Managing Insecticide Resistance

A resistance management plan is a critical component of any integrated pest management (IPM) program. In order to develop a resistance management program you need to understand the mode of action of the products available and the biology of your target pests.

For years entomologists have been telling growers to rotate insecticides by mode of action. The mode of action is the mechanism by which the pesticide kills the pest. Determining the mode of action of an insecticide has become easier over the last few years. Newer insecticide labels have the mode of action group listed on the top of the first page. You can also find a complete listing of the mode of action groups in a number of locations. These include OHP’s Chemical Class Chart (http://www.ohp.com/) and BASF’s Pest Management Guide (http://www.betterplants.com/).

There is still debate over how many times a product can be used before you need to rotate to another product and how different products should be in the rotation program. Your first step should be to read the label and see if there are any label restrictions regarding resistance management. Most products will limit the total number of applications per year. One extreme is the Pedestal® label which states “Do not make more than two (2) applications of Pedestal per crop per year.” In addition to a limit of the total number of applications that can be made, a products label may also have other use restrictions.

A general rule of thumb is that you want to rotate to a different mode of action for each insect generation. Products that kill by desiccation or smothering, such as soaps and oils, can be used anytime in a pesticide rotation scheme without negatively impacting resistance management programs.

There are a few instances where products in different mode of action groups have the same or similar modes of action, examples include 1) cross-resistance between organophosphates and carbamates and 2) pymetrozine (Endeavour®) has been shown to be cross-resistant to neonicotinoids in Bemisia tabaci. It is also important to take note if there is a letter after the mode of action group number, such as 4A with the neonicotinoids. Products with different letters within the groups have different modes of killing the insect, although the end result appears similar or the active ingredients have very similar chemical structures. One example is MOA Class 9. Although Endeavor (9B) and Aria (9C) are both selective feeding blockers, they can be rotated with each other since each product has a different target site on the insect.

Unfortunately, many people do not understand how resistance develops. Insecticide resistance is the genetically based, inherited ability of an individual to survive exposure to an insecticide that is lethal to other individuals in the population. That is a nice scientific definition. Here is a very simplistic way to visualize resistance. You have 1000 aphids on an oleander and because you have not been rotating insecticides 10 individuals or 1% of them are resistant to your favorites insecticide. After you spray there are 100 aphids left on the plant. Assuming the resistant individuals were not impacted by any other mortality factor they now comprise 10% of the population. You decide that a second insecticide application is need a month later. The there are now 2000 aphids on the plant and 200 are resistant to our favorite insecticide (2000 x 10% = 200). Your spay tech does a phenomenal job spraying and kills all the susceptible aphids, but the 200 aphids not impacted by the spray are still on the plant. A week later you decide you want to sell the plants without any aphids and have the plants sprayed again with your favorite insecticide and to your surprise you are unable to detect any decrease in the population. This is a very simplistic hypothetical situation, but hopefully give you a way of visualizing how resistance can develop.

As illustrated above, it takes a number of generations for an insect species to develop resistance to an insecticide. Generally, the shorter the generation time the faster the species can develop resistance. According to the Insecticide Resistance Action Committee (http://www.irac-online.org/) there are four mechanisms that may cause an insect population to become resistant to insecticides. Some insects may actually exhibit more than one of the mechanisms at a time.

Metabolic resistance. This is the most common mechanism of insecticide resistance. Resistant insects use internal enzymes to detoxifying or destroy the insecticide’s toxin more rapidly than a susceptible insect. The resistant insect may also be able to rid its bodies of the toxic molecules.

Altered target-site resistance. The second most common mechanism of resistance is a result of the target site where the insecticide toxin binds becoming altered. This modification reduces the ability of the insecticide to kill the insect.

Behavioral resistance. Resistant insects detect or recognize the insecticide and avoid the toxin. The insect may stop feeding or move to an area where there is no insecticide.

Penetration resistance. The resistant insect’s outer cuticle develops barriers that slow an insecticides ability to penetrate into the insect.

