Illinois Pesticide Review
July / August 2012
In This Issue
- Guidance When Testing for Herbicide Injury
- Pesticide Residue Testing Labs
- Flawed Research Confirmed in Pesticide Study
- Greenbook.net – A Pesticide Label Website to Check Out
- New Studies Link Neonicotinoids with Bee Reduction
- New Guide Focuses on Practical Solutions
- Implications of Bt Hybrid Use in Illinois
- US House Limited Clean Water Act
- The Science Behind Chemical Resistance on Labels
Guidance When Testing for Herbicide Injury
Every summer, Extension Specialists and plant diagnosticians get calls from clients with injured plants. Often, herbicides and other chemicals are the suspected cause of the damaged or dead tissue or bizarre growth. People often want to see proof that their suspicions are correct and they'll ask how they can test the plants for the suspected chemicals. At that point, we share a list of chemical residue testing labs, which is included below.
However, we also caution our callers about the possible expenses that can be generated with these tests. Unfortunately, one can rack up a bill of several hundred to thousands of dollars and still not learn what killed one's plants. However, testing can be a valuable tool and provide needed evidence in a case of suspected herbicide drift. So, what is a person to do?
I decided to simply pick a testing lab and call to learn more. A.P.T. Labs, Inc. in Wyomissing, PA was first on my list and Tim was kind enough to spend a few minutes before he left for the day to explain some of the limitations and expenses involved in these tests. For more information about the chemicals A.P.T. can test for, check out their website: http://www.aptlabsinc.com/.
If foul play is suspected and it is believed that someone has intentionally applied a chemical to kill a neighbor's vegetation, Tim said that glyphosate (Roundup, Kleenup, Avail, and others) is often a good first chemical to test for. Overall, it is relatively inexpensive and easy to obtain by the general public. He said that a very high percentage of the cases he sees are due to the misuse of glyphosate from disgruntled homeowners attempting to reclaim their view by taking matters into their own hands and killing the vegetation that is blocking the way. He said it takes a high dose to kill trees. They will die back in the fall and then have new growth, which will then die off. Essentially, the plant keeps coming back. Tim said they can test for glyphosate for $300.
If cupping and curling of leaves and twisting of petioles are the typical injury symptoms, then it is recommended that a phenoxy screen of 15 compounds including picloram, triclopyr, dicamba, and 2,4-D is run. This is offered for $450.
An NP screen (Nitrogen Phosphorus), which covers 50-60 different compounds including bromacil, atrazine, and alachlor, is also offered. This one costs $500. If soil sterilants and brush killers are suspected, this is the recommended test.
Tim says people can spend a lot of money and still not be able to pinpoint exactly what chemical was applied. He suggests that clients take samples immediately, and if they aren't certain about testing, they should store the samples in a freezer. Then they will have them in case testing is done later. Both soil and vegetation can be frozen using a zippered top bag. In most cases a quart-sized bag is sufficient. Samples should be taken from the hardest hit areas. Tree samples should be taken from the tips of the branches trying to bud out. Soil samples should be taken to a 6 inch core depth.
Another lab I contacted had slightly different advice about sample storage. I didn't catch the name of the person I spoke with at Pacific Agricultural Laboratory, but he was also very helpful. He advised that samples simply be stored in an open bag in the refrigerator for up to 1 – 1.5 weeks. If testing will be done at a much later time, then freezing is OK. Problems can arise when frozen plants are shipped and thawed. They can really be in bad shape for testing. For best results, it is essential that clients call their chosen lab first and work out the sample procedure and shipping details before sending samples.
I asked Pacific Agricultural Laboratory for a couple of rough estimates and was given similar ballpark prices. They can test for glyphosate for $345 and run a phenoxy screen for $220. Please keep in mind these are ROUGH estimates so don't quote me on any of these prices. I'm including them merely to provide a basic idea of the costs involved rather than simply repeating that testing can be expensive. And there are other labs too. I picked A.P.T. and Pacific Agricultural Laboratory at random. I trust there are subtle price differences among all of them. Some labs such as Midwest Laboratories have price lists on their website.
