NE PMC Insider
Internal newsletter of the Northeastern Pest Management Center.
Issue 13, July 2002
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NE PMC InsiderInternal newsletter of the Northeastern Pest Management Center. Issue 13, July 2002 |
Northeast
National
- Delaware: June 25 issue of Pesticide Briefs
- Maryland: Tomato Spotted Wilt Virus
- Audubon International Certifies 500
- New Jersey: NJinPAS website
- New York: Pest Management Practices in Public School Districts
About the Insider
New Pesticide Brifes have been posted at:
http://www.udel.edu/pesticide/briefs.htm
contents:
(1) ATRAZINE RISK ASSESSMENTS RELEASED; COMMENTS REQUESTED ON RISK
MITIGATION
(2) METHIDATHION REREGISTRATION
(3) BUSH PROCLAIMS JUNE NATIONAL PEST MANAGEMENT MONTH
(4) IR-4 PROGRAM
(5) METHYL BROMIDE ON CUT FLOWERS.
(6) IR-4 AND SECTION 18'S
(7) NEW METHYL BROMIDE ALTERNATIVE - FURFURAL
(8) PESTICIDE CANDIDATES FOR RISK MANAGEMENT DECISIONS
(9) REASSESSMENT OF NON-CONTRIBUTING OP TOLERANCES
(10) FACT SHEET ON WEST NILE VIRUS
(11) BALTIMORE MAN DIES OF WEST NILE VIRUS
and more to come later this week. Its been a busy month!!
submitted by Susan Whitney
IPM REPORT AS OF JUNE 26, 2002
TOMATO SPOTTED WILT VIRUS (TSWV).
By now you have probably heard about the tomato spotted wilt virus problems in Maryland and neighboring states. TSWV, a member of the thrips-transmitted tospovirus group, affects vegetable and field crops such as tomatoes, peppers, peanuts, potatoes, and tobacco. However, it is occasionally found in many ornamental and greenhouse crops. This growing season, TSWV was first detected in newly transplanted tobacco fields in St. Mary's and Prince George's Counties. I've included below a news release prepared by Dave Conrad, which summarizes what we currently know about the situation on tobacco. Since the mid-80s, epidemics of tomato spotted wilt virus have been troublesome throughout the South. TSWV has been a serious disease problem on tobacco in the flue-cured regions of Florida, Georgia and southern South Carolina. The disease has already caused major losses in Georgia fields and more cases are being reported every day. So far this season, the disease has showed up earlier than normal and further north in the eastern states. North Carolina tobacco and potato growers have reported serious losses due to TSWV which spread across the state rapidly. Moderate levels of the disease have been detected in potato plots at the Painter Research Station on the VA Eastern Shore according to Dr. Sam Alexander (Plant Pathology), and have occurred in tomatoes on the VA Eastern Shore and Tidewater Area, according to Clifton Slade (Virginia Cooperative Extension) and my counterpart, Dr. Tom Kuhar, at Painter.
In the past, Maryland growers have had sporadic problems with TSWV on processing tomatoes due to transplants already infected or infested with the thrips vector shipped in from the south. We solved this problem by producing our transplants in local greenhouses with strict thrips management. However, this is the first time that TSWV has occurred in commercial fields with transplants produced locally in outdoors seedbeds, suggesting the possibility of overwintering of thrips that vector the disease.
