Ladybirds

[Plasticman]

Found at least 30 ladybirds and at least 5 different types hibernating in my porch. Never seen so many in one place before and I'm intriged to know why different varieties group together in such a way?

[Klaas Reißmann]

Looks like 5 different types, but it is one species: Harmonia axyridis. Those overwinter in sometimes very huge masses. In German we call it "aggregate", but I have no idea if it is so called in English, too.

In its origin Harmonia axyridis normally overwinters in rock faces. The very bright walls of the rock faces can be seen from a long distance. Our white window frames, white painted walls etc. have the same optic, so the beetles reach to our houses. The first arrivals give off some pheromones that attract others that will give off pheromones, too, and in this way the numbers of beetles can rise up to huge numbers of a million beetles and more.

At least they overwinter in cracks like those between wall and window and even in holes like those of a roller shutter casing and in this way even in quiet places like your porch.

Regards
Klaas

[Plasticman]

Thanks Klass, this pic was taken last year. They're back again this year but only half the numbers.

Simon

[sarahwest]

The common name for these is Harlequin ladybird, see Harlequin Ladybird Survey - home for more info and to record your sightings

[Paul mabbott]

There's also a lot more on this forum, e.g.
Harlequin Ladybirds

As the sun gets higher at this time of year they'll start becoming active.