Floridas citrus industry was delivered another blow last fall

					Citrus Greening Found in Florida
Scientists determine best course of action

F    lorida’s citrus industry was delivered another blow last fall
     when Huanglongbing, also known as citrus greening or
yellow dragon disease, was identified in south Miami-Dade
County. Citrus greening may be the most serious citrus disease
in the world. It is widespread in Asia, Africa, and Saudi Arabia.
    Citrus greening is a bacterial disease that attacks the
vascular system of plants. Once infected, there is no cure for
the disease. Where the disease is endemic, citrus trees
decline and die within a few years. Bacteria are transmitted primarily
by insect vectors (citrus psyllids), but can also be spread through
plant grafting and movement of infected plant material.
    Asian citrus psyllid, the insect that carries the Asian strain
of citrus greening, was found for the first time in the U.S. in Delray
Beach in 1998. However, no disease infection was found at that time.
                                                                  were discontinued
Quarantines and other control actions were implemented, butContinued on page 2
when psyllid populations quickly spread and became established throughout the state.
                                                                      Continued on page 2

 Citrus Canker Program Changes
 In January, the USDA withdrew funding for the eradication
 program due to the projection that as many as 200,000
 acres of commercial citrus could become exposed to
 citrus canker within the next year due to the impacts of
 the 2004/2005 hurricane seasons. Other set backs                         % of commercial trees
 involved legal constraints that hindered program                                    destroyed
 operations for nearly four years and caused as many
 as 200,000 additional trees to become infected. All involved parties are extremely
 disappointed that eradication was not achieved. However, the effort to eradicate
 canker from the state was by no means for naught. The citrus industry generates
 $9 billion dollars annually, a large portion of which contributes to Florida’s healthy
 economy. For the ten years that the program protected the industry from canker,
 we helped preserve a $90 billion economic asset to the state. Once the science
 indicated that eradication was no longer possible, state and federal agriculture
 officials began working with the scientific community to develop a strategy for an
 overall citrus health response program that will encompass control and suppression of
 citrus canker, citrus greening, citrus tristeza virus and other plant pests and diseases.
 The plan will be finalized within the next few months.
                                           Citrus Greening Found in Florida                                               Continued from page 1
 Richard Gaskalla
 Recipient Florida
                                           However, cooperative greening surveys by DPI and USDA were intensified and
 Nursery, Growers
                                           ultimately led to the discovery of citrus greening in 2005.
 and Landscape                                 On-going citrus greening survey: As part of a cooperative effort between
 Association’s 2005                        the state and the USDA, targeted surveys were conducted in communities with
 Friend to the                             concentrations of people from countries where citrus greening is endemic, because
 Industry Award                            they may be at higher risk of receiving infected plant material. In August 2005
                                           during one of the targeted surveys in Homestead, two citrus trees were identified
 “This award was presented to              as showing symptoms of citrus greening. Laboratory testing confirmed the disease.
 Richard for many reasons, among               What is being done? An Incident Command Post was immediately estab-
 which is the leadership he and his        lished co-directed by USDA and DPI personnel. A delimiting survey began to try
 DPI team continually exhibit in           to identify the outer edges of the infection. Strategic meetings were held and a
 helping the industry successfully         science panel was named. Through January 2006, greening had been identified
 navigate through pest and disease         in eleven counties. Program updates can be found on the DPI Web site.
 episodes.”                                    All greening host plants in regulated areas are under quarantine and cannot
 - Ben Bolusky, FNGLA                      be moved. Psyllid host plants must be treated and confirmed to be psyllid free.
 Executive Vice President
                                               Disease control challenges: There are many challenges associated with
                                           this disease including a limited knowledge of the host range of the disease;
                                           difficulty in detection of the pathogen before symptoms are shown, which can
                                           take years; the risk of illegal importation of infected plant material; and, the
                                           disease can be graft transmitted from apparently healthy budwood sources.
CITRUS HEALTH                                  During early strategic planning meetings, the science panel discussed the
RESPONSE PLAN                              feasibility of eradication with regulatory officials. There was a consensus that
State and federal agriculture officials,   the estimated length of time of the disease’s presence in Florida, difficulty of
citrus industry representatives, and       detecting infected trees in a timely manner, movement by a small innumerable
the University of Florida Institute of                                          insect vector, and limitations of diagnostic
Food & Agriculture Sciences are                                                 tools precluded making eradication of the
developing a comprehensive plan for                                             disease feasible.
commercial citrus growers. The plan                                                Now, in addition to regulatory measures,
will address the management of                                                  best management practices are being devel-
citrus pests and diseases including                                             oped to assist industry and backyard citrus
citrus canker, citrus greening, citrus                                          growers control this and other citrus diseases.
tristeza virus and others. The plan will                                        These are just the first steps in what unfortu-
involve a multi-layered approach that                                           nately promises to be a long-term managment
will include enhanced surveillance                                              program.
and reporting, strict sanitation
controls, management of disease                                                              Contact: Wayne Dixon dixonw@doacs.state.fl.us
vectors, registration for fruit
movement, and certfication of
disease-free status.
The plan will also address residential
citrus management strategies which
will include public information and        Dr. Susan Halbert surveying for citrus greening
education programs.