TSWV is vectored exclusively by thrips. Only nine of the more than 5000 described thrips species are proven vectors. Three of these, Frankliniella fusca (tobacco thrips), F. occidentalis (western flower thrips, WFT) and Thrips tabaci (onion thrips) are the chief vectors in the southern United States. Of these, the western flower thrips, has the broadest host range affecting a diverse variety of ornamental and vegetable crops. WFT is the chief TSWV vector in greenhouse settings around the world, as well as in vegetable growing regions in the south where it can overwinter. Tobacco thrips is the major vector in tobacco and peanut fields, whereas the onion thrips vector a strain of tospoviruses in onion and garlic crops. Both species are widely distributed in tropical, warm, and cool temperate areas around the world. In the mid-Atlantic states, WFT can overwinter in greenhouses, whenever temperatures are favorable for their development and host plants (including weeds) are available for food. Field infestations appear to be somewhat local and often occur later in the season in the proximity of greenhouses with a history of high incidence of WFT. A recent study showed that adult thrips can overwinter outdoors in nectarine orchards in southeastern Pennsylvania. This spring capture followed high WFT population densities in the fall and a milder than normal winter. Obviously, the record mild winter that just passed has probably accounted for the unusual occurrence of TSWV problems. Successful overwintering of WFT and other thrips species in outdoors habitats can result in the spread of TSWV to perennial weed hosts early in the spring. In one study, Canadian researchers collected weeds both in and near greenhouses where there was a history of TSWV. Many weeds were found to be both susceptible to TSWV and suitable hosts for thrips to lay eggs. Fifty species, including such common weeds as redroot pigweed, chickweed, lambsquarters, bindweed, thistle, galinsoga, pineapple weed, burdock, shepherd's purse, purslane, and black nightshade may be susceptible to TSWV.
Hopefully, our TSWV problems are the result of an unusual mild winter and thus probably would not occur following a normal or severe winter. However, in a typical scenario, TSWV will appear sporadically in an area, perhaps for years, then suddenly surge to epidemic proportions in agriculturally important host plants. Wherever TSWV incidence has increased enough to cause economic losses, it has remained a chronic problem. This pattern has been repeated in India, Australia, Hawaii, and in the southern United States. In some areas of California and Hawaii, tomato can no longer be grown due to TSWV infection.
Scouting for specific vectors of TSWV for control decisions is not feasible. Identification of different thrips species is very difficult in the field because most species are similar in appearance. Western flower thrips adults are slender, about 1.5 mm long, yellowish, and hold their fringed wings over their backs. Larvae are smaller and wingless, but otherwise resemble adults. Thrips are commonly found in the underside of leaves and in flowers and generally move quickly to shelter when disturbed.
The vector-virus relationship between thrips and TSWV is important to understanding how virus spread occurs. The tospoviruses replicate in their thrips vectors, thus the insects not only spread the virus, but serve as a virus host. Thrips cannot transmit tospoviruses unless they acquire the virus during their immature stages. When larvae feed on infected plants, ingested virus crosses the midgut barrier and enters the salivary glands. A midgut barrier in adults prevents virus ingested during this stage from moving to the salivary gland. While the insects remain infective for life, there is no evidence of transovarial passage from one generation of thrips to the next. The adult thrips is the critical stage for transmitting the virus between plants, since this winged stage is more mobile that the wingless larval stage which tends to remain on the same plant upon which it emerged. Thrips feed upon plants by rupturing leaf epidermal cells and slurping up the contents with a mixture of their saliva. It is at this point that the virus, being released with their saliva, has the opportunity to enter damaged plant cells and infect the plant. The thrips life cycle varies from 7 to 14 days at fluctuating temperatures between 68 to 98 F, so there are multiple generations on weed hosts and during the growing cycle of crop plants.
A systemically infected plant cannot be cured. Upon finding infected plant material the best course of action is to dispose of the plant as soon as possible. One infected plant can serve as a source to any other susceptible plant nearby. However, roguing out symptomatic plants is not always effective as a control for secondary infections because TSWV has often spread before symptoms develop. Generally, controlling weeds, avoiding contaminated host plants near the vegetable crop, and eliminating thrips in greenhouses is the best way to manage this problem.
To repeat, once symptoms start developing in the field, it is often too late to head off an epidemic. In general, the use of insecticides to control thrips has been an ineffective means of suppressing TSWV. In theory, lowering overall thrips populations with insecticides should effectively reduce in-field spread of TSWV. However, insecticides have proven to be ineffective at suppressing primary infection, which accounts for most virus transmission. There are several reasons why insecticides have not been effective for control of TSWV. Thrips tend to be hidden in flowers and buds (resulting in incomplete spray coverage), have a rapid life cycle with a high reproductive potential (eggs inserted in plant tissue are unaffected and hatch quickly replenishes the population), and have a wide host range including many weeds (thrips are constantly being blown into fields from these external virus reservoirs). In addition, widespread resistance has made chemical control more difficult. For example, resistance to certain pyrethroids, carbamates, organophosphates and abamectin, (not labeled for thrips) has been documented in certain thrips populations in the field. In my studies of nontarget effects of Bt and conventionally-sprayed nonBt sweet corn, high populations of thrips are relatively unaffected by Warrior treatments. This should give you an idea of how difficult it is to control a virus vector which only have to feed for 5 minutes to transmit the disease.
