Don't know what the vector is. Could be from water. Maybe it was watered during a cooler part of the day and the water got on the leaf containing the spores, and stayed on the leaf without being dried out before the spores germinated, I really don't know - it's a wild guess.
Could also be an insect that had spores on its body and it landed in that spot, I really can't say this definitively either.
Suffice it to say, something carried the spores there, and I just don't know what it is.
Could just as easily be dumb luck. Fungal spores can be carried by air as well. Just happened to be that some spores may have been airborne and landed on that part of the leaf and germinated, idk.
Last edited by King_of_orchid_growing:); 03-05-2013 at 11:21 AM..