                                                                                                        Asian citrus psyllid (size app. 3-4 mm)

                                                                                                            Left, Asian citrus
                                                                                                            psyllid parasite,
                                                                                                            (size app. 1 mm)
                                                                                                                  Right, Asian citrus
                                                                                                                    psyllid parasite,
                                                                                                                   (size app. 1 mm)
   Lopsided pummelo fruit                  Lemon tree with mottled leaves
                            Biocontrol Programs at Forefront
                            Successful endeavors and new initiatives

                            M       ass rearing of the phorid fly, the parasitizer of imported fire ants (IFA), enters its fifth year,
                                    while two new programs begin under cooperative agreements with USDA and UF/IFAS.
                             One uses a leaf-feeding beetle, Gratiana boliviana, to counter the spread of tropical soda apple
                             (TSA), an aggressive weed overwhelming state pasturelands . The other agreement funds the
                             production of two parasitic wasps, Anagyrus kamali and Gyranusoidea indica, as well as a predatory
                             beetle, Cryptolaemus montrouzieri, to be released against the pink hibiscus mealybug (PHM), a
Phorid fly attacking ant
                             recently introduced pest which is a serious threat to agriculture, forestry and the nursery industry.
                                 IFA annually cost the U.S. $5 billion in losses to households, businesses, schools, govern-
                             ments, and institutions, as well as $750 million in agriculture losses. In 2005, over 2.2 million
                             phorid flies of two species combined were reared at the Biological Control Rearing Facility in
                             Gainesville in support of a program developed by USDA scientist Sanford Porter. Flies were
                             shipped to twelve states and Puerto Rico for release against the IFA. Florida has had eight
                             releases since program inception with more scheduled in 2006. Establishment and distribution
                             of the phorid flies continue to be closely monitored, but at least half have successfully over-
                             wintered, a key criteria for success.
Tropical soda apple fruit        TSA was identified in Florida in 1988 and has since spread throughout the state. It is a tre-
                             mendous problem for cattle ranchers because it overgrows productive pastures. In natural and
                             recreational areas, it displaces natural fauna. G. boliviana will be reared in two screen houses in
                             Ft. Pierce. The voracious beetles will be distributed to areas with large stands of TSA across the
                             state to defoliate the plants, hindering their growth. UF/IFAS scientist, Dr. Julio Medal, con-
                             ducted six years of research on the beetle to confirm its efficacy and ensure no harmful side
                             effects to other crops.
                                 PHM was first reported in the state in June 2002 and immediately a biocontrol initiative,
                             developed by the USDA, was begun that involved importing and distributing the two previously
                             mentioned host-specific parasites. These releases have had a dramatic effect controlling the
Tropical soda apple parasite spread and also the damage done in specific locations by PHM. However,
                                                 continually attaining these parasites from insectaries in
 Biocontrol Contributes to                       California or Puerto Rico is cost prohibitive. Thus a
                                                 permanent rearing program for the two parasites and
 Control of Asian Citrus Psyllid                 the predatory beetle will be established in Gainesville
  Dr. Ru Nguyen, FDACS-DPI, has been             to ensure the production numbers necessary for
  rearing and releasing two parasites of the     effective control of the PHM in Florida.
 Asian citrus psyllid in small numbers for                       Contact: Ed Burns burnse@doacs.state.fl.us     Pink hibiscus mealybug
 the last seven years.
 The eulophid ectoparasite Tamarixia             Beekeepers in the white suits - they’re the good guys
 radiata (Waterston) is established in                    The beekeeping industry has been struggling with fluctuations in honey
 areas where it has been released and has                 prices and reduced production due to pests and diseases. Now they’re
 shown parasitism levels as high as 90%.                  facing a public relations challenge due to the increasing numbers of
 The encyrtid endoparasite                                Africanized honey bees in the state. Honey bees are an integral compo-
 Diaphorencyrtus aligarhensis (Shaffee          nent of Florida agriculture - without the bees to pollinate, our fresh food supply
 et al.) has not been successfully              would be reduced by one third. Beekeepers have enjoyed a symbiotic relationship
 established and parasitism levels are          with their rural and urban neighbors because of the gentle nature of the European
                                                honey bee. Now that the more defensive Africanized honey bees are infiltrating
 much lower. No hyperparasitism of
                                                the state, entering through ports, natural pathways, and in colonies returning from
 these parasites has been observed by
                                                pollination stints in other states, the beekeeping industry, with help from DPI and
 Dr. Nguyen.                                    others, is working hard to educate the public about the impor-
 Success of these parasites in citrus           tance of bees. Learn more about the beneficial beekeeping
 groves has often been limited by the           industry at www.floridabeekeepers.org
 insecticide spray programs which have          As for the risks associated with the Africanized honey bee, as
 killed parasites as well as citrus pests.      with any potentially dangerous insect, be aware of your
                                                surroundings and learn how to protect yourself from stinging
 In residential areas where little or no
                                                insects at www.doacs.state.fl.us/pi
 spraying is done, high rates of
 parasitism occur.                                                   Contact: Jerry Hayes hayesg@doacs.state.fl.us
     Pest du Jour: Chilli Thrips                                                                               DPI Points of Interest
                                                                                                                     Ed Burns, a 25-
     In October 2005, chilli thrips (Scirtothrips dorsalis
     Hood) were found on roses in Palm Beach County.                                                                 year DPI
     This is the first identification of chilli thrips in the                                                        employee,
     U.S. This insect is a serious pest with a wide range of                                                         promoted to
                                                                                                                     Bureau Chief of
     distribution and a host range of up to 100 species from
     40 different families including many crops. Chilli
                                                                                                        Development & Biological Control.
     thrips species is extremely difficult to differentiate
     from other thrips in the field. Adult chilli thrips have                                                          Abbie Fox promoted to
     a pale body with dark wings and are less than 2 mm in                        Adult chilli thrips                  Assistant Chief of
     length. This thrips is mainly a foliage feeder; it does                    (size app. 3/4 mm)                     Methods Development &
     not feed on flower pollen. It apparently is capable of                                                            Biological Control.
     spreading tomato spotted wilt virus on peanut, peanut necrosis virus, peanut chlorotic                            With Ed and Abbie at the
                                                                                                                       helm, look out pesky plant
     fan virus, and tobacco streak virus. Chilli thrips is a pest of strawberries in Queensland,
                                                                                                                       pests and diseases.
     Australia; a pest of tea in Taiwan; a major pest of citrus in Japan and Taiwan; cotton in
                                                                                                                       Richard Weaver appointed
     the Ivory Coast; soybeans in Indonesia; and of peanuts, chillies and castor bean in
                                                                                                                       administrator of the Botany
     India. Severe infestations can result in total defoliation and potentially heavy crop loss.
                                                                                                                       Section. His experience
     The current known Florida distribution is restricted to Palm Beach County. What this                              includes curator of the
     will mean to Florida agriculture is unknown, but early survey results indicate that the                           Arnold Arboretum, Harvard
     impact may not be as damanging as first thought.                                                                  University.
                                                 Contact: G.B. Edwards edwardg@doacs.state.fl.us

