Foreign Invasion threat to farming

In honor of #NationalInvasiveSpeciesAwarenessWeek

A Plant Doctor's House Calls

Creeping MenaceForeign terrorists have been invading our farms and environment for a long time. These terrorists are called Invasive species. An invasive species is a plant or animal that is not native to a specific location (an introduced species); and has a tendency to spread, which is believed to cause damage to the environment, human economy and/or human health. Species that are moved or migrate to an area where they have not been to before can disrupt the ecology of an area because the native species have not evolved to interact with the newcomer. There may be no natural predators to keep the new species in check or the new species may find a food source that has no defense against the newcomer. There are invasive pests that have invaded our forests, waterways, homes and fields.

The following are just a few I’ve chosen to highlight from the USDA APHIS…

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Why Keep the E.P.A?

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On February 3, 2017 Rep. Matt Gaetz [R-FL-1] introduced a bill titled H.R.861 – To terminate the Environmental Protection Agency. There are certainly plenty of people, mainly business owners and some farmers, who are pretty fed up with the layers and layers of regulations and associated paperwork that keeps them from doing the work they want to be doing. Many farmers see some of the EPA’s regulation as vastly overreaching to the point of threatening to put them out of business. Rep. Gaetz wrote in a letter to colleagues about his bill stating that “Our small businesses cannot afford to cover the costs associated with compliance, too often leading to closed doors and unemployed Americans,” and that “It is time to take back our legislative power from the EPA and abolish it permanently.” I certainly do not deny that there are problems regarding how regulations affect people and businesses. The language Gaetz’s bill states that the EPA will terminate at the end of 2018. There seems to be no plan on what happens to all the laws the EPA is currently administrating. There is certainly a lot of uncertainty about the future of the EPA under the current administration. There are many reasons why we should keep the EPA. For a reminder, read Why We Need the EPA. My concern is what will happen to our crop protection industry if the EPA suddenly disappears?

The federal law that directly affects pesticide use is called the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). After World War II there was a sharp increase in chemical use in many industries, including farming. This act was passed back in 1947 and was enacted “to address the growing issue of potential environmental damage and biological health risks associated with such widespread use of insecticides”1. FIFRA’s basic function is to “govern the registration, distribution, sale, and use of pesticides in the United States2. The original act required anyone selling pesticides in interstate commerce to register them with the USDA and there was very little required to get a product registered.

In the early 1960’s after the break through publication of Rachael Carson’s book Silent Spring, many people became more aware of the problems pesticides were causing to the environment and potential hazard to human health as well. Many issues started to get noticed, not just environmental and threats to public health but also safety issues for agricultural workers. When the EPA was formed in 1970 the administration of FIFRA was moved to that agency.

Making sure that our crop protection products are safe and effective is an essential role that the EPA has for farmers. We need products that are proven to work, that they can be used safely by our workers and, also,  around our homes, since many of us live on our farms. dreamstime_xxl_83065129We need to make sure our products are safe for our consumers and that our land and water are safe for the future generation that we will be passing our farms down to, not to mention just being good stewards of the land in general. These are all goals that farmers and the EPA have in common. The data the EPA collects and reviews from registrants and the data that the agency produces through their own scientific reviews are essential in order to defend the use of products, easing fears made by those that make false claims of health and environmental harm, and justifying the need to stop using products that no longer fit the safety goals stated above. Without the science done at the EPA, crop protection products are at risk from lawsuits by groups trying to ban any pesticide use and new products that we need will not be able to get registration.

FIFRA does not mandate that the EPA should be the agency in charge of administering the act but it is uniquely qualified to do so. The program could be moved to the FDA or back to the USDA but those agencies are not set up to do the environmental science needed to evaluate crop protection products.  Since science being done on air, water and other areas the EPA regulates ties in closely to all aspects of farming, keeping the regulation of pesticides at the EPA would keep the science needed all under the same agency and allow for better communication and shared resources. If anything the EPA needs more funding, upgraded technology to do better toxicology screening faster, more scientists with the needed expertise and, hopefully, more with a background in crop protection and agriculture.

Another idea of getting the federal government out of what the EPA does and let the states run their own programs is also highly problematic. Now the EPA does the bulk of the work sifting through the data and approving product registration, safety and use regulations. Many states do look at the EPA registration packages and make changes for their local conditions but if each state had to do the entire task of registering a product the costs would be astronomical and the potential for conflicting regulations across state lines could make interstate commerce of crop protecrtion products unmanageable.

