During the battle on the Nemesis, the armada nearly annihilated Megatron and the entire crew, and would have succeeded if wasn't for Arcee and Team Prime, who defeated Airachnid. After that, Airachnid's remaining forces joined the Decepticon crew for some time time.
Later when Airachnid was freed from her stasis prison, she returned and assembled her army again and tried to take over the Warship. Their attack failed as Soundwave groundbridged them to Cybertrons' moon. Airachnid, now a Vampiric Terrorcon, sucks the energon out of her army one by one as they line up for their turn.