For more information on tomato spotted wilt, there is plenty of information via the Internet. In particular, good images of disease symptoms on tomato can be found at http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Tomatoes/Tom_SpWilt/Tom_SpWiltPhotoList.htm
Also, Ethel Dukty in our Plant Diagnostic Lab on campus has TSWV ImmunoSTRIP Tests that can be used for the detection of TSWV. Additional information on purchasing kits can be obtained online at http://www.agdia.com/cgi_bin/catalog.cgi/39300
From the Desk of: David L. Conrad
Extension Regional Tobacco Specialist
University of Maryland
For Release the Week of June 24, 2002
TOMATO SPOTTED WILT VIRUS (TSWV) CONFIRMED IN MARYLAND
A viral disease known as Tomato Spotted Wilt Virus (TSWV) has been found in Maryland Type 32 tobacco on farms in St. Mary's and Prince George's Counties. It is highly probable that this virus disease will appear in all tobacco producing counties in the State of Maryland.
TSWV first appeared in Georgia in 1986. Since then it has been a major field disease in the flue-cured regions of Florida, Georgia and southern South Carolina. The virus is spread by thrips. In tobacco the major vector is known as the tobacco thrips (Frankliniella fusca). The Western Flower Thrips (Frankliniella occidentalis) have been associated with TSWV on other crops and may be a vector here in Maryland as well. TSWV is picked up by juvenile thrips feeding on host plants with the virus. TSWV may be spread by both juvenile and adult thrips. In tobacco adult thrips are believed responsible for most infection.
Leaf symptoms include necrotic banding along and around the main veins, target ring spots, leaf twisting with symptoms only on one side of the mid-rib, leaf scorching, and/or general necrosis of bud leaves. Early in the season the lower stalk may show a dark sunken stem resembling soreshin. Later in the growing season black streaks may be seen moving down the stalk from infected leaves. Plants, after infected, may develop these symptoms on one side or the entire stalk producing rapid wilt, yellowing, and death.
Presently in Maryland we must rely on what the flue-cured region has learned in dealing with this disease. Three general conclusions on this disease are known.
1. TSWV can occur in tobacco plant beds or greenhouses but several research projects have made no conclusions between plant sources and the final incidence of the disease.
2. Secondary spreading is due to juveniles feeding on infected plants in the field and furthering disease spread as they move about as infected adults. Research results to date suggest TSWV arising in this manner is not as significant as initial infection.
3. Most infections that lead to symptom development and plant death apparently occur right after transplanting. Symptoms may appear immediately or as much as 6 weeks after thrips feeding.
Growers should be advised at this time there is no control known that is 100% effective. Current recommendations made during tobacco transplant production season include the pesticide Orthene 97P that is considered somewhat effective against tobacco thrips. In the field, flue-cured recommendations include a combination of Admire 2F plus Actigard. However, Actigard is not registered for use in Maryland. If growers have not completed transplanting they are strongly encouraged to apply Admire 2F utilizing the float tray drench procedure or transplant water application technique. Rescue treatments utilizing registered tobacco insecticides are not recommended since most infections occur right after transplanting during the thrips feeding process. Research results to date from the flue-cured tobacco-growing region document the ineffectiveness or variability of rescue treatments.
It is important to know that information is not readily available in Maryland on the effectiveness of these treatments. Remember this is the first year that we have known this disease to develop in our tobacco-growing region. As we learn more about TSWV and the control of the thrips vectors, information will be passed along to the county agricultural Extension agents in the tobacco producing counties. The Central Maryland Research and Education Center, Upper Marlboro Facility and the St. Mary's County Extension Office have in their possession the TSWV ImmunoSTRIP Tests that can be used for the detection of TSWV. This test can be performed on location or at county field offices. Feel free to contact Ben Beale, county agricultural Extension agent in St. Mary's County at 301-475-4484 or David L. Conrad, Extension Regional Tobacco Specialist, at 301-627-8440.
