Monday, June 8, 2009

Beetlemania on Rodgersia.

One of my favourite garden plants is Rodgersia pinnata, a member of the Saxifragaceae from temperate East Asia. I planted it for the attractive leaves.

Right now it is in flower. The long spikes bend toward the light, and try to ensnare postal delivery people and the paper boy. The flowers have a light, sweet scent.

I noticed yesterday that the blossoms were speckled with brown dots, which, under slightly closer inspection turned out to be beetles. (Click to see.)

I believe these are dermestid beetles, of the odious carpet beetle gang. I always associate them with the defleshing of zoological specimens, or the attacking of poorly-preserved taxidermy. (The larvae dine on such putrefying things.) I didn't expect them to be drawn to a pleasant-smelling plant, but apparently they are, and feed on pollen(?). Perhaps a different species?

An interesting question--and a great plant, that not only has interesting leaves, but also provides zoologica to puzzle over.


Wanderin' Weeta said...

Those are carpet beetles. The adults eat pollen of certain flowers; it's only the larvae that eat your collections.

I've read that the adults eat pollen from daisies, asters, and spirea. I can add, from experiment, maple, dead nettle, and apple blossom. Now we can add Rodgersia. It's a saxifrage; I'll try my beetles on other saxifrages to see what happens.

Hugh said...

I thought that they might be attracted to more stinky plants, because they need that ability (stinkophilia) to find a place to lay eggs. They're more complicated (and more Catholic) than I supposed.

kompoStella said...

great plant, indeed - the flowers are very elegant and those leaves look so much like chestnut?!

Hugh said...

Yes, they do look chestnut-like. Maybe that's part of what makes them appealing (I like chestnut trees).