also: こなが
noun
diamondback moth; cabbage moth
A small moth whose larvae are a major pest of cruciferous vegetables.
コナガはキャベツの大敵だ。
The diamondback moth is a major enemy of cabbages.
農家はコナガの防除に苦労している。
Farmers are struggling to control diamondback moths.
The origin is uncertain. The kanji 小菜蛾 literally means 'small vegetable moth'.