Harmonia axyridis
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2008-07-06T14:53:24Z
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{{Refimprove|date=January 2008}}
{{Taxobox
| name = ''Harmonia axyridis''
| status = secure
| image = Harmonia_axyridis.jpg
| image_width = 200px
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| classis = [[Insect]]a
| ordo = [[beetle|Coleoptera]]
| familia = [[Ladybird|Coccinellidae]]
| genus = ''[[Harmonia (genus)|Harmonia]]''
| species = '''''H. axyridis'''''
| binomial = ''Harmonia axyridis''
| binomial_authority = [[Peter Simon Pallas|Pallas]], 1773
}}
{{wikispecies|Harmonia axyridis|Asian lady beetle}}
The '''Asian lady beetle''' ('''''Harmonia axyridis'''''), also known as the '''Multicolored Asian lady beetle''', '''Harlequin lady beetle''' (because of the species' tendency to vary in [[color]] from [[orange (colour)|orange]] to [[yellow]] to even [[black]]), and '''Halloween lady beetle''' (because it invades homes in October in preparation for hibernation), is a well-known [[Invasive species|non-native]] insect common in both [[North America]] and [[Europe]].
When the species first "hit" the UK, it received the label of "the many-named ladybird". Among the names listed were: Multivariate, Southern, Japanese, and Pumpkin ladybird<ref name=Londonsurvey>Ladybird Survey page "''Harmonia axyridis'' (Pallas) in Britain" [http://www.ladybird-survey.pwp.blueyonder.co.uk/H_axyridis.htm] Accessed 7 Jan 2008</ref>
''Note:'' species in the family [[Coccinellidae]] are known as '''[[ladybird]]''' in the UK; hence, the British name is '''Harlequin Ladybird'''.
==Background==
This species was possibly established in North America as the result of introductions into the [[United States]] in an attempt to control the spread of [[aphid]]s. Whatever the source, in the last two decades, this insect has spread throughout the United States and [[Canada]] and has been a prominent factor in controlling aphid populations. However, many people now view this species as a nuisance, partly due to their tendency to overwinter indoors and the unpleasant odor and stain left by their bodily fluid when frightened or squashed. It is also currently increasing in [[Europe]] to the detriment of indigenous species, due to its voracious appetite which enables them to out-compete and even eat other lady beetles, as it also does in the United States.
===North America===
In the U.S., the first attempts to introduce it took place as far back as 1916. Repeated efforts were not successful. In the early 1980s, aphids were causing significant problems for growers of [[pecan]] trees, so the [[United States Department of Agriculture]] again attempted to bring the insect into the country—this time in the southeastern United States, using beetles brought from their native region in northeastern [[Asia]]. After a period of time, USDA scientists concluded that their attempts had been unsuccessful. However, a population of beetles was observed near [[New Orleans, Louisiana]] around 1988, though this may have been an accidental introduction event independent of the original, planned efforts. In the following years it quickly spread to other states, being occasionally observed in the [[Midwest]] within about 5–7 years, and becoming common in the region by about 2000. The species was also established in the northwest by 1991, and the northeast by 1994, in the former case quite possibly involving additional introductions, rather than reaching there from the southeast. It is reported that it has heavily fed on [[soybean aphid]]s (which recently appeared in the U.S. after coming from [[China]]), supposedly saving [[farming|farmers]] vast sums of money in 2001. However, in addition to its household pest status, it has been reported to be a minor agricultural pest (contaminating crops of tender fruits and grapes)[http://www.oardc.ohio-state.edu/grapeipm/insects_attacking_flower_cluster.htm][http://ohioline.osu.edu/b919/0011.html] in [[Iowa]], [[Ohio]], [[New York]], and [[Ontario]][http://www.omafra.gov.on.ca/english/crops/resource/2007achieve.htm], and native ladybird species have experienced often dramatic declines in abundance in areas invaded by ''H. axyridis''. Despite the troubles the Asian lady beetle causes, many farmers still view it as a [[beneficial insect]].
===Europe===
In Europe, the species was first seen in [[Belgium]] in 2001. It spread fast and has spread through western [[Germany]] (2002), [[the Netherlands]] (2003), northern [[France]] (2004), the [[United Kingdom|UK]] (2004), [[Poland]] (2006) and [[Scandinavia]] (2007). In the UK, there have now confirmed sightings throughout the South East , west to Cornwall and the west coast of Pembrokeshire (Wales), and north to north Lancashire, north Yorkshire and south Durham (county)<ref>UKSurvey [http://www.harlequin-survey.org] Accessed 24 Nov 2007</ref>. Its spread is of particular concern as this species has the potential to jeopardise the native species due to its being a very effective aphid predator. When this food source becomes scarce, it will eat lady beetle eggs and larvae, and butterfly/moth eggs and caterpillars.
