- Author: Stephanie Parreira
Invasive species are plants, animals, fungi or microbes that are not native to an area, but can quickly establish, multiply, and become pests. These species can hurt the environment, agricultural production, and even human health in some instances (e.g. the mosquito Aedes aegypti). According to the USDA, invasive species are responsible for $137 billion per year in economic losses in the United States.
In agricultural systems, invasive species may reduce yields, render crops unmarketable, or make rangeland unfavorable to livestock. In natural areas, they may squeeze out native species, change soil quality, and increase the frequency or intensity of wildfires.
Some of these species have been introduced intentionally (e.g., yellow sweetclover, which was originally imported from Europe as a forage species for livestock), while others arrived by accident (e.g., the glassy-winged sharpshooter which came to California inadvertently through nursery stock shipments).
Just one species can be detrimental to crop production and revenues. The invasion of spotted-wing drosophila, for example, caused conventional raspberry growers in California to lose $36.4 million in revenue between 2009 and 2014, and would have reduced California raspberry yields by as much as 50% without control efforts.
The spread of invasive pests has become more prevalent in recent decades, and is linked to several factors, including global travel, produce trade, and climate change. Many invasive pests spread by human movement—medusahead, for example, has long awns on its seeds that easily attach to clothing and animal fur, to be carried to other locations. A recent study by UC scientists also determined that due to climate change, invasive weeds are shifting their ranges at a faster rate than native plants, and will likely cause more problems in agriculture and natural resources in the future. The yellow starthistle, an invasive plant that dries out soil and degrades rangelands, is one of the pests that will expand its range further north in California (and beyond) due to climate change.
While invasive pests can be a major challenge to growers and land managers, there are successful stories of stopping exotic pest invasions with well-coordinated eradication efforts. Recently, the California Department of Food and Agriculture (CDFA) declared the European Grapevine Moth eradicated from California after no moths were found in the state from 2015 to 2016. This was due to a rapid response, largely by the UC Cooperative Extension scientists after the moth was discovered in Napa vineyards in 2008.
Here's what you can do to keep from introducing or spreading invasive species:
- Fully cooperate with agricultural inspections at the California state border and in your fields. When coming into California from another state, declare any plant or animal material that you have in your vehicle. Inspectors will thoroughly examine your materials or crops to make sure that they do not hold any invasive pests. This greatly reduces the chance that your activities will spread harmful invasive species.
- Check and clean your clothes, shoes, and equipment before you move from one location to another. For example, thoroughly cleaning your shoes with water and a disinfectant after hiking through an area known to have sudden oak death will prevent you from tracking the pathogen into uncontaminated areas. Similarly, checking your clothes or shoes for weed seeds before leaving an area will keep you from spreading invasive weeds.
- “Burn it where you buy it.” Burn firewood in the same place you purchased it, rather than buying it and transporting it elsewhere. If you must transport firewood, be sure to declare it at the border and have it inspected, as described above.
- Report invasive pests in your area. CDFA has a tool for reporting pests, but you can also contact your agricultural commissioner or UC Cooperative Extension to do so.
To learn more about invasive species, visit the UC IPM website. You will find a list of invasive insects, plants, diseases, and vertebrates in California, as well as links to other organizations and regulatory agencies that are also working to reduce their numbers.
- Author: Cheryl Reynolds
The California Department of Pesticide Regulation (DPR) runs the most extensive Pesticide Residue Monitoring Program in the nation and is hard at work ensuring that the fruit and vegetables we purchase and consume are free from illegal pesticide residues. Just last month, DPR detected residues of a pesticide not registered for use on grapes and fined the grower $10,000 for using a pesticide in violation of the label and for packing and attempting to sell the tainted produce.
Cases like this are rare in California but remind growers how important it is to apply pesticides correctly by following all pesticide label directions. Understanding and following label instructions is the focus of a new online course developed by the University of California Agriculture and Natural Resources Statewide Integrated Pest Management Program (UC IPM).
Proper Pesticide Use to Avoid Illegal Residues is targeted to those who apply pesticides or make pesticide recommendations. It explains what pesticide residues are, how they are monitored, and highlights important residue-related information from several sections of pesticide labels. In addition, the course identifies the following as the most important factors leading to illegal residues:
Using a pesticide on a crop or against a pest for which it is not registered
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Applying pesticides at an incorrect rate
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Ignoring preharvest intervals, re-treatment intervals, or plantback restrictions
Course participants are presented with several real-life scenarios. They must search through actual pesticide labels to determine if the scenario illustrates proper use of pesticides or if the described situation could potentially lead to illegal residues.
The overall goal of this course is to have participants follow pesticide label instructions when they return to the field. Following the label can eliminate incidences of illegal pesticide use.
Proper Pesticide Use to Avoid Illegal Residues is published just in time for pest control advisers and pesticide applicators who are still a few units short to renew their licenses or certificates with DPR. The course has been approved for 2 hours of Pesticide Laws and Regulations continuing education units (CEUs) from DPR and costs $40. If you don't need CEUs, but are still interested in viewing the course content, check it out for free on YouTube.
DPR recommends that renewal packets be submitted before November 1 in order to receive your renewed license or certificate by December 31, as the processing time can take up to 60 days. For additional online courses that UC IPM offers, visit the online training page.
