noun
Hexacentrus japonicus; Hexacentrus unicolor (katydid species)
Rare term for a type of katydid; the more common name is 馬追い (うまおい). The kanji 虫 is added to specify the insect.
See also: 馬追い
馬追虫は、馬追いとも呼ばれるキリギリスの仲間だ。
The uma-oimushi, also called uma-oi, is a kind of katydid.
More common name for the same insect; 馬追虫 is a rare variant with the explicit insect kanji.
Compound of 馬追い (uma-oi, 'horse chaser', from the insect's song resembling a horse driver's call) and 虫 (mushi, 'insect'). The exact derivation is uncertain.