                      Question:                                     From DPI’s EMAIL Bag                 Florida Department of Agriculture
                      Dear Sir or Madam: Thank you for your attention. I was bit today by a
                                                                                                         & Consumer Services
                      strange spider (I believe) though I’m fairly certain it is non-poisonous.
                      Still it burned as bad if not worse than a fire ant bite. About an eighth of       Charles H. Bronson, Commissioner
                      an inch in size. Black underneath and forward but has a seemingly                  Division of Plant Industry
                      hard back that actually looks like a seashell you would see on a hermit            Richard Gaskalla, Director
     crab, white and oval with reddish dots in a pattern that resemble an elaborate smiley
     face with ears. There are a few light spots underneath at the back. Sounds crazy. I                 Plant Industry Update
     do not have the ability to send a photo but I have enclosed a quick bit map sketch                  Editor: Denise Feiber, APR
     (best I could do). It got under my shirt somehow. Please just ease my mind and tell                 Copy Editor: Ellen Dyck
     me this is some sort of crab spider? Thank you very much.                                           Designer: Katrina Vitkus
                                                                                                         Photographer: Jeffrey Lotz
     Answer: Hello. Nice drawing! This is Gasteracantha                                                  Comments to: feiberd@doacs.state.fl.us
     cancriformis (a Latin name which means crab-like spiny body), a                                     352/372-3505 x102
     spiny orbweaver, family Araneidae. The bite, as you found out, can
     cause a temporary burning sensation. It is not otherwise                                            VISIT US ONLINE
     dangerous. Hope this helps. Feel free to contact me if you have
                                                                          G. cancriformis
     further questions.
     Sincerely, G. B. Edwards, Ph.D. [Your Friendly Neighborhood Spiderman]


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Gainesville, FL 32614-7100