The first evidence of resistance is usually reduced efficacy against the target pest even when the pesticide was properly applied at the recommended rate. If you suspect a pest population is developing tolerance to a particular chemical, continued use or increasing the rate of the product will only accelerate the rate of resistance selection, eventually leading to complete control failure. If you are applying an insecticide that is not longer effective you are wasting money on labor and insecticides that will have no impact on the pest population.

If you suspect insecticide resistance or need further information, please do not hesitate to contact me, the insecticide company, or your local extension specialist.

New Predatory Fly May Help Control Greenhouse & Nursery Pests

If you think you have a fungus gnat problem, you may want to take a second look. A 'new' insect is showing up in Texas greenhouses and nurseries. Some growers have seen the fly and made the assumption that it must be bad. For once this is not an insect you will need to control. Coenosia attenuate, an old world hunter fly, was first identified in 2004 at Nortex Greenhouses in Collin County. Since that time, this beneficial fly has also been identified in Cherokee and Smith County. I am sure if I looked I would be able to find it in many additional counties. In North America, this hunter fly was previously known to occur in New York, California and Ontario, Canada. In California, C. attenuate is associated with gerbera, roses, poinsettia and chrysanthemum production.

Coenosia attenuate resembles a small housefly. They range in size from 2.5 mm to 4 mm. The female has a dark grey body and black legs while the male has pale yellow legs. You can observe the adult flies perched on plants, pipes, or other objects in the greenhouse. These predators actually wait to fly out and grab any flying insect of suitable size. The prey is then subdued by stabbing them with specialized mouthparts. Hunter flies prey on insects such as fungus gnats, shore flies, whiteflies, winged aphids and leafminers. Once prey is stabbed, they return to their perch to feed. Each adult occupies a defined territory and sometimes territorial “dogfights” can be observed when boundaries are compromised.

Adult flies lay their eggs in the soil and the developing larvae are predators of fungus gnats and shore flies. Research conducted at Cornell University indicates that this is an effective predator of fungus gnat larvae.

We sampled fly populations at Nortex Greenhouse for a year. It appears from these results that this predator is capable of managing fungus gnat populations, especially in pot plants.

If you see a new fly showing up in your greenhouse do not automatically reach for the nearest bottle of insecticide. Have the fly identified. Coenosia may prove to be a valuable biological control agent. Even more importantly, one you do not need to purchase!

Shine in ‘09: High Performance Management to Survive Turbulent Times

Webinar Series Sponsored By
The Ellison Chair in International Floriculture and
Texas AgriLife Extension

This webinar (web-based seminar) series is designed to assist you in making better (more informed) managerial decisions in the midst of an economic downturn that is literally turning markets upside down. In this hypercompetitive market, the competitive advantages you enjoy today may vanish with breathtaking speed and frequency. Truly, in this type of environment, the things you don’t know can hurt you!

You may be saying to yourself: “I don’t have time and can’t afford to attend another meeting.” That’s the beauty of a webinar – it only takes an hour out of your day; you don’t have to spend money traveling anywhere; and you can ‘attend’ sitting in front of your own computer!

Ask yourself these questions…

· Are business profits shrinking and you’re not sure why?
· Are you uncertain how sustainability can help your business?
· Has marketing become more of a challenge?
· Has your business been impacted by the economic downturn?
· Are operating costs spiraling out of control?

If you answered yes to any of these questions; if you feel the business climate continues to deteriorate; or if you are worried about the future of your business, then you need to attend this webinar series and learn useful strategies to increase your firm’s bottom line!

March 9, 2009 -- 11:00 a.m. CST (1 hour) – Dr. Charlie Hall, Texas A&M University
Webinar 1 Topic: Action Points to Survive the Downturn – Developing and fine-tuning your downturn strategies to ensure your business will survive!

April 14, 2009 – 11:00 a.m. CST (1 hour) – Dr. Don Wilkerson, Texas AgriLife Extension
Webinar 2 Topic: Differentiating By Being Sustainable – Being proactive by developing your own sustainability code of ethics can help set you apart from the competition!

May 12, 2009 – 11:00 a.m. CST (1 hour) – Dr. Jennifer Dennis, Purdue University
Webinar Topic 3: Marketing Green! The “green” marketing strategies you need to thrive in a maturing marketplace!

