Their primary staples are other insects and small aquatic vertebrates .
Like other members of the Nepidae , they have a pair of nonretractable cerci - like breathing tubes on the terminal abdominal segment , a characteristic which readily distinguishes them from the Belostomatidae .
members ' primary staples are other insects and small aquatic vertebrates .
Like other members of the Nepidae , they have a pair of nonretractable cerci - like breathing tubes on the terminal abdominal segment , a characteristic which readily distinguishes them from the Belostomatidae .