If herbicide injury is suspected on plants, certainly a great resource is the University of Illinois Plant Clinic. Plant diagnosticians can guide you through the process of finding answers. Learn more at http://web.extension.illinois.edu/plantclinic/. If residue testing in needed, a phone call to a lab can provide additional needed direction and assistance.
As a reminder, time is of the essence if you wish to file a drift complaint with the Illinois Department of Agriculture. Complaints must be filed within 30 days of noticing injury symptoms if administrative action is desired. For more information, please call the IDA's Bureau of Environmental Programs at 1-800-641-3934 (voice and TDD) or 217-785-2427.
A list of chemical residue testing labs follows.
Pesticide Residue Testing Labs
University of Illinois Extension Specialists and Educators commonly get questions about where to send plant and soil samples for analysis of pesticide residues. The following list of labs may provide some assistance. Please be sure to contact individual labs regarding specific compounds for testing. Confirm all information by phone before sending samples. Please note that this list may be incomplete. Inclusion does not mean endorsement.
A&L Great Lakes Laboratories
3505 Conestoga Drive
Ft. Wayne, IN 46808-4413
APT Labs Inc.
1050 Spring St.
Wyomissing, PA 19610
Environmental Micro Analysis Inc.
460 N. East Street
Woodland, CA 95776
Midwest Laboratories, Inc.
13611 B St.
Omaha, NE 68144-3693
Minnesota Valley Testing Lab
P.O. Box 249
1126 N. Front St.
New Ulm, MN 56073-0249
Pacific Agricultural Laboratory
12505 N.W. Cornell Rd.
Portland, OR 97229-5651
2121 East Washington Blvd.
Fort Wayne, IN 46803-1328
Soil – Plant Analysis Lab
University of Louisiana at Monroe
Chemistry and Natural Sciences Building, Room 117
Monroe, Louisiana 71209-0505
South Dakota Agricultural Laboratories
Brookings Biospace Suite 105
1006 32nd Avenue
Brookings, SD 57006-4728
Flawed Research Confirmed in Pesticide Study
Research is important in the registration of pesticides and their continued use. Companies spend millions of dollars to get pesticides registered with the USEPA. Once the product is registered, more tests are done by the companies, but also by other scientists. Often these tests look at health hazards from long-term exposure.
One such test was published in two notable journals in 2005 linking paraquat, maneb and possibly atrazine in influencing neuronal mechanisms in Parkinson's disease. Of course, this caused quite some concern.
This past June, though, the University of Medicine and Dentistry, New Jersey and the Office of Research Integrity of the Department of Health and Human Services, confirmed that the research was flawed with faked documentation of studies that never took place. The journals have agreed to publish retractions, and the researcher has agreed not to seek federal funding or serving on advisory committees for 7 years.
This is a cautionary tale of what can go wrong with published research. Only because a fellow University researcher questioned some practices did an investigation begin that took 7 years to conclude. You can imagine the publicity the journal articles received when they were first published, and expenses the chemical companies shelled out for further research.
That's not saying that all research is suspect, whether from chemical companies, university researchers, or others. Journal articles are peer-reviewed. Research submitted to the USEPA is also peer-reviewed by non-chemical company scientists. Falsified research, though, doesn't benefit anyone and can end up costing millions of dollars to the pesticide industry, the government and research institutions.
Even though it took 7 years, at least we now know the truth about that particular study. For those who want more information, check out: http://the-scientist.com/2012/06/29/parkinsons-researcher-fabricated-data/.
Greenbook.net – A Pesticide Label Website to Check Out
When someone asks if a certain product can be used on a specific crop, or what products can be used to control certain pests on specific plants, pesticide educators often go to Greenbook.net (www.greenbook.net) to find the answer.
Part of the reason is the magnitude of their search engines. Greenbook announced that it has surpassed 8,000 product records on its internet database. More than several hundred new products are processed per week, all the while the current project listing is constantly updated to reflect the supplemental labeling and update versions provided by the manufacturers.
