Eastern Hammertail

Efferia aestuans (Linnaeus, 1763)

An Eastern Hammertail in Montgomery Co., Maryland (07/21/2017). (Photo ID: 130168 - Psn: 10)

An Eastern Hammertail in Montgomery Co., Maryland (07/21/2017).

View Record Details Photo by Steve Scholnick MBP List

A male Eastern Hammertail near Loch Raven Reservoir, Baltimore Co., Maryland (8/28/2007). (Photo ID: 1611 - Psn: 14)

A male Eastern Hammertail near Loch Raven Reservoir, Baltimore Co., Maryland (8/28/2007).

View Record Details Photo by Steve Collins MBP List

A female Eastern Hammertail in Baltimore City, Maryland (6/6/2007). Determined by Herschel Raney/BugGuide. (Photo ID: 46075 - Psn: 15)

A female Eastern Hammertail in Baltimore City, Maryland (6/6/2007). Determined by Herschel Raney/BugGuide.

View Record Details Photo by Thomas Wilson MBP List

An Eastern Hammertail in Harford Co., Maryland (8/16/2013). (Photo ID: 17756 - Psn: 20)

An Eastern Hammertail in Harford Co., Maryland (8/16/2013).

View Record Details Photo by Mark Johnson MBP List

A male Eastern Hammertail in Caroline Co., Maryland (7/15/2020). Determined by Chris Cohen and Ken Wolgemuth/BugGuide. (Photo ID: 324732 - Psn: 20)

A male Eastern Hammertail in Caroline Co., Maryland (7/15/2020). Determined by Chris Cohen and Ken Wolgemuth/BugGuide.

View Record Details Photo by Dave Webb MBP List

An Eastern Hammertail in Montgomery Co., Maryland (8/28/2017). (Photo ID: 130275 - Psn: 45)

An Eastern Hammertail in Montgomery Co., Maryland (8/28/2017).

View Record Details Photo by Steve Scholnick MBP List

An Eastern Hammertail in Baltimore Co., Maryland (8/1/2020). (c) Frode Jacobsen, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 346733 - Psn: 45)

An Eastern Hammertail in Baltimore Co., Maryland (8/1/2020). (c) Frode Jacobsen, some rights reserved (CC BY-NC).

View Record Details Photo by Frode Jacobsen MBP List

A female Eastern Hammertail in Dorchester Co., Maryland (9/1/2017). Determined by Bob Biagi/BugGuide. (Photo ID: 88047 - Psn: 55)

A female Eastern Hammertail in Dorchester Co., Maryland (9/1/2017). Determined by Bob Biagi/BugGuide.

View Record Details Photo by Mark Etheridge MBP List

An Eastern Hammertail in Baltimore Co., Maryland (7/1/2020). (c) Frode Jacobsen, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 344284 - Psn: 55)

An Eastern Hammertail in Baltimore Co., Maryland (7/1/2020). (c) Frode Jacobsen, some rights reserved (CC BY-NC).

View Record Details Photo by Frode Jacobsen MBP List

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). (Photo ID: 16367 - Psn: 62)

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014).

Photo by Bill Hubick MBP List

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). (Photo ID: 16368 - Psn: 64)

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014).

View Record Details Photo by Bill Hubick MBP List

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). Determined by Steve Collins. (Photo ID: 16366 - Psn: 65)

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). Determined by Steve Collins.

Photo by Bill Hubick MBP List

An Eastern Hammertail in Baltimore Co., Maryland (8/17/2020). (c) Frode Jacobsen, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 350832 - Psn: 65)

An Eastern Hammertail in Baltimore Co., Maryland (8/17/2020). (c) Frode Jacobsen, some rights reserved (CC BY-NC).

View Record Details Photo by Frode Jacobsen MBP List

An Eastern Hammertail in Howard Co., Maryland (9/12/2014). (Photo ID: 17378 - Psn: 71)

An Eastern Hammertail in Howard Co., Maryland (9/12/2014).

View Record Details Photo by Kurt Schwarz MBP List

An Eastern Hammertail feeding on prey in Harford Co., Maryland (7/28/2010). (Photo ID: 46076 - Psn: 72)

An Eastern Hammertail feeding on prey in Harford Co., Maryland (7/28/2010).

View Record Details Photo by Bill Adams MBP List

A female Eastern Hammertail with prey in Baltimore City, Maryland (9/10/2008). Determined by Herschel Raney/BugGuide who notes, <em>E. aestuans</em>

A female Eastern Hammertail with prey in Baltimore City, Maryland (9/10/2008). Determined by Herschel Raney/BugGuide who notes, E. aestuans "love cloth and pants and shirts."

View Record Details Photo by Thomas Wilson MBP List

An Eastern Hammertail in Howard Co., Maryland (9/12/2014). (Photo ID: 17379 - Psn: 75)

An Eastern Hammertail in Howard Co., Maryland (9/12/2014).

View Record Details Photo by Kurt Schwarz MBP List

An Eastern Hammertail in Montgomery Co., Maryland (7/11/2017). Determined by Ben Coulter. (Photo ID: 98414 - Psn: 75)

An Eastern Hammertail in Montgomery Co., Maryland (7/11/2017). Determined by Ben Coulter.

View Record Details Photo by Esther Smith MBP List

A female Eastern Hammertail in Dorchester Co., Maryland (8/8/2019). Determined b Bob Biagi/BugGuide. (Photo ID: 148115 - Psn: 75)

A female Eastern Hammertail in Dorchester Co., Maryland (8/8/2019). Determined b Bob Biagi/BugGuide.

