- Author: Pamela Kan-Rice
The California Department of Pesticide Regulation has awarded $1.34 million in grants to UC ANR scientists for research on pest control alternatives to the banned pesticide chlorpyrifos.
"Finding less-toxic alternatives to pesticides like chlorpyrifos, and promoting their adoption and implementation throughout California, is a priority, and our grant programs play a vital role in reaching those goals," DPR Director Val Dolcini said.
The grants, awarded through DPR's Research Grants Program, will go to the following researchers:
- Mark Hoddle, UC Cooperative Extension entomology specialist, UC Riverside, "Taking Chlorpyrifos out of Citrus: Maximizing IPM of Argentine Ant and Sap Sucking Pests with Biodegradable Hydrogels, Infra-Red Sensors and Cover Crops." ($500,000)
- Dong-Hwan Choe, UC Cooperative Extension urban entomology specialist, UC Riverside, "A sustainable boric acid liquid bait delivery system (as alternative to chlorpyrifos sprays) for the management of pest ants in agricultural settings." ($340,467)
- David Haviland, UC Cooperative Extension IPM advisor for Kern County, "Hydrogel baiting systems for sugar-feeding ants in California grapes and citrus." ($500,000)
"These researchers are at the cutting edge of their fields and I'm really pleased that DPR can support their efforts," said Dolcini.
Full descriptions of each research project are available on DPR's website.
Funding for these grants came from a one-time $2.1 million General Fund allocation to DPR for research projects that advance safer, more-sustainable pest management alternatives to chlorpyrifos. DPR previously funded three research grants for alternatives to chlorpyrifos research.
Following California's historic decision to end use of the pesticide chlorpyrifos in 2019, DPR and the California Department of Food and Agriculture (CDFA) convened the Alternatives to Chlorpyrifos Work Group to evaluate potential alternatives. The work group's report outlines actions that can further support agriculture and the health of local communities, farmworkers and the environment.
- Author: Rachael Freeman Long
- Author: Daniel H Putnam
- Author: Ian Grettenberger
The end is near for chlorpyrifos (Lorsban) applications in many California crops, now on a faster timetable than previously anticipated. This results from a recent agreement between CA Department of Pesticide Regulation (CA-DPR) and pesticide manufacturers to withdraw their products beginning in a few months (February 2020).
This is a major issue for alfalfa, since it is one of the most popular wide-spectrum insecticides for management of key alfalfa pests. These include the alfalfa weevil, Hypera postica, which chews on the foliage (Figure 1, Figure 2) and the aphid complex (several species) which suck juices from the plant – see UC IPM website http://ipm.ucanr.edu/PMG/selectnewpest.alfalfa-hay.html ).
Use of chlorpyrifos has declined in the past two years (due to increased restrictions) but still it was used on 153,000 acres of alfalfa hay in California 2017 (CA-DPR Pesticide Use Report and Figure 3).
Figure 1. Alfalfa weevil larva, a key pest in California's alfalfa fields in the spring months (January-May), reducing yields and quality from feeding on the foliage. Chlorpyrifos has been widely used to control this pest, but in 2020, growers will need to look for alternatives. (Photo: Ian Grettenburger)
What are the alternatives? Unfortunately, there are few alternative products available for alfalfa weevil control specifically. Examples include pyrethroids like Warrior, Steward, Malathion and Entrust (spinosad used for organic production). These have their own limitations, both in terms of efficacy and environmental impacts.
Unfortunately, alfalfa weevils frequently reach economic damaging thresholds in California and many growers find it necessary to spray. There are some other aphid-specific insecticides that would help with aphids but not with alfalfa weevil.
The problem of pesticide resistance. Weevil resistance to pyrethroids is beginning to be a problem throughout the Western states, including select areas in California such as the intermountain and low desert production areas. With the loss of chlorpyrifos, the over-use of a single class of insecticide could be a major challenge.
It has been a long-standing recommendation of the UC Integrated Pest Management Program to rotate insecticide classes to prevent insecticide resistance, in addition to ONLY spraying when thresholds reach an economic level. However, the reductions in active ingredient possibilities may exacerbate resistance.
What drives the withdrawal of chlorpyrifos? Chlorpyrifos was on the way out nationally in 2017 under Obama, but the EPA decision was reversed suddenly in March 2017 as administrations changed (see blog: Chlorpyrifos ban Averted at Last Minute). Chlorpyrifos was subsequently limited by California EPA (and now banned) since it has been designated as a toxic air contaminant and associated with negative health effects in sensitive groups. Chlorpyrifos has been around for many years and used to control pests on a variety of crops, including alfalfa (primarily weevils), as well as on almonds, citrus, cotton, grapes and walnuts. Chlorpyrifos is marketed as Lorsban, Vulcan, Stallion, Cobalt, and Lock-On among others.
The agreement between DPR and manufactures states that:
- All sales of chlorpyrifos products to growers in California will end on Feb. 6, 2020.
- Users can continue to use chlorpyrifos products until December 31, 2020.
- Until then, all uses must comply with existing restrictions, including a ban on aerial spraying, quarter-mile buffer zones and limiting use to crop-pest combinations that lack alternatives.
- Product take-back will occur through normal business practices/channels – with outreach to growers to explain the terms of continued use.
A few products that apply chlorpyrifos in granular form (e.g. for cutworm control), will possibly be allowed to remain on the market (but not registered for use in alfalfa).
