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.

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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

Apple Maggot.—It is fortunate that the apple maggot, often called the railroad worm because of its winding tunnels all through the fruit, is not as serious a pest as the codling moth for it is much more difficult to control with a poison.

From Project Gutenberg