### ARS research to Combat Invasive Species

The United States Department of Agriculture (USDA), Agricultural
Research Service (ARS) conducts research in extremely diverse areas
involving prevention, control and management of invasive species. For
example, ARS provides research in support of action agencies such as the
Animal and Plant Health Inspection Service (APHIS), to reduce the rate
of introduction of invasive species, and to rapidly detect, identify and
eradicate incipient species. We also work closely on this issue with
States and local governments; with the USDA Cooperative States Research,
Education, and Extension Service (CSREES), Forest Service (FS), Economic
Research Service (ERS), Natural Resources Conservation Service (NRCS),
and others; State Agricultural Experiment Stations (SAES); with many
Department of Interior (USDI) agencies; with the Department of Defense;
the private sector; and with international partners. ARS also conducts
extensive research on the long-term management of established invasive
species, emphasizing biologically based integrated pest management
activities. The estimate for ARS invasive species research for FY 2000
is \$70 million.

Selected projects against invasive weed, arthropod and disease pests in
which ARS plays a major role are discussed below.

## WEEDS

**Melaleuca, *Melaleuca quinquenervia***

-   Melaleuca is a tree introduced from Australia at the turn of the
    century. Well adapted to Florida wetland areas, it occupies about
    1.5 million acres, and expands at about 50 acres per day. It is a
    very serious threat to southern wetlands.

-   Melaleuca has displaced native wetland vegetation in the Everglades
    National Park, Big Cypress National Preserve, the Everglades
    Conservation Areas, Loxahatchee National Wildlife Refuge, and Lake
    Okeechobee, and waterways of the South Florida Water Management
    District.

-   Current economic losses from melaleuca have been estimated at about
    \$170 million/year. Herbicidal controls are prohibitively expensive,
    of limited effectiveness, and are non-specific, adversely affecting
    native plant communities. Current control methods depend upon
    hand-pulling or cutting.

-   Classical biological control, using specific natural enemies from
    Australia, is the safest and most economical option for sustainable
    management of melaleuca. ARS has scientists stationed in Australia
    and Florida to locate, test, and apply insect biological control
    agents against melaleuca.

-   The first biological control agent for melaleuca, the weevil,
    *Oxyops vitosa*, was released in April 1997. This weevil is already
    impacting melaleuca at release sites and is spreading to other
    locations.

-   ARS has many other insects in various stages of evaluation for
    biological control of melaleuca.

-   Program funding is provided by a consortium of ARS, the Army Corps
    of Engineers, the South Florida Water Management District, the
    Florida Department of Natural Resources, the Florida Department of
    Environmental Regulation, and Dade County.

**Leafy Spurge, *Euphorbia esula***

-   The search for natural enemies of leafy spurge was based out of the
    ARS European Biological Control Laboratory, now located in
    Montpellier, France. Nine leafy spurge biological control agents
    were established in the Western United States because of these
    activities.

-   In particular, *Aphthona* flea beetles have been particularly
    promising so far, dramatically reducing leafy spurge at release
    sites. Leafy spurge is the first weed target of an ARS *Areawide
    Pest Management Program*. This program brings together ARS and our
    customers and partners from four Western States (North Dakota, South
    Dakota, Montana and Wyoming) in a special *TEAM Leafy Spurge*
    effort.

-   *TEAM Leafy Spurge* sponsored *Spurgefest 99*, held in Medora, North
    Dakota, June 29-July 1, 1999, at which representatives of the
    Secretaries of Agriculture and Interior spoke and made presentations
    of awards to key *TEAM Leafy Spurge* members.

-   The program is expected to provide nearly \$4.6 million over 5
    years, nearly half of which supports efforts by partners at
    universities and State departments. Additional biological control
    agents have been located in Europe, which will be tested and
    released in the United States if acceptably specific.

**Saltcedar, *Tamarix ramosissima***

-   Saltcedar is a serious weed of riparian areas in the western United
    States. It infests over one million acres, and is spreading.

-   Saltcedar is difficult and expensive to control, given its high
    regenerative capacity and high seed production. The only hope for
    long-term management of salt cedar is biological control combined
    with revegetation.

-   ARS conducts research on saltcedar out of our Albany, California,
    laboratory, as part of the new Exotic and Invasive Weed Research
    Unit, and Temple, Texas, as part of the Grassland Soil & Water
    Research Laboratory.

-   Over 10 years ago, ARS initiated a biological control program to
    release herbivorous insects from the native range of *Tamarix*
    against this weed in the United States.

-   Extensive host-specificity testing was conducted and the leaf
    beetle, *Diorhabda elongata*, and the mealybug, *Trabutina
    mannipara*, were considered safe for release.

-   However, before releases were initiated, it was discovered that an
    endangered bird, the southwestern willow flycatcher, was utilizing
    saltcedar in parts of Arizona, New Mexico, and Nevada as a nesting
    substrate. Because flycatcher populations were so low and the
    possibility of extinction was high, the USDI Fish and Wildlife
    Service (FWS) wanted to proceed very cautiously with a biological
    control program against saltcedar. They wished to release the
    beetles only at sites far from where the flycatcher was utilizing
    saltcedar and to conduct careful research on the capacity of the
    beetles to damage saltcedar and to disperse. Extensive negotiation
    with FWS resulted in an agreed release plan.

-   Late in July of this past year, APHIS in cooperation with the FWS
    approved the release of the leaf beetle, *Diorhabda elongata*, into
    ten test areas in six states. Releases of the leaf beetle from China
    and Kazakstan were made in 1999 in room‑sized cages in California,
    Colorado, Nevada, Texas, Utah and Wyoming. The permits were approved
    following the publication of an Environmental Assessment, a public
    comment period and the issuance of a *Finding of No Significant
    Impact* (*FONSI*).

-   The releases were conducted within room sized field cages (some as
    large as 12 x 20 feet) so that beetle numbers could build up on
    natural Tamarix plants under the observation of the scientific teams
    evaluating their effectiveness. Once overwintering has been achieved
    and adequate numbers of beetles are available within the test sites,
    the beetles will be released into the open environment for further
    assessment.

-   Detailed monitoring plans have been developed and are currently
    being implemented to characterize not only the population growth and
    impact of the beetles on saltcedar, but also to assess the impact of
    the biological control program on other vegetation and wildlife in
    the test areas

-   To oversee these tests, a multi-agency *Saltcedar Biological Control
    Consortium* has been developed with membership of 35 of Federal,
    State and private groups all interested in the management of this
    invasive plant.

