Scouts being picked off by threats/wasps(?), attrition nor full on assault calculated to be in hive's favor....

Solution: Curb scout losses into an advantage.

Ask bees about the nesting, hunting, breeding, etc. habits of their ancient wasp enemies.  

New 'marker' scout caste to be created--

'Marker' scouts are to be extremely lightweight, cheap, fast, and capable of flight.  

These scouts are not designed to live for extended periods of time; but rather, die for the greater good of the hive.

'Marker' scouts should contain a gland that constantly produces an inert, but highly concentrated, and easily trackable pheromone only detectable by the hive.

Upon seeing its target, a 'marker' scout should have a secondary gland that then activates the tracking pheromone, as the primary gland is sent into overdrive.  Scout is then to throw its body onto its target, causing its carapace to rupture violently; leaving said target relatively unharmed, but a walking beacon for the hive to follow.

A large swarm of marker scouts is to be released to comb to forest-- seeking any wasp activity; aided with knowledge provided by the hive's bee allies.