March flies in May

Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.    

Bibio species (Diptera: Bibionidae)

March flies get their name from the frequent occurrence of the adult flies in southern states during the month of March. They are commonly found on Christmas trees, often in large numbers, in the spring and summer. The larvae or maggots are usually found in enriched organic soils feeding on decaying organic matter. Neither the flies or maggots are known to bite, but a few species of root feeders have been reported to cause economic damage in sod farms. The maggots should not be a problem in Christmas trees and probably are beneficial in that they help breakdown organic matter. Controlling March flies with insecticides is not necessary.

Close up of March flies on Black Hill spruce
Photo 1. Close up of March flies on a Black
Hill spruce.

March flies on Scotch pine candles
Photo 2. March flies on Scotch pine candles.

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