The bees, it turns out, really don't know much about own old enemy. They do know wasps are hiveminded and live in nests, sometimes building said nests up in trees or high places but sometimes even in the ground. The wasps tend to attack suddenly and in great swarms; they work together to take down larger prey, and only rarely go hunting for smaller things alone. So if a lone wasp is ever spotted, it's probably just trying to scout, but that's perhaps even more dangerous, for the wasps adore honey and will apparently massacre an entire hive just to steal its honey and sometimes even eat the larvae.
Beyond that, the bees claim that they wouldn't know anything about the loathsome wasps. They've never made any efforts to launch an offensive against the wasps, viewing it as utterly futile given that the giant wasps are easily capable of killing a dozen bees each. The wasps hunt other insects and will gladly wage war to feast upon the fallen, but for the bees, fighting the wasps can offer no benefit and risk only utter ruin. Whenever they see a lone wasp scout, they do everything in their power to kill and silence it lest its nest learn of their presence and launch a raid.
But if the bees should ever fail to spot and kill a wasp scout, and sometimes if they even so much as suspect that there might be wasps nearby, they take the precaution of abandoning their hive and fleeing elsewhere. They note that sometimes certain birds prey upon the wasps and help to cull their numbers, but at the same time those birds will readily eat bees, so they have never been able to successfully pursue any sort of alliance with the wasps' enemies. But if we would be able and willing to kill off the wasps, the bee queen nearest to us ensures that it would gain us the gratitude of just about every bee colony in the land.
Regarding our search efforts in the far end of the forest, we began to redouble our efforts by sending groups of scouts, some of which developed more advanced tracking pheromones. We sent a few larger groups into the areas where we seemed to have had the most scouts go missing, and we quickly discovered the culprit--more beetles! We accidentally discovered a small group of them trying to head west and leave the forest, and they attacked upon sight. Fortunately a few scouts from that group managed to successfully flee and live to tell the tale.
We don't know whether this means that there's an entire second nest of them that's been hiding out here, or if these are just the exiled remnants of the nest we conquered. Either way, in a fashion similar to how the bees did everything they could to ensure that one wasp scout never returned to its hive, these beetles seem to have been trying very hard to hide from our scouts and kill any that witnessed them or discovered signs of their presence. Unfortunately, that very strategy is what drew our attention to them. The governor in charge of the fallen log and its fungi farms (who has continued working on the beetle breeding program, to some limited success) is naturally an eager proponent of subduing this group of beetles as well, but if that is the path that we choose, we'd best hurry because it seems that at least some of the beetles are fleeing the deep parts of the forest to get even farther away from us.
Coating the entire bottom of the sandpit in a woody mesh is going to take a fairly large investment in time and resources. Several hundred worker drones have been devoted to the task, but because we're confident that the new floor will be able to retain water, we've started simultaneously digging a small channel to the nearby riverbank. Rather than relying on infrequent rains to keep the pond full, the hope is to have a small waterway with a removable floodgate (though rather than one solid, cohesive gate it's probably going to end up being more like a pile of rubble that acts as a dam; but that's no matter, we have the manpower to dismantle and replace the dam as necessary) so that we can empty or fill the pond whenever needed. Assuming no delays, the construction will hopefully be done in the near future.