2 adjectives to describe larvae

And with a qualm of horror the boy saw that, attached to Mr. Carrington's cheek, to his bare arm, and to his thigh, and lashing furiously with their lithe brown muscular bodies, were three of these horrible larvae, their great jaws buried deep in his flesh and sucking for dear life.

He examines fences, the under part of the eaves of houses, and the woodpile, and destroys, in the course of his foraging, many an embryo moth and butterfly which would otherwise become the parent of noxious larvae.

2 adjectives to describe  larvae