Plummers Island Research Articles

A Plant-Bee Visitation Network for Plummers Island, MD

Plummers Island is a small island located in the Potomac River in Montgomery Co., MD. Bees have been collected and cataloged from Plummers Island since 1909, but their floral associations have not been thoroughly described. As bees are important pollinators of natural and managed terrestrial ecosystems, monitoring their floral host choices is an important step towards proper land management and conservation practices. We collected bees from flowering plants on and adjacent to Plummers Island over two seasons and characterized their interactions using a bipartite plant-bee visitation network. Seven hundred and forty individual bees visited 30 species of flowering plants currently classified in 17 different genera. The resulting network was characterized by nested, asymmetrical interactions, but did not show strong evidence of either extreme generalization or specialization. The plant with highest interaction frequency score (species strength) was the invasive poison hemlock, Conium maculatum (Apiaceae), while the common sweat bee, Augochlora pura (Halictidae) had the highest interaction strength for the bees. We discuss these results considering species phenology and potential sampling biases and compare them to previous records for the island.

New records of Microlepidoptera (Insecta: Lepidoptera) from Plummers Island, Maryland, U.S.A., with comments on Lepidoptera inventories

The results of over 100 years of inventory work on the Lepidoptera of Plummers Island, Montgomery County, Maryland, U.S.A., were summarized recently in a volume dedicated to the invertebrate fauna of that site. That work documented a cumulative total of 836 species of Lepidoptera. To that list I add 20 species: Niditinea sabroskyi Metz, Davis & Davis, 2018 (Tineidae), Tinea carnariella Clemens, 1859 (Tineidae), Tinea apicimaculella Chambers, 1875 (Tineidae), Elachista illectella (Clemens, 1860) (Elachistidae), Pseudocherlaria walsinghami Dietz, 1900 (Gelechiidae), Coleotechnites thujaella (Kearfott, 1903) (Gelechiidae), Coleotechnites quercivorella (Chambers, 1872) (Gelechiidae), Trypanisma prudens Clemens, 1860 (Gelechiidae), Abrenthia cuprea Busck, 1915 (Glyphipterigidae), Argyresthia oreasella Clemens, 1860 (Argyresthiidae), Aethes terriae Sabourin & Miller, 2002 (Tortricidae), Aethes razowskii Sabourin & Miller, 2002 (Tortricidae), Aethes sexdentata Sabourin & Miller, 2002 (Tortricidae), Aethes mymara Razowski, 1997 (Tortricidae), Aethes promptana (Robinson, 1869), (Tortricidae), Spinipogon resthavenensis Metzler & Sabourin, 2002 (Tortricidae), Clepsis listerana (Kearfott, 1907) (Tortricidae), Gretchena amatana Heinrich, 1923 (Tortricidae), Rhopobota finitimana (Heinrich, 1923) (Tortricidae), and Exelastis pumilio (Zeller, 1873) (Pterophoridae). Ten of the species are represented by historical records that previously were overlooked, the other 10 species have been collected since 1998.

Earthworms (Annelida: Clitellata) of Plummers Island, Maryland, U.S.A., with description of a new species

Abstract The earthworm fauna of Plummers Island, Maryland, U.S.A. was surveyed, recording a total of 12 species belonging to the families Lumbricidae, Acanthodrilidae, Megascolecidae, and Sparganophilidae. In addition to the well known peregrine lumbricids and megascolecids the island harbors four North American endemic species: Eisenoides lonnbergi (Michaelsen, 1894) (Lumbricidae), Sparganophilus tamesis Benham, 1892 (Sparganophilidae), Diplocardia caroliniana Eisen, 1899, and furthermore, a new species, Diplocardia zicsii sp. nov. (Acanthodrilidae).

Diarrhena obovatain the Potomac River Watershed: A New Invader?