In other words, if there's a product to control a pest on a crop, Greenbook.net can provide the information.
"We've streamlined several of our processes in order to keep up with client demand and the ever-expanding number of manufacturers and products in the worldwide pesticide marketplace," said Chris Fox, Greenbook Director of Digital Product Development.
"Greenbook is in a significant growth mode so expect additional releases in the near future as we continue to invest in our database, search functionality, Web Services, and plant protection decision tools," Fox concluded.
Greenbook first started in the business more than 25 years ago producing bound references of product labels. They also have developed software programs; provided comprehensive label management services to chemical manufacturers; and licensed data to precision-agriculture and turf management software providers. They are based in Lincolnshire, IL. While the company still produces those publications, it's much easier to use their search engines than thumb through pages after pages of pesticide labels.
New Studies Link Neonicotinoids with Bee Reduction
Photo 1. Honey bees can be killed when visiting flowers treated with insecticides.
Photo 2. Honey bee colonies are susceptible to CCD caused by various stress factors.
There is worldwide concern about the loss of pollinators during the last few years. Colony Collapse Disorder (CCD) in honey bees, in which large numbers of bees abandon their hives, has been present since at least 2006. There has been a large decline in bumblebees noticed in California and elsewhere with a possibility of the extinction of one or more species.
These reductions appear to be caused by a variety of stresses making the bees less capable of fending off diseases and other factors. Insecticides have always been a suspected culprit in these declines with neonicotinoids being of prime concern. Some neonicotinoids have widespread use and their systemic activity within the plant can result in their presence in pollen and nectar.
One neonicotinoid, imidacloprid, has been heavily implicated. It is known that imidacloprid is incorporated into the pollen and nectar of some plants, but not others. A French study several years ago found that honey bees exposed to sublethal dosages of imidacloprid frequently were unable to find their way back to their colony. Although successfully repeated at least once in Europe, similar studies in the U.S. were unable to repeat these results, making the research suspect. Clothianidin, another neonicotinoid, has also been implicated in bee losses.
Honey bees do not return to their hives for a number of reasons. Obviously, those who are caught and eaten by predators do not return to their hives. However, individuals that have diseases or parasites will leave the hive and not return. This behavior reduces the likelihood of the disease or parasite spreading through and eliminating the hive. It also makes it difficult to locate the involved bees and determine the cause of the abandonment.
Two new studies in Europe published in the digital version of the journal Science in March 2012 produce additional concern about neonicotinoid insecticides and bees. The journal Science is one of the most highly regarded journals in the world. These two studies utilized high-quality methodology and analysis, making them more likely to be repeatable.
One study addresses imidacloprid and bumblebees in Great Britain ("Neonicotinoid Pesticide Reduces Bumble Bee Colony Growth and Queen Production." By Penelope R. Whitehorn, Stephanie O'Connor, Felix L. Wackers, Dave Goulson. Science, Vol. 335 No. 6076, March 30, 2012). Pollen and sugar water containing a nonfatal dose of imidacloprid was fed to 50 bumblebee colonies, Bombus terrestris, for two weeks. They were then released to forage outdoors. At the end of the season, the colonies were 8-12% smaller than the 25 control colonies that were not fed any imidacloprid.
The colonies receiving the imidacloprid produced, on average, about two queens per colony. The untreated colonies averaged 14 queens per colony. Bumblebees produce annual colonies; the workers and original queen die at the end of the growing season. New colonies are started each year by overwintering queens produced the previous year. Many overwintering queens die during the winter and also in the early spring when they are starting their new colonies. Mortality due to disease, predation from mammals and birds, and starvation from insufficient pollen and nectar sources are common. A reduction in queen production translates into a reduction in potential colonies the following year.
Previous laboratory and field studies have not shown a reduction in bumblebee queen production. The hypothesis is that neonicotinoids may affect bees' memory. It is postulated that foraging bees exposed to neonicotinoids forget how to get back to their colonies. Even a relatively small percentage increase in bees not returning to the colony may result in a reduction of available food to develop new queens.