Science is the backbone of every aspect of agriculture. We rely on it for almost everything we do.  We should be working on making the EPA better at what they do, not getting rid of it entirely. The EPA has plenty of experience in place to continue to do the work we need in the area of crop protection products. Regulations should be based on sound science but not just when the regulations fall in our favor. We can’t defend sound science on one hand when we are trying to save a product under registration and throw it out when a regulation restricts us. A hearing held February 7th by the House Committee on Science, Space & Technology promised to focus on “Making the Environmental Protection Agency great again” got off on the wrong foot, in my opinion, when the committee chair Lamar Smith suggested that the agency had “relied on questionable science based on nonpublic information that could not be reproduced, a basic requirement of the scientific method” 3. Trying to label science you may not agree with as “questionable” in order to shape policy is what is being done and threatens to be the “nail in the coffin” for the EPA.

Limiting the type of science the EPA can use by suggesting they are using “questionable science” and not following the basics of the scientific method because it can’t be “reproduced” will limit the science needed by the EPA. Only using public information would greatly limit what science can be used or evaluated. Only using science that can be “reproduced” also limits science as it does not allow for scientists to look at changes in methodology or allow for other scientific designs to be used to study the same issue. Not all lab studies can be reproduced, especially if you are trying to transfer what you see in the lab to field conditions.

Weakening the EPA is not in our industry’s best interest. Changes in how regulations are made should be focused on using the science with local stakeholders to craft programs and best use practices to make sure all of the goals of safe farming for agriculture and the environment are met. We should be looking to strengthen EPA regional offices so that they have the staff and funds needed to work with local stakeholders. Legislation like the Wasteful EPA Programs Elimination Act4, introduced by Rep. Sam Johnson (R-Texas), calling for the closure all of the EPA’s regional offices is not the way forward. Focused, targeted, well thought out programs with input from all sides should be the way forward. People have lost trust that science is being used to make regulations that will benefit them. Only by working together and actually listening to each other can regulators and stakeholders rebuild trust in the system.

Footnotes

  1. History of the EPA.” Wikipedia. Accessed February 09, 2017. .
  2. Summary of the Federal Insecticide, Fungicide, and Rodenticide Act.” EPA. January 10, 2017. Accessed February 09, 2017. .
  3. Harvey, Chelsea. “The hearing was titled, ‘Making EPA great again.’ Scientists are afraid the opposite will happen.” The Washington Post. Accessed February 09, 2017.
  4. H.R.2111 – 114th Congress (2015-2016): Wasteful EPA Programs Elimination Act of 2015.” H.R.2111 – 114th Congress (2015-2016): Wasteful EPA Programs Elimination Act of 2015 | Congress.gov | Library of Congress. April 29, 2915. Accessed February 11, 2017.

Harvest is Upon Us

This is the time of year when all the crops are going into harvest. I thought I would share what goes on in some of the crops I works with during this very busy part of the season. At this point most of my work is done. It is report card time and I get to see how well I did keeping the pests low when I see how the product comes off the plants.

Tomatoes: the tomatoes I work with are the processing varieties. These primarily go into paste which is shipped all over the world and used to make all the great tomato products you are familiar with. Some are also used for sliced, diced and whole peeled canned products. They are machined harvested. Workers are on the machine to help sort out the MOT (materials other than tomatoes) and any other thing not wanted to get into the truck. There are drivers for the tractors pulling the trailers through the fields and drivers for the trucks taking the trailers to the plant.

Cantaloupes: These are harvested and either packed in the field or taken to an indoor packing plant. They may be in the field for a number of weeks, picking as the melons become ripe. This video is a good one showing the entire process.

Cotton: This will be harvested in the early fall in my area. My job is to recommend products to apply to get all of the leaves dried and removed from the plant before the crop can be harvested. This video clip from the TV show America’s Heartland shows what comes next.

Almonds: As the nuts dry and open they are ready to be shaken off the tree. Then they continue to dry on the ground and when they are ready they are swept into rows, picked up by a small trailer and loaded into trucks off to the processing plant. Walnuts are also picked in much the same way.

Peaches and Nectarines: This harvest starts in late April and goes all summer. They are hand harvested and the crews move from field to field as the varieties become ripe.