Diarrhena obovata (Gleason) Brandenburg is a woodland grass primarily of the central United States in the Mississippi River drainage (Brandenburg et al. 1991). Isolated occurrences of D. obovata in the Appalachian and Piedmont regions of the mid-Atlantic states have been found in the last several decades, and the species is or has been considered to be a rare native species in Pennsylvania (Rhoads and Klein 1993); in West Virginia, Virginia, and New York (NatureServe 2011); and (as Diarrhena americana Beauv.) in Maryland (Maryland Natural Heritage Program 2003). The taxonomic concept of D. obovata was first recognized by Gleason (1952a, 1952b) as Diarrhena americana Beauv. var. obovata Gleason. Brandenburg et al. (1991) elevated var. obovata to species rank by proposing the new combination D. obovata, after discovering consistent morphological differences between D. americana var. americana and var. obovata that corresponded to largely allopatric ranges for the two taxa. Most recent floristic authors (e.g., Barkworth et al. 2007, Brandenburg 2007, Rhoads and Block 2007, Weakley 2011) follow Brandenburg et al. (1991) in recognizing D. obovata as a distinct species. D. americana (in the narrow sense of Brandenburg et al. [1991], and as is used in this paper, unless otherwise noted) occupies mostly the Ohio River basin in the central Appalachians and interior plateaus, with a disjunct distribution in the Ozark region. Although it overlaps the range of D. americana, D. obovata occurs primarily in the central Mississippi and lower Missouri River drainages of the upper midwestern United States (Brandenburg et al. 1991, Barkworth et al. 2007, Brandenberg 2007). The former treatment of D. obovata under D. americana (in the broad sense) occasionally has created ambiguity about which one of the two taxa has been represented when D. americana has been recorded in literature and databases. D. obovata apparently was first reported in Maryland, as D. americana (in the broad sense) without note of variety, by Rodney Bartgis in 1988 (Maryland Natural Heritage Program, unpublished data), several years prior to the recognition of D. obovata as a species by Brandenberg et al. (1991). At the time of Bartgis’ report, Brown and Brown (1984) had listed D. americana as potentially occurring [only] for Maryland. Shortly after this discovery, Bartgis showed me this occurrence along the Potomac River near Plummers Island in Montgomery County. In ensuing years, additional records of Diarrhena, reported as D. americana (in the broad sense), were made from along the Potomac and the Chesapeake and Ohio (CO Wiegand and Becker 1995). In 1995, I reported a colony of D. americana (in the broad sense) from along the CO Accepted March 24, 2012. DOI: 10.2179/11-044

Update and analysis of fish occurrences in the lower Potomac River drainage in the vicinity of Plummers Island, Maryland—Contribution XXXI to the natural history of Plummers Island, Maryland

On a local scale, the biota of the Plummers Island, Maryland, vicinity is among the most intensively studied in the world. The fishes occurring in Potomac River and its tributaries in the vicinity of that island have been subjected to periodic scrutiny since the early 1900s, with the latest thorough analysis published in 2002. Herein, we present an updated and comparative analysis of this fish fauna using data gathered over the past decade. Our findings reveal that the complement of fish species that inhabits the area is particularly dynamic in nature. Compared to data presented in 2002, we report a net increase in the numbers of species (up to 93 species) occurring or formerly occurring near Plummers Island. These changes are the result of the return of several migratory species fostered by improved fish passage on the Potomac River, the return of some native resident fishes, and the establishment of additional nonnative species that now constitute 22–35% of the fauna, balanced against several probable extirpations. Species involved in these changes are treated in detail, and a number of novel records, vouchered and nonvouchered, are discussed. Factors that likely play key and interrelated roles in the dynamic nature of the Plummers Island area fish fauna, including hydrographic context and anthropogenic activities, are revisited and discussed. Particular emphasis is placed on the importance of improved practices in the documentation of local species occurrences in the future.

A Checklist of the Bees (Insecta: Hymenoptera) and Their Floral Hosts at Plummers Island, Maryland

Plummers Island, Maryland has been studied by naturalists for over 100 years. The bees collected on the Island and the immediately adjacent mainland represent six families, 41 genera, and 232 species. About 20% (47 species) are parasitic and do not collect pollen. Most bees are generalist (polylectic) foragers, but there are a few species that appear to visit only a few species or genera of plants (oligolectic foragers). Three exotic species are among the fauna, including the European honey bee (Apis mellifera L.). Based on historical specimens in the collection of the National Museum of Natural History, Smithsonian Institution (USNM), and contemporary survey efforts, the number of bee species on the Island appears to have increased since the 1920s–1960s, and there is no evidence of local species extinction. It is possible that the use of Malaise and pan traps in addition to hand nets have increased collecting efficiency so that the increase in species richness is an artifact of collecting techniques rather than a biological phenomenon. Alternatively, increased species richness may reflect the resiliency of bees and an increase in available nesting sites as heavily shaded forests of the eastern United States have become open through deforestation and urbanization. While the vegetation of the Island has matured through natural succession, the surrounding Washington, D.C. metropolitan area has seen major urban, industrial, and infrastructure development and the resultant opening of forests, increasing bee habitat. Plummers Island is likely a refugium for surrounding bee populations.

