Bee Careful!

Though this picture is of a bee in clover, there are many other flowering
plants in Christmas trees that bees may be attracted to.

Christmas tree pests are very active this spring, and growers are finding they need to treat for mites and for twig aphids. Thanks to chemical mowing, Christmas tree fields are full of flowering ground covers, especially wild mustard and purple deadnettle. These are favorites for bees. That's great for wildlife and biodiversity, but it presents a problem when trees need to be treated with an insecticide.

I wrote the following article for LIMBS & NEEDLES in 2008 with the help of Dr. David Tarpy at NCSU. The information is still appropriate. It gives good information on how to protect the bees that are in your Christmas trees. Basically, the best way to do this is to avoid spraying when bees are actively foraging. Target treatments of an evening or night.

There were several products we use today that weren't mentioned in the article because they weren't used at the time this was written.

• Safari (dinotefuran) is highly toxic to bees.
•  Movento (spirotetramat) is not toxic to the adult bees, but if it is taken back to the hive, it will affect how the bee larvae develop. 
• Envidor (spirodiclofen) is slightly toxic to bees and may cause a problem in contaminated pollen and nectar. 
• None of these products should be sprayed in areas where bees are actively foraging.

Bees and Trees -- LIMBS & NEEDLES article from 2008

By Jill R. Sidebottom, North Carolina State University

We have lots of clover in our Christmas tree fields now. That’s great news. Clover adds nitrogen to the soil and reduces erosion. It also provides forage for bees. That’s a wonderful thing – most of the time. However, when a Christmas tree grower needs to apply an insecticide, having bees actively foraging in the field can present a problem.

Being insects, it is perhaps not surprising that most insecticides are toxic to bees. Even some organic insecticides will kill bees. The wrong pesticide, applied at the wrong time, will not only kill the bees foraging at the site but can be carried back and kill the entire colony. The good news is that pesticide poisoning of honey bees can usually be kept to a minimum if beekeepers and pesticide applicators take certain precautions.

Most pesticide labels have a special warning about bees and other beneficial arthropods. For example, the label from Dimethoate reads as follows:

ENVIRONMENTAL HAZARDS
This pesticide is highly toxic to bees exposed to direct
treatment or residues on blooming crops or weeds. Do
not apply this product or allow it to drift to blooming crops
or weeds if bees are visiting the treatment area.

This language clearly places the responsibility for the safe use of this pesticide squarely on the applicator. Beekeepers can help applicators by making them aware of their hive locations, covering their hives with wet burlap, or even moving the hives during times of pesticide exposure. But the responsibility ultimately falls back on the pesticide applicator to make sure that bees are kept safe.

In the NCSU beekeepers notes, “Reducing the Risk of Pesticide Poisoning to Honey Bees”  contains a table with different pesticides and their relative toxicity to honey bees. I have reproduced the tables, in part, showing the materials that are used in western North Carolina on Christmas trees.

GROUP 1 – HIGHLY TOXIC. Severe bee losses may be expected if the following pesticides are used when bees are present, or if the product is applied near beehives or within a day after application to foraging bees in the pesticide application area.

• Abamectin
• Acephate (Orthene)
• Carbaryl (Sevin)
• Chlorpyrifos (Lorsban)
• Dimethoate
• Imidacloprid (Provado, Merit)
• Malathion
• Permethrin (Astro)
• Spinosad
• Thimethoxam (Flagship)

 GROUP 2 – MODERATELY TOXIC. These pesticides can be used in the vicinity of bees IF dosage, timing, and method of application are correct; but these products should never be applied directly on bees in the field or at the colony location (apiaries).

• Bifenazate (Floramite)
• Disulfoton (Di-Syston)
• Endosulfan (Thiodan)
• Fluvalinate (Mavrik)

 GROUP 3 – RELATIVELY NONTOXIC. These pesticides can be used around bees with a minimum of injury if the dosage, timing, and method of application are correct. Never apply pesticide directly to the beehive.

• Diflubenzuron (Dimilin)
• Esfenvalerate (Asana)
• Pymetrozine (Endeavor)

If the pesticide you are interested in is not listed here, you can sometimes find the LD₅₀’s for bees under the MSDS (Material Safety Data Sheets). A material is considered ‘highly toxic’ if the LD₅₀ is less than 2 µg (microgram or 1/1,000.000 of a gram) per bee. It is ‘moderately toxic’ if the LD₅₀ is 2 to 10.99 µg per bee; ‘slightly toxic’ if it is from 11 to 100 µg per bee; and ‘practically non-toxic’ if it is from 50 to 100 µg per bee. For instance, the contact LD₅₀ for bifenthrin (Talstar) is reported as 0.01462 µg/bee, which would make it highly toxic.

The LD₅₀’s for bees can be somewhat misleading, though, because they express the pesticide toxicity to the individual bee. A product that is moderately toxic but that is applied in a form that is similar to pollen and is collected and concentrated along with the pollen can kill the entire colony.

