Dendrobium bigibbum - self-pollinating?
 

I have a few bigibbums in flower in my greenhouse at the moment and noticed that a couple of the flowers appear to have been pollinated. I find this a bit odd for 2 reasons: 1. Flying insects generally don't get into the greenhouse, 2. bigibbum is a species found nearly 2, 000km north of where I live so it would be unusual to have the same pollinators and I have a garden full of native orchids that are found in my region and not once have any of them been insect-pollinated. So my suspicion is that these flowers have pollinated themselves.

Anyonw know whether autogamy has been seen in this species?

:bump:

A local orchidists suspects that ants could be responsible, apparently they try to predate on the pollinia.

Well I was checking my plants today and noticed something stuck in a flower of one of the bigibbums: a dead Blue-Banded Bee. Not sure if getting stuck was a consequence of visiting the wrong species, but the corpse did have the pollinia stuck to its back.

My guess would be ants too.

Your bees have blue butts.
That's so adorable.