-   Biological control with natural enemies and revegetation with native
    plants are the cornerstones of this integrated weed management
    program.

-   Program goals include re-establishment of native vegetation, with
    significant benefit to native fauna such as the southwestern willow
    flycatcher and the native arthropods and microorganisms that
    occurred on the native flora.

## Giant salvinia, *Salvinia molesta*

-   Giant salvinia has recently been found in the Palo Verde District,
    the lower portion of the Colorado River and in a large portion of
    the Imperial Irrigation District Canal system. The only option for
    long-term, affordable management of giant salvinia is biological
    control, using a small weevil from South America, *Cyrtobagous
    salviniae*.

-   The Commonwealth Scientific and Industrial Research Organisation of
    Australia introduced *C. salviniae* against *S. molesta* in
    Queensland and in Papua New Guinea in 1980 and 1982, respectively.
    The program was so successful that the Organisation won the United
    Nations *Science Prize* for contributions to a developing country
    for this program. The weevil has since been introduced in several
    African and Asian countries, with spectacular success, generally
    within three years. It is one of the outstanding successes in
    biological weed control.

-   In the United States, the first specimens of *C. salviniae* were
    collected in Florida on a floating fern, *Salvinia minima*, in 1960.
    *S. minima* was introduced into Florida from South America
    around 1928. *S. minima* is a major aquatic invasive species in
    Louisiana and Texas, but not in Florida (presumably due to feeding
    by *C. salviniae*), which suggested that the weevil wasn't there.
    Subsequent surveys were conducted in Texas and Louisiana, which
    confirmed that the weevil was not present in those States.

-   A second invasive *Salvinia* species from South America, *S.
    molesta*, was found in Texas in 1998, and a *Salvinia* Task Force
    was established to coordinate efforts against the weed. Dr. Ted
    Center (ARS Aquatic Plant Control Research Unit, Ft. Lauderdale, FL)
    was contacted by the Task Force about biological control of *S.
    molesta*. Dr. Center applied to the Animal and Plant Health
    Inspection Service for permits to release *C. salviniae* collected
    in Florida in Texas and Louisiana. APHIS granted the permits, which
    were signed by both States. Dr. Center also called the appropriate
    Agriculture Department contacts in each State, who enthusiastically
    welcomed release of the weevil. He made the first release of *C.
    salviniae* on *S. molesta* in Texas in mid-June 1999. Recoveries
    were made at release sites in Texas in October and November, and
    establishment is likely.

## Kudzu, *Pueraria montana* var. *lobata*

-   Kudzu is a non‑native invasive weed from eastern Asia that occupies
    more than 7 million acres in the United States.

-   Kudzu was deliberately introduced into the USA starting in the 1800s
    for erosion control and for livestock forage. It now occurs from
    Florida to New England and westward to Nebraska, Oklahoma and Texas,
    and is spreading by over 120,000 acres a year.

-   Economic losses occur widely due to reduced land productivity, and
    environmental losses occur due to competition with natural
    vegetation in sensitive areas, reducing biological diversity.
    Although chemical (herbicides) and mechanical (mowing) controls are
    used, there is currently no economically or environmentally
    affordable method of controlling kudzu.

-   Biological control, using safe natural enemies, appears to be the
    best option for management of kudzu.

-   As part of this program, ARS scientists C. Douglas Boyette and
    Hamed K. Abbas, located at the Southern Weed Science Research Unit
    in Stoneville, Mississippi, in collaboration with H.L. Walker at
    Louisiana Technical University, isolated a strain of the fungus
    *Myrothecium verrucaria* from sicklepod.

-   Sicklepod, *Senna obtusifolia*, is an introduced leguminous weed of
    agronomic crops that is found in the southeastern United States. The
    fungal strain from sicklepod that was tested against kudzu is
    relatively broad spectrum, including some crops and some weeds, but
    not including economically important hardwood and softwood trees.
    However, it can be used safely because it is applied as a living
    herbicide, and doesn\'t spread to untreated areas. In greenhouse and
    field studies, the scientists found that the strain killed 100
    percent of kudzu tested.

-   The researchers are doing extensive toxicological studies on the
    fungus, and are pursuing a bioherbicide patent.

## Scotch thistle, *Onopordum* *acanthium* 

-   Scotch thistle is an extremely invasive thistle weed that occurs in
    at least 35 States, primarily California, Idaho, Nevada, Oregon, and
    Washington. It is an important invasive weed in croplands,
    grasslands and natural areas.

-   Scotch thistle is also a serious weed in Australia, and the
    Australian Commonwealth Scientific and Industrial Research
    Organization has worked on biological control of the weed for over
    15 years. Several potential biological control agents have been
    tested, and the United States is capitalizing on this research.

-   Three weevils species are being evaluated for release in the United
    States. Testing on the first species (*Lixus cardui*) indicates that
    native *Cirsium* spp. thistles may be attacked, and it is likely
    that this species will not be proposed for release.

-   A new species of *Lixus* from France is currently being tested at
    the ARS Exotic and Invasive Weed Research Unit in Albany,
    California, and appears promising. The third weevil species, which
    attacks rosettes (*Trichosirocalus* n. sp.), was collected in Spain
    this summer, and is currently the most highly rated candidate.

-   Biological control of Scotch thistle will be a long-term project,
    and other Federal, State and international partners are closely
    involved in planning and implementation of the project

**Old World climbing fern, *Lygodium microphyllum***

-   *Lygodium* is an invasive weed in south Florida where it threatens
    many wetland communities in the Everglades ecosystem.

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-   *Lygodium* is native to wet areas in the Old World tropics and
    subtropics from west Africa to eastern and southern Africa, and
    eastern India through southeast Asia to northern Australia and the
    Pacific to Tahiti.

-   The fern entered Florida as a commercial ornamental plant and was
    first documented to have become naturalized in 1965. However its
    explosive growth and rapid spread are relatively recent and it is
    now causing concern because of its dominance of native vegetation in
    many communities. In the last two years alone, it has increased from
    60,000 acres to more than 100,000 acres.

-   *Lygodium* is considered to be a good target for biological control.
    First, it belongs to a taxonomically isolated group, not closely
    related to native or economic plants in Florida. Second, the plant
    is not known to be a weed in its native distribution. Third,
    non-biological control methods are environmentally damaging and too
    expensive to use on the scale required to control the plant.