On the other hand, highly toxic materials may cause less of a problem if bees are not actively foraging in the area. Be sure to check fields the day before spraying to determine if bees are actively foraging. For instance this summer, some of the clover flowers are drying up because of the drought, and bees are no longer present. Also, if materials are applied in the late afternoon (after 3 pm) or even at night, the impact on bees will be reduced. Some growers have successfully used Dimethoate, for instance, near hives if the material is applied in the late evening and is dried before the bees start foraging the next day.

Reducing drift is also important in reducing the likelihood that the material contacts beehives. Air-blast sprayers are more dangerous than pressurized-pump sprayers. If a pesticide application is being made by air, then it is the contractor’s responsibility to notify any beekeepers that have “registered” apiaries (one or more hives of bees) within 2 miles of the area to be aerially sprayed. These regulations are defined in the N.C. Pesticide Laws and the person responsible for the notification is the person who contracts for the aerial application.

More information of bees can be found at the apicultureprogram at NCSU. Another important link is to the North Carolina State Beekeeper’s Association. This is a good place to look at see if the county you have Christmas trees in has a beekeepers association that you can contact about the local of hives near your Christmas tree fields. Finally, you can contact the NCDA&CS ApiaryInspection Service for official apiary records and registration.

The NCCTA is currently advertising the environmental benefits of Christmas trees. If bee kills are associated with Christmas tree production, however, it will be hard to defend such a claim.

Special thanks to David Tarpy, Associate Professor and Extension Apicolturist, NCSU, for helping review this article.

New Pesticide Safety Training Materials

The folks at North Carolina State University have put together a training packet for Christmas tree growers to share with their Latino farmworkers. Called the Pesticides and Farmworker Health Toolkits (click to see information at NCSU), the programs are specific to the different commodities grown in North Carolina. The standard kit includes:

--Introductory DVD for trainers,
--Flip-chart in Spanish (with discussion guides for trainers and colorful visuals illustrating the trainer’s message for the audience),
--One-page illustrated handouts in Spanish,
--Interactive materials, including jug and labels and symptom charade cards,
--Totebag.

The one for Christmas trees is hot off the presses. We used it at a Latino farmworker safety training on July 13 in Foscoe. Held at Hawk Mountain Tree Farms, the training included several stations, one of which was pesticide safety. I helped Jim Hamilton, Watauga County Director and Charles Clark and Travis Snodgrass, both with NCDA conduct the training.

Jim Hamilton explaining about chemical resistant footwear.

Charles Clark and Jim Hamilton use the flipchart to teach workers about pesticide toxicity.

In these training materials, the toxicity of different materials is related to a stop light. Very toxic materials having a "Danger" signal word have a red light, materials that have a "Warning" signal word show a yellow light, and the least toxic materials with a "Caution" signal word have a green light. The handout in Spanish is divided into insecticides and herbicides and feature the most commonly used pesticides with their respective signal words. Symptoms of pesticides exposure are also shown.

Workers can take this chart home, showing the common materials used for Christmas tree production in NC.

The flipchart also lists routes of pesticide exposure and symptoms of pesticide poisoning. Jim Hamilton also describes in Spanish parts of the body that require greater protection from pesticide exposure in the following video:

Flipchart showing routes of pesticide exposure -- dermal and inhalation. 

Fit tests for pesticide respirators were also reviewed by Travis Snodgrass. First cover the filters. If the respirator fits properly, you won't be able to breath in more air. All air passes through the filter. Second, cover where air is released from the respirator when you breath out. With that covered, you shouldn't be able to blow more air out of the mask. This demonstrates that the filters can't be bypassed.

Cover the filters and if the mask fits, you can't pull more air into the mask.

Cover where air comes out of the mask, and you can't push more air out.

The toolkits should be available soon for growers at the NCSU Toxicology Extension website. Some will be available from the county extension offices. We hope to get on video more safety trainings in the coming months and put them on YouTube so that they are available to everyone.

Updated website on pesticides

The web site with pesticides labeled for Christmas trees has been updated. Click here http://www.ces.ncsu.edu/fletcher/programs/xmas/pesticides/index.html for the link.

There is a lot of information at this site. Practically all pesticides labeled for Christmas trees are listed. That includes insecticides, herbicides and fungicides. There may be some others that are labeled. Glyphosate alone has multiple products that can be used in Christmas trees. But hopefully this web site will include most that are regularly used by the industry in North Carolina. (If there are others you would like to add, just let me know!)

On the site is the following information for each material:

• The common name -- that's the name you see on the package.
• Type of pesticide and the uses for the product.
• Active ingredient -- that's the name of what actually is working in the pesticide.
• Active ingredient concentration -- let's you know how many pounds of active ingredient are in each gallon or pound.
• The chemical family -- so you can see which materials are related to each other.
• The manufacturer.
• The EPA registration number -- you need to list this in your pesticide records. Also, when you talk to NCDA&CS folks, have that number so they can quickly pull up the product.
• Use/Signal word -- whether the product is labeled CAUTION, WARNING or DANGER.
• REI -- the restricted reentry interval. Be careful though. What is listed is for normal reentry. There may be additional cautions on the label for special circumstances.
• The rate -- which includes the maximum amount that can be applied each year when applicable.
• PPE -- the personal protective equipment required for applicators. Again caution as there may be special PPE required for handlers or other workers or uses.

