Page Banner

United States Department of Agriculture

Agricultural Research Service

U.S. National Parasite Collection

Animal Parasites: U.S. National Parasite Collection

U.S. National Parasite Collection

By J. Ralph Lichtenfels, Eric P. Hoberg, and Patricia A. Pilitt


U.S. Department of Agriculture, Agricultural Research Service, Biosystematics and National Parasite Collection Unit, BARC-East, Building 1180, Beltsville, MD 20705-2350


To recognized scientists and institutions for research


5,000 volumes; 60,000 reprints

Number of

95,000 lots


12,000 lots


J.R. Lichtenfels, E.P. Hoberg, P.A. Pilitt
Phone: (301) 504-8444, fax: (301) 504-8979

Home page

The U.S. National Parasite Collection contains parasites of humans and animals (fig. 1). It is one of the world's largest parasite collections and is the major repository of helminth type specimens for North American parasitologists and for others who lack adequate facilities. Using their personal collections as a nucleus, Charles Wardell Stiles and Albert Hassall founded the collection in 1892.


Stiles and Hassall were two parasitologists employed in the USDA Bureau of Animal Industry, which was a predecessor of the Agricultural Research Service. Stiles was an American who had studied in Europe, and Hassall was born and trained in England. As a result, some of the oldest specimens in the U.S. National Parasite Collection are from Europe and date from the middle of the 19th century.

Figure 1. Tissue-dwelling parasites in the U.S. National Parasite Collection

Figure1. Tissue-dwelling parasites in the
U.S. National Parasite Collection

During its existence, the collection has had various names, and constituent collections have added additional names. The collection was known initially as the Bureau of Animal Industry (BAI) Collection, and a catalog of parasites in the collection was published (Stiles and Hassall 1894). The catalog stated that "all types of the BAI Collection will be permanently deposited in the United States National Museum . . ." (USNM). To accomplish this, Stiles proposed in 1894 that the Smithsonian Institution establish a department of zoology or helminthology and volunteered to serve as honorary curator. In March 1894, Stiles was appointed custodian of the USNM Helminthological Collection by the secretary of the Smithsonian Institution. This appointment began a tradition, still in effect, in which the curator of the National Parasite Collection also serves as a research associate of the Smithsonian Institution. The USNM Helminthological Collection has been continuously curated since 1892 by USDA scientists. If specimens ever were transferred physically to the Smithsonian, they were returned in 1936, a time that appears to coincide with the movement of the BAI Collection from Washington, DC, to new laboratory facilities in Beltsville, MD.

Over the years as bureau, agency, and division names changed, the BAI Collection became known as the Zoological Division Collection, the Animal Parasite Collection, the Beltsville Parasite Collection, and the USDA Parasite Collection. Since 1894, there have been two constituent collections, the BAI Parasite Collection and the USNM Helminthological Collection, each using blocks of catalog numbers for entries but all catalog numbers being part of a single numerical series. In 1969, Becklund proposed the overall name National Parasite Collection for these two constituent collections; he chose this name because it incorporates a broad range of organisms. Lichtenfels added "U.S." to the name to differentiate the collection from similar collections in other countries.

Although helminths are the largest group in the collection, other groups include parasitic protozoans, pentastomes, lice, mites, ticks, and other miscellaneous parasites. Many of the parasites were collected during USDA survey and eradication programs. About half of the specimens are stored in small bottles in a solution of 92 parts 70 percent ethanol, 3 parts formalin, and 5 parts glycerine. The others are mounted permanently on glass microscope slides. In addition to Stiles and Hassall, the collection has been curated by B.H. Ransom, M.C. Hall, A. McIntosh, W.W. Becklund, and M.B. Chitwood and is currently curated by J.R. Lichtenfels, E.P. Hoberg, and P.A. Pilitt. Other USDA researchers closely associated with the collection over the years include B.G. Chitwood, E.B. Cram, G. Dikmans, J.T. Lucker, E.W. Price, and E.E. Wehr.