Table grapes are picked and packed in the field.

Raisins can be harvested by hand and laid onto the paper trays on the ground or, as labor becomes more expensive, growers can use machines to shake the grapes off the vines and laid on the paper trays.

Wine grapes are picked much the same as mechanical raisin grapes harvest except they go into the trailers and out to the winery.

Thanks to all the wonderful videos being shared by farmers throughout the state for sharing with everyone what you do. Don’t forget to thank a farmer for your food and clothes.

 

 

The use of some toxic pesticides may be warranted.

Not all pesticides are created equal and some, as we all know, are more toxic than others. The EPA has been reviewing the data on many of the older pesticide categories for some time now and using new guidelines to determine if their uses are still safe.

One active ingredient that is going through this process is Chlorpyrifos. Because of its high mammalian toxicity it is getting a good review. The EPA has made some changes to how this product is being used with its first ruling back in 2000 eliminating all residential uses except for roach bait in protective bait stations. Then back in 2002 it banned the use of the product on tomatoes and made some further restrictions on its use on citrus, tree nuts and other crops. In 2012 the EPA limited the use of chlorpyrifos by lowering application rates and creating no-spray buffer zone requirements.

“Chlorpyrifos can cause cholinesterase inhibition in humans at high enough doses; that is, it can overstimulate the nervous system causing nausea, dizziness, confusion, and at very high exposures (e.g., accidents or major spills), respiratory paralysis and death.”1 Most of the issues with this product has been occupational exposures that applicators would experience and most of those concerns have been addressed through training and strict personal protective equipment requirements.

Why does keeping the use of this product matter for agriculture? Chlorpyrifos is used in corn and soybeans and, because of the large number of acres of these crops, these uses are the largest for this product. Many of these applications are seed treatments, but it is also used on fruits and nut trees, and a limited number of vegetable and row crops as well. Uses have already been restricted as a result of the EPA’s re-registration process. For example, on fruit trees and grapes, it can only be used during the dormant season and on citrus and vegetable crops the harvest intervals have been greatly increased. Most of the foliar application on crops are done because there are pests that are very difficult to control and this product happens to be one of a few that will work. Aphids on asparagus, broccoli, cabbage, and soybeans, as well as leaffooted plant bugs on almonds, are the most common needs for a foliar application I come across. Even though there are other products that can work to control these pests, the lack of products to rotate with means the loss of chlopyrifos runs the risk of developing resistance to those few products faster. “Matthew E. O’Neal, Iowa State University entomologist said when it comes to soybeans there should be some concern about what a chlopyrifos ban could mean in years to come. ‘My concern is if we get into a situation where we have a resistance to the other classes of insecticides used for aphids we’re going to need an alternative,’ he said. ‘Chlorpyrifos is commonly used by farmers for aphids and other pests in soybeans. If one class of insecticide replaces its uses in soybeans, this could increase the likelihood of resistance occurring. In four or five years that’s when you’d start to notice there are is no chlopyrifos and you’re looking for something that works.'”2 This warning holds true for the other critical uses as well. Without the use of chlopyrifos in asparagus for aphids those growers will have a hard time getting a crop to market as many other aphid control products are no longer effective on asparagus aphids.

Knowing that the EPA was reviewing the uses of chlopyrifos and that some concerns (which I will address later) had been brought up, University of California, California Department of Pesticide Regulation and industry stakeholders made a thorough assessment of the critical uses of chlopyrifos in some key crops grown in California and have made some recommendations on how to successfully manage the use of this product. The 198 page document reviews the key uses of chlorpyrifos in four key crops in the state. “The four crops represent $10 billion in annual revenue and cover 2.4 million acres of cropland. During the period of 2002-2012, 61% of the total chlorpyrifos use was recorded on these four crops.”3 The study pointed to an overall decrease in the use of chlorpyrifos with some years showing a slight increase, no doubt due to spikes in pest pressure. These spikes in the amount of product used has caused concern in some areas due to the human and environmental risks associated with chlorpyrifos. Note: since the CDPR report came out a new product to control aphids in alfalfa has been registered and the situation for that crop and chlorpyrifos use has improved.

