Dendrobium bigibbum - self-pollinating?

[Orchidsoutdoors]

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?

[WhiteRabbit]

[Orchidsoutdoors]

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

[Orchidsoutdoors]

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.

[plucker]

My guess would be ants too.

[Ordphien]

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