-   The ARS biological control program is currently focused on surveys
    for natural enemies of *Lygodium* species in the fern\'s native
    range, including Australia and Southeast Asia. Preliminary surveys
    in Southeast Asia and Australia have identified promising natural
    enemies, including pyralid moths and sawflies.

-   Host specificity research will be conducted in our Brisbane,
    Australia and Gainesville, Florida laboratories.

## 

**Arundo/Giant Reed, *Arundo donax***

-   Arundo/giant reed, is the largest and most aggressive member of the
    three species that are known to the genus. It is native to tropical
    and temperate regions of the old world and is thought to originate
    on the Indian Subcontinent of Asia.

-   It is now found from the Mediterranean Sea to Sri Lanka and is
    expected to occur in other parts of Southeast Asia. *A. donax* was
    thought to be introduced into the United States in the 1700s by
    French settlers and was used as both windbreaks and as roofing
    materials.

-   It was first documented in California in the early 1800s by early
    Spanish settlers in the Los Angles area. It has now extensively
    spread throughout the state and is found infesting riparian areas
    from the Mexican border to areas well north of San Francisco along
    the coast and up to Redding in the Central Valley.

-   Arundo readily invades riparian channels, especially in disturbed
    areas and reduces ground-water recharge, compromises water quality,
    chokes riverside and stream channels, and interrupts surface water
    flow and flood control, contributes to mosquito habitat, displaces
    native plants, eliminates native habitat for wildlife, and poses
    extreme fire danger.

-   It has been cited as being responsible for the loss of two major
    freeway bridges in southern California during flood conditions as
    plant debris builds up under these structures and has caused
    extensive water damage costing millions of dollars in Riverside
    County.

-   ARS is working with several groups in California to both understand
    Arundo growth and development and to locate, test and potentially
    introduce new biological control agents for this pest plant.

-   Chemical control is extremely costly and requires several follow up
    treatments including the removal of old plant debris.

-   Biological control offers the best option for long-term, affordable
    and environmentally friendly management of Arundo. The ARS European
    Biological Control Laboratory (Montpellier, France) in cooperation
    with ARS Albany have initiated a foreign exploration program in 1999
    which has already located potential agents in the Mediterranean
    Basin and have additional trips planned this winter into India and
    Sri Lanka.

## Cape or German Ivy, *Delairea odorata*

-   Cape ivy, also known as German ivy, is a perennial South African
    vine that was introduced into the United States as an ornamental
    plant. This vine (referred to as *Senecio mikanioides* in older
    literature) has become naturalized and a serious pest in several
    states.

-   In California, it now occurs along the entire coastline, from San
    Diego to southern Oregon, where it smothers and replaces native
    vegetation in a variety of natural habitats, including scrubland,
    grassland, riparian forests, as well as fence lines, right-of ways,
    pastures, and tree plantations.

-   In Hawaii, this vine has become naturalized at numerous drier,
    upland sites on the Big Island, at elevations ranging from 1700-7700
    ft.

-   Numerous federal and state parks and reserves in both states are
    impacted by Cape ivy. As an example, Golden Gate National Recreation
    Area has received a \$600,000 award from National Park Service for
    controlling Cape ivy during 1999-2000. The National Park Service
    considers it as a threat to 12 listed or rare native plant species,
    two federally listed butterfly species, as well as compromising the
    habitats for freshwater shrimp and Coho salmon.

-   In 1998, USDA-ARS, with the assistance of numerous environmental and
    government agencies, launched a biological control project targeting
    Cape ivy.

-   ARS conducts research on Cape ivy at our Albany, California,
    laboratory, as part of the Exotic and Invasive Weed Research Unit.

-   ARS established a cooperative project in South Africa, and local
    scientists there are completing an initial survey of natural enemies
    of this vine. Over 200 insect species have already been found
    attacking Cape ivy in South Africa, and a half-dozen show promise as
    potential biological control agents.

-   Host range evaluations of some of these potential agents are
    scheduled to begin in 2000.

-   Partnerships will be developed with citizens and groups affected by
    Cape ivy on the mainland and in Hawaii.

**Yellow Starthistle, *Centaurea solstitialis***

-   ARS scientists stationed at the European Biological Control
    Laboratory conducted detailed ecological investigations over several
    years to determine the natural enemy complex for yellow starthistle.
    High priority natural enemies were tested for safety.

-   Five biological control agents have been established for yellow
    starthistle: two flies, *Urophora sirunaseva* (released in 1984) and
    *Chaetorellia australis* (1988), and three weevils, *Bangasternus
    orientalis* (1985), *Larinus curtis* (1992) and *Eustenopus
    villosus* (1990). This complex of natural enemies is widely
    established, and contributes to reduce yellow starthistle.

-   In 1996, ARS scientists discovered that a new fly, *Chaetorellia
    succinea*, was established. It was determined that this cryptic
    species, nearly identical to *C. australis*, was probably a
    contaminant in a shipment from Greece in 1991.

-   Host-specificity testing of the new fly is being completed, and
    preliminary indications are that it is unlikely to cause significant
    damage to non-target species, and may help in biological control of
    yellow starthistle.

**Tropical Soda Apple (TSA), *Solanum viarum***

-   TSA has been called \"the plant from Hell.\" It was introduced into
    southern Florida from Brazil several years ago. The plant is now
    well established over half of the Florida peninsula, and is rapidly
    spreading from southern Florida to other states of the South, with
    serious outbreaks confirmed in Georgia and Mississippi, and
    sightings as far north as Pennsylvania.

-   TSA is a serious pest primarily in pastures and uncropped areas but
    has the potential to invade cropped fields as well.

-   The most important means of spread of TSA is through the manure of
    cattle. Seeds have also been spread in bags of composted manure sold
    to gardeners, and in hay from infested pastures, as well as by
    wildlife.

-   TSA is a coarse plant with attractive fruits that animals like, and
    when they eat the fruits it takes a week or more for the seeds to
    pass through the digestive system. Cattle that have grazed in
    infested pastures need to be quarantined during that period to avoid
    spreading the weed.

-   Natural enemies of TSA and other *Solanum* spp. are being sought in
    Brazil by ARS and partners.

