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| Overwintering aggregation of the Multicoloured Asian Ladybird, near Antwerpen
(Photo: Wouter Vanreusel) |
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| Overwintering aggregation of the Multicoloured Asian Ladybird, near Antwerpen
(Photo: Rollin Verlinde) |
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| Larvae of the Multicoloured Asian Ladybird often behave as intraguild predators
towards the larvae of indigenous aphid predators [here feeding on a larva of the two-spot
Ladybird, Adalia bipunctata] (Photo: Louis Hautier) |
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| Adult of the Multicoloured Asian Ladybird
(Photo: Jeroen Mentens) |
Taxonomic name:
Harmonia axyridis (Pallas)
Synonyms:
Common names: Asian lady beetle,
Asiatischer Marienkafer, halloween lady beetle,
harlequin lady beetle, Japanese lady beetle, la
coccinelle asiatique, multicolored Asian lady
beetle, multivariate lady beetle, pumpkin lady
beetle, southern lady beetle, veelkeurig aziatisch
lieveheersbeestje
Organism type: insect
Harmonia axyridis (lady
beetle) is native to Asia and has been used
extensively around the world for biological control
of various aphid species. While it is a popular
control agent, it has also brought with it several
negative effects. Its establishment appears to
decrease the diversity of native Coccinellidae.
Harmonia axyridis can also quickly become a human
nuisance when it seeks shelter during the winter
months and takes up residency in the walls and
insulation of houses and other structures.
Surprisingly, Harmonia axyridis has also attained
status as a pest of fruit production; particularly
in the vineyards of the Midwestern USA.
Description
Adults of
H. axyridis, which are larger than most of
other ladybird species, measure 5-8mm. They are oval
in shape and are convex. The elytra usually display
a wide transverse "keel" at the apex. They are a
highly coloured polymorphic with elytra ranging from
pale yellow-orange to black bearing 0-19 spots. The
head, antennae and mouthparts are generally straw
yellow but are sometimes tinged with black. The
pronotum is similarly straw yellow with up to five
black spots, or with lateral spots usually joined to
form two curved lines, an M-shaped mark, or a solid
trapezoid. The larvae which have tubercles and
spines are elongate and somewhat flattened, mature
larvae are distinctive in their colouring. The
overall colour is mostly black to dark bluish-gray,
with a prominent bright yellow-orange patch
extending over the dorso-lateral lobes of abdominal
segments 1-5 on each side (Adriaens et al.
2003; Koch, 2003).
Similar
Species
Hippodamia
convergens
More
Occurs
in:
agricultural areas, natural forests,
planted forests, riparian zones, ruderal/disturbed,
scrub/shrublands, urban areas, wetlands
Habitat
description
Harmonia axyridis are
known to colonise a wide range of habitats. They are
found in cropping areas, meadows and semi-natural
areas (Branquart, 2004). In North America they are
found on a variety of nursery, ornamental, and field
crops, including cotoneaster, rose, Christmas trees,
apple, pecan, alfalfa, wheat, cotton, tobacco, and
small grains (Cornell University, 2004). In Belgium
they have ben recorded on deciduous trees,
especially lime (Tilia sp.) and maple
(Acer sp.). They tend to overwinter in
buildings where they aggregate in secluded dark
places (Branquart, 2004).
General
impacts
Intraguild predation by H.
axyridis is seen as a potential mechanism
leading to displacement of native coccinellid
species. H. axyridis appears to be a top
predator in the guild of aphidophagous insects. Many
studies indicate that H. axyridis uses other
members of the aphidophagous guild as a food source
(Koch, 2003). The intensity of predation by H.
axyridis on other guild members appears to be
inversely related to aphid density (Burgio et
al. 2002).
In a study conducted by Koch
et al. (2003) the authors found that H.
axyridis can act as a potential stressor to
populations of monarch butterflies (Danaus
plexippus).
Cornell University (2004) states that, "H.
axyridis has become a major nuisance to
homeowners because of its habit of invading houses
and buildings in large numbers while searching for
protected sites to over winter in the fall and
appearing again on warm, sunny days in February and
March. In addition, beetles may get in picnic food
and drinks; "swarm" like bees and land on people."
Jones and Boggs (Undated) report that, H.
axyridis demonstrate a defense mechanism called
reflex bleeding. When disturbed, they exude a
yellow-orange body fluid. This has a foul odor and
can permanently stain walls, drapes, carpeting, etc.
Some people are sensitive or allergic to the fluid
that secrete, it can cause a stinging sensation and
contact dermatitis.
There is concern that H. axyridis may be a
pest of fruit production. Koch et al. (2004)
and Koch and Hutchinson (2003a) report that during
autumn, the beetles show a tendency to aggregate on
late season fruits, such as grapes, apples, and
raspberries. In some cases, H. axyridis has
been reported feeding on fruits that have been
damaged by birds or other insects. They further
state that the extent of this damage is uncertain
but that there is greater concern over the beetle
becoming a contaminant in vineyards. The difficulty
in removing beetles from clusters of grapes may
result in the beetles being crushed with grapes
during processing and contamination of wine being
produced.