Copepod Crustaceans Collected on and Near Plummers Island, Maryland

Copepod (Crustacea) species diversity was remarkably low on Plummers Island, Maryland, and its immediate environs over a year-long sampling period in 1996 and 1997, compared to that previously and contemporaneously reported nearby within the Potomac River Basin; only two species were found on the Island and two others in the adjacent side channel of the Potomac River. Subsequent sampling in 2004 resulted in records of eight species, seven of which were not found in 1997; six of these were collected on the Island. One explanation for the paucity of species in 1996–1997 is the extreme floods of January and September 1996; the January flood reached a height not recorded since 1972 and destroyed canal locks. These floods scoured much of the Potomac floodplain and may have caused severe local population losses. The scarcity of aquatic microhabitats on the Island undoubtedly also contributed to the low local diversity.

A Checklist of the Darkling Beetles (Insecta: Coleoptera: Tenebrionidae) of Maryland, with Notes on the Species Recorded from Plummers Island Through the 20th Century

Species occurrences of darkling beetles (Coleoptera: Tenebrionidae) are listed for the historically collected locality of Plummers Island, Maryland, on the Potomac River just upstream from Washington, D.C. The list is compared to that of the currently known Maryland species, which includes a number of new state records and range extensions. Notes on some of these occurrences and the absence of certain species are discussed. Maryland records from multiple sources now total 128 species of this family of insects. Plummers Island records, from the beginning of the 20th century to the present, include nearly 50% of the state's fauna, and an additional 25% of the state's tenebrionids are expected there.

Freshwater Triclad Planarians (Turbellaria) from Plummers Island, Maryland

Five species of freshwater triclad planarians were found on Plummers Island and the adjacent mainland property, Montgomery County, Maryland. One species (Dugesia [G.] tigrina) occupying the Potomac River and a tributary, is tolerant of degraded habitat. The other four occupy vernal pools (Hymanella retenuova and Phagocata velata) or spring-seeps (Phagocata morgani and Paraplanaria dactyligera) and appear to be indicators of high quality aquatic habitat. These five species represent 36% of the total known Maryland fauna of 14 species.

Scorpionflies and Hangingflies (Insecta: Mecoptera) from Plummers Island, Maryland

ABSTRACT The National Insect Collection was searched for specimens of Mecoptera collected on or near Plummers Island, Montgomery County, Maryland, and the records were taken from those found. A special effort was made in 2004 and 2005 to collect insects on or adjacent to Plummers Island, using a number of techniques. In addition to the usual ultraviolet light traps, two Malaise traps were operated during the season in 2005. Eleven species of Mecoptera were identified from this material: nine taken in the 1900s and three in 2004–2005. They belong to four families and four genera. Most are species widely distributed over eastern North America, and none is considered endangered.

Inventory of the Nolidae, Erebidae, and Noctuidae (Insecta: Lepidoptera) of Plummers Island, Maryland

From 1902–2005 six species of Nolidae, 88 species of Erebidae, and 118 species of Noctuidae have been recorded from Plummers Island, Montgomery County, Maryland. Extensive collecting conducted from 1998–2005 resulted in five species of Nolidae, 70 species of Erebidae, and 88 species of Noctuidae. Only the Nolidae had sufficient specimens collected from 1902–1930 to compare with collections taken from 1998–2005. Five species were present from 1902–1930, and five from 1998–2005 with no change in species richness. A 20% species turnover was noted, with one extinction and one colonization. Owing to probable under-sampling from 1902–1930, the Erebidae and Noctuidae show a 37% and a 32% increase, respectively. This is contrary to other studies at Plummers Island, which showed a decrease in species richness. Species accumulation curves were based only on material collected from 1998–2005. Both abundance and incidence-based estimators were used to predict six species of Nolidae, 79–102 species of Erebidae, and 101–135 species of Noctuidae. Of the total of 212 species for all three families, 75.9% of the species were represented by 10 or fewer specimens. A checklist of the Nolidae, Erebidae, and Noctuidae, and their monthly abundances from 1902–2005 is provided.

Caterpillar-Host Plant Relationships Recorded from Plummers Island, Maryland (Insecta: Lepidoptera)

During the summers of 2004 and 2005 host plant associations of larvae of Lepidoptera were studied on Plummers Island, Maryland, with an emphasis on the family Limacodidae (slug caterpillars). A total of 37 species from 12 families was recorded, representing 79 caterpillar-host plant combinations. Eleven species of Limacodidae were collected and reared from six target host plants—box elder (Acer negundo L.), sugar maple (Acer saccharum Marshall), pawpaw [Asimina triloba (L.) Dunal], pignut hickory [Carya glabra (Mill.) Sweet], spicebush [Lindera benzoin (L.) Blume], and red oak (Quercus rubra L.).