After the sudden death of Willard W. Becklund at age 47 in 1970, MayBelle Chitwood became curator of the National Parasite Collection until her retirement in 1973. Since 1973, the collection has been under the care of J. Ralph Lichtenfels, who has been assisted by Patricia A. Pilitt since 1977. Patricia Pilitt is the daughter of Allen McIntosh, who curated the collection from 1930 to 1962. In 1990, Eric P. Hoberg joined the staff of the Biosystematic Parasitology Laboratory (BPL) (now the Biosystematics and National Parasite Collection Unit) and now shares curatorial duties with Lichtenfels and Pilitt.

and Facilities

The collection includes about 95,000 lots of specimens. An individual lot consists of one to thousands of specimens. Additions to the collection receive the next available catalog number. Specimens are not grouped taxonomically. A Checklist of Types in the U.S. National Parasite Collection was published in 1978. The types are listed by species within phylum or class, and an index of genera is included. Copies of the Checklist of Types are available from J.R. Lichtenfels, E.P. Hoberg, and P.A. Pilitt (see contributors section for addresses and phone numbers). The collection includes about 12,000 type lots, including about 4,000 holotypes.

In addition to the 95,000 cataloged lots, several large blocks of specimens have not been cataloged. These include the H.B. Ward Collection, the Hoffman-Bangham Collection of Parasites of Freshwater Fishes, and the Southeastern Cooperative Wildlife Diseases Study Collection of Parasites of White-tailed Deer. After Ward died, his collection was shipped to Beltsville along with its card file and logbook records. Although Allen McIntosh and Bill Becklund cataloged the types in the Ward Collection, most of it remains uncataloged except for Ward's records.

In 1986, the Hoffman-Bangham Collection of Parasites of Freshwater Fishes was moved to Beltsville from the Fish and Wildlife Service Fish Farming Experiment Station at Stuttgart, AR, following the retirement of Glenn L. Hoffman. It includes the personal collections of G.L. Hoffman and R.V. Bangham and a collection of Myxosporidia compiled by H.S. Davis. The Hoffman-Bangham Collection consists of more than 8,000 slides in boxes and numerous small vials in a steel chest of drawers. The specimens are indexed according to Hoffman's original records but have not been cataloged into the records of the U.S. National Parasite Collection.

The Southeastern Cooperative Wildlife Diseases Study Collection of Parasites of White-tailed Deer was moved to Beltsville in 1988 and contains 2,193 Odocoileus virginianus from 13 southeastern states. Each lot consists of a composite sample of all species collected from one deer and placed into a single vial. Detailed records of host and parasites are available, but the parasites are not indexed; consequently this collection has not been cataloged into the records of the U.S. National Parasite Collection, except for specimens used in recent studies.

In addition to the large constituent collections listed above, significant personal collections of the following individuals are housed at Beltsville as part of the U.S. National Parasite Collection. Those followed by an asterisk have been cataloged fully: F.W. Douvres, J.H. Fischthal*, A.O. Foster*, A. Goldberg, E.P. Hoberg, R. Honess, R.A. Knight, D.C. Kritsky*, R.E. Kuntz*, G.R. LaRue, D.R. Lincicome, E. Linton*, G.A. MacCallum, J.H. Sandground*, L. Schultz, and H.J. Van Cleave. The uncataloged personal collections can be accessed only through original logbooks, host records, or, in some cases, by taxonomic grouping.

The collection has been housed in its present location at the Beltsville Agricultural Research Center since 1960. The facilities were improved by the addition of moveable steel shelving on rails (compactors) in 1984 and the addition of systems for fire suppression, electronic detection of intrusion, and fire surveillance in 1988. Current storage space can accommodate 10-15 years of normal accessions (about 1,000 lots per year).


A limited identification service is provided, with priority given to parasites of veterinary or medical importance. Emphasis is placed on the preparation of illustrated keys and manuals that permit many parasitologists to identify their own specimens.

Other services associated with the collection include a liberal and efficient loan program of specimens and an open-door policy for visiting scientists. Literature cannot be borrowed but is available to visitors. A microscope will be provided for visiting scientists, but visits must be prearranged.


Cataloged specimens of the U.S. National Parasite Collection were indexed by host and parasite scientific names in a card file until 1990, when a computerized catalog system was adopted. Because the host and parasite card indices prepared until 1990 are by genus and then species, users had to know all possible genera in which a species may have been cataloged. The pre-1990 records recently were entered into the computer database by the curators, students, and volunteers.

The new computer system provides all necessary labels, logbooks, and reports and allows logical searches for any string of characters in all fields. It is not available online.


