New Jersey Butterflies

Explanation of Species Accounts

Summary List of County Records

Recent Unusual Occurrences

All locations given are counties.

* These species are also represented by pre-2015 records.

Natural Strays—species out of range in NJ that are represented by only one or very few observations, photographs, or specimens, dating to 2015 or later, and that probably reached NJ naturally.

• Zebra Swallowtail (Essex, 2000, photographed; Sussex, 7/2/04, sighting; Monmouth, 9/26/06, sighting; Monmouth 7/3/12, photographed; Cape May, 7/28/14 & 6/26/18, photographed & 5/24/19, sighting; Essex 8/19/15, sighting; Salem, 8/22/20, photographed) *
• Large Orange Sulphur (Cape May, 9/28/22, photographed)
• Dainty Sulphur (Cape May, 9/28/07, photographed, 1st state record; Warren, 8/13/12, photographed; Bergen, 7/25/23, photographed) *
• Great Purple Hairstreak (Cape May, 6/15/17, photographed)
• Gulf Fritillary (Cape May, 7/17-8/10/02 [multiple sightings of same individual], 7/13/08, 8/16/11, 9/24/11; Ocean, 8/13/11, photographed; Morris, 10/17/19, photographed) *
• Southern Broken-Dash (Cape May, 7/20/22, photographed)
• Eufala Skipper (Cape May, 11/18/21, photographed) *
• Brazilian Skipper (Cape May, 8/28/10, 9/19/12-10/7/12, 7/15/14-7/16/14, 8/14/17-11/5/17 and many observations from various locations within the county 2018 thru 2021; Cumberland, 7/7/18, photographed; Essex, 7/26/18, photographed; Salem, 8/25/18, photographed; Middlesex, 8/30/18, photographed; Atlantic, 9/3/20, photographed) *

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Non-natural Occurrences—species well out of range that probably arrived in NJ as intentional releases or horticultural stowaways, dating to 2015 or later.

• European Peacock (Gloucester, 8/3-5/14, photographed; Union, 3/3/24, photographed.) Probable stowaway or possible migrant from apparent naturalized Canadian colony. *
• Queen (Mercer, 7/17/01, photographed; Essex, 06/03, sighting; Monmouth, 7/20/03, sighting; Cape May, 10/5/08, photographed; Bergen, 9/2/18, photographed.) These are all likely releases. *

Historical Occurrences

The Historical Occurrences list includes species reported as having occurred in New Jersey prior to 2015, but whose presence has not been confirmed since. The list below is based mainly on information in Iftner and Wright 1996 (I&W) and Gochfeld and Burger 1997 (G&B) as well as more recent observations from credible observers—see Bibliography - Butterfly Identification & Distribution for full citations. All locations given are counties.

Former Residents—species for which the existence of a former population in NJ is well known to current observers or documented by numerous historical records.

• West Virginia White (I&W: specimens Passaic, Warren, Morris; lit. records Union, Sussex)
• Acadian Hairstreak (Not seen in New Jersey since a single sighting in Sussex 2012.)
• Silver-bordered Fritillary (Not seen in New Jersey since the early 2000's.)
• Regal Fritillary (I&W: specimens Bergen, Passaic, Sussex, Warren, Morris, Essex, Union, Hunterdon, Middlesex; lit. records from 7 additional counties.)
• Harris’ Checkerspot (I&W: specimens Bergen, Passaic, Sussex, Warren, Morris, Union, Somerset, Hunterdon. The most-recent reports were sightings from Sussex and Morris 1994, and a different location in Morris 1996, photographed. Unconfirmed single-observer sightings Morris 2000 and 2003.)
• Silvery Checkerspot (I&W: specimens Bergen, Passaic, Sussex, Warren, Morris, Essex, Union. B&G: specimens from Gloucester and Mt. Holly. Unconfirmed single-observer sighting Sussex 2006.)
• Mitchell’s Satyr (I&W: specimens Sussex, Warren, Morris. Last reported in Sussex 1985.)
• Mottled Duskywing (I&W: specimens Bergen, Passaic, Sussex, Morris, Essex, Hudson, Union, Hunterdon, Gloucester; lit. records from 4 other counties.)
• Arctic Skipper (Last reported from Sussex in 2005.)
• Appalachian Grizzled Skipper (I&W: specimens Bergen, Passaic, Sussex, Warren, Morris, Essex, Union.)

