water bug

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

水生昆蟲, 水蟲

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.
我看到一隻大水生昆蟲在池塘裡游泳。
Some people confuse cockroaches with water bugs.
有些人把蟑螂和水生昆蟲混淆。