USDA - APHIS - Plant Health, Plant Protection and Quarantine

Technical Advisory Group for Biological Control Agents of Weeds

Appendix E
Suggested Format For Test Plant Lists

Introduction
This appendix provides a suggested format for test plant lists for biological control agents of weeds in North America. Note that the preliminary information about a target weed and a candidate agent may be incomplete at this point in the research. The proposed list will be the bulk of the submitted information.

Cover Page
Prepare a cover page for the test plant list with the following information. This information provides TAG with a contact point for questions and with references for tracking.

Date submitted to TAG.
Name of researcher or petitioner with affiliation and a contact point within North American, including an address, telephone number, FAX number, and email address.
Target weed including its species, genus, family, and common names. Identify whether the week is targeted for the first time. If not, include the number of the previous petition assigned by TAG.
Identify proposed agent(s), if any.
Where the studies will be conducted--list both foreign and U.S. quarantine facilities.

Introduction to the Test Plant List

Nature of the Problem:
Give a brief summary (one to two paragraphs) of the problems caused by the weed. Items to consider:

History of introduction and spread of the target weed.
The weed's present distribution in North America.
Sectors affected and magnitude of program (e.g., agricultural, natural, rangeland).
Consensus that the weed is a suitable target for control.

Proposed Action:
This host plant list is to notify TAG of our intent to begin a biological control program for the control of [weed]. [Weed] has been declared a noxious weed in [list States] and is considered a target for biological control. Your comments on the accuracy, appropriateness, and thoroughness of this list would be appreciated.

Target Weed Information

Taxonomy:

Full classification (including species, genus, family, and order), synonymy, and common name.

The taxonomist who identified the target weed, including names, organizations, and locations.

Problems in identification or taxonomy of the group.

Origin and location of herbariums containing voucher specimens and the date of depository. (The voucher specimen referred to here is the one used as representative of the population that occurs in the area where the researcher has conducted the studies.)

Description:
Provide a general physical description of the target weed, complete enough that a person encountering it in the field could identify it.

Distribution of the Target Weed:
Describe the distribution of the target weed using maps, as appropriate. Include the following information:

Native range (map).
Areas of introduction throughout the world, pattern of movement, and apparent limits (map).
Present distribution in North America (map).
Range areas of potential spread in North America (map).
Genetic variability.
Habitats or ecosystems where this weed is found in North America.

Taxonomically Related Plants:
Identify the economically and environmentally important plants that are closely related to the target weed. These are crops, ornamentals, and native plants including threatened and endangered species. If possible, identify how closely these may be related to the target weed.

Distribution of Taxonomically Related Plants:
Describe the distribution and habitats in North America of the closely related plants—those identified under the previous heading, Taxonomically Related Plants.

Life History:
Explain the life history and general biology of the target weed. Discuss the factors that are believed to contribute to the plant's weediness.

Impacts:
Indicate any and all impacts. Use the following list as a guide; not all areas listed below are applicable to all weeds.

Beneficial uses, honey bees, forage, ground cover, fruit, etc.

Social and recreation uses (value as ornamentals).

Impact on threatened and endangered species.

Economic losses, including direct control costs.

Health—poisonous, allergens.

Regulatory—noxious weed, restricts trade.

Effects on native plant and animal populations.

Impact of weed control on nontarget plants.

Effects on ecosystem functions and ecological relationships.

Other, e.g., aesthetic.

Alternative Management Options:
Describe alternative options for managing the target weed.

Historical options—what has been done before.
Current options—biological, chemical, cultural, etc.
Potential options—new herbicides or biological control agents used or released in other countries.

Known Host Range of Candidate Biological Control Agent:
This information is optional. If known, provide it.

Name(s) and taxonomic classifications.

Literature records indicating what other plants have been attacked.

Field collections and observations, including maps and data.

Literature on host range of closely related species to candidate agent.

Test Plant List

Categories of Test Plants:
The usual strategy for developing a test plant list for evaluating biological control agents of weeds in North America is based on A. J. Wapshere (1974), A Strategy for Evaluating the Safety of Organisms for Biological Weed Control, published in Annals of Applied Biology. The strategy is based on the phylogenetic approach, where closely related species are theorized to be at greater risk of attack than are distantly related species.