So don't hesitate -- space is limited! Go to http://ellisonchair.tamu.edu/webinar.htm to register. There is no charge for the first three webinars in this series, so reserve your space today!

Meetings to address insect control on greenhouse & nursery crops

Now that it is starting to warm up, crop producers need to be thinking about how to properly manage insect pests on their crops. I have designed an integrated pest management course to help ornamental crop producers better manage insect and mite pests. The three hour course will be offered in Canton, Fort Worth, Houston, Jacksonville and McKinney (see dates below).

The meetings will cover:

• An overview of the insecticides and miticides on the market today.
• The biology of the major insect and mite pests to provide effective control.
• Developing management programs that will decrease the likelihood of pests developing tolerance to key insecticides.

Producers attending will gain a better understanding of how to successfully use the insecticides and miticides on the market today, and how they fit into an integrated pest management program.

Those attending will be eligible to earn three continuing education units, one in the integrated pest management and two in the general category, toward renewal of the their Texas Department of Agriculture pesticide applicators license.

Texas certified nursery and certified landscape professionals will receive three continuing education units toward recertification.

Preregistration is $25 per person and can be done online with a check, credit or debit card at http://agrilifevents.tamu.edu/. At-the-door registration will be $35, checks and cash only.

The trainings will be held at these locations and times:

• In Canton, from 1:30 - 4:30 p.m. on Feb. 10 at the Farm Bureau Building, 281 E. Hwy 243.
• In Fort Worth, from 9 a.m. to noon on March 5 in the AgriLife Extension office, Tarrant County Plaza Building, 200 Taylor Street, Suite 500. Driving directions can be found at http://tarrant-tx.tamu.edu/map.htm.
• In Houston, from 12:30.-3:30 p.m. on March 11 at the AgriLife Extension office in Harris County, 3033 Bear Creek Drive.
• In Jacksonville, from 1-4 p.m. Feb. 26 at the Woodman of the World Building, 1800 College Avenue.
• In McKinney, from 1:30- 4:30 p.m. Feb. 25 at the Landing at Myers Park & Event Center, 7117 County Road 166. More information can be found at http://www.co.collin.tx.us/parks/myers/MyersCC.pdf .

Maps and other information are available at the East Texas Nursery and Greenhouse IPM Program website.

For more information: Contact Scott Ludwig at 903-834-6191 or swludwig@tamu.edu

Pest Management Conference

If you are a floriculture producer you should consider attending the Society of American Florist's Pest Management Conference. This should be one of the best conference yet. Oh yea, did I mention I am biased since I am a conference co-chair along with Cristi Palmer (IR-4) and Jim Bethke (Univeristy of California Cooperative Extension).

Growers who attend the 25th Anniversary Pest Management Conference, Feb. 19-21 in San Jose, Calif. will unearth a wealth of valuable information including innovative cropprotection techniques to battle pests and diseases. More than 25 new sessions make this year's conference a can't miss. The conference is being presented by SAF in partnership with Greenhouse Grower Magazine.

Top experts in the field will share the latest research in education sessions and zero in on the latest pest and disease control techniques. Topics on the agenda include implementing sustainable and integrated pest management, increasing the effectiveness of insecticides and fungicides, dealing with treatment-resistant problems, halting invasive and emerging pests, finding better ways to diagnose diseases and training a multilingual workforce to identify and treat problems.

Tabletop exhibits give attendees a chance to check out the newest pest control products and equipment. There's also an optional field trip to local growing operations set for Thursday, Feb. 19 from 12 p.m. to 5 p.m. Attendees can get an up close and personal look at integrated pest management growing operations in the San Jose area. Headstart Nursery, growers specializing in vegetable transplants, ornamental plugs and Cal Color Growers, which produces bedding and plant liners are just two stops on the enlightening excursion.

This year, SAF is partnering with Greenhouse Grower magazine to produce the association's annual conference. The synergy "just makes sense," says Bob West, group publisher for MeisterMedia Worldwide, which publishes Greenhouse Grower, Today's Garden Center and Ornamental Outlook magazines. "This is a very content-rich conference, and our publications reach the entire floriculture industry," he says. "Any time you bring together two groups with the expertise of SAF and Greenhouse Grower, it can only have a positive effect for the industry."

