Something that helped me finally get it was to build nest in only one direction out from the queen. (right, that is) The Mole Crickets will only spawn on your nest tiles, so this keeps them from reaching the queen from a direction your warriors are cut off from.
It also helps to have wider pathways, say 3-4 tiles instead of only 1. Without upgrading, there is no need for walled off brood chambers. This obviously helps with getting a good surround. Fighting a swarm of crickets in a 1 tile hallway is a hopeless battle... It seems crickets can stack in a single tile almost as much as ants can. 5-6 crickets vs 5-6 ants at a time equals a lot of lost food, and if your workers can't get past them, that might mean no reinforcments.
And finally for the last battle, you can clear out a large area just below the room with the 6 adults. Had group 1 out of sight to the left, group 2 out of sight to the right, and group 3 far to the south. After the beetles killed my diggers and leave their chamber, I swarm them from all sides.