Category 1—Genetic types of the target weed species (varieties, races, forms, genotypes, apomicts, etc.) found in North America.
Category 2—North American species in the same genus as the target weed, divided by subgenera (if applicable). Include information on economically and environmentally important plants.
Category 3—North American species in other genera in the same family as the target weed, divided by subfamily (if applicable). Include information on economically and environmentally important plants.
Category 4-Threatened and endangered species in the same family as the target weed divided by subgenus, genus, and subfamily. Be sure to include all endangered and threatened species in the genus of the target weed. Consult the U.S. Fish and Wildlife Service very early in the project. See Appendix F for guidelines to comply and to expedite any review necessary because of protected species.
Category 5—North American species in other families in the same order that have some phylogenetic, morphological, or biochemical similarities to the target weed. Include information on economically and environmentally important plants.
Category 6—North American species in other orders that have some morphological or biochemical similarities to the target weed. Include information on economically and environmentally important plants.
Category 7—Any plant on which the biological control agent or its close relatives (within the same genus) have been previously found or recorded to feed and/or reproduce.

Suggested Strategy for Developing a Test Plant List:
The following steps are only a suggested strategy for developing a test plant list. Follow this strategy along with the scheme developed by Cronquist (Appendix I) and the references listed in Table 10-1 on page 10.6.

Outline the families in the same order as the target weed using Cronquist's System of Angiosperm Classification in Appendix I on page 14.3.

Examine the placement of the target weed family in the classification systems of Thorne and Dahlgren which are available in a concordance of plant family names as per Cronquist, Dahlgren, Reveal, Takhtajan, and Thorne. This concordance has been prepared by James Reveal, Norton-Brown Herbarium, University of Maryland, College Park, Maryland. See the USDA-APHIS Concordance of Family Names.

If both Thorne and Dahlgren place a new family in the order of the target weed, consider that family when developing a list of Category 5 plants. If only one of the systematists places a new family in the order of the target weed, consider that family when developing a list of Category 6 plants. Look for economically or environmentally important species in the new families that occur in the target areas.

In developing a list of test plants for each category, the references listed in Table 10-1 may be useful.

Table 10-1: Helpful References for Developing Test Plant Lists

Helpful References*:

For Categories:

Vascular Plant Nomenclature, Three classification systems: Cronquist's System of Angiosperm Classification, Thorne's and Dahlgren's. See Appendix I for Cronquist's system. All systems are available on the world wide web (WWW) at: http://www.inform.umd.edu/pbio/usda/usdaindex.html

5, 6

Andersen Horticultural Library's Source List of Plants and Seeds. Isaacson, R.T. (1993 or later edition)

1, 2

Hortus Third, A Concise Dictionary of Plants Cultivated in the United States and Canada. Bailey, L.H. and Bailey, E.Z. (1976)

1, 2, 3, 5

A Synonymized Checklist of the Vascular Flora of the United States, Canada, and Greenland. Kartesz, J.T. (1994)

1, 2, 3, 5

Dictionary of Economic Plants. Uphof, J.C.Th. (1968)

2, 3, 5

Manual of Cultivated Plants. Bailey, L.H (1951)

2, 3, 5

The Plant Book. Mabberley, D.J. (last printing 1996)

2, 3, 5, 6

Families and Genera of Spermatophytes Recognized by the Agricultural Research Service. ARS Technical Bulletin 1796

3, 5

The Germplasm Resources Information Network (GRIN). Data base that is available on the WWW at: http://www.ars-grin.gov/npgs/tax/

1, 2, 3

The Plant List of Accepted Nomenclature, Taxonomy, & Symbols (PLANTS). Data base that is available on the WWW at: http://plants.usda.gov/plants/qurymenu.html

2, 3

List of Endangered and Threatened Species, including candidate species. Fish & Wild-life Service. Available on the WWW at: http://www.fws.gov/ r9endspp/endspp.html

2, 3, 4

Gray's Manual of Botany. Fernald, M.L. (1970)

2, 3, 5

North American floras that include the release areas

2, 3, 5, 6

*Full references are listed in Appendix H.

Summary Table
Summarize in a table format, all the species being considered for testing. Include pertinent literature references that are helpful in describing rationale. List the species in phylogenetic order, i.e., distantly to closely related to the target weed.

NOTE: In actual host testing of potential biological control agents, not all these plants are expected to be used. Depending on the feeding behavior or life cycle of the agent, the researcher would select representative plants from each category with physical features similar to those on which the agent normally feeds. For example, if the agent's larvae overwinters in a large tap root, annual plants or those with fibrous roots could be disregarded.

Perspective of Risk
Briefly discuss how the selected species should enable you to make inferences about risk of attack on untested species. Indicate the limits of allowable attack within the phylogenetic hierarchy of the test plant list, and why. Include pertinent literature references that are helpful in describing rationale.