The ten mosquitoes had been dispersed throughout the area earlier. When Zhou Fei had first appeared, Wang Baole had immediately assessed the considerable disparity in their power. It was possible to kill Zhou Fei, but the probability of that happening was too low.
He had planned accordingly. He would kill the man if possible. If not, he had to at least frighten him off!
It was due to those considerations that he hadn't sent out the mosquitoes and had decided to first use his many Numinous Treasures as a distraction before executing a surprise attack with his Dharmic Armament. He had even uttered the beginning of the scripture inwardly, as both a scare tactic and a means to temporarily augment his abilities and complete the final strike!
At the same time, he had thought of a backup plan in case he had failed, and that was… the mosquitoes!