Hard to miss achievement, mission 8

[Æðelræd of Beamfleote]

Has anyone else had trouble getting any hornet tankers to spawn? Not one has spawned no matter how long I sit on the final hive

[MeToLee]

Just get near the final hive with your troops. they will be all over you.

[Lotor13]

hornet tankers (1 or2) spawn in in final assault, after You clean 4 hives arround main square (2nd part of mission), before You are able to attack final hive

So You need to be ready - to have helicopter with elite ability

[Darth Glorious]

You have to farm it before destroy the last outside nest because if you unlocked the Ravagers, hornet tankers won't spawn anymore...

[Anvil]

I recommend getting this achievement on "Easy" difficulty.

Even after spawning the Ravagers, it's still possible to get the achievement.

Build up your forces to the point where you can cover all the bug spawns and keep them suppressed.

SAVE YOUR GAME OFTEN - you can get easily wiped on this map.

Then engage the final hive - when you get it down to 0 - do not clear it. Have your tier 3 Pegasus at a safe distance and ready nearby. When the central hive recovers it will spawn a Hornet tanker. Use your ground forces to focus fire on the hornets, and have your heavy units drop the HP of the tanker. When the HP of the tanker is ~50% or less, have ground units hold their fire and launch the Executioner missile - you'll get the achievement.

You can then go for the other achievement as well since you've suppressed the bugs enough to give you time to build the three missile batteries.

Hope this helps.