The other research study was conducted in France ("A Common Pesticide Decreases Foraging Success and Survival in Honey Bees." By Mickaël Henry, Maxime Beguin, Fabrice Requier, Orianne Rollin, Jean‐François Odoux, Pierrick Aupinel, Jean Aptel, Sylvie Tchamitchian, Axel Decourtye. Science, Vol. 335 No. 6076, March 30, 2012). In this study, 600 honey bees were fitted with electronic identifiers that allowed them to be counted electronically when they returned to the hive. The bees were fed a mixture of sugar water containing low doses of thiamethoxam, another neonicotinoid insecticide. The doses used were determined to be similar to those that the bees would be exposed to in nature.
The bees were then released up to one kilometer (0.6 miles) from the hive. The bees were released in areas where they had been previously as well as in areas that were new to them. Only about one-half of the bees dosed with thiamethoxam returned to the hive compared with those that did not receive any insecticide. This translates into less food, pollen and nectar coming back to the hives, resulting in weaker hives.
One concern is that the insecticide doses were administered all at once rather than smaller doses repeated throughout the day as is more likely in nature.
The source for much of the above was obtained from news articles posted on The Xerces Society web site. The Xerces Society is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat. Those articles can be found on The Xerces Society web site at http://www.xerces.org/
Although these two studies appear to indicate that neonicotinoid insecticides might be responsible for pollinator reductions, there are other research studies that indicate the opposite. Additional research has pointed at one or more other factors. Insecticide use may be one of the stresses causing colony collapse disorder and other pollinator reductions, but these reductions are apparently due to a number of factors.Phil Nixon
New Guide Focuses on Practical Solutions
The Pacific Northwest Agricultural Safety and Health Center has published a guide titled "Practical Solutions for Pesticide Safety: Protecting Agricultural Pesticide Handlers." The guide is a collection of solutions and ideas identified on farms, and reviewed and developed between farmers, educators and researchers in Washington State.
The book can be easily downloaded as a PDF file from http://depts.washington.edu/pnash/practical_solutions. The guide is in English and Spanish.
There are many great ideas that can be incorporated into farm operations, as well as commercial applicator situations. More than likely, some will elicit a slap on the forehead and a "why didn't I think of that?" to "well, that seems like a good idea but not for me."
The guide is easy to follow and deals mainly with ideas to improve the environment and the pesticide applicator's health. If you don't want to download the entire document, you will find it informative to just look at the guide, and then print the pages that apply to you.
Implications of Bt Hybrid Use in Illinois
Insecticide and other pesticide resistance is a major concern of pest management in Illinois. Pesticide resistance is more likely when one pesticide is used to the exclusion of other pesticides and other integrated methods of control.
For many years, the use of Bt hybrids in which genes from the bacteria Bacillus thuringiensis have been implanted into the genes of corn and other crops has reduced the reliance on insecticide applications to achieve control of key pests. These implanted genes cause the genetically modified plants to produce the toxin naturally produced by the Bt bacteria that controls some insect pests.
Heavy use of these Bt hybrids is likely to shorten the length of time for resistance to build up in the affected pests. Their use when pest pressure is low continues this resistance development although the use of these Bt hybrids in those years would not be needed to avoid yield reductions.
Overuse of Bt hybrids and other genetically modified plants shortens the time span that they will be effective. As they lose effectiveness, they will need to be replaced with new hybrids with implanted genes that produce insect control products or a return to more insecticide applications to achieve economic pest control.
Ninety-five percent of the producers who participated in the regional 2012 Corn and Soybean Classic meetings last January said they planted a Bt hybrid in 2011. This very high use rate has been common for several years across Illinois in spite of low numbers of key insect pests such as the European corn borer and the western corn rootworm.
Intense use of Bt hybrids is also anticipated for the 2012 growing season. "I have questioned the wisdom of applying such intense selection pressure on insect populations when many of the pest species are well below economic levels in most producers' fields," said University of Illinois Extension Entomologist Mike Gray. Nonetheless, this pattern is not expected to change.