View Record Details Photo by Mark Etheridge MBP List

Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). (c) Bill Hubick, all rights reserved (Photo ID: 1487413 - Psn: 78)

Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). (c) Bill Hubick, all rights reserved

View Record Details Photo by Bill Hubick MBP List

Eastern Hammertail with Diptera prey in Anne Arundel Co., Maryland (8/26/2017). (c) Bill Hubick, all rights reserved. (Photo ID: 1172985 - Psn: 90)

Eastern Hammertail with Diptera prey in Anne Arundel Co., Maryland (8/26/2017). (c) Bill Hubick, all rights reserved.

View Record Details Photo by Bill Hubick MBP List

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 1332439 - Psn: 143)

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC).

View Record Details Photo by Pamela Cowart-Rickman MBP List

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 1332438 - Psn: 144)

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC).

View Record Details Photo by Pamela Cowart-Rickman MBP List

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 1332440 - Psn: 146)

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC).

View Record Details Photo by Pamela Cowart-Rickman MBP List

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 1332445 - Psn: 166)

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC).

View Record Details Photo by Pamela Cowart-Rickman MBP List

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (<a rel='license' href='http://creativecommons.org/licenses/by-nc/4.0/'>CC BY-NC</a>). (Photo ID: 1332444 - Psn: 178)

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC).

View Record Details Photo by Pamela Cowart-Rickman MBP List

Map Snapshot

41 Records

GA AL WA FR CL MO HO BA BC HA CE PG AA CV CH SM KE QA CN TA DO WI SO WO

Status

Can be very common in open habitats. This species lands on whatever surface is convenient, and may even land on observers. The genus Efferia s.l. is quite speciose, and some dipterists split it up into a number of smaller genera. Following that classification, this species would be placed in Nerax.

Description

Female has long, distinctive ovipositor.

Seasonality Summary

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Resources

View at iNaturalist Search Google Images Search MBP Facebook posts

View images at BugGuide

Citations

No citations linked for this taxon yet.

Use of media featured on Maryland Biodiversity Project is only permitted with express permission of the photographer.

An Eastern Hammertail in Montgomery Co., Maryland (07/21/2017). View Record Details Media by Steve Scholnick.

A male Eastern Hammertail near Loch Raven Reservoir, Baltimore Co., Maryland (8/28/2007). View Record Details Media by Steve Collins.

A female Eastern Hammertail in Baltimore City, Maryland (6/6/2007). Determined by Herschel Raney/BugGuide. View Record Details Media by Thomas Wilson.

An Eastern Hammertail in Harford Co., Maryland (8/16/2013). View Record Details Media by Mark Johnson.

A male Eastern Hammertail in Caroline Co., Maryland (7/15/2020). Determined by Chris Cohen and Ken Wolgemuth/BugGuide. View Record Details Media by Dave Webb.

An Eastern Hammertail in Montgomery Co., Maryland (8/28/2017). View Record Details Media by Steve Scholnick.

An Eastern Hammertail in Baltimore Co., Maryland (8/1/2020). (c) Frode Jacobsen, some rights reserved (CC BY-NC). View Record Details Media by Frode Jacobsen.

A female Eastern Hammertail in Dorchester Co., Maryland (9/1/2017). Determined by Bob Biagi/BugGuide. View Record Details Media by Mark Etheridge.

An Eastern Hammertail in Baltimore Co., Maryland (7/1/2020). (c) Frode Jacobsen, some rights reserved (CC BY-NC). View Record Details Media by Frode Jacobsen.

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). Media by Bill Hubick.

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). View Record Details Media by Bill Hubick.

A female Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). Determined by Steve Collins. Media by Bill Hubick.

An Eastern Hammertail in Baltimore Co., Maryland (8/17/2020). (c) Frode Jacobsen, some rights reserved (CC BY-NC). View Record Details Media by Frode Jacobsen.

An Eastern Hammertail in Howard Co., Maryland (9/12/2014). View Record Details Media by Kurt Schwarz.

An Eastern Hammertail feeding on prey in Harford Co., Maryland (7/28/2010). View Record Details Media by Bill Adams.

A female Eastern Hammertail with prey in Baltimore City, Maryland (9/10/2008). Determined by Herschel Raney/BugGuide who notes, E. aestuans "love cloth and pants and shirts." View Record Details Media by Thomas Wilson.

An Eastern Hammertail in Howard Co., Maryland (9/12/2014). View Record Details Media by Kurt Schwarz.

An Eastern Hammertail in Montgomery Co., Maryland (7/11/2017). Determined by Ben Coulter. View Record Details Media by Esther Smith.

A female Eastern Hammertail in Dorchester Co., Maryland (8/8/2019). Determined b Bob Biagi/BugGuide. View Record Details Media by Mark Etheridge.

Eastern Hammertail in Anne Arundel Co., Maryland (9/11/2014). (c) Bill Hubick, all rights reserved View Record Details Media by Bill Hubick.

Eastern Hammertail with Diptera prey in Anne Arundel Co., Maryland (8/26/2017). (c) Bill Hubick, all rights reserved. View Record Details Media by Bill Hubick.

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC). View Record Details Media by Pamela Cowart-Rickman.

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC). View Record Details Media by Pamela Cowart-Rickman.

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC). View Record Details Media by Pamela Cowart-Rickman.

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC). View Record Details Media by Pamela Cowart-Rickman.

Eastern Hammertail in Kent Co., Maryland (8/13/2025). (c) pcowartrickmanphoto, some rights reserved (CC BY-NC). View Record Details Media by Pamela Cowart-Rickman.

Source: Wikipedia

Wikipedia content unavailable for this taxon.