Stoned wasps.
 

I am noticing that every now and then a wasp hangs around an orchid, in an abnormal way, a bit like a terminal stoner.
Eventually I find their body tucked inbetween the leaves.

Anyone able to shine a light on this?

I occasionally find a bee that has committed suicide in a Laelia anceps by crawling in and getting stuck... Clearly one that was not too bright, to jam itself into a tight space that it can't get out of. Maybe nature's way of culling out the dumb ones?

I notice a lot of bees and wasps around my cymbidiums...before the flowers have opened.
After that, not a single one.

Death by orchid. Not a bad way to go.

They're just looking for a nice place to die and spend their last minutes :) . This clearly shows that your orchids are pretty.

But seriously this is just brutal. I've seen wasps fly close to my orchids but they never suicide. Maybe my orchids are not a pretty enough place to die. Oh well.

Maybe they're attracted to the scent, something we can't smell.

Many orchids are bee pollinated after all.

I'm not sure if this is what's going on, but some orchids reportedly mimic the pheromones of some wasps:
BBC - Earth - Three tricks orchids use to lure pollinating insects
Still, not a bad way to go?

Pesticides?

bil, do you use any systemic insecticides? Imidacloprid (for one) will be present in the flowers, pollen, and nectar of treated plants. It's a neurotoxin to insects, and may be a factor in colony collapse disorder in bees--they take the pollen back to the hive. I've used it, but only very selectively on indoor plants--it does work well against mealy bugs, but would also get any pollinators working the flowers. Maybe not such a good way to die after all.:(

Systemic, and contact, insecticides do cause insects to die. That is their purpose. In most cases, insecticides (contact or systemic) should be used only when there are existing pests. I don't mind losing the occasional wasp if I can control scales and mealybugs.

The "stoner" wasps could certainly be caused by insecticides.