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Natural Strays—species well out of range in NJ that are represented by only one or very few observations or specimens, dating to before 2015.

• Canadian Tiger Swallowtail (Sussex, 6/9/01, photographed, 1st state record)
• Palamedes Swallowtail (Cape May, 9/12/08, 7/28/13)*
• Mustard White (I&W: specimen Sussex, 7/8/66)
• Silvery Blue (Sussex, 5/28/11, photographed, 1st state record)
• Atlantis Fritillary (I&W: specimens Warren, Middlesex. G&B: two 1978 Morris specimens from one locality)
• Green Comma (I&W: specimen Sussex)
• White Peacock (G&B: sighting Cumberland 1988)
• Whirlabout (I&W: specimens Middlesex, Cape May; lit. records Camden, Atlantic, Salem)

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Non-natural Occurrences—species well out of range that probably arrived in NJ as intentional releases or horticultural stowaways, dating to between 2000 and 2014.

• Soldier (Atlantic, 10/6/02, sighting.) A likely release.
• Mimic (Cape May, 9/4/02, photographed. Photo published in Winter 2002 American Butterflies.) A likely release.
• Monk Skipper (Monmouth, 9/18/05, photographed.) A likely agricultural stowaway.

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Former Status Uncertain—species for which too few NJ records exist to determine whether they represented a true population; species for which identification problems make interpretation of historical records extremely difficult; and species suspected to have been introduced.

• Acmon Blue (I&W: specimen Camden, but apparently [G&B] from a population strongly suspected to have been introduced.)
• Northern Crescent (G&B: “…only recognized as a distinct species [from Pearl Crescent] in 1980, hence its historical status cannot be determined.” “Cannot reliably be identified by sight.”)
• Tawny Crescent (I&W: lit. records Camden, Atlantic. B&G: “May have been a rare resident in SW NJ….”)
• Carolina Satyr (I&W: lit. record Burlington. G&B cite Schweitzer as “no twentieth century records.” Also “Status uncertain; either formerly a rare and local resident in southern NJ which is now extirpated, or only a historic stray which may have occasionally bred.”)
• Golden Banded-Skipper (I&W: lit. records Gloucester, Salem, probably the same cited by Shapiro (1966): Salem [1959] and Gloucester [1962]. G&B: “Probably only an accidental visitor, but possibly a rare resident, now extirpated.”)
• Confused Cloudywing (I&W: specimen Burlington; G&B: virtually impossible to separate from Northern/Southern except by genitalic examination of males. “No evidence that it is or was resident in NJ.”)
• Zarucco Duskywing (I&W: lit. records Union, Camden, Salem, Cape May. Similar to Horace’s, Wild Indigo. Only indication of possible residency is Shapiro’s (1966) statement that it was “scarce to occasionally common, Coastal Plain only.”)
• Columbine Duskywing (I&W: specimens Passaic, Sussex, Warren, Morris, Essex, Hunterdon, Middlesex, plus lit. records from Inner Coastal Plain farther south. G&B: Impossible to separate visually from Wild Indigo; usually done by association with hostplant [which can also be used by Wild Indigo].)
• Persius Duskywing (I&W: specimens Passaic, Sussex, Middlesex, Ocean, Gloucester, Salem; lit. records Essex, Union, Camden, Atlantic. G&B consider interpretation of very old records in doubt since the very similar Wild Indigo was not accorded separate species status until 1936. Persius may have formerly been more common and have had “a drastic decline from Massachusetts to New Jersey. It is possible that this is another of the boreal species that has retreated northward.”)

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Literature Record Only—species represented only by records from the literature (reviewed by I&W), with no citations or dates given.

• Southern Dogface (I&W: Essex)
• Orange-barred Sulphur (I&W: Monmouth)
• Early Hairstreak (I&W: Sussex)
• Twin-spot Skipper (I&W: lit. record Camden; G&B: records of 2 specimens taken same day, between 1900 and 1910, Camden. Apparently these specimens were not reviewed by I&W, as they indicate only a literature record from Camden.)

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Record Questionable—species represented by NJ specimen records, but whose occurrence in NJ seems so implausible as to suggest that the information on the specimen label is inaccurate or incomplete.

• ‘Karner’ Melissa Blue (I&W: specimen Sussex, but their inclusion of “NJ” [in quotes] suggests that I&W either questioned whether the specimen is actually from NJ or chose Sussex County as the most likely location for a specimen labeled only “NJ.”)

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