Head to www.pestconference.org for full program details and online registration. For more information, contact Laura Weaver, (800) 336-4743, lweaver@safnow.org.

Topic covered will include:
Ways to Increase Chemical Efficacy: New Techniques and Strategies
Speaker: John Erwin, Ph.D., University of Minnesota

Manipulating Crop Fertilization to Enhance Pest Management
Speaker: Carlos Bogran, Ph.D., Texas AgriLife Extension Service

Re-circulating Water Without Sacrificing Crop Health
Speaker: Chuan Hong, Ph.D., Virginia Tech

Predators, Parasites and Bankers
Speaker: Lance Osborne, Ph.D., University of Florida

Neonicotinoid Insecticides: History, Properties & Pest Management Strategies
Speaker: Frank Byrne, Ph.D., University of California, Riverside

Efficacy of the Neonicotinoids As Related To Uptake
Speaker: Ron Oetting, Ph.D., University of Georgia

Best Use of Neonicotinoids for Pest Management
Speaker: James Bethke, University of California, Riverside

Strategies for Resistance Management: Thrips and Others
Speaker: Scott Ludwig, Ph.D., Texas AgriLife Extension Service

Strategies for Resistance Management: Downy Mildew and Others
Speaker: Mary Hausbeck, Ph.D., Michigan State University

Foliar Pathogen Management
Speaker: David Norman, Ph.D., University of Florida

What You Can't See,Can Hurt You!
Speaker: Mary Hausbeck, Ph.D., Michigan State University

Management Tricks for Reducing Weeds
Speaker: Cheryl Wilen, Ph.D., University of California, San Diego

A History of Success: University Research Transforms Grower Practices and Profits
Speaker: Ron Oetting, Ph.D., University of Georgia

Strengthening Workforce Education When Language is a Barrier
Speakers: Carlos Bogron, Ph.D., Texas AgriLife Extension Service and Jan Hall, Paul Ecke Ranch

Invasive Pests & Pathogens: What Can We Do?
Speaker: Lin Schmale, Society of American Florists

Invasive Organisms: I've Found One, What Do I Do Now?
Speaker: Helene Wright, USDA-APHIS

Managing Invasive Pathogens: A case study with Sudden Oak Death
Speaker: Steve Tjosvold, University of California Cooperative Extension

Managing Invasive Insects
Speaker: Lance Osborne, Ph.D., University of Florida

And Just What Is Causing This Problem?
Speaker: Ann Chase, Ph.D., Chase Research Gardens

Managing the Unmanageable
Speaker: David Norman, Ph.D., University of Florida

Dealing With Viruses
Speaker: Debra Matthews, Ph.D., University of California

Rhodococcus Infections in Ornamental Plants
Speaker: Marilyn Miller, Oregon State University

So That's What That Was...and Other Surprise Diseases
Speaker: Colleen Warfield, Ph.D., University of California Cooperative Extension

New & Emerging Pests: Are Area Wide Pest Management Programs the Answer?
Speaker: Mike Parrella, Ph.D., University of California

Floriculture survey deadline approaching

Dr. Charlie Hall posted the following information on his "Making Cents" Blog.

Floriculture producers in the following states who generate $10,000 or more in gross annual sales are urged to complete the U.S. Department of Agriculture's annual Floriculture Production Survey by mid-January. Surveys were mailed on Dec. 8, 2008.

The states included in the annual survey include California, Florida, Hawaii, Illinois, Maryland, Michigan, New Jersey, New York, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina, Texas, and Washington.

The survey provides the only detailed information about the production and sales of cut flowers, flowering, bedding and foliage plants, and cultivated florist greens. Without grower input, the government is left without the necessary data to gauge these crops' contribution to the nation's economy. In 2007, the combined wholesale value for the 15 states surveyed was $4.1 billion.

Growers can use the information as a benchmark to identify state and national trends. Government policymakers use the data at the state and national levels to appropriate resources. Reliable data is also crucial to obtaining research funding, government support and ensuring the industry receives its fair share of limited funding. Ten major floriculture organizations have endorsed this effort and their presidents have signed the letter accompanying the survey.

