Butterfly Records for Maryland, Delaware, and the District of Columbia
The assembled lists and charts available from this link present all substantiated historical records of butterfly species ever to have been recorded, collected, or observed within the states of Maryland and Delaware as a whole and within their various counties and the District of Columbia and Baltimore City. To access the main pages for Maryland, Delaware, or D.C., click on the desired link under the category “Local and Regional Lists and Info” in the right-hand panel of this page. You will see that each destination page contains conveniently printable lists divided by county (where applicable) and also cumulative state and city lists for the above jurisdictions. Also available on both the Maryland and Delaware pages will be conveniently printable “Occurrence Charts” that indicate a current record presence or absence within each of the counties of these states (and Baltimore City and District of Columbia) for all state-recorded butterfly species. Within all charts, you will see either a check mark (✔) or occasionally the symbols A, S, and X. Within the butterfly lists, only the occasional symbols are given. The check mark indicates that a record already exists for a species. The latter three symbols indicate, respectively, that there is a past species record, but the record is due either to an Accidental occurrence, a Stray, or that the species is considered to be eXtirpated now in the specified jurisdiction. These indicators are described in more detail in the section below entitled “Accidental, Stray, and Extirpated Species.” Separately available as described in more detail in the section below entitled “Species Occurrence Levels and State Range” will be a printable table that gives biological information including occurrence level, flight period, general habitat, plants typically visited by adults, larval hostplants, and state range for each Maryland butterfly species. Please also access and read the discussion under the right panel link entitled “Butterflies of Unknown Status in MD, DE, and DC” where a separate listing and butterfly occurrence research project is described. Everyone with a field interest in current jurisdictional butterfly occurrences can contribute to this project. Records in all lists and charts are based on material appearing either in available published Lepidoptera literature or otherwise known to the author Richard H. Smith, Jr. from his field work and numerous lepidopterist contacts. Major references for all of the included records are listed at the end of this page. The data timespan of the references for the majority of the material covers the period from the early twentieth century up to the present.
Mr. Smith has maintained such lists for several years as coordinator of butterfly species records for Maryland, Delaware, and the District of Columbia for the former USGS NPWRC website “Butterflies of North America” and for the current successor website “Butterflies and Moths of North America.” The butterfly lists on this website and on BAMONA will be updated by late January each year and so will represent the latest and most complete listings of all butterfly species ever reported and substantiated in each of the above jurisdictions. We will attempt to maintain consistency between butterfly records on this local website and on the BAMONA website.
Note that by definition of the listing process here and on BAMONA, if a species does not appear under a particular county or city, the reason for its absence is merely that no one has yet reported it for that particular jurisdiction. There is no reason to conclude that the absence of a record implies that a species does not occur naturally in a particular jurisdiction; however, absences from entire regions, such as from the Allegheny Plateau or Lower Coastal Plain regions of Maryland, would more strongly support such a conclusion.
Several of the files for the records are in PDF format; if you don’t have Adobe Acrobat, download the free Adobe Reader.
Accidental, Stray, and Extirpated Species
Based on the known typical geographic ranges and habitat areas for the species recorded under each of the jurisdictional lists presented via the links above, we must conclude that certain of these records represent occurrences that are the result of either unusual strays or accidental introductions. Also, it has become apparent from field work and from butterfly enthusiasts’ observations over the past 15 years that several of the species have been extirpated from a number of the jurisdictions for which we have past records. Some of the extirpations are even statewide and appear to be relatively recent. Most of these disappearances, we suspect, are due to human induced habitat loss or adverse habitat alteration. Other suspected reasons include wider use of powerful modern pesticides, alien insect predators and parasitoids, effects of invasive alien plants, effects of browse of over-abundant deer on native larval hostplants and adult nectar sources, and inability of a species to adapt to minor shifts in seasonal temperature and drought extremes and vegetative profiles caused by global climate change. In consideration of these species occurrence aspects, selected species records within each of the lists and charts above are assigned the symbols A, S, or X, to indicate that the species record is due, respectively, to either an Accidental occurrence, a Stray, or that the species is considered to be eXtirpated now in the specified jurisdication. Detailed definitions of these indicators are given below.
Accidental (A) – indicates a species not known to stray widely and whose natural range and habitat are considerably outside of the jurisdiction of record; thus, the record is probably due to an accidental introduction or to an escape from an enclosed local live display.
Stray (S) – indicates a species that is not resident nor known to migrate or immigrate regularly into the jurisdiction of record, but which is known to exhibit occasional isolated occurrences considerably outside of its normal range, including at least one occurrence in the jurisdiction of record.
Extirpated (X) – indicates a species that was once resident in the jurisdiction of record, but no new reports have been logged for it in the jurisdiction of record within at least the past 15 years.
