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United States Department of Agriculture

Agricultural Research Service

Asa Fitch's Aphid Notes
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Fitch Notes Title Image
  Gary L. Miller, Ethan C. Kane, Jonathan Eibl, and Robert W. Carlson

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Background    Dr. Asa Fitch's (1809-1879) place in entomology is well deserved. Trained as a medical doctor, Fitch abandoned medicine to pursue entomology. In 1854, the New York State Legislature authorized Fitch to study insects, thus making him the first professional entomologist ever appointed by a state. Fitch published over 200 reports, and articles on a broad range of insects and related topics beginning in 1845. After Fitch's death, his entomological collection and library was broken up and sold to various collectors and the balance of the collection was purchased by the U.S. National Museum. It was probably at this time that his aphid collection and aphid notes eventually found their way to the National Aphidoidea Collection in Beltsville, MD.

After languishing for more than 100 years, the Fitch notes are now databased and are available to everyone to access on the USDA's Systematic Entomology Laboratory web page. Users are able to search and view nearly 800 pages of hand-written notes that encompass 190 taxa. In addition to their scientific importance, the notes are also extremely valuable from an historical point. They yield glimpses of his personality, current sayings, and reflections on life in the mid-19th century.


The Aphid Notes: An Overview

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Fitch's aphid notes contain a treasure trove of information. Typically, notes were written on 4" X 6" sheets of paper in small script and sometimes are on recycled galley proofs and handbills (Figure 1). Aside from being remarkably well preserved, his notes contain extensive information on aphid life history, morphology, predators, and host plants.

Fitch's notes provide a rare glimpse of innovative 19th century entomology. Information contained therein is still relevant today. For example, his notes provide some of the earliest dates available for some invasive species of aphids in North America.

 
Systematics & Taxonomy    Fitch's notes served as the basis for his species descriptions. An example (Figure 2) is illustrated with his description of the white pine aphid, Cinara strobi (Fitch). For this species, Fitch documented nomenclatural changes, descriptions, measurements, and color variation. However, there are some differences between the notes and descriptions.

 

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Other published works and descriptions are noted as they pertain to various species (Figure 3). Some notes pertain to nomenclatural debates (e.g., with Lichtenstein over Phylloxera vitifoliae) with some of the leading entomological authorities of his day. Also included are various keys ("Synopsis") to subgenera and species of aphids (Figure 4).

 
Although not profusely illustrated, notes with some of the species descriptions contain corresponding drawings (Figure 5 top) and lithographic copies of his published figures (Figure 5 bottom).

 

Biology    Fitch expressed a strong interest in the reproductive potential of various aphid species. His notes on the "multiplication of aphids" contain careful counts and observations that extended for 10 consecutive days (Figure 6).



He was also diligent in recording host plants and damage, collection dates (even supplementing dates for subsequent years), habitat, range, predators, and parasitoids (Figure 7). Many of the recorded host plants were from his property near Salem, New York.

 


Phenological observations are included within his notes. Fitch drew correlations between precipitation, aphid population explosions, plant diseases, and bird predation (Figure 8). The "bird question" was a subject of hot debate during the mid-19th century and Fitch was not to be excluded from the topic.

 



In addition to these subjects, Fitch spent some of his time developing aphid control methods that included various uses of tobacco such as "tobacco water," dusting with snuff, and, "burning tobacco paper." He also realized that aphid-tending ants were instrumental in dispersal of some species of aphids. To this end, he experimented with various ant-excluding barriers that included plaster of Paris, "gas tar," and chalk with varying degrees of success.

As a consummate collector in addition to being one of the few aphidologists active in his day, Fitch's collection records and observations provide some of our earliest glimpses into the North American aphid fauna. While there are some questions concerning Fitch's "species concept" versus current concepts some of his included aphid species, there is little confusion given the morphology and associated host plants for others. Fitch recorded observations of native as well as invasive species of aphids. His reference citation of the cabbage aphid, Brevicoryne brassicae (L.), in 1791 (Figure 9 top) is possibly the earliest record of an invasive aphid for North America.  He was the first to record several other invasive aphids (e.g., Calaphis betulicola - 1854; Cavariella pastinacae - 1855; Cryptomyzus ribis -1854; Euceraphis punctipennis - 1847; Liosomaphis berberidis - 1846 (Figure 9 bottom); Periphyllus aceris - 1847). These dates place establishment of some species more than 40 to 60 years prior to published records. Dates of establishment are invaluable for tracking the spread of invasive species as well as determining the invasive component of the North American aphid fauna.


Suggested Reading

Barnes, J. K. 1988. Asa Fitch and the Emergence of American Entomology. New York State Museum Bulletin 461, 120 pp.

Foottit, R. G., S. E. Halbert, G. L. Miller, E. Maw, L. R. Russell. 2006. Adventive Aphids (Hemiptera: Aphididae) of America North of Mexico. Proc. Ent. Soc. Wash. (in press)

Mallis, A. 1971. American Entomologists. Rutgers University Press, 549 pp.


Citation Format

Citations of this website should should be formatted as follows:

Miller, GL, Kane, EC, Eibl, J, and Carlson, RW. 2006. Resurrecting Asa Fitch's Aphid Notes: Historical Entomology for Application Today. Available at: http://www.ars.usda.gov/ba/psi/sel/fitch.html. Accessed: .


Last Modified: 11/8/2013
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