The Biosystematics and National Parasite Collection Unit develops new information on the diagnosis, identification, classification, and distribution of parasites of animals, especially those of veterinary and medical importance, using comparative morphology and biochemical and molecular genetics techniques within the context of modern phylogenetic methods for analysis. The program is centered on helminths of ruminants and food safety. Current objectives include (1) developing classifications for subfamilies of Trichostrongylidae, including generic concepts for Ostertagiinae (fig. 2); (2) preparing identification keys to helminth parasites of domestic and wild ruminants of North America; (3) defining biodiversity of helminth fauna of bovids and cervids of Holarctic origin; (4) determining the relationship of species of Trichinella and developing classification of the species within the genus; (5) expanding services of the U.S. National Parasite Collection to include depositories of frozen tissue and a database on germplasm. The U.S. National Parasite Collection also supports general biodiversity research on parasitic fauna of vertebrates and historical biogeography and cospeciation analyses.

Figure 2. Adult male nematode showing diagnostic features

Figure 2. Adult male nematode
showing diagnostic features

1911 Published illustrated keys to nematode parasites of ruminants
1916 Monographed nematode parasites of small mammals
1927 Monographed nematode parasites of birds
1945 Published (and later revised in 1964) Check List of Internal and External Parasites of Domestic Animals in United States, Its Possessions, and Canada, including data on distribution

Identified exotic African red tick (Rhipicephalus evertsi), enabling eradication within relatively short period of a known vector of several important diseases of livestock

1961 Identified rat lungworm (Angiostrongylus cantonensis) from a human brain, resulting in discovery that a nematode is the causative agent of parasitic or eosinophilic meningoencephalitis in the South Pacific
1970 Published checklist of internal and external parasites of deer in North America
1971 Published descriptions and keys to many common nematode parasites of ruminants
1971 Discovered larvae of eyeworm (Thelazia gulosa) in face fly (Musca autumnalis), the first natural vector for eyeworm of cattle in eastern North America
1973 Published first manual for identification of parasites in tissue sections, including 249 figures of parasites in lesions
1975 Published illustrated keys to helminths of domestic equids, providing necessary working tool for renewed research on parasites of horses
1978 Published list of types in U.S. National Parasite Collection
1980 Published keys and new classification for Strongyloidea
1980 Published keys and new classification for Ancylostomatoidea
1980 Determined larval nematode in shellfish was parasite of marine turtles
1982 Published guide to parasite collections of the world
1983 Established synlophe as most useful character for identifying species of Trichostrongyloidea (fig. 3)
1985 Described developmental stages of heartworm of dogs
1986 Discovered Nematodirus battus in North America (fig. 4)
1991 Published first phylogenetic analysis of Eucestoda (tapeworms) (fig. 5)
1991-93 Published identification keys to medium stomach worms (Ostertagiinae) of ruminants
1992 Developed specific DNA probes for Trichinella spp.
1992 Revised systematics of Trichinella
1992 Proposed Arctic Refugium Hypothesis to explain the evolution of host-parasite associations in the Arctic region
1994 Discovered introduction of equine strain of Echinococcus granulosus in North America
1994 Published identification key for large stomach worms (Haemonchus) of ruminants
1994 Published first phylogenetic analysis of the Trichostrongylidae
1994 Developed DNA probes for species of large stomach worms (Haemonchus)
1994 Developed DNA probe for fecal eggs of nematodes of cattle
1994 Published keys to genera of tapeworms of the order Tetrabothriidea
1995 Discovered perivulval cuticular pores with hypodermal glands in Trichostrongyloidea
1995 Named a new genus of pathogenic lungworm in Nearctic ruminants
1995 Described a new pathogenic nematode in ratites introduced to North America
1995 Proposed Arctic Refugium Hypothesis to explain the evolution of host parasite associations in the Arctic region
Figure 3. Ridges (synlophe) on the body surface of a nematode
Figure 4. Eggs of the nematode Nematodirus battus

Figure 3. Ridges (synlophe)
on the body surface of a

Figure 4. Eggs of the nematode
Nematodirus battus

Figure 5. Typical head of a tapeworm

Figure 5. Typical head of a

Return to Contents page of Systematic Collections of the Agricultural Research Service

Return to ARS Newsletters and Publications

Last Modified: 2/6/2002
Footer Content Back to Top of Page