Here in Greece we have an almond tree with a strange wasp activity going on for weeks now. The branches of some parts of the tree are densely covered with mottled brown bugs about 3mm long. The wasps do not eat them but are doing something with them and then eating a dark substance that falls on the ground below. I suspect it's a symbiotic relationship or perhaps the wasps are farming the bugs for a substance they produce, rather like ants do with aphids. I have searched on line and found nothing. Can anyone on here explain what's going on?