-   ARS conducts research on TSA at three locations: Tifton, Georgia
    (biology and life cycle characteristics of TSA; screening for
    herbicide efficacy on TSA); Orlando, Florida (control of TSA in
    vegetable production systems); and Stoneville, Mississippi (survey
    data; establishing how the weed is spread; physiology and biological
    control of TSA).

-   In all cases the work is cooperative with APHIS, Cooperative
    Extension Service, State Experiment Stations, and other agencies. An
    informal working group involving State and Federal personnel from
    Florida, Alabama, Georgia, Mississippi, and North Carolina meets
    regularly to share information and coordinate efforts.

-   ARS research established that TSA is well adapted to conditions as
    far west as Austin, Texas, and that it is potentially a more serious
    pest in the Mississippi Delta than in Florida. ARS cooperative
    research involving all three locations has developed a promising
    management strategy to gain control of the weed.

-   Biologically based management of TSA may be the best long-term,
    sustainable solution to this invasive weed.

-   ARS will continue current work on TSA; jointly with State Experiment
    Stations and other Federal agencies, develop and expand a
    coordinated approach to this invasive exotic weed. We will develop
    improved methods of detection and control of TSA, and decreased rate
    of spread to new areas.

-   If acceptably specific biological control agents are found in South
    America, their use could help reduce the spread of TSA, and may be
    the only mechanism available for cost-effective management in the
    long term.

## ARTHROPOD PESTS

**Asian Longhorned Beetle (ALB), *Anoplophora glabripennis***

-   The ALB, a pest of hardwood trees, invaded the United States from
    China. First discovered in Brooklyn, NY, in 1996, the beetles have
    also damaged and killed maples and horse chestnuts in Chicago and on
    Long Island, NY. The beetle larvae bore into hardwood and cause
    severe damage to many trees, including sugar maples, apple, ash,
    birch, black locust, elm, hibiscus, mulberry, poplar, aspen, Russian
    olive and willow.

-   ALB have been reported in warehouse cargo in Alabama, California,
    Florida, Georgia, Indiana, Maine, Massachusetts, Michigan, New
    Jersey, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina,
    Texas, Washington, and Wisconsin. Action agencies have been
    attempting to eradicate the beetle by destroying infested trees.

-   Unless eradicated, the ALB could denude Main Street U.S.A. of shade
    trees, affect lumber and maple sugar production, threaten tourism in
    infested areas, and reduce biological diversity in forests. Billions
    of dollars could be lost.

-   ARS has developed a research program in alignment with a Science
    Advisory Panel convened to address programmatic needs, as verified
    by the States of New York and Illinois and the USDA Forest Service.
    Congressionally appropriated new funds and temporary funds are being
    used to support both State and Federal agencies. ARS is developing
    technologies that will be used by APHIS for eradication. Long-term
    management strategies are being developed in the event that this
    pest cannot be eradicated. ARS has developed a 5-year research and
    action plan with its cooperators that include ALB fundamental
    biology and systematics; population ecology and dispersal; detection
    and survey; biological control; chemical, cultural, and mechanical
    control; and IPM.

-   The USDA response to this threat is a model of collaboration for
    work on a newly introduced insect pest. USDA imposed an interim ban
    on import of untreated wood products from China last December, and
    is working on a permanent rule for regulating the import of
    untreated wood from around the world. These actions are essential
    for stopping and slowing the entry of invasive pests, including more
    Asian longhorned beetles. APHIS, with support from the Forest
    Service and many State and local partners, is leading an aggressive
    survey effort to ensure existing Asian longhorned beetle populations
    are detected and eradicated.

-   APHIS, ARS and FS are conducting a coordinated research and
    development program to provide new knowledge and technology
    essential for more effective survey and control. In particular, two
    pheromones that attract ALB in laboratory tests were isolated by ARS
    scientists at the Insect Chemical Ecology Laboratory in Beltsville,
    Maryland, and were tested in the field in China. If the tests are
    ultimately successful, a pheromone-based trap may be developed with
    partners.

-   At the ARS Beneficial Insects Introduction Research Unit in Newark,
    Delaware, work has progressed in determining ALB biology (in
    collaboration with the State University of New York at Syracuse).
    ALB was found to disperse 1400 m per year, much farther than the
    100-200 m previously reported. This information can be used by APHIS
    to readjust quarantine boundaries.

-   Also, in collaboration with ARS' Sino-American Biological Control
    Laboratory and the Chinese Academy of Forestry, work has been
    initiated to define the natural complex of the ALB and related
    beetles in China, information necessary for importation of natural
    enemies of the beetle. A wasp and a parasitic beetle show particular
    promise as biological control agents. Finally, improved methods for
    detecting infested trees are being developed in collaboration with
    the State University of New York at Syracuse. Movements by ALB
    larvae can be differentiated from carpenter ants, even against
    significant background noise. Currently, APHIS is relying on sight
    to identify beetle holes in trees to determine which trees need to
    be removed.

-   In cooperation with Cornell University, work is underway to identify
    and develop pathogens from the ALB's native distribution, as well as
    to evaluate North American strains of a fungal pathogen used
    extensively to control beetle pests (including development of bait
    trap methods for pathogen auto-dissemination), to develop wood-and
    cellulose-based diets for rearing ALB, to translate Chinese
    literature and, in cooperation with Beltsville, Maryland, to prepare
    an identification guide. IPM support is being provided to Newark,
    Delaware.

-   USDA is working with many partners with other Federal agencies,
    universities, local and State governments to increase public
    awareness and participation in combating this serious pest.

**Glassy-winged Sharpshooter (GWSS), *Xylella fastidiosa* /Pierce's
Disease (PD)**

-   GWSS strains cause a number of devastating diseases of agricultural
    crops, ornamentals, and forest and shade trees. These include PD of
    grapevines, almond leaf scorch, phony peach, plum leaf scald,
    oleander leaf scorch, and leaf scorch diseases of oaks, maples and
    sycamores.

-   With the arrival of the GWSS vector in southern California in the
    mid-1990's, potential damage to agricultural and ornamental crops is
    now acute. Over 700,000 acres of wine, table, and raisin grapes in
    California are threatened (current value \$2.8 billion per year), as
    is California's \$9 billion per year wine industry. California
    growers have no effective means for controlling PD or its GWSS
    vector.