The first Asian lady beetle to be found in [[Jersey|Jersey, Channel Islands]] was located in St Catherines Woods in February 2007. It is presumed that it was blown over from the French coast.
==Biology and behavior==
[[Image:HarAxy ontwikkeling.jpg|thumb|right|300px|Life cycle]]
Asian lady beetles [[hibernation|hibernate]] in cooler months, though they will wake up and move around whenever the [[temperature]] reaches about 50°F (10°C). Because the beetles will use [[crevice]]s and other cool, dry, confined spaces to hibernate, significant numbers may congregate inside walls if given a large enough opening. They often congregate in sunlit areas because of the [[heat]] available, so even on fairly cold winter days, some of the hibernating beetles will “wake up” because of [[solar heating]]. These large populations can be problematic because they can form [[swarm]]s and linger in an area for a long time.
The Asian lady beetle, like other lady beetles, uses [[Methoxypyrazines|isopropyl methoxy pyrazine]] as a [[defensive chemical]] to deter predation, but also contains this chemical in its [[hemolymph]] at much higher concentrations than many other lady beetle species. These insects will “[[reflex bleeding|reflex bleed]]” when agitated, releasing [[hemolymph]] from their [[arthropod leg|legs]]. The liquid has a foul [[odor]] (similar to that of dead [[leaf|leaves]]) and can cause [[stain]]s. It is believed that some people have [[allergic reaction]]s when repeatedly exposed to lady beetles (especially dead ones). Sometimes, the beetles will bite humans, presumably in an attempt to acquire salt, although many people feel a pricking sensation as a lady beetle walks across the [[skin]]. Bites normally do no more harm than cause irritation although a small number of people are allergic to bites<ref>Medscape [http://www.medscape.com/viewarticle/547512?src=mp] Accessed October 18, 2006</ref>.
[[Image:Harmonia axyridis01.jpg|thumb|left|300px|Different patterns]]
These beetles can sometimes be difficult to identify because of the variations in color, spot size, and spot count of the [[elytra]]. The easiest way to identify an Asian lady beetle is to look at the [[pronotum]] and see if the black markings look like a letter “W” or “M” (depending on if the marking is viewed from the front or the back). There is more white on the pronotum in this species than in most native North American species.
==Control==
These beetles have the ability to squeeze through the smallest of openings, even through a closed window. Although some consumers have reported positively on the effectiveness of spraying with home [[insecticide]]s{{Fact|date=April 2008}}, the only way to fully prevent a home invasion is to tape the windows shut so they cannot get through these cracks. Others suggest tolerating the insects as long as the invasion is relatively mild or using a vacuum cleaner to remove the pests with less mess.
==References==
<references/>
== External links ==
{{Commons|Harmonia axyridis}}
*[http://www.cirrusimage.com/beetles_multicolored_Asian_ladybird.htm Asian Ladybug: diagnostic photos, male and female specimens]
*[http://www.cirrusimage.com/beetles_ladybird.htm Ladybugs of North America - diagnostic photos and information]
* [http://www.wildlifetrust.org.uk/cheshire/news_ladybird.htm Help survey the harlequin ladybird's UK invasion (illustration of the wide variety of shell patterns that may be observed)]
* [http://www.insectscience.org/3.32/ An extensive review of literature on the multicolored Asian lady beetle]
* [http://www.ipm.msu.edu/beetleFAQ.htm The Multi-Colored Asian Lady Beetle FAQ]
* [http://www.harlequin-survey.org Report sightings of the Harlequin Ladybird in the British Isles]
* [http://www.nev.nl/nieuws/2004/vrns-2004-07_bestanden/gezocht.html Report sightings of the Harlequin Ladybird in the Netherlands]
* [http://www.thisisjersey.com/code/showarchive.pl?ArticleID=1622February2007&year= Report of the harlequin ladybird being found in Jersey Channel Islands]
==Image gallery==
<gallery>
Image:H_axyridis.JPG|''H. axyridis'' f. ''succinea''
Image:ExochomusQuadripustulatus.jpg|Black variety (f. ''spectabilis'') of ''H. axyridis''
Image:Ladybug on fennel plant.JPG|''H. axyridis'' on a plant in the [[Apiaceae]] family
</gallery>
[[Category:Coccinellidae]]
[[Category:Invasive animal species]]
[[Category:Biological pest control agents]]
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