Also on this site is a link to all the labels and MSDS sheets for these products. 

This information is provided for your convenience. If you see any errors, please let me know. Updates will be made as necessary. But be sure to review the label that comes with the material you are using. That is what you should always go by.

Pesticide Safety Web Site

Farm safety is a big topic these days. As stated on the OSHA homepage for agricultural operations, “Agriculture is one of the most hazardous industries in the nation. Farming is one of the few industries in which the families (who often share the work and live on the premises) are also at risk for fatal and nonfatal injuries.” These dangers are compounded when most farmworkers are Latino, and even Spanish may be their second language. Their understanding of English is often limited, making them an especially vulnerable work force.


To help growers comply with existing laws, and to draw together resources from many states, a Christmas tree farm safety web site has been developed. 


Information is organized in several categories including general farm safety, equipment safety, shearing safety, pesticide safety (by far the biggest section), and harvest safety. Many resources are available in Spanish. There are links to pertinent laws, laws for record keeping, forms to record worker training, and videos on many topics.

So check it out at: www.ces.ncsu.edu/Christmastrees/farm-safety

Updates on Website

As seen from some recent letters to the editors of the High Country Press, the public continues to be concerned about the production of Christmas trees in the area. Also, as we get nearer to Christmas, the media including blogs and other social media question the environmental safety of real Christmas trees. Because of this, I have revised the information on the web site, "Frequently Asked Questions about Christmas Trees and the Environment." This web site is found at: http://www.ces.ncsu.edu/fletcher/programs/xmas/environment/index.html

The updated information reflects new pest control practices, updated cancer rates for mountain counties, and newly available links. The site can be used as an overview for concerned citizens or references for reporters.

If you have any questions, comments, see any errors or have additional information that should be added, let me know.

A Word About Spray Suits

Lots of folks wear the basic disposable Tyvek coveralls when applying pesticides. These state that they are not water proof, yet lots of folks use them when applying not just dry pesticide formulations, but wet formulations and even high pressure sprayers.

On Friday, Jerry Moody and I applied some materials for fall control of algae. We don't think they will work, but we wanted to be sure. One thing that some growers are doing is spraying bleach on trees to clean them up. We tried that last year, but with a backpack mistblower. This year we tried it with a high pressure sprayer to see if that will work any better since it didn't work at all last year. I sprayed a 3% solution of bleach on about 30 large trees with a high pressure sprayer, doing a thorough job of coverage. I wore a white tyvek suit.

Well, look at my shirt at the end of the job. My purple shirt was bleached where the zipper on the Tyvek suit was. If it had been a pesticide, I would not have been protected from it.

Take home message? When spraying with a high pressure sprayer, you need something water proof.

We'll let you know in a couple of weeks what kind of algae control we got.

(And I liked that shirt too!)

Respirators

As more research is being done on the chronic effects of low level exposures to pesticides, it continues to be apparent that pesticide use can adversely affect the health of the pesticide applicator. That's why it's important that people wear the appropriate personal protective equipment, and even use more PPE than is required, especially when treating Christmas trees with a high pressure sprayer.

One of these pieces of equipment is the respirator. In my opinion, anyone treating trees with a high pressure sprayer should use a respirator. This is true whether you are using horticultural oil or a synthetic pesticide. Few materials require the use of a respirator on the label, but since you are continually walking through the spray, that is the best way to reduce exposure.

Some of the commercial applicators have purchased the helmets with motorized forced air which completely cover the head. These offer the most protection, and are the easiest to wear. They keep the worker cool, and don't require a lot of effort to breath through them.

But a lot of people still depend on either the full or 1/2 face respirator with attached cartridges which are certainly less expensive. However, there are several issues with these.

1. They don't cover the entire face, and in fact the ear canal is one area of skin that is particularly thin and will readily absorb pesticides. The rate of absorption is far higher than the skin on your palm or forearm. Using a hood on a spray suit will eliminate this problem.

2. Many people don't fit the respirator closely enough to the face. I've seen several folks wear respirators that just hang on their face. The respirator is supposed to fit snugly so that all air breathed in passes through the cartridges. And yes, when you do this, they will fog up. But, when the fit isn't snug, contaminated air can come in through the sides. If a man has a beard or mustache, this can interfere with the fit. In fact, it is best not to have facial hair when using a respirator.

3. The third issue then becomes one of applicator's health. Some people's lungs just aren't strong enough to pull air through the respirators.We all know how tiring it is to wear a hot spray suit and respirator and walk through trees spraying with a hose. You have to have good heart and lungs to be able to do this demanding work.

In fact, OSHA regulation 1910.134 requires workers be properly trained in using a respirator, that a fit test be conducted, and that the worker is certified by a doctor as being physically fit enough to use the respirator. These requirements have largely been overlooked in agricultural circles, but that may be changing.

So be safe. Check the fit on your respirator, and use it like it was intended.