Harlequin Ladybirds

[Paul mabbott]

Searching around London a couple of days ago, found very few ladybirds but, of those found, most were 'harlequins' in all life stages. However, also heard of another find (by Marcel Ashby) who had a convergent ladybird (Hippodamia convergens) in his fridge, presumably from imported food. Not yet confirmed but it's a very distinctive beetle:
Hippodamia convergens
Gets its name from the two diagonal, convergent white marks on the forebody.
This is an American species which can easily survive in our climate so potentially another invader ....

[Imaginos]

Originally Posted by Paul mabbott

Searching around London a couple of days ago, found very few ladybirds but, of those found, most were 'harlequins' in all life stages. However, also heard of another find (by Marcel Ashby) who had a convergent ladybird (Hippodamia convergens) in his fridge, presumably from imported food. Not yet confirmed but it's a very distinctive beetle:
Hippodamia convergens
Gets its name from the two diagonal, convergent white marks on the forebody.
This is an American species which can easily survive in our climate so potentially another invader ....

Had four Haxy's in the suction traps so far this year (all reported).

What is the life history of convergens? Is it likely to be as damaging as the Harlequin potentially is?

[Paul mabbott]

In temperate-cool north America at least, it behaves very much as 7-spot and other native aphidophages. It doesn't have the continuous mating which makes H. axyridis so prolific. Like Haxy, it is a very dispersive species and has been noted overwintering in large numbers in the Rockies.
Strange that it's not been imported before (apparently); the 7-spot and other European ladybirds colonised N. America a long time ago but seems not to have happened in reverse.
Might be worth noting that although H. convergens used to be one of the most abundant ladybirds in N. America it appears recently to have declined in numbers due to competition and predation from H. axyridis and also the 7-spot ...

Originally Posted by Imaginos

Had four Haxy's in the suction traps so far this year (all reported).
What is the life history of convergens? Is it likely to be as damaging as the Harlequin potentially is?

[Paul mabbott]

This is a reminder to those on the other thread that Harmonia axyridis, the 'harlequin' ladybird should be reported to one of the many surveys listed in this thread! Cheers, Paul

[honeybee]

where did the halequin originate from in the first place? Apparently they bite and cause a nasty reaction in some people, was on radio 4 today prog, can listen again on net, i missed it.

[aeshna5]

They are an Asian species introduced to US + Europe as biological control for aphids/scale.

Generally they don't bite people + probably no more than say 7-spot; it's just a tiny nip. Guess some people are allergic to all manner of things, so it's no surprise that some people may be allergic,as they are to other insect bites/stings.

[henrya]

aeshna5 is right. Nothing to worry about - Harlequins don't go round biting people any more than any other ladybird.

henrya

[Paul mabbott]

Indeed, they are an east Asian species with quite a wide range from Siberia to southern China including the Pacific coast and Japan. they're sometimes referred to as the 'Japanese ladybug' (this species has as many names as it has patterns) because the ones imported to USA (and apparently Europe) came from Japan and thus we only get a *few* of the natural pattern variants.

There is no evidence that their bite is any worse than that of other ladybirds (or other beetles) *but* when they are present in large numbers then, obviously, there is a greater statistical chance of them biting you! They don't have a venom or anything like that ....

They are in flight now and, today, I've found (possibly) the first South Yorks one ....

Originally Posted by honeybee

where did the halequin originate from in the first place? Apparently they bite and cause a nasty reaction in some people, was on radio 4 today prog, can listen again on net, i missed it.

[honeybee]

I didn't hear Today this morning but I'm told that's what they said...I do remember a few years back that bumper ladybird year where people were reporting being nipped, I guess like you say, if there are more there's gonna be more risk. They're nymphs are spikey though aren't they, making them less edible to predators wheras our native ones are softer.

[Paul mabbott]

Well, like all predatory beetles (and other invertebrates) when there are a lot of them then there is going to be competition for food and they'll take a bite of anything they come across ... and remember that for the past month there have been very few aphids around so they will be seriously hungry ....

Our 'common' ladybird larvae look soft but they contain toxic or, at least, unpalatable (taste one and see) chemicals but some of the less often observed species have quite spikey larvae (back to the Bryony ladybird thread ..... ). Possibly the spikes look threatening but most ladybird larvae will eat smaller stages of most other species (or their own), as will hoverfly larvae &c &c ....

Originally Posted by honeybee

I do remember a few years back that bumper ladybird year where people were reporting being nipped, I guess like you say, if there are more there's gonna be more risk. They're nymphs are spikey though aren't they, making them less edible to predators wheras our native ones are softer.