-   On January 21, 2000, Deputy Secretary Richard E. Rominger and ARS
    Administrator Floyd P. Horn charged the Agricultural Research
    Service (ARS) Pacific West Area and National Program Staff to assess
    research and implementation needs for combating the GWSS and PD
    epidemic. On February 17-18, 2000, ARS convened a Response Team of
    senior level technical experts and program managers to provide this
    assessment.

-   The near-term focus is reduction of GWSS populations, since methods
    to combat PD directly are more problematic.

-   In late 1999, APHIS allocated temporary funding (\$360,000) for
    insecticide treatments to citrus and grapes. APHIS, ARS
    \[represented by T. Henneberry (Phoenix) and E. Civerolo (Davis)\],
    and the California Department of Agriculture (CDFA) are coordinating
    a pesticide trial on citrus, expanding pesticide trials to grapes,
    and developing a plan for the 2000 season. Particular attention will
    be given to immediate treatment of grapevines at the border of the
    vineyards, where GWSS adults were observed by the Team to be
    accumulating.

-   ARS provided \$100,000 temporary funding in FY 1999 to the
    University of California (UC) as part of a greater effort to develop
    an integrated pest management plan for PD. These funds will be used
    to determine GWSS biology (UC-Riverside) and behavior and to develop
    molecular markers for identifying host resistance genes in grape
    (UC-Davis).

-   The State of California has appropriated \$750,000 per year for
    three years for PD research, to be matched by \$250,000 per year
    grower funding. GWSS/PD Task Forces (State or Governor's; University
    of California) were convened to determine research needs, and a
    separate review panel is in the process of allocating these funds.

-   Other funding (\$250,000) by the local governments in Temecula City
    and Riverside County is available for additional research.

-   ARS (Davis), with UC-Davis and CDFA researchers, will cooperatively
    evaluate Actigard to induce resistance to Xf infection in the
    Temecula Valley this season.

-   ARS (Weslaco), with UC-Riverside and CDFA researchers, have
    initiated efforts to explore for biological control agents of GWSS.

-   ARS (Kearneysville), with UC-Riverside, will investigate the
    feasibility of adapting ARS-developed kaolin clay technology
    (Engelhard Corp.) to repel GWSS from grapes.

-   If suitable, and desired by its California partners, ARS (Phoenix)
    will transfer its silverleaf whitefly ELISA monitoring technology to
    California researchers for adaptation to GWSS.

**Small Hive Beetle (SHB), *Aethina tumida***

-   SHB is an exotic nitidulid beetle, native to South Africa. It was
    first observed in Florida in honey bee hives in St. Lucie County in
    June of 1998 by the Florida Department of Agriculture and Consumer
    Services (FDACS).

-   During July 1998 SHB was found in five other counties in Florida.
    The bee colonies in these counties were put under state quarantine,
    and their movement out of the state was banned. However, since then
    additional infested hives have been reported in 11 states - Georgia,
    South Carolina, North Carolina, New Jersey, Pennsylvania, Maine,
    Massachusetts, Minnesota, Wisconsin, Ohio and Iowa. In some cases,
    entire bee yards have been destroyed by SHB which feeds on brood and
    fermenting honey.

-   Over 1000 hives are estimated to have been lost to SHB. Bees are
    known to abandon the beetle infested hives. Consequently, this
    introduced pest from South Africa is causing a high level of anxiety
    in U.S. commercial beekeepers, both in the southeastern United
    States, as well as in the entire national bee industry.

## Pink Hibiscus Mealybug (PHM)

-   PHM was first reported in the Western Hemisphere (excluding Hawaii)
    in Grenada in 1994, where it was found infesting several crops.

-   The immature stages of PHM feed on plants and cause damage by
    injecting a toxin.

-   PHM can infest, reproduce, and cause severe damage on 200+ genera in
    70 different families of plants, including cotton, citrus, many
    vegetables, grapes, ornamentals, and other species of major
    importance to U.S. agriculture. APHIS has estimated the mealybug's
    potential cost to the U.S. at \$750 million per annum.

-   Since its first detection in Grenada, it has spread rapidly through
    the Caribbean Islands where it is causing damage in the U.S. Virgin
    Islands of St. Thomas, St. John and St. Croix, and Puerto Rico. In
    1999, it was discovered to have invaded the mainland, in southern
    California (south of San Diego), where it is considered to be an
    established, invasive species. This rapid spread and wide host
    range, makes the PHM a severe threat to agriculture in the United
    States.

-   To slow the spread and reduce damage caused by this pest, APHIS, in
    collaboration with ARS, has implemented a biological control program
    throughout the Caribbean Basin. On some islands, e.g., St. Kitts,
    this effort has already caused the pest to decline to tolerable
    levels. The program has now been transferred to California; however,
    it is not known whether parasites currently available for release,
    ones adapted to moist subtropical areas, will be effective in the
    hot, dry areas of southern California.

-   ARS has assisted APHIS in this program through the collection,
    identification, quarantine clearance, and delivery of biological
    control agents from Africa, Asia, and Hawaii. APHIS is also using
    ARS Caribbean facilities to rear parasites for release. ARS is
    working with APHIS to develop a pheromone-based trap.

-   In FY 1998, ARS expanded its biological control program in Southern
    Florida to assist in controlling exotic insect pests such as the
    PHM, by adding two new SYs to Ft. Pierce; this laboratory
    collaborates with work in the Caribbean area. Temporary funding
    (\$200,000) from FY1999 will be used in FY 2000-2001 to conduct
    research in France, Australia, Beltsville, and at the University of
    California-Riverside to address the PHM problem in California,
    primarily by expanding biological control/integrated pest management
    and pheromone-isolation efforts.

-   ARS believes that exotic insect pests such as the PHM, the
    *Paracoccus marginatus* mealybug (now in the Dominican Republic),
    vine mealybug, silverleaf whitefly, brown citrus aphid, thrips
    palmi, citrus root weevil, and others, will continue to be major
    problems for United States agriculture.

-   ARS agrees with APHIS that a specific "SWAT Team" approach is needed
    to address these threatening pest problems and that whenever
    possible, these problems should be addressed before the pests invade
    the United States.

**Imported Fire Ant (IFA), *Solenopsis invicta***

-   IFA currently infests over 300 million acres in 13 southern States.
    Since February 1997, there have been periodic infestations of fire
    ants in California. Some of these infestations in almond orchards in
    Karen County were traced back to infested bee hives imported from
    other States for almond pollination.