- Author: Kathleen Reyes
- Author: Ashley Van Vliet
- Author: Vonny M. Barlow
The Integrated Pest Information Platform for Extension and Education (iPiPE) is dedicated towards creating a nationwide data base system that tracks various crop pests and diseases. The program aims to address the need for a more efficient form of pest and disease management in crops to increase profit by decreasing the amount 
iPiPE is currently collaborating with several integrated pest management programs (IPM) and universities across the United States in order to refine the online system and begin to introduce iPiPE to the agricultural community. Here at the University of California's Cooperative Extension facility in Blythe, CA, entomologist Dr. Vonny M. Barlow is currently working on his second year with Euchsistus servus and iPiPE interns 
iPiPE interns Reyes and Van Vliet have been responsible for working with Dr. Barlow in gathering data and sharing their findings in the iPiPE online data system. Their work with the system is serving as a trial to help the program enhance their system features and allow a collection of data to save in order to begin the creation of the pest and disease tracking content for future pest management practitioners. Reyes and Van Vliet have also made efforts to be advocates for iPiPE by reaching out to PCA's and growers through different forms of communication methods. Outreach methods included emails, phone calls and personal meetings. As a form of educating growers and PCA's about iPiPE, a handout with information about the goals and benefits that the 
iPiPE's efforts in creating a change in culture by launching their data system has been ambitious and it is the hope of the program that in time the agricultural community will hop on board and take note of the many benefits a nationwide database system can offer. Before that time comes, however, iPiPE will continue to devote its attention to encourage growers and PCAs to join the movement as well as optimize its content for the future benefit of the agricultural industry.
- Author: Ashley Van Vliet
- Author: Kathleen Reyes
- Author: Vonny M. Barlow
Entomologist, Dr. Vonny Barlow of the University Cooperative Extension is in the process of continuing his research with Euschistus servus, or Brown Stink Bug (BSB),in cotton. Results from Barlows' studies have contributed to more effective management of BSB in Southern California.
In the eastern states, primarily Georgia, boll rot and cotton staining created by the BSB has become a substantial issue. Initially there was fear that BSB and associated boll rot could cause significant cotton losses in California which prompted many to make chemical applications. In fact, these chemical applications exceeded the regular 3-4 insecticide applications every season, sometimes substantially.
Dr. Barlow is currently in the second year of his experiment which he began over 1 month earlier than in 2015. Three commercial cotton fields were selected to establish experimental plots. Among the three fields, sixteen sampling 
At each sampling locations three data points are gathered. The first data sampling consisted of recording the number of BSB taken from each pheromone trap every seven days. Next, sweep samples consisting of 20 sweeps per trap location are collected and sorted in the laboratory for total numbers of BSB. Finally, stink bug damage to cotton bolls is assessed with 10 cotton bolls per each trap location selected and taken to the lab were they are “cracked”, and processed for; external and internal feeding punctures, stained cotton lint and presence of boll rot. By the end of the season we will have hand processed over 7,000 cotton bolls for this project.
The results of the experiment during the first year demonstrated that there is no significant aggregation of BSB along cotton field perimeters, contradicting what was previously predicted. Pheromone traps yielded greater stink bug numbers than sweep sampling over the same time period. However, the use of pheromone trapping is intensively laborious. It was also demonstrated that the use of 20% internal boll “warts” was not a useful indicator for “triggering” a chemical applications since it was shown that there is no relationship between presence of internal boll warts and cotton boll rot. It appears that even though boll warts when present, are not a “pathway” for bacteria that causes boll rot in Southern California. This may be due to the sometimes harsh environment of California's southern desert which may make the cotton plant leaf surface inhospitable to bacteria. Altogether these findings suggest that insecticide applications for the BSB in Southern California does not need to take place, saving growers from costly applications every season.
- Author: UC Statewide IPM Program
Various insects, birds, and other animals pollinate plants. Bees, especially honey bees, are the most vital for pollinating food crops. Many California crops rely on bees to pollinate their flowers and ensure a good yield of seeds, fruit, and nuts. Pesticides, especially insecticides, can harm bees if they are applied or allowed to drift to plants that are flowering.
Our mission at the University of California Agricultural and Natural Resources (UC ANR), Statewide Integrated Pest Management Program (UC IPM) is to protect the environment by reducing risks caused by pest management practices. UC IPM developed Bee Precaution Pesticide Ratings to help pest managers make an informed decision about how to protect bees when choosing or applying pesticides. You can find and compare ratings for pesticide active ingredients including acaricides (miticides), bactericides, fungicides, herbicides, and insecticides, and select the one posing the least harm to bees.
A group of bee experts in California, Oregon, and Washington worked with UC IPM to develop the Bee Precaution Pesticide Ratings. They reviewed studies published in scientific journals and summary reports from European and United States pesticide regulatory agencies. While the protection statements on the pesticide labels were taken into account when determining the ratings, it is important to stress that UC IPM's ratings are not the pollinator protection statements on the pesticide labels. In a number of cases, the ratings suggest a more protective action than the pesticide label.
The UC IPM ratings also include active ingredients that may not be registered in your state; please follow local regulations. In California, the suggested use of the bee precaution pesticide ratings is in conjunction with UC Pest Management Guidelines (for commercial agriculture) and Pest Notes (for gardeners). Each crop in the UC Pest Management Guidelines has a link to the Bee Precaution Pesticide Ratings database and provides guidance on how to reduce bee poisoning from pesticides.
For more information on protecting bees from pesticides, see UC IPM's Protecting Natural Enemies and Pollinators, and use the Bee Precaution Pesticide Ratings.