The major cause for concern now is the previously identified drinking water issues and dealing with a petition from the Natural Resources Defense Council (NRDC) and Pesticide Action Network North America (PANNA). This is the petition the court has addressed in determining that the EPA timeline for evaluating the drinking water issue was not adequate. The EPA’s 2014 revised human health risk assessment confirmed a potential risk to drinking water in small watersheds near areas where chlorpyrifos is widely used. These small watersheds are generally less than 40 square miles and in small regions of the country. The examples are outlined in the revised risk assessment. 4 “The 2014 assessment included a refined drinking water assessment for the Pacific Northwest and the Southeast, but not the entire country. The EPA has determined that safe levels of chlorpyrifos may be exceeded for people whose drinking water is derived from certain vulnerable watersheds in parts of the United States.  the EPA is continuing to work on its refined regional drinking water assessment in order to identify those vulnerable watersheds.”5

Can the drinking water issues be addressed without banning all the uses for chlorpyrifos? Since the problem seems to be isolated to small watersheds near well-defined areas of high chlopyrifos use, it seems that other ways to mitigate the problems should be examined. The work published in the CDPR “Chlorpyrifos Critical Use” report shows that a well thought out approach to this problem is achievable. The report outlines uses to focus on and best use practices to hopefully reduce levels of chlopyrifos in surface water that are exceeding tolerances. Research and education are key components of the process. Farmers and those making pest control decisions need to be aware of the potential problems surrounding the use of chlorpyrifos and need to be willing to make decisions that will help keep the product out of local waterways. But in order for such an approach to work, all stakeholders involved must be on board and willing to follow best use practices.

California’s State Water Resources Control Board has surface water monitoring programs in place and have been monitoring water for a number of contaminants including, but not limited to, certain pesticides, such as chlorpyrifos. Their Irrigated Lands Regulatory Program has many years of data showing where contaminants have been found and at what levels. Data since 2006 has shown some improvements in surface water chlorpyrifos contamination but some areas are still showing exceedances, and some of those areas were not involved in the crops mentions in the DPR critical use program. More investigation and outreach seems to be needed.

So what does all this mean for the fate of chlorpyrifos? Unfortunately the regulatory process does not have a good track record for making policy based solely on scientific evidence, and there are many public groups that have very little patience with any attempt to develop programs that will keep pesticides they are not happy with in use. Research, data collection, programs, and outreach all take time and money. Budgets are tight ,and the number of people with expertise in these areas are declining, making resources available to work on these issues very tight. Public distrust of government regulators is on the rise at the same time government continues to cut budgets for the science needed to address these issues. EPA is forced to rely more and more on industry supplied data which increases the public distrust of the current system. The current public comment period for the proposal to revoke the tolerances for chlopyrifos will be over by the end of the year. Stakeholder groups on both sides of the issue are currently sending in their views on the matter. It would be nice to see a measured and thought out approach to making sure this product can still be used where it is needed come out of this process.

Footnotes
1. http://www2.epa.gov/ingredients-used-pesticide-products/chlorpyrifos
2. You’ll Still Have Pesticide Options If Lorsban’s AI is Banned – DTN
3. CDPR Critical Use Report
4. EPA’s revised human health risk assement for chlopyrifos
5. Proposal to Revoke Chlorpyrifos Food Residue Tolerances

 

Thankful for our food

As we prepare our Thanksgiving day feast it may be a good time to reflect on what it takes to get that food to your table. There are many people in many industries that work hard to bring us the abundance of food we have come to take for granted when we go to our local grocery store. As a plant doctor, I will use this post to summarize what my part of the “food chain” contributes to your Thanksgiving feast.

What is on your table?

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As you can see, without the benefits of crop protection products, organic or conventional, yields would suffer and the abundance of food we rely on would decrease making our Thanksgiving feast much more expensive.

Do you like pie?

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Plant bugs of all types are very hard to control. Even organic farmers have problems with these pests. Organic pesticides only deter these bugs for a short time making multiple applications necessary to protect the crop. Nasty little buggers!

Modern technology is doing more to increase yields and decrease the amount of pesticides needed to bring food to your table. Not so long ago many of our crop protection chemicals were broad spectrum and applied in pounds per acre. Now they are more targeted to the pest, safer for beneficial insects, safer for workers and applied in oz per acre. Better application techniques make spraying these low rates effective with less impact on the surrounding environment.

Agriculture has many challenges ahead of it to be able to bring more food to a growing population with less land and other resources.

