Tetranychoidea Pests Ranking Model and List
A report concering mites in the superfamily Tetranychoidea was completed in 2006 through a cooperative agreement between the The Acarological Society of America and The United States Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS). The report is entitled
A Ranking Model
and List to Identify Foreign Tetranychoidea Pests
of Agricultural and Environmental Significance to the United States
Authors:
Carl C. Childers (Project Leader), University of Florida, Lake Alfred, FL
Dr. Warren C. Welbourn, Florida Department of Agriculture & Consumer Services, Gainesville, FL
Dr. Norman J. Fashing, College of William and Mary, Williamsburg, VA
Tetranychoidea pests in order of importance based on the nine ranking criteria (Table 8)
The report consists of a number of tabular lists and fact sheets. Above is a quick link to the ranked list believed to be of most use. An outline of the entire report follows, including links to several of the other tables and information within the report.
The full report includes tables not mentioned below, and species fact sheets. To see any of this material, please contact Michael Hennessey, at [email protected].
A Ranking Model and List to Identify Foreign Tetranychoidea
Pests
of Agricultural and Environmental Significance to the United States
The ranking model includes nine associated selection criteria to identify potential exotic Tetranychoidea pests of agricultural, sylvan, ornamental and environmental significance to the United States.
The nine criteria are dynamic and will change as APHIS increases databases of plant interceptions or mites in the different genera and species listed. The ratings are described in Table 1. Further information will hopefully be updated through ongoing literature searches to identify the geographical spread of one or more of these mite pests as well as new information on their biology, host plants, feeding damage and economic importance outside of the United States.
The nine criteria used to rank the taxa include:
(1) Value of impacted economic crops. More work is needed in this area to accurately determine the values of various ornamental plants as well as less common tree species used for lumber, furniture, landscape, paper or pulp. Data are lacking for a variety of commonly grown vegetables. William Luppold, U. S. Forest Service, NE-4805, Princeton, WV 24740 provided help for this criterion.
(2) Number of Tetranychoidea interceptions from potential high risk countries between 1995 and 2005.
(3) Distribution. Geographical regions or continents.
(4) Numbers of identified Tetranychoidea interceptions from specific plant genera.
(5) Host plants. Many Tetranychoidea species tend to be polyphagous.
(6) Damage Potential.
(7) Number of identified interceptions of different Tetranychoidea genera between 1995 and 2005.
(8) Reproductive potential based on maximum egg production per female described in Table 7.
(9) Vectors of Disease. Included are two genera of Tetranychoidea that have been identified as vectors of one or more plant viruses (e.g. Brevipalpus (Tenuipalpidae) and Petrobia (Tetranychidae). Petrobia latens (Muller) is the vector of Barley yellow streak mosaic virus in the United States.
A total of 394 Tetranychidae species and 12 species in the family Tenuipalpidae have been identified as potential exotic threats to United States agriculture, sylvan or ornamental plants (Table 8). Table 8 lists the species in order of importance based on the ranking criteria. A fact sheet or circular for each of these species is included in the report.
The ranking values of the 406 potential exotic mite pests range from a maximum score of 495 to 136. There were 25 mites that had values between 495 and 400 and 54 mites with values from 398 to 303. A total of 251 mite species had values from 299 to 200 and 76 mite species had values from 198 to 136. The median ranking value for these mites was 242.
Two different unique situations are included among our list of important mite species. First, the top three ranked species of potential exotic pest mites include: Brevipalpus californicus (Banks), B. obovatus Donnadieu, and B. phoenicis (Geijskes) (Acari: Tenuipalpidae) (Table 8). All three of these mite species occur within the United States. However, all three are reported vectors of a Rhabdovirus-like disease called citrus leprosis. They are the only known vectors and this disease does not occur within the United States. The rationale for introducing this virus via infected mite vectors is presented in Childers and Derrick (2003. Experimental and Applied Acarology. Volume 30 (1-3): 1-226). These same three species of Brevipalpus have been reported as vectors of several other related viral diseases in coffee, passion fruit, orchids and various ornamental plants (see Childers and Derrick, 2003).
A second instance that is somewhat unique involves Cenopalpus pulcher (Canestrini & Fanzago) (Acari: Tenuipalpidae). This mite is a serious pest in Europe and in some Mediterranean areas. However, the same mite species occurs in one isolated area in Oregon and is not considered a pest. Rodrigues et al (2004. Experimental and Applied Acarology 34:275-290) compared a “Montpellier” strain of C. pulcher to the Oregon strain and found low similarity between the two populations. It was suggested that this Oregon strain may not have been introduced from Europe.
This report clearly shows the importance of the Tetranychoidea to United States agriculture, sylvan and ornamental cropping systems as well as to the well being of our environment. Increasing safeguards are warranted to prevent the entrance of one or more of these potentially serious mite pests into this country.
In addition to the direct funding for this project we want to acknowledge the support and indirect funding from the University of Florida, Citrus Research and Education Center in Lake Alfred, Florida; the Florida Department of Agriculture & Consumer Services, Division of Plant Industry in Gainesville, Florida; USDA, ARS, Systematic Entomology Laboratory in Beltsville, Maryland and the USDA, APHIS, PPQ, Plant Inspection Facility in Humble, Texas.
Carl C. Childers, Project Leader