This odd, wet, cool weather is the perfect condition for slime mold. Throw in some organic matter and they seem to appear out of nowhere, which is what they do. Lots of individual cells come together in a colony and they move in concert.
When I first saw these in an email attachment, I thought it might be firefang, an actimoycetes fungus
or a fungal decomposer like Schizophyllum commune
or maybe insect eggs or even frost. But they are a slime mold.
Slime molds live off dead tissue, so dont worry about them in the orchard.
The group on the leaves and mulch which appear as granules are a Physarum species. The one that looks like dog vomit is a Fulgio species.
A little more on the dear stuff:
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=24159