There are still many challenges ahead. Environmental issues to solve. Promises of new technology such and Genetically Modified crops and other new technologies like CRISPer are just a few things science is looking into to make sure everyone on this planet has enough to eat. GMO technology has already  reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68% (from an articled penned by Klumper and Qaim in 2014; a meta study that summarizes his findings of 147 original studies on the impact of GMOs). 
With the help of modern agriculture techniques, hunger is disappearing but we still have a long way to go before the problems of food insecurity disappears as well.
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As our technology continues to improve, better solutions arise and agriculture continues to tackle the challenges of producing more food with less resources and keeping our environment, workers and families safe and healthy. The more we know the better we do. It is a challenge we take on with pride.

What does a Plant Doctor do after harvest?

As harvest winds down to a close the hard part of my job as a Plant Doctor is slowing down as well. But just because the crops have been harvested doesn’t mean that there aren’t pests to deal with. Now is the time to evaluate how things went during the season. After harvest and during the winter when trees and vines are dormant is a good time to see what may be in store for next year as well.

Almond harvest, seen below, is generally finished in September. Walnuts go into late October.

  In the nut crops, almonds and walnuts, I have samples of the nuts from each block take before the nuts were removed from the field. I crack the nuts open and look for any worm or other pest damage. I’ll crack about 200 nuts on every block (my friends who bake get the good ones). On almonds, ants can eat the nuts when the hulls have split and when the nuts have been shaken off the trees and drying on the ground. If your ant control wasn’t good, you’ll see damage in the crack outs. Other damage that can be seen on almonds is damage from stink bugs.

Stink bug on almond

Stink bug can damage nuts late. Kernels of damaged nuts either become wrinkled and misshapen, or if already hardened before bug damage, will contain a black spot at the puncture site.

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Navel Orange worm in almond

Another pest you can find in either nut is the Navel Orange worm. Not really sure where it got it’s name but it is a pest primarily of nuts. Can be a pest in pomegranates too. They usually attack the nuts late, after the hull and husks have split. The key to controlling this pest it to make sure the populations do not get out of control early in the season. Since they go into the nuts, they are almost impossible to control once they get in.

Another worm that can be found in walnuts is the Codling moth. If you see damage from Navel Orange worm in walnuts it generally means your Codling moth control probably wasn’t very good. Navel Orange worm usually gets into walnuts through the holes left by early Codling moth damage.

After the leaves are off of the trees it is important to take a look and make sure there are no nuts still hanging in the trees. These “mummy” nuts will be places where Navel Orange worm will survive over the winter. Mummy nuts are removed from the almond trees with workers using poles to knock them down. If there is enough rain, most of the nuts will fall as they get heavy with moisture. You don’t want to have more than an average of 1-2 mummy nuts in a tree throughout the orchard. My job is to go around and count these mummies and determine if they need to come off.

Another important task in the winter, on all the tree crops, is to examine scaffolds, limbs, branches, and prunings for scale insects and mites. Walnut scale, San Jose scale, frosted scale nymphs, and European red mite eggs can all be found by examining the wood during the dormant period.  I’ll gather about 100 samples of smaller twigs for every block. I usually bring them home and look at them in the warmth of my kitchen.

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Pile of frass at entrance of peach twig borer hibernaculum.

In the late winter, usually after the first of the year, I’ll decide, based on what I’ve found during the checks I’ve mentioned above and on observations made during the year, what stone fruit and almond trees will need a “dormant spray”. This is a spray that we put on the trees just before they start to wake up for spring. Disease such as shot hole and leaf curl will over winter as spores on the wood and those can be controlled in the dormant spray. Scale, mites and any worms that over winter in the trees, can also be controlled at this time. Peach twig borer overwinters on the tree as a first- or second-instar larva within a tiny cell, called a hibernaculum, that is located in crotches of 1- to 3-year-old wood, in pruning wounds, or in deep cracks in bark. The overwintering site is marked by a chimney of frass and is especially noticeable when first constructed or before winter rains set in. Larvae emerge in early spring, usually just before and during bloom, and migrate up twigs and branches where they attack newly emerged leaves, blossoms, and shoots. Dormant spray will help control this pest.