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Galen Dively <gd7@umail.umd.edu>
topsubmitted by Sandy Sardanelli, Maryland IPM
FOR IMMEDIATE RELEASE- 7/2/02
Contact: Jean Mackay, Director of Educational Services
Audubon International
(518) 767-9051, extension 13
Audubon International Celebrates 500 Certified Audubon Sanctuaries Worldwide
SELKIRK, NY- Audubon International, a not-for-profit environmental organization dedicated to improving the quality of the environment, is proud to announce the certification of its 500th Audubon Cooperative Sanctuary. Certified properties account for more than 173,000 acres of land that is managed to protect wildlife and environmental quality and include backyards, schools, golf courses, cemeteries, and a variety of corporate sites that have achieved Audubon International’s highest standards for environmental management. While the majority of certified properties are located in the United States, Certified Audubon Cooperative Sanctuaries are also located in 10 countries worldwide, including Australia, Canada, Costa Rica, Guam, Philippines, Portugal, Scotland, Singapore, Spain, and Sweden.
“In an era where we see increasingly complex environmental problems, Audubon International has dedicated itself to helping people from all walks of life be part of the solution,” stated Audubon International President Ronald Dodson. “Certified Audubon Cooperative Sanctuaries exemplify what can be done when people make a commitment to good environmental stewardship and sustainable resource management right where they live.”
Certified properties range from sites that have large freshwater wetlands, restored prairies, and pristine mountain streams to those with small butterfly gardens, outdoor learning areas, and backyard nest boxes. Regardless of size, all demonstrate a full range of environmental management activities. To achieve certification, property managers must conduct a site assessment to evaluate management practices and environmental conditions. They then implement a variety of measures to improve wildlife habitat, conserve water and energy, reduce waste, involve people in conservation activities, and document outcomes.
“Certified Audubon Cooperative Sanctuaries are not national parks or designated wilderness areas,” explained Jean Mackay, director of educational services for Audubon International. “More important, they are places right in our own communities where the environment is valued and actively cared for.”
“While we need to protect pristine natural areas,” Mackay said, “We can’t ignore the fact that the key to a better environment lies much closer to home, in the actions we take to improve and protect water, wildlife, and overall environmental quality on our own properties and in our own communities. An increasing number of Certified Audubon Cooperative Sanctuaries gives us hope for a better environmental future.”
For a complete listing of the 500 Certified Audubon Cooperative Sanctuaries, comments from certified property managers, and case studies featuring a variety of these sites, visit http://www.audubonintl.org/programs/acss/500certified.htm. Properties are listed by state and internationally.
Audubon International is a not-for-profit 501 (c)(3) environmental organization dedicated to improving the quality of the environment, with an emphasis on helping people become actively involved in good environmental stewardship and sustainable resource management.
The organization was established in 1987 to find ways to address environmental problems by working cooperatively, and in partnership with, a diverse array of organizations and individuals to improve environmental quality on the lands they manage. More information can be found at: http://www.audubonintl.org.
submitted by Joellen Zeh
We have added a page to the NJinPAS website that chronologically lists all postings made to any of the NJinPAS open enrollment listservs. http://www.pestmanagement.rutgers.edu/NJinPAS/listservpostings.htm. Now that the page is up and running, I should be able to add postings as they are made. We will subsequently add a search function to this page so that you can search by date, topic, or listserv.
If you would like to receive the topic-specific postings such as Section 24C's, Section 18's or Crisis Exemptions, you should enroll in the individual listservs (these types of specific postings are not made to NJinPAS Network to minimize mass mailings). We encourage you to take advantage of this, and pass it on to your fellow stakeholders. Enrollment to the eight open enrollment listservs can be easily completed online @ http://www.pestmanagement.rutgers.edu/NJinPAS/listservs.htm.