Uses
Harmonia
axyridis is widely used as a biocontrol agent
for reducing pest aphid populations in greenhouses,
orchards and gardens in North America since 1916 and
in Western Europe since 1982 (Adriaens et al.
2003; Koch, 2003). In several cases, this
coccinellid has proven to be an effective biocontrol
agent, particularly in pecans groves in southern
USA.
Notes
Adriaens et
al. (2003) offer the following reasons as to why
H. axyridis is such a successful and good
colonizer. Firstly, it has a wide trophic niche (the
niche the organism occupies in the food chain) and a
high level of phenotypic plasticity (their behaviour
or morphology varies with changing environmental
conditions) for several life-history traits;
secondly its voraciousness and intra-guild
interactions with other aphidophagous species and
finally its strong dispersal capacities and ability
to undertakes long range migrations to
over-wintering sites.
Geographical
range
Native range: Asia (Tourniaire
et al. 2000). The presumed native
distribution of H. axyridis extends from the
Altai Mountains in the west to the Pacific Coast in
the east, and from southern Siberia in the north to
southern China in the south (Koch, 2003)
Known
introduced range: Europe, North America, and
South America (Koch, 2003; Adriaens et al..
2003; Jones and Boggs, UNDATED; De Almeida and da
Silva, 2002).
Introduction pathways to new
locations
Biological control: H.
axyridis has been widely used for reducing pest
aphid populations in greenhouses, orchards and
gardens in North America since 1916 and in Western
Europe since 1982 (Koch, 2003; Adriaens et
al. 2003).
Other: The argument has
been made that the current populations of H.
axyridis in North America may have stemmed from
accidental sea-port introductions (Koch,
2003).
Local
dispersal methods
Natural dispersal
(local): Cornell University (2004) states that,
“H. axyridis has become a major nuisance to
homeowners because of its habit of invading houses
and buildings in large numbers while searching for
protected sites to over winter in the fall and
appearing again on warm, sunny days in February and
March".
Management
information
Physical: Management of
H. axyridis in the household setting begins
by preventing the beetles from entering the
building. Any cracks or holes leading from the
exterior to the interior of the home should be
sealed with caulking or covered with a fine mesh
screen (Koch and Hutchison 2003a).
Chemical: In cases of persistent and
severe infestations, exterior applications of
insecticides (e.g., synthetic pyrethroids) can be
applied to prevent H. axyridis from entering
a building (Koch, 2003; Koch and Hutchison 2003b).
The insecticides should be applied prior to the
infestation, and focused around windows and doors,
as well as along the foundation and under the eves
of the roof ( see methods
). Researchers are also evaluating the
repellents (e.g., camphor and menthol) to prevent
beetles from entering buildings (Koch, 2003).
Mechanical: Once the beetles enter a
building, they can be removed manually or by
sweeping or vacuuming. If a vacuum is used, it is
advised that a stocking be place over the distal end
of the vacuum hose to prevent beetles from passing
into the holding container of the vacuum ( see methods
). In addition, traps (primarily black light
traps) are available for removineg H.
axyridis once they enter a building ( see methods
), but the efficacy of these traps remains
uncertain.
Nutrition
Adriaens
et al. (2003) state that, "H. axyridis
preys mostly on tree-dwelling hemipteran insects
such as psyllids, scale insects and aphids". In
addition, H. axyridis will also feed on
immature stages of other Coleoptera and Lepidoptera,
and plant material such as pollen and injured fruits
(Koch, 2003).
Reproduction
Harmonia
axyridis may produce up to 1,642 to 3,819 eggs
per female over their entire life span, at a rate of
about 25 eggs per day. Eggs are typically laid in
clusters of 20 to 30 eggs (Koch, 2003).
Lifecycle
stages
Harmonia axyridis undergoes a
holometabolous life cycle (meaning those insects
that undergo a complete change i.e., complete
metamorphosis) going through the egg, four larval
instars, pupal and adult stages. Studies show that
temperature has an effect on the adult weight and
the rate of development of the stages. The diet of
the beetle is also known to have an effect on larval
development (Koch, 2003). The results of a study
(LaMana and Miller, 1998) show that at 26º C on a
diet of the pea aphid Acyrthosiphon pisum,
the mean duration of each stage is as follows: egg
2.8 days, first instar 2.5 days, second instar 1.5
days, third instar 1.8 days, fourth instar 4.4 days,
pupa 4.5 days. Koch (2003) states that adults
typically live for one to three months, but may live
up to three years.
Reviewed by: Dr. Etienne
Branquart, Belgian Biodiversity Platform (SPO)
Ministere de la Region Wallonne. Belgium
Dr.
Robert Koch, Department of Entomology, University of
Minnesota, USA
Principal sources: Adriaens
et al. 2003 The Multicolored Asian
Ladybird Harmonia axyridis Pallas
(Coleoptera: Coccinellidae), a threat for native
aphid predators in Belgium?
Koch,
R.L., 2003. The multicoloured Asian lady beetle,
Harmonia axyridis: a review of its biology,
uses in biological control and non target
impacts.
Compiled by:
National Biological Information
Infrastructure (NBII) & IUCN/SSC Invasive
Species Specialist Group (ISSG) |
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Last Modified: Monday,
29 August
2005
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