MALB consists of egg, four larval
instars, pre-pupa, pupa and adult. In temperate
regions overseas the egg stage will take four to
five days, the larval stage about three weeks and
the pupal stage one week. Adults typically live for
a year. Adults overwinter in large groups in an
inactive state.
An exotic plant pest is a disease causing
organism or an invertebrate not present in
Australia and which threatens agricultural
production, forestry or native and amenity plants.
Acknowledgments
Figure 1 courtesy of Gyorgy Csoka, Hungary Forest Research
Institute, Bugwood.org
Figure 2 courtesy of Bill Ree Texas A&M University, Bugwood.org
Figure 3 courtesy of Susan Ellis, Bugwood.org
Figure 4 courtesy of Daren Mueller, Iowa State University,
Bugwood.org
Figure 5 courtesy of Joseph Berger, Bugwood.org
Habitat
© State of New South Wales through the Department of Trade and
Investment, Regional Infrastructure and Services 2015. You may copy,
distribute and otherwise freely deal with this publication for any
purpose, provided that you attribute the NSW Department of Primary
Industries as the owner.
MALB is an adaptable insect living in a wide
variety of habitats from urban and agricultural
areas to forests, wetlands and fields. MALB
commonly lives on trees, particularly fruit trees
which support large numbers of aphids upon
which it feeds.
Disclaimer: The information contained in this publication is based on
knowledge and understanding at the time of writing (March 2015).
However, because of advances in knowledge, users are reminded of
the need to ensure that information upon which they rely is up to date
and to check currency of the information with the appropriate officer of
the Department of Primary Industries or the user’s independent
adviser. PUB 15/72 Published by the NSW Department of Primary
Industries.
2
NSW Department of Primary Industries, March 2015