Thank you.submitted by Patricia Hastings
topThe NYS Community IPM Program oat Cornell University has released Pest Management Practices: A survey of public school districts in New York State (Braband, Horn and Sahr). This 21-page bulletin presents results from 603 completed surveys representing 741 districts in New York. The survey was jointly developed and administered by the NYS Education Department, the NYS Department of Health, and the NYS Community IPM Program. It is not yet available online, but apparently will be at www.nysipm.cornell.edu/comm/school.html. For copies, contact NYS IPM Program, NYSAES, Geneva, NY 14456. Refer to publication NYS IPM Number 613.submitted by Lynn Braband
topWhen is a pest not a pest? How can you reduce disease risks from mosquito or tick bites? How can biology help you keep ants and rodents out of your home? What strategies are available to minimize risks from pesticide poisonings and environmental contamination?
These and other topics are covered by a new resource designed to help educators teach students about pests and pesticides and have fun at the same time. This on-line and print resource include crossword puzzles, word searches, interactive quizzes, scavenger hunts, memory games and other fun activities designed to stimulate young minds in a dynamic, non-textbook fashion to learn about Integrated Pest Management, or IPM.
Why Educate our Students about IPM?
Pests and pesticides both can present unacceptable dangers to health and the environment, from pest-borne illnesses such as Lyme disease, West Nile virus and Hantavirus, to accidental poisonings and environmental contamination by pesticides. Children are especially at risk because of their behavior, including playing on floors and lawns were pesticides are more likely to be applied and pests are more likely to be found. Children can also have weaker defenses against both pest and pesticide dangers.Everyone can work towards reducing exposure to potentially harmful chemicals and pests. Integrated Pest Management (IPM) is a proven system for resolving pest problems effectively while minimizing pesticide use, often at a reduced cost compared to routine application of pesticides. Yet public awareness, appreciation and support for IPM is very low. Teaching children about IPM can help reduce risks to health and the environment, and improve public support for IPM research and adoption in communities and agriculture.
What is IPM?
IPM in agriculture, homes, schools and elsewhere includes these important parts: Accurate information and training on how to recognize pests and conditions that create pest problems, and on pest biology and all the options available to deal with problem pests; planning and prevention to fix conditions that create pest problems; inspection, trapping or other ways are used to spot pests and conditions that cause pest problems; record keeping to keep track of pest outbreaks, note actions taken to reduce pest problems, and evaluate results; and pre-defined action levels that describe when it's right to act to fix pest problems that threaten health or livelihood.In IPM, pesticides are a last resort. When needed, the least-toxic choices are used in a way that minimizes dangers to humans and all other non-target organisms. Using pesticides whenever pest problems are found is not IPM!
New Resource
IPM "Homework" is an on-line, interactive web site including quiz, crossword, word search, matching, and other fun puzzles and games for elementary grade students. The site, operated by the IPM Institute of North America, Inc., was developed with support from U.S. EPA and the National Foundation for IPM Education. Companion print-version documents are also available for download at www.ipminstitute.org/homework.htmsubmitted by Tom Green
Access to this page is not restricted. Nortification of new issues of the Insideris sent to NE PMC Advisory Council members; NE PMC Information Network project leaders; NE PMC IPM Commodity Working Group members; IPM Coordinators in the Northeast; subscribers to PMC-L. Email Jim or Liz to offer submissions or suggest changes.
Jim VanKirk, Coordinator 315-787-2378 jrv1@cornell.edu
topJohn Ayers, Director 814-865-7776 (voice) email
Liz Thomas, Information Specialist 315-787-2626 egt3@cornell.edu
A web page with the address http://nepmc.org/insider/current.html always holds the most recent issue.
Each issue will also continue to have its own unique location at http://nepmc.org/insider/mmmyyyy.html, where "mmm" is 3 letter abbreviation for the month and "yyyy" is four digit year designation.
A list of links to all issues can be found at http://neipmc.org/news_ontargetarchiveindex.cfm
Centers for Pest Management are sponsored by the United States Department of Agriculture
This page developed and managed by Jim VanKirk, NE PMC Coordinator