If you have received one of the surveys, please take the time to complete it if you have not already done so. Producers who fail to return a completed questionnaire by Jan. 20 will be contacted by telephone or in person to complete the survey.

Overture Registered for Thrips and Caterpillars

Overture 35 WP Insecticide is a new class of insecticide marketed by Valent Professional Products that is active against thrips and caterpillars. This new insecticide contains the active ingredient pyridalyl. This product has an unknown mode of action. Overture is a contact insecticide that is applied as a foliar spray.

Overture is only registered as a greenhouse product. Hopefully, Valent will be able to obtain a registration that will allow Overture to be used outdoors.

Control of thrips is often not seen for 7 to 14 days after treatment. With the recent concern regarding western flower thrips resistance to Conserve, Overture can be a valuable component of a rotation program. Overture should be considered most effective when used as a preventative treatment or as a rotation product. Overture will be an excellent product to use in rotation with Conserve, Pylon and other thrips insecticides.

I have conduced a number of trial evaluating Overture. The results varied slightly depending on the western flower thrips population I was evaluating. However, in all the trials, Overture resulted in a decrease in thrips population. When tested against a western flower thrips population that was resistant to Conserve, the Overture treatments resulted in thrips control after 14 days.

Overture has provided excellent control of chilli thrips. It’s also effective in controlling many lepidopterous larvae, including azalea caterpillar, cabbage looper, tobacco budworm and many more.

For more information on efficacy trials conducted with Overture and other insecticides against chilli thrips, gladiolus thrips, weeping fig thrips and western flower thrips check out a report recently published by the IR-4 Ornamental Horticulture Program. This report can be found at http://ir4.rutgers.edu/ornamental/summaryreports/thripsdatasummary2008.pdf
This report summarizes 26 experiments in which 38 different active ingredients were evaluated.

Sherman Clem Receives Distinguished Achievement Award

Sherman Clem has been recognized by the Southern Chapter of the Horticultural Inspection Society with its Distinguished Achievement Award. If you ever have been lucky enough to have Sherman as your Department of Agriculture inspector, you will agree that this is a well deserved award.

Sherman Clem is a Senior Inspector for the Texas Department of Agriculture and is the lead inspector for the Smith County/Tyler rose industry and the point of contact agency wide on rose related issues. More recently he has taken on the task of lead inspector to control the flow of regulated articled into the state of Texas.

In choosing a Distinguished Achievement Award winner, the Horticultural Inspection Society considers an individual's performance to HISSC and/or the state where employed; recognition from peers in the plant industry; ability to work harmoniously with other inspectors and solve problems on plant protection issues; and the promotion of high standards and sharing of expertise with fellow employees and members of the HISSC.

The inspector who nominated Sherman noted that he has "demonstrated extraordinary customer service to the nursery industry" throughout his 34-plus year career.

Congratulation Sherman!

Temporary Meeting Registration Problem

If you have tried to register online for the East Texas Nursery and Greenhouse Conference this week and have been unable to get though to the site you have discovered that the site is down. The Conference Services' website has been down since at least Monday. They have been working to get the site back up. At this time they hope to have the site back up by the end of the day Thursday (10/16/08). However, that is an estimation.

Conference Services is taking phone registrations at 979-845-2604. You can still mail in your registration form with a check.

I am sorry for any inconvenience this may have caused.

Help Wanted - Extension Assistant

The East Texas Nursery and Greenhouse IPM Program in Overton, TX has a full time position open for an Extension Assistant to conduct research and demonstration projects related to greenhouse and nursery pest management. Duties include: applying pesticides, keeping detailed records of procedures and data, record and analyze data, conduct statistical analyses and prepare reports for inclusion in scientific and technical publications using computers and relevant software. Maintain plants and insects for research in greenhouses and outdoor nurseries. Assist with preparing fact sheets, web pages, and brochures. Aid in organizing and conducting meetings, workshops, field days and other educational activities. More information is available at http://greatjobs.tamu.edu. The NOV number for the position is 03778. For more information contact me at 903-834-6191 or swludwig@tamu.edu.