This is The Younger Gods, book four of David Edding's Dreamers series.
The insects are a hive species and the queen is called Mother in the book. It opens with Mother musing about humans:
And so it was that Mother began to alter the children which would go forth from the nest to search for things-to-eat in the lands beyond the high hills. And many were her alterations, for the man-things that dwelt in the lands beyond the high hills were very clever and they used weapons that were not parts of their bodies.
And this gave Mother great concern, for it is most unnatural for any creature to take up things that are not parts of their bodies to use as weapons. Then it came to Mother that if the man-things could do this, could not her children do so as well? She sent forth more of the seekers of knowledge to find creatures who had unusual parts of their bodies that gave them advantages in the search for things-to-eat.
The bit with the insect using two bows is in chapter two of the part The Last Generation:
"They want—and need—to see everything, Rabbit." Then Keselo gasped. "What is that thing?" he exclaimed.
Rabbit stared at the creature Keselo had just pointed out. "She actually tried to imitate Longbow!" he exclaimed.
"It looks that way to me too," Keselo agreed, "but it has six limbs instead of only four, and it's carrying two bows instead of only one."
"Now this I want to see," Rabbit declared. "If that thing shoots two arrows at the same time, it can kill more of its enemies than any other bug thing could ever manage."
Keselo and Rabbit watched closely, and sure enough, the archer bug was killing two lion-bugs—or beetle-bugs—at the same time. The dead bugs with arrows in them began to pile up.