Pseudoscorpions from Plummers Island, Maryland, with the Reported Use of Empty Snail Shells by Arthropods

Two species of pseudoscorpions, Tuberocreagris rufula (Banks) and Chthonius virginicus Chamberlin, are reported from Plummers Island, Maryland. Several specimens of C. virginicus were found in empty snail shells, and although this behavior has been reported previously, it is not well documented.

An Overview of the Lepidoptera (Insecta) of Plummers Island, Maryland

ABSTRACT Based on the examination of approximately 8100 specimens of Lepidoptera in the collection of the National Museum of Natural History and a review of relevant literature, we document 836 species in 488 genera and 48 families from Plummers Island, Maryland. Although the Lepidoptera are probably the best studied insect order on Plummers Island, data from the Washington, D.C. area indicate that there likely are many more microlepidoptera and butterflies on the site that are yet to be documented. Most families that were sampled adequately both historically (1901–1920) and in recent years (1998–2005) show a reduction in species richness and considerable species turnover. However, interpretation of these data is difficult owing to differences in sampling techniques and sampling frequency over the last 100 years.

Pyraloidea and Their Known Hosts (Insecta: Lepidoptera) of Plummers Island, Maryland

From 1902–2005, 75 species of Crambidae and 48 species of Pyralidae were collected on Plummers Island, Montgomery County, Maryland. An annotated list of the two families is provided, along with photographs of all recorded species. The Pyraloidea of Plummers Island have wide distributions in eastern United States with some species occurring as far west as Texas and a few others ranging from coast to coast. Hosts recorded in the literature are given, but they are unknown for 36% of the species. The majority of Pyraloidea feed on vascular plants, but hosts are diverse including algae, scale insects, and immatures of wasps, and bagworms.

The Cerambycidae or Longhorned Wood-Boring Beetles (Insecta: Coleoptera) of Plummers Island, Maryland

ABSTRACT Based on historical records in the collection of the National Museum of Natural History, Smithsonian Institution, Washington, D.C., 63 species of Cerambycidae (Coleoptera) are reported from Plummers Island, Maryland. This number represents 24.9% of the Maryland cerambycid fauna. Specimens were collected from March to September, with July yielding the highest total (160 or 38.8%). Only 25 specimens were collected after 1927: three in 1931, three in 1932, one in 1933, one in 1941, 16 in 1968, and one in 2004. Four specimens of the state-listed endangered species Dryobius sexnotatus Linsley were collected prior to 1920.

Coccinellidae or Ladybird Beetles (Insecta: Coleoptera) of Plummers Island, Maryland

Based on historical specimens in the collection of the National Museum of Natural History, Smithsonian Institution, Washington, D.C., 25 species of Coccinellidae (Coleoptera) were collected on Plummers Island between 1902 and 1960. This represents approximately 32% of the recorded fauna of Maryland. Neoharmonia venusta venusta (Melsheimer) was the most commonly collected species.

Trichoptera (Caddisflies) Collected on and Near Plummers Island, Maryland in 2004 and 2005

During 2004 and 2005 insects were collected on or adjacent to Plummers Island, Montgomery County, Maryland using an ultraviolet light trap (2004 (2005) and two Malaise traps (2005). Forty-seven species of Trichoptera were identified from this material, representing 13 families and 25 genera. Most of the species are common and widely distributed over eastern North America, and none is considered of special concern or sensitive.

Hydrophiloidea (Insecta: Coleoptera) of Plummers Island, Maryland

Eighteen species of Hydrophiloidea were collected on Plummers Island, Maryland between 1903 and 1972, representing 17.5% of the known fauna of Maryland. Of these, eight species are aquatic and ten are terrestrial. The most commonly collected species were Cymbiodyta chamberlaini Smetana and Enochrus cinctus (Say).

Silphidae or Carrion Beetles (Insecta: Coleoptera) of Plummers Island, Maryland

Based on an examination of the collection of the National Museum of Natural History, Smithsonian Institution, Washington, D.C., seven species of Silphidae (Coleoptera) were collected on Plummers Island, Maryland, from 1905 to 2004. This is 38.8% of the known silphid fauna of Maryland. The most commonly collected species is the habitat- and carrion-generalist Nicrophorus tomentosus Weber.