David Element's Wildlife Web Page Beetles 16 Ladybirds 5

David Element

Wildlife Photography

and Digital Video Images

_ Beetles 16 - Ladybirds 5 - Harlequin Ladybirds

HARLEQUIN LADYBIRD Harmonia axyridis succinea (TYPICAL 19-SPOT FORM)

HARLEQUIN LADYBIRD Harmonia axyridis succinea

HARLEQUIN LADYBIRD Harmonia axyridis forms conspicua and spectabilis

HARLEQUIN LADYBIRD Harmonia axyridis forms succinea and spectabilis

HARLEQUIN LADYBIRD Harmonia axyridis (LARVA, PRE-PUPAE AND PUPA)

HARLEQUIN LADYBIRD Harmonia axyridis (PUPAE)

NOMENCLATURE OF COLOUR FORMS:

The "19-spots" even when they have zero or twenty-five spots are succinea; the four- (or 6-) spot melanics are spectabilis and the 2-spot melanics are conspicua. (courtesy of Paul Mabbott)

The Harlequin Ladybird Harmonia axyridis, a rather attractive (but potentially very damaging) alien ladybird species, has recently been recorded at various sites in the UK - see: http://news.bbc.co.uk/1/hi/sci/tech/4348881.stm for associated news report of Tuesday 15th March 2005. These beetles are Asian in origin and they have been artificially introduced to the USA and several European countries as a form of biological pest control. It would appear that the consequences of earlier artificial introductions of alien species have either never been learned, poorly researched, or otherwise rashly dismissed by those responsible. In the case of the Harlequin Ladybird there are doubtless sophisticated naturally occurring population control factors (e.g. predators, parasites, fungal, bacterial or viral diseases, prey species population cycles) which would keep the numbers in check in their own habitat. However, these same factors are not (yet) operational in the UK. It is highly likely that the parents of the first UK-bred generation have arrived by emigration from the northern coast of Belgium - although the arrival of some beetles in produce cannot be ruled out. The Harlequin adults and pupae are both very variable (see photographs), and only some of the recognised colour forms have been illustrated here. However, the white spots on the sides of the pronotum are very obvious in all variant adults and the larvae and pre-pupae are very easy to separate from all of the native British species as they have distinctive orange markings. Several stages of the life-history may be observed at the same time and this species may be capable of producing at least three broods during a single season if conditions are favourable (and the very warm Autumn of 2005 could not have been more ideal). This insect is predatory on the same prey items (aphids, etc.) as the native ladybird species, but unfortunately also on those useful insects which naturally control garden and crop pests themselves, namely lacewings, hoverfly larvae and other ladybirds. If Harlequin Ladybirds become numerous (and they will) then the natural balance between these predator and prey species could be irreparably damaged. Any sighting of this variably marked species should be reported and any suspected specimen collected for expert identification - although this exercise is now pointless in most of the London suburbs as this species has already established itself almost everywhere in significant numbers. Be warned - several other perfectly harmless species also have very variable colour patterns, so the illustrations of these other species should also be examined closely before sending specimens. Although variable in size, very small adult ladybirds will not be Harlequins. For further instructions and information about the biology of this beetle see: http://www.harlequin-survey.org and for the current status in London see below:

And for further identification photographs see:

http://www.gen.cam.ac.uk/newdept/research/labs/Majerus/haxyridisphotes.htm

This insect is relatively large and oval in shape and some individuals are slightly larger than the native Seven-spot Ladybird. Eyed and Cream-streaked Ladybirds are also large, but these are more restricted in distribution (mainly found in coniferous woodlands). Some smaller native ladybirds are also very variable in appearance - see Beetles 7 for reference photographs of Two-spot and Ten-spot Ladybirds.

Paul Mabbott, London Ladybird Recorder, has posted survey information about the current status of this species in London on the following webpage: http://www.ladybird-survey.pwp.blueyonder.co.uk/harlequin.htm. According to Paul's compiled data this ladybird is now believed to be absent from only five London Boroughs. Paul has included a 'Stop Press' page: http://www.ladybird-survey.pwp.blueyonder.co.uk/H_axyridis.htm#alert with an up-to-date on-line assessment of the status of this beetle in the UK. These ladybirds seem to have a strong association with certain trees, particularly Sycamore, Lime and Horse Chestnut and it is worth examining the bark and leaves and also any walls, fences underneath these trees for evidence of this species. The photographer has already recorded hundreds of adults, larvae, pre-pupae and pupae at a time of year when ladybird activity is normally far from obvious (late October - December 2005) and all of these stages have been found during the cold snap which followed a sudden change in wind direction in mid November. Indeed, three freshly emerged adults were discovered after dark on a very wet, cold and windy day in early December and there were plenty of pupae and even an occasional larva visible! Many of the recently emerged adults are presumed to have begun their hibernation at the time of writing as the numbers have dropped significantly. For a species which had only been present in the UK for some 15 months the rate of spread has been quite spectacular and it is highly likely that the Seven-spot ladybird will be ousted from its position as the most familiar British ladybird within only a few years - if that!

There is also a new general ladybird survey web-site at: http://www.ladybird-survey.org for records of other species.

Dr. Mike Majerus may be contacted at: m.majerus@gen.cam.ac.uk .

RECOMMENDED READING:

'LADYBIRDS', MICHAEL E. N. MAJERUS, NEW NATURALIST, HARPERCOLLINS, 1994. ISBN 000 219934 3 (HARDBACK); ISBN 000 219935 1 (PAPERBACK) - a fascinating read.

'LADYBIRDS', M. E. N. MAJERUS & P. W. E. KEARNS, THE RICHMOND PUBLISHING CO. LTD., 1987

'LADYBIRDS OF SURREY', ROGER D. HAWKINS, SURREY WILDLIFE TRUST, 2000. ISBN 0 9526065 5 0 - see: http://www.surreywildlifetrust.co.uk/ for further information about the Surrey Wildlife Atlas series.

'A FIELD GUIDE IN COLOUR TO BEETLES', K. W. HARDE, BLITZ EDITIONS, 1998. ISBN 1-85605-448-9

'THE BEETLES OF SURREY - A CHECKLIST' DR JONTY DENTON, SURREY WILDLIFE TRUST, 2005. This is the only one of these publications which contains any reference to Harlequin Ladybirds in the UK!

RECOMMENDED WEBSITES:

LONDON LADYBIRD SURVEY: http://www.ladybird-survey.pwp.blueyonder.co.uk/ CONTACT PAUL MABBOTT, LONDON LADYBIRD RECORDER, FOR FURTHER INFORMATION ABOUT THE LONDON AND ESSEX LADYBIRD AND GROUND BEETLE SURVEYS.