Species Occurrence Levels and State Range
Lynn Davidson of the Maryland Department of Natural Resources Wildlife & Heritage Division and Mr. Smith have composed, and Mr. Smith has recently updated (in 2013), the Maryland Butterflies Biological Summary and Checklist which contains information on occurrence level, flight period, general habitat, nutrition sources visited by adults, larval host plants, and state range for each of the 158 species and subspecies ever recorded in Maryland. The Occurrence Level (OL) column in the checklist specifies the current assessment of the rarity and occurrence status of each species. The State Range column indicates the current distribution in Maryland and cites the historical distribution and stray status of each species in each of the primary Maryland geographic regions. This list may be accessed at the link below. The list may be printed as four sides of 11″ x 8-1/2″ sheets in landscape format for personal use.
Reporting Record Sightings
Interested lepidopterists, butterfliers, and collectors are invited to inquire about currently listed records and to contribute records that appear to be new for any of the above jurisdictions. Potential new records should be submitted by e-mail to Richard H. Smith at Richard.Smith@jhuapl.edu. The reporter should be able to qualify his or her records by at least a photograph or a very thorough explanation depicting the specimen’s distinguishing characteristics for identification. In the case of record submissions for small hairstreaks and skippers, usually only a clear photograph will qualify for indisputable proof of identification. Field data should also be included and should consist at least of specific locality (details at the discretion of the reporter), exact date seen, and any associated nectar plants, larval hosts, and habitat or butterfly activity information of note.
Butterfly List References
Opler, Paul A. 1983 (April). County Atlas of Eastern United States Butterflies (1840-1982). Office of Endangered Species, U.S. Fish and Wildlife Service, Washington, DC 20240.
Lepidopterists’ Society Season Summaries for years 1959 to present (published annually by The Lepidopterists’ Society, Los Angeles County Museum of Natural History, Los Angeles, CA 90007).
Personal field notes and collection of the author (Richard H. Smith, Jr.) and communications with numerous local amateur and professional lepidopterists I have known from the late 1960’s to the present.
Maryland and District of Columbia
Clark, Austin H. 1932. The butterflies of the District of Columbia and vicinity. U.S. National Museum Bulletin No. 157. 337pp.
Wagner, Warren H., Jr. 1941. District of Columbia butterfly notes (Lepidoptera: Rhopalocera). Entomological News (published by the Academy of Natural Sciences, Phila., PA 19103) 52(7): 196-200 and 52(9): 245-249.
Simmons, Robert S. and Andersen, William A. 1956 to 1984. Notes on Maryland lepidoptera: Contribution #1 in Lepidopterists News (1956) and Contributions #2 (1962), #3 (1963), #5 (1976), and #6 (1979) in Journal of the Lepidopterists’ Society (both published by The Lepidopterists’ Society, Los Angeles County Museum of Natural History, Los Angeles, CA 90007). Contributions #4 (1970(71)), #7 (1978(80)), #8 (1978(80)), #9 (1978(80)), #10 (1981(83)), and #11 (1984) in Journal of Research on the Lepidoptera (published by the Lepidoptera Research Foundation, Inc., Beverly Hills, CA 90210).
Fales, John H. 1974 (December). Check-list of the skippers and butterflies of Maryland. Chesapeake Science (continued as journal Estuaries starting in 1978; published by the Estuarine Research Federation, University of Mississippi, University MS 38677) 15(4): 222-229.
Opler, Paul A. 1982 (February). Butterflies and skippers of the Washington, D.C. area (District of Columbia, Montgomery Co., and Prince Georges Co., Maryland, Alexandria Co., Arlington Co., and Fairfax Co., Virginia). Office of Endangered Species, U.S. Fish and Wildlife Service, Washington, DC 20240.
Fales, John H. 1987(March). The butterflies of Rock Creek Park, Washington, D.C. The Maryland Naturalist (published by the Natural History Society of Maryland, Baltimore, MD 21218) 31(1): 5-24.
Notes from the Frank Morton Jones collection (late 1890’s through 1930’s) at the Yale Peabody Museum, New Haven, CT, accumulated by Dr. David M. Wright from Lansdale, PA in winter 1985-86.
Notes from the Frank Morton Jones collection (late 1890’s through 1940’s) and other specimens (1950’s to 1980’s) at the University of Delaware collection, Dept. of Entomology, Newark, DE 19717, accumulated by Dr. David M. Wright from Lansdale, PA in winter 1985-86.
Shapiro, Arthur M. 1966. Butterflies of the Delaware Valley. Special Publication of the American Entomological Society, 1900 Benjamin Franklin Pkwy., Philadelphia, PA 19103. (lithoprinted in the USA by Cushing-Malloy, Inc., Ann Arbor, MI 1966). 79pp.
Woodbury, Elton N. 1994. Butterflies of Delmarva. Delaware Nature Society, Inc. and Tidewater Publishers, Centreville, MD 21617. 138pp.