Walnut Husk Fly Rhagoletis suavis Loew  


The Walnut Husk Flyt is found throughout the eastern North America.


The Walnut Husk Fly breeds and lay eggs in the husks of nearly mature walnut fruits in early autumn. The larvae burrow into and feed on the husk, producing black, slimy husks that stain and stick to the shell. The maggots can sometimes be seen crawling in the husks.

Husk maggots and husk flies do not penetrate into the nut, so the taste and color of the nutmeat are not affected. However, the slimy nature of the husks reduces their value to commercial nutmeat producers because the husk is difficult to remove. The infested husks also make the nuts unattractive and undesirable to the private walnut grower (USDA Forest Service General Technical Report NC-57).


The Walnut Husk Fly feeds on the fruit of Black Walnut.

There are 5 records in the project database.

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A female Walnut Husk Fly in Montgomery Co., Maryland (9/3/2018). Photo by Steve Scholnick. (MBP list)

A Walnut Husk Fly in Frederick Co., Maryland (9/9/2016). Photo by Mark Etheridge. (MBP list)

A Walnut Husk Fly in Harford Co., Maryland (10/7/2016). Photo by Dave Webb. (MBP list)

A Walnut Husk Fly in Baltimore Co., Maryland (7/24/2017). Determined by V. Belov/BugGuide. Photo by Emily Stanley. (MBP list)

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