railroad worm

American  

noun

1. the larva of a fruit fly, Rhagoletis pomonella, that burrows through apples, forming tunnels that sometimes appear on the skin as faint depressions or darkened trails: a serious pest of apples in colder regions of North America.

---

Etymology

Origin of railroad worm

First recorded in 1905–10

Example Sentences

Insects typically can’t see red, Marek says, but it’s thought that the railroad worm can.

From National Geographic • Jun. 30, 2018