When Bt hybrids entered the market place in 1996 and for many years thereafter, the use of a 20 percent refuge was the standard protocol for the Corn Belt, based upon the use of Bt hybrids aimed primarily at the European corn borer, which express a high dosage level of Cry proteins.
In 2003, Bt hybrids were commercialized for corn rootworms, and similar refuge requirements were implemented across the Midwest, even though the Bt hybrids targeted at corn rootworms were not high dose and the mating characteristics, along with dispersal patterns of adult corn rootworms, are different than those of corn borers.
Why were the refuge requirements similar for such distinctly different insects?
"Because of familiarity, convenience, and thus, the greater likelihood of implementation of the 20 percent structured refuge by producers rather than tailoring refuge requirements to the unique biological characteristics of corn rootworms," said Gray.
Today producers have more flexibility with respect to the type of refuge they implement. Although more than half of the producers at the 2012 Classics indicated they intend to use the 20 percent structured refuge this growing season, the seed blend (refuge-in-a-bag) strategy is gaining popularity as more pyramided Bt hybrids enter the marketplace.
At the 2012 Classics, producers were asked if they planted a refuge in 2011. On average, 83 percent of producers said they had established a refuge. The proper establishment of refuges will become increasingly important as more acres are planted to Bt hybrids, selection pressure increases, and the threat of the development of western corn rootworm resistance looms.
Approximately 37 percent of the producers who took part in the 2012 Classics will use a seed blend as their refuge and hedge against insect resistance development.
"From a convenience angle, it's easy to see why this approach will increase in popularity," said Gray. Of concern is the anticipated reduction in the volume of non-Bt seed produced by the seed industry as refuge requirements drop from 20 percent levels, which could make it more difficult for producers to purchase elite germplasm from non-Bt product lines. Access to non-Bt hybrids by producers is important if the industry wants to maintain an integrated approach to pest management across the Corn Belt.
From a University of Illinois news release; first four paragraphs written by Phil Nixon.
US House Limited Clean Water Act
In June, the US House of Representatives refused to include an amendment that would have given the US Army Corp of Engineers the right to expand the Clean Water Act to include private lands not connected to "navigable" water. House democrats sought to expand The Clean Water Act to give the Army Corp of Engineers authority on small headwater streams and wetlands.
Organizations lined up on both sides of the issue. Wildlife organizations were for expansion to protect fishing and hunting habitats. Agriculture organizations continue to oppose further restrictions on landowners and farmers.
Without the amendment, the status quo on private lands and the Clean Water Act is maintained.David Robson
The Science Behind Chemical Resistance on Labels
Photo: Research indicates that gloves made of nitrile rubber, butyl rubber, and plastic laminates are the best for the vast majority of pesticide formulations.
As a result of recent NIOSH efforts, discussion has occurred about possibly changing pesticide labels and the chemical resistance charts. Questions have been asked by those involved about what scientific work has been done in this area.
Joanne Kick-Raack of the Pesticide Education Program at Ohio State University recently shared one of many publications that resulted from a large EPA-sponsored project focused on chemical resistance of gloves to pesticides. This summary article from 1992 (which can be found on the PSEP website) was used to develop the Chemical-Resistance Category Selection Chart that is still used today.
The study looked at the various types of materials used in the production of gloves for pesticide applicators. The idea was to see how resistant to permeation various materials were.
One of the initial findings was that the pesticide carrier solvent usually penetrated the materials first, before the actual active ingredient. We've commented over the years that just because it's called an "inert ingredient" doesn't mean it's 100% safe.
The research indicates that nitrile rubber, butyl rubber, and plastic laminates are the best for the vast majority of pesticide formulations. Natural rubber polyvinyl chloride (PVC) materials provided the least protection and shouldn't be used. Of course, the authors also note that their recommendations are based solely on chemical resistance considerations and that other factors such as glove sizing, tactility, dexterity, comfort, durability, cost, and proper use must also be considered.Michelle Wiesbrook and David Robson