-   In November 1998, new infestations in two nurseries and 70 ant
    mounds along a roadside in Orange County near Irvine in Southern
    California were reported. This infestation was later found to cover
    18 acres. Periodic seasonal infestations expand as far north as
    Maryland and Pennsylvania.

-   ARS scientists, together with APHIS experts, serve on the Science
    Advisory Panel set up by the California Department of Food and
    Agriculture (CDFA) in 1998. CDFA and the Panel recommended two
    strategies: a short-term strategy includes treatment of all mounds
    with baits, insecticidal drenches and granules (and even hot water)
    to reduce the IFA populations; and a long-term strategy includes a
    minimum of two aerial bait applications per year for a four- to
    five-year period, and biological control using imported natural
    enemies.

-   In 1999, ARS released the first natural enemy of IFA, a phorid fly,
    in Florida. It is established at some sites, and is spreading
    slowly. Augmentation of the distribution of the phorid is needed,
    and is being pursued by ARS with our customers and partners.

## 

**Fruit Fly, *Bactrocera* spp.**

-   The guava fruit fly, the Oriental fruit fly, and several other
    related flies of the genus *Bactrocera* are characterized by the
    males being attracted to methyl eugenol.

-   ARS scientists in Hawaii and elsewhere developed an extremely
    effective, economical eradication procedure, called the male
    annihilation technique, which takes advantage of this feature to
    lure males to insecticide-treated traps where they are killed.

-   The attractant is very potent and this technique has been used on
    numerous occasions to eradicate Oriental and related flies in
    California and elsewhere.

**Africanized Honey Bees (AHB), *Apis mellifera***

-   These species are well established in Arizona, California, New
    Mexico, Puerto Rico, Texas, and part of the Virgin Islands. During
    FY 1997 AHB expanded their range only slightly in Texas and New
    Mexico. However, in Arizona they crossed over the central mountain
    range and are now found in all counties and at altitudes below 8,000
    feet elevation.

-   It is now conceivable that they will reach the Four-Corners area
    within 1-2 years. In California, Africanized bees have reached San
    Diego and are in Los Angeles. The most recent data from ARS traps
    along the Rio Grande River indicate that over 80 percent of swarms
    captured are Africanized. ARS anticipates the migration of AHB to
    Louisiana.

-   Methods developed by ARS are effective for control of AHB swarms and
    removal of feral foraging populations on high-usage public land.

## DISEASES

**West Nile Virus (WNV)**

-   WNV is an arthropod (insect)-borne virus.

-   It was isolated in the Western Hemisphere for the first time in the
    summer of 1999. The virus infects people, birds and horses and was
    isolated from several mosquito species. While the virus causes a
    mild disease in healthy human adults, it can be severe in the very
    young and elderly.

-   In New York City, which seemed to be the epicenter of the
    infections, at least 5 people died of the disease in 1999. On Long
    Island approximately 20 horses were infected and a significant
    number of those died from the disease. A number of bird species were
    affected both in zoos in New York and Connecticut as well as
    domestic crows in which there was a large die-off. Virus was
    isolated from dead birds and groups of mosquitoes in a number of
    Northeastern and Mid-Atlantic States.

-   The big question at the end of the mosquito season was whether the
    virus would overwinter in mosquitoes or animals. Unfortunately, the
    virus has been isolated from mosquitoes collected in early March
    2000.

-   ARS has programs in place to help deal with the potential
    consequences of a WNV reappearance this year:

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-   ARS scientists have infected chickens and turkeys to assess the risk
    of U.S. livestock to WNV virus. The species do produce virus but the
    virus, in these experiments, did not cause disease.

-   ARS has developed two new types of adult mosquito traps. In a
    cooperative effort with Yale, Centers for Disease Control (CDC) and
    the Bronx Zoo, these traps are being used at the zoo to determine
    mosquito types at the zoo, to test trapped mosquitoes for presence
    of WNV and to determine feasibility of "trapping-out" as a means of
    mosquito control.

-   ARS and the CDC are cooperating in a risk assessment program based
    on previous geographic distribution information on the virus.

-   ARS continues to interact with the APHIS Emergency Preparedness
    Program and provides technical assistance for their efforts on WNV.

## Plum Pox Virus (PPV)/Sharka Disease

-   Plum pox, caused by the PPV, is a very serious virus disease of
    *Prunus* species (stone fruits and some nuts) including peaches,
    plums, apricots, nectarines, cherries, and almonds. It is
    transmitted by grafting and by several species of aphids commonly
    found in orchards.

-   PPV can cause losses of 80-100 percent in susceptible varieties due
    to lower yields and blotched or misshapen unmarketable fruit.
    Varying degrees of tolerance have been described and used in
    breeding programs, but high levels of natural resistance have not
    been described.

-   PPV has occurred in Europe and the Middle East for many years and in
    Chile since 1992. APHIS and ARS scientists positively identified PPV
    for the first time in the United States in October 1999 in
    commercial peach orchards in Adams County, Pennsylvania (near
    Gettysburg). Some growers reported seeing similar symptoms as early
    as 1997. The disease has a latent period in trees (period of time
    between infection and symptoms) of 3 to 5 years, so it is likely
    that the virus was introduced several years before.

-   APHIS and the Pennsylvania Department of Agriculture have placed the
    area of known infection under quarantine and are planning a program
    aimed at determining the extent of infection and eradicating the
    disease.

-   PPV is quarantined by most countries, including the United States,
    and importation of budwood and rootstock are prohibited from areas
    where PPV is known to occur. Quarantine actions would have a
    devastating impact on the *Prunus* nursery industry in Pennsylvania
    and wherever else the disease is found.

-   In the early 1990\'s, ARS scientists in Beltsville developed a
    rapid, sensitive and specific test for PPV. This test was used to
    confirm the presence of PPV in Pennsylvania. In 1991, ARS scientists
    in Kearneysville, West Virginia, developed genetically engineered
    plum trees that continue to show a high resistance to the virus.
    Regulatory and research planning sessions were held in Pennsylvania
    in December, 1999, to assist in the development of regulatory
    strategies and identify both short-term and long-term research
    objectives. From these sessions, a listing of research objectives
    and proposals was developed. NPS has shared a copy of this list with
    the National Peach Council.