Grapes generally don’t need much attention after harvest. This year however, the vine mealybugs were so bad I am considering doing some post harvest sprays. These pests will go down below ground and spend the winter on the roots, only to come back up again next season. The fewer going down will mean less coming back up, or at least I hope so. These warm winters are not helping. We are not getting the winter knock down of pest populations we usually see. Monitoring for these pests during the winter entails digging around at the base of the vine to see what kinds of population levels are hiding out.

Citrus leaves with citrus leafminer larvae,

Citrus is a year round crop. The new crop is developing as the old crop is maturing and getting ready to pick. Trees are always green and pests can be found all year. Most of the time pest are not much of an issue in the winter. But when the winter is warm, like it has been the last few years, some pests can keep active. Red scale usually is dormant in the winter but last winter you could pick up males flying around in the traps even in the winter. So going out a couple time a month to keep an eye on what is going on is a must. Bean thrip is sometimes active in these warm winters and some of the export markets don’t what to see them so if fruit is going to these markets, bean thrip need to be dealt with. If not, I just ignore them. Citrus leaf and peel miners can also remain active in the fall if temperatures remain warm.  Citrus tree will put on their last flush of growth in the fall so you want to keep these miners off the leaves.

About this time of year we are expecting (and hoping) for rain so sprays on the citrus for brown rot and Septoria spot are being applied. Certain export markets don’t want certain disease so you need to keep the fruit clean. As the weather gets cooler and hopefully wetter, the snail will come out from under the trees and make baiting for them easier. They are a real pain. Did you know snail eat oranges?

Brown garden snail.

 

 

 

 

Alfalfa will go dormant when it gets cold enough. The only thing to watch out for there are aphids. Certain ones, like cowpea and blue alfalfa aphid can damage the plants if they build up to significant levels.

Last but not least, WEEDS. In all the crops and on the bare row crop beds, weeds will be something to contend with all winter. If it gets cold enough weeds will stop growing or grow slow enough not to worry about too much. There are spray that will go out that will keep them from coming up but most need to be rain activated so if we don’t get enough rain, they do not work very well. We need all the moisture we get in the soil, not being sucked up by weeds. Weeds are my constant bane of existence all year long.

What else does a plant doctor do in the winter? Education!! Plenty of meetings to learn and keep up with all the new technology, pest trends, research, etc. In California I need 40 hours of continuing education to keep my state license but I generally get more than that. So much to keep up on. Always learning.

Note: Thanks for the UCIPM website for all the great photos. These are much better than I could take.

Foreign Invasion threat to farming

Creeping MenaceForeign terrorists have been invading our farms and environment for a long time. These terrorists are called Invasive species. An invasive species is a plant or animal that is not native to a specific location (an introduced species); and has a tendency to spread, which is believed to cause damage to the environment, human economy and/or human health. Species that are moved or migrate to an area where they have not been to before can disrupt the ecology of an area because the native species have not evolved to interact with the newcomer. There may be no natural predators to keep the new species in check or the new species may find a food source that has no defense against the newcomer. There are invasive pests that have invaded our forests, waterways, homes and fields.

The following are just a few I’ve chosen to highlight from the USDA APHIS Hungry Pest website:

gypsy moth“The Asian gypsy moth (AGM) is a destructive, non-native pest that feeds on over 600 types of plants. Large infestations of AGM can completely defoliate trees, leaving them weak and more susceptible to disease or attack by other insects. If defoliation is repeated for two or more years, it can lead to the death of large sections of forests, orchards, and landscaping.” Not only damaging our forests but our landscaping in our cities.

Imported Fire Ants are nasty pests. If you have run into these and have been attacked, you’ll know why. They also damage crops and attack livestock.

giant-snailGiant African Snail is one of the most damaging snails in the world because it consumes at least 500 types of plants and can cause structural damage to plaster and stucco structures. This snail can also carry a parasitic nematode that can lead to meningitis in humans.

Some of these pest have been here a long time and have become “established”. The Asian Tiger Mosquito arrived a long time ago, hitching a ride in some imported tires from China. This mosquito carries West Nile Virus (Link for more on West Nile Virus for WebMD). West Nile virus infects humans and horses. Invasive mosquitoes are also carrying yellow fever, Dengue fever and chikungunya fever.

HydrillaInvasive plants can cause problems as well. Hydrilla is an aquatic plant that invaded Florida and has spread across the country. It is an aggressive plant that out competes native aquatic species and destroys native aquatic ecosystems.

