onion fly
noun
a small grey dipterous insect, Delia antiqua, that is a serious pest of onions. The larvae destroy the bulbs
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Examples from the Web for onion fly
Historical Examples of onion fly
It might be, continued the latter kindly, that youve been bitten by the Diptera onionensis, otherwise known as the onion-fly.
Left Half HarmonRalph Henry Barbour