## Citrus Bacterial Canker (CBC), Asian Strain

-   CBC, caused by *Xanthomonas axonopodis pv. Citri*, is endemic in
    many citrus-production areas around the world. CBC quarantine
    actions by many countries affect international trade of fresh citrus
    fruit.

-   The disease has occurred from time to time in the U.S. where control
    involved quarantine and destruction of affected trees. An extensive
    eradication campaign in Florida from 1984 to 1992 cost \$200 million
    and involved 20 million trees.

-   CBC was again identified in September, 1995, in the Miami area,
    likely introduced via fruit or nursery stock brought in from a
    foreign country. A 13.5 square mile residential area was initially
    affected. Subsequent spread has expanded the affected area to more
    than 280 square miles (including parts of Broward County) and the
    quarantine area to more than 500 square miles.

-   Florida counties infected by year are: 1995 -- Dade; 1997 --
    Broward; 1998 -- Manatee; 1999 - Collier, Hendry, West Palm, and
    Hillsborough.

-   The Florida Department of Agriculture and Consumer Services (FDACS)
    has established the following restrictions in efforts to prevent
    spread: (1) no transport of fruit within 100 miles of the infected
    area to outside locations; (2) measures to prevent spread of the
    bacterium on workers' clothing and equipment; (3) no movement of
    citrus through the Miami Airport or from Florida to California,
    Texas, Arizona, Puerto Rico, or Guam; and (4) destruction of all
    infected trees and removal of recent growth on all trees within a
    125 ft. radius.

-   Recent ARS studies indicate that the 125 ft. distance should be
    increased to 1900 ft. This finding was the basis for a new rule that
    will be implemented as resources permit.

-   In late 1999, canker was detected in 45+ trees in a Homestead,
    Florida, commercial lime orchard. This is the first CBC detection
    south of Miami and a quarantine of this area will shut down the lime
    industry there.

-   In late 1999, canker was detected in 2+ trees on residential
    properties in Palm Beach. This is the furthest northward spread on
    the east coast and is a grave threat to the Indian River citrus
    producing area, which is only slightly further north.

-   In 1999, about \$22 million was spent for survey and eradication. In
    2000, the budget is \$31 million.

-   To date, 250,000 trees have been destroyed, 114,000 on commercial
    orchards, 70,000 on abandoned groves, and the rest on residential
    properties.

-   ARS, at the request of APHIS and FDACS, assisted in determining the
    extent of infection, rate of spread, and foci of infection. As a
    member of the Florida Citrus Canker Risk Assessment Committee, ARS
    also helped review FDACS procedures and facilities for canker
    diagnosis.

-   ARS epidemiological studies have been the basis for current
    eradication policies and are used to estimate future spread and to
    target resources.

-   ARS supports APHIS, FDACS, and industry efforts to eradicate CBC in
    Florida.

-   ARS developed a DNA-based assay for rapid detection of the CBC
    bacterium.

**Other ARS Programs Against Invasive Species**

**The USDA-ARS Areawide Pest Management Partnership Program: An Integral
Component of the USDA-IPM Initiative**

-   The USDA Land Grant University Integrated Pest Management (IPM)
    Initiative, commenced in 1994, reflects the redirection and
    combination of old and new resources of USDA and Land Grant
    University Programs into a single coordinated and cooperative effort
    with farmers, private consultants, and industry to achieve the
    national goal of IPM on 75% of the crop acres by the year 2000. ARS'
    major contribution to this initiative, and within the framework of
    the Initiative's Strategic Plan, resides within the Agency's
    Areawide Pest Management Program, as well as with its ongoing
    base-funded IPM research projects.

-   In 1995 the Agricultural Research Service implemented an Areawide
    Pest Management Initiative with the goal of demonstrating the
    positive impacts and advantages to farmers and ranchers of such a
    program through increased grower profits, reduced worker risks from
    chemical pesticides, an enhanced environment, and a proven
    superiority of a strategy that incorporates biologically-based pest
    control technologies. Four multistate projects were put in place for
    invasive insect and weed pests and have resulted in widespread
    adoption of environmentally sound technologies by farmers and
    ranchers into IPM and sustainable agriculture systems. These pests
    included codling moth on apples and pears in the Pacific Northwest,
    corn rootworm in the Midwest, leafy spurge in the northern Plains,
    and stored product insects in the Midwest. The Areawide IPM Program
    focuses on management of pests where existing technologies
    (including pheromones, biological control agents and alternatives to
    chemical pesticides) are most effective when used over a multi-state
    or multiregional area. The success of the program is dependent on
    full partnering and participation between ARS, CSREES, FS, ERS,
    APHIS, SAES and extension facilities, farmers and ranchers, and
    other private sector (consultants, industry, etc.) entities.

-   [Codling Moth Areawide Program]{.underline}. An areawide suppression
    for codling moth was implemented in 1995 in Washington, Oregon and
    California on apples and pears using pheromones to disrupt or
    prevent mating. Although this project was completed in 1999,
    additional funding has been provided for fiscal year 2000 to support
    the transition phase of the program for the growers. This was a
    five-year, ARS-led study out of Wapato, Washington to suppress
    codling moth populations and reduce damage below economic thresholds
    with a minimum use of pesticides. Populations of codling moth were
    reduced to almost undetectable levels at some of the project sites.
    The cost of control was less in the mating disruption-treated
    orchards than in orchards treated with conventional pesticides. The
    number of pesticide sprays were reduced in all mating disruption
    orchards and were entirely eliminated at most of the project sites.
    In 1994, before the areawide program was initiated, only 11,000
    acres were treated with the mating disruption technology in
    Washington State. In 1999, more than 75,000 acres were under the
    technology. It is estimated that the orchard growers realize a
    savings of \$400 per acre using mating disruption, since the use of
    the primary insecticide, Guthion, has decreased. Guthion is one of
    the organophosphate insecticides that could be impacted and lost as
    a result of the *Food Quality Protection Act* of 1996 (*FQPA*).

-   [Corn Rootworm Areawide Program]{.underline}. Corn rootworms are the
    targets of almost half of the insecticides used in row crops. ARS'
    5-year areawide IPM program in the Midwest states of South Dakota,
    Indiana, Illinois, Kansas, and Iowa, as well as in Texas, using an
    adult corn rootworm attract and kill technology, has yielded corn
    rootworm reductions of more than 70-90 percent in most of the test
    sites after four years. A number of corn growers have expressed
    interest in undertaking their own programs using this new
    technology. A 90% reduction in the amount of prophylactic soil
    insecticide applied to U.S. corn grown in the Midwest United States
    could result in \$300 million estimated savings. The program is led
    by ARS out of Brookings, South Dakota and was initiated in 1996.