The need for alternatives. UC Cooperative Extension advisors and specialists throughout the state are working on developing alternatives to chlorpyrifos in many crops. This work is being supported through the current California state budget, which has appropriated more than $5 million in grant funding for the purpose.
- DPR will award more than $2.1 million in grants to fund projects that identify, develop, and implement safer, practical, and sustainable pest management alternatives to chlorpyrifos.
- CDFA will award approximately $2 million in grants to expand outreach about innovative, biologically integrated farming systems that reduce chemical insecticide inputs. Crops that have used chlorpyrifos will be a priority.
- CFDA will also fund approximately $1.5 million in research to develop alternatives to chlorpyrifos that provide safer, more sustainable pest management solutions.
Non-pesticide options. There are important non-pesticide approaches for weevil and aphid management, including grazing to reduce winter stem egg-laying, early harvest, and introduction of biological controls which are detailed in our IPM guidelines, http://ipm.ucanr.edu/. Additionally, scouting for pest numbers and predation (infected larvae which reduce impacts of the pests) are important tools.
Critical need for alternatives. However, in spite of many of these efforts, many growers have found it necessary to spray (Figure 3), and now will have to look hard for viable alternatives. Following UC IPM guidelines for managing pests, including selecting locally adapted varieties with high levels of pest and disease resistance, are important steps to managing pests and reducing reliance on pesticide use in alfalfa fields.
Figure 3. Map of Chlorpyrifos applications, CA, 2013-2017. Chlorpryifos has been used throughout the major alfalfa growing areas of California (Intermountain, Central Valley, and Desert) for many years, mostly for alfalfa weevil and aphid control - a practice which will wind down in 2020. Data: CA Pesticide Use Report.
This article was originally posted in Alfalfa & Forage News.
- Author: Jeannette E. Warnert
The California Department of Pesticide Regulation has formed a work group to find alternatives to the pesticide chlorpyrifos that will help farmers manage insect pests when a state ban on the chemical goes into effect, reported Kerry Klein on Valley Public Radio.
Klein interviewed David Haviland, UC Cooperative Extension entomology advisor and a member of the work group.
“This is an important topic,” Haviland said. “Chlorpyrifos has had a lot of benefits to agriculture for many years. At the same time, it does have some negative issues associated with it that were the reason that the product has been proposed to be discontinued.”
Chlorpyrifos is a common insecticide used under the trade names Lorsban, Lock-on and generic formulations to control ants, stink bugs, aphids, whiteflies and other pests. UC IPM coordinated a comprehensive report on chlorpyrifos in 2014, commissioned by DPR, outlining critical uses of the pesticide in alfalfa, almonds, citrus and cotton. The report details the insecticide's use patterns as compared to other pest control tactics, such as resistant varieties, mating disruption, field sanitation and other insecticides.
The new work group will develop short-term and five-year action plans to identify safer, more sustainable pest management tools, practices, and alternatives in a wide array of crops. They will seek solutions that are safe for workers, communities and the environment, able to adequately control targeted pests, and cost effective. In addition, the work group will consider the issues of efficacy, soil health and climate change.
The solutions might include combinations of other pesticides to help protect the dozens of crops on which chlorpyrifos is used. Haviland says the group will prioritize the most urgent needs first: “Who's really going to take a hit from the ban, and from there, what is the best way to go forward,” he said.
Along with Haviland, UC Agriculture and Natural Resources is represented on the new work group by UC IPM advisor emeritus Pete Goodell and UCCE field crops advisor Michael Rethwisch.
"On Wednesday, May 8, 2019, the State of California announced it would ban the use of chlorpyrifos by canceling registration of the pesticide by the Department of Pesticide Registration. Chlorpyrifos use in agriculture has been under federal and state regulatory review for the last several years. Chlorpyrifos for use in structural pest control and for sale in consumer products ended in 2000 due to a voluntary agreement between the manufacturers and EPA.
"University of California Agriculture and Natural Resources (UC ANR) carries out the Land-Grant mission of University of California to seek scientific solutions to address society's needs and problems. As a part of UC ANR, the Statewide Integrated Pest Management Program (UC IPM) provides research-based information to manage pests while protecting human-health and the environment. UC scientists have spent many years researching alternatives to chlorpyrifos and educating state-licensed pest control advisers on effective use of the alternatives. For example, improved integrated pest management of insects in almonds eliminated the need for winter application of chlorpyrifos on the 1,390,000 acres of almonds in California. Overall, this work contributed to the greater than 50% decrease in chlorpyrifos use in all of California agriculture from 2006 to 2016.
"In 2014, UC IPM started a two-year project, funded by California Department of Pesticide Regulation, to identify the pest-crop situations where there were no or few alternatives to chlorpyrifos. That project identified specific needs for additional research on alternatives to manage weevils and aphids in alfalfa, leaf-footed bug and stink bugs in almond, ants in citrus, and aphids and whiteflies in cotton. UC research and extension continues to seek solutions to these difficult pest management problems. Previous research in many other pest-crop situations had already identified and supported implementation of alternatives to chlorpyrifos.
"UC ANR will continue to work closely with the State of California and agriculture to protect the health of Californians and our environment while providing effective pest management solutions to farmers."
For more information, contact:
Jim Farrar
(530) 750-1249, jjfarrar@ucanr.edu
- Author: Ben Faber