also: こバエ
noun
small fly; fruit fly; drain fly
Refers to small flies commonly found indoors, such as fruit flies, drain flies, or fungus gnats. Often used in the context of household pests.
See also: 蠅
台所にコバエが発生した。
Small flies have appeared in the kitchen.
生ゴミからコバエがわいた。
Small flies bred from the garbage.
ハエ is the general term for 'fly', while コバエ specifically refers to small flies like fruit flies.
Compound of 小 (ko, 'small') and 蠅 (hae, 'fly'). The reading こばえ is a rendaku form of こはえ.