-   [Leafy Spurge Areawide Program]{.underline}. Leafy spurge, an exotic
    weed that costs millions of dollars in losses each year, infests
    over 1,000,000 acres of rangeland. The pest can be virtually
    eliminated by the use of insect natural enemies, grazing practices,
    and other technologies. ARS at Sidney, Montana has led an effort to
    design an areawide integrated pest management program to deal with
    this noxious weed. Field days, tours of control sites, and
    demonstrations of research technology have increased since the
    initiation of the program in 1997. Program managers and cooperators
    (TEAM Leafy Spurge) have been devising and demonstrating practical
    leafy spurge management strategies that can be applied to common
    habitats and land being utilized in the Upper Great Plains. During
    the 1998 field season, TEAM Leafy Spurge coordinated and provided
    timely collection and delivery of a total of 1.9 million *Aphthona*
    species beetles to TEAM Leafy Spurge researchers and weed managers
    in Montana, North Dakota, South Dakota and Wyoming. The leafy spurge
    areawide project has been initiated as a partnership between the ARS
    in Sidney, Montana; APHIS; North and South Dakota State
    Universities; and Montana State University; in cooperation with
    ranchers, FS, CSREES, the Bureau of Land Management, National Park
    Service and the state Departments of Agriculture, and will run
    through fiscal year 2001. In 1999, at the *Spurgefest Field Day*
    held on June 29 to July 1 in Medora, North Dakota, scientists
    involved with the program gave away an additional 10 million
    *Aphthona* flea beetles to ranchers and land managers.

-   [Stored Grain Insects Areawide Program]{.underline}. In 1997 ARS
    implemented an areawide pest management program on stored grain
    insects in the Midwest United States, specifically in Kansas and
    Oklahoma. ARS scientists and scientists from Kansas and Oklahoma
    State Universities are the key participants in the stored-grain
    insect project, with farmers and operators of grain elevators as
    team members. It was determined that this project met the criteria
    of an areawide concept because grains are moved from the farm to
    country elevators or network and satellite elevators, to terminal
    elevators, to mills, and to overseas export terminals. This is
    analogous to the movement of insects between fields, except stored
    grain and the pests associated with them are transported by truck
    and railcar. Currently, phosphine gas and other insecticides are
    used for pest control in stored grains. The technology being used
    for this project will include early aeration to cool grain and
    decrease insect and mold population growth, as well as other
    technologies such as monitoring models for forecasting, safe
    grain-storage periods, sanitation, and other tactics as needed. This
    project will run through fiscal year 2001.

-   [Fruit Flies in Hawaii]{.underline}. In fiscal year 2000, ARS
    initiated a fifth areawide program in the Hawaiian Islands for
    management of fruit flies using male annihilation, baits, biological
    control, and sterile male fruit flies as needed. The target species
    include Mediterranean, melon, oriental and Malaysian fruit flies.
    The overall goal is to suppress these pests below economic
    thresholds. Fruit flies, especially the oriental and Mediterranean,
    continue to show up in mainland United States, and the technologies
    being demonstrated in Hawaii could enhance suppression and
    eradication programs of these invasive species elsewhere.

-   [Miscellaneous Other Areawide-Related Partnership
    Programs]{.underline}. From 1992-1999 ARS has led Federal and State
    scientists in a nationally-coordinated research effort to develop
    technologies for mitigation of the silverleaf whitefly problem in
    ornamental, vegetable, melon, and fiber crops across the southern
    United States, and in greenhouses. This insect has been responsible
    for over \$ 2 billion in crop loss, damage, and control since its
    introduction into the United States in 1986. Areawide,
    community-based management approaches covering all affected
    commodities have emerged as the best strategy. Some crop management
    and community-oriented farm practices, such as water-use patterns,
    proximity of alternate host crops and spatial considerations have
    been implemented, resulting in whitefly population reduction. An
    excellent insecticide resistance management program has been
    implemented to conserve a major insect growth regulator
    (imidocloprid) found effective under the program. A number of other
    management tools have been developed and adopted by growers,
    including crop rotating, host-free periods, crop residue and weed
    destruction, host resistance, and biological control (fungi,
    parasites and predators). Overall losses have not increased in
    agricultural communities where the silverleaf whitefly is a factor
    in crop and horticultural production and have declined in a number
    of cases.

-   In Mississippi, an areawide project that was initiated in 1990 and
    completed in 1998 used early-season spraying of an insect virus to
    suppress populations of the bollworm and tobacco budworm, thus
    decreasing the need for chemical insecticide treatments for these
    cotton pests. With the advent of Bt cotton, however, farmers have
    not adopted the virus technology to any great extent, although if
    resistance develops, the virus technology could be a backup. This
    project was replaced in 1998 with an areawide pest management
    program for the tarnished plant bug and managed out of Stoneville,
    Mississippi. The Program uses new insecticidal chemicals, pheromone
    trap, natural enemies (in spring weed hosts), reduction of wild host
    plants and other IPM practices.

-   A community-based field trial study for control of the blacklegged
    tick and lyme disease by treating deer using a four-post feeding
    automated treatment system in the northeastern United States was
    implemented in 1997.

**FOR ADDITIONAL INFORMATION, PLEASE CONTACT THE ARS INVASIVE SPECIES
COORDINATORS:**

Dr. Ernest S. Delfosse

USDA, ARS, National Program Staff

National Program Leader for Weed Science

The George Washington Carver Center

5601 Sunnyside Avenue

Building 4, Room 4-2238

Beltsville, MD 20705-5139 USA

Telephone: 301-504-6470

Facsimile: 301-504-6191

E-mail: esd@ars.usda.gov

http://www.ars.usda.gov

NPS Service Center: 301-504-4650

and

Dr. Kevin J. Hackett

USDA, ARS, National Program Staff

National Program Leader for Biological Control

The George Washington Carver Center

5601 Sunnyside Avenue

Building 4, Room 4-2228

Beltsville, MD 20705-5139 USA

Telephone: 301-504-4680

Facsimile: 301-504-6191

E-mail--kjh@ars.usda.gov

http://www.ars.usda.gov

NPS Service Center: 301-504-4650