water bug

US /ˈwɑː.t̬ɚ ˌbʌɡ/
UK /ˈwɑː.t̬ɚ ˌbʌɡ/
"water bug" picture
1.

percevejo d'água, inseto aquático

any of various insects that live in or on water, especially a large aquatic bug (family Belostomatidae) that can inflict a painful bite

:
I saw a large water bug swimming in the pond.
Eu vi um grande percevejo d'água nadando no lago.
Some people confuse cockroaches with water bugs.
Algumas pessoas confundem baratas com percevejos d'água.