What are some of the more important invasive species that agriculture has to deal with? There are quite a few. First I’ll cover a few that directly impact the crops and then I’ll explain some other ways invasive pest cause problems for agriculture.

Let’s start with one that is something I’m dealing with directly, the Asian citrus psyllid. This pest feeds on the new leaf growth of citrus trees cause the leaves to twist and die back. They are not a particularly difficult insect to control. The biggest problem with this pest is that it can, if infected, transmit a bacteria that causes Huanglongbing (HLB or citrus greening) disease.

Citrus GreeningHuanglongbing causes shoots to yellow, asymmetrically (blotchy mottle), and results in asymmetrically shaped fruit with aborted seeds and bitter juice. The disease can kill a citrus tree within 5 to 8 years, and there is no known cure for the disease.This has already devastated the citrus industry in Florida. It has spread to California, first detected in the Los Angeles area. Even with strict regulations in place about moving citrus trees (the pest does not get on the fruit) it still managed to move from Florida to LA and now up into California’s central valley, the largest citrus growing area in the state.Until just a few months ago none of the psylids found were infected with HLB. Quarantines are in place around areas where the psylids have been caught and this means a lot of extra work if you have to move your fruit to a packing house outside of the area. This includes, but not limited to, spraying pesticides before each pick. A farmer may go through and pick many times before all the fruit is harvested.

BMSBAnother invasive pest headed my way but not yet here is the Brown Marmorated Stink Bug (BMSB). It “has been detected in California. Wherever BMSB takes up residence, it causes severe crop and garden losses and becomes a nuisance to people. The ability of BMSB to hitchhike in vehicles and planes has allowed it to spread rapidly to new areas. Since it was introduced to the United States from Asia in the 1990s, BMSB has become established in the mid-Atlantic states as well as in Portland, Ore., and Los Angeles”. (from UCIPM website). This pest has recently been found in large numbers in the Sacramento area and has been found Stockton. A number of other native stink bugs are pests in agriculture  They are not easy to control and usually require harsher pesticides to get rid of them. The BMSB has been found to be very hard to control and will definitely be a big impact to our IPM programs as they infest a large number of crops.

These are just two but there are many. Many that have come into California and many that are being tracked for possible entry. You can see a pretty comprehensive list for California here

But other countries are watching us as well and they have their own lists and things they do not want us introducing into their environments. This creates issues for farmers because the packers and shippers must ensure what they are exporting comply with the importing countries regulations concerning these pests. Following is a summary of a few of our pests that we have to take extra measures to control and monitor, and why, in some cases, this causes a problem in our IPM programs.

The Oriental Fruit Moth is a common pest that mainly infests stone fruit (Peaches, Nectarines, Plums, etc). Mexico does not have this pest (or so they claim) so they do not want any fruit coming across the border that may have any of this pest in it. Growers and Packers who want to ship fruit to Mexico must pay into a program for extra monitoring for this pest. This includes paying for inspectors for Mexico to be on site during the growing and harvest season, increased trap density and the costs to have people check these traps more frequently than on a non export field, Since you are not allowed to have ANY of this pest in your fruit you need to make sure you spray every hatch (one a month) even if your trap catches do not indicate a serious infestation. Any trap catches and you are required to spray and you can’t use any of the newer more environmentally friendly products because Mexico doesn’t think they work as well. You really can’t have a good IPM program with someone else dictating what you have to do.

fuller rose beetleFuller Rose beetle is a pest that will lay it’s eggs on citrus fruit, under the stem and can be hard to find. South Korea doesn’t want it. Even if you don’t have it in your fields you are required by the packers to spray at least once before harvest. The citrus industry exports a lot of product and there are other spray programs that are dictated more for appeasing the export markets than for what is going on in the field.

A few years back we had an outbreak of European Grapevine Moth that had hitched a ride on some smuggled grapevines from France over to Napa. They hung out in the Napa area, slowly building populations before someone noticed these were not our common type of worm generally found. Napa doesn’t normally have a big problem with worm pests and this one was causing a lot of problems especially for organic growers. Then it moved. Someone brought infested wood down to Fresno and then the export of table grapes came to a halt. For me, it was just another worm pest that was easily dealt with in my current program but in order to satisfy export markets areas with the pest were quarantined and when and what to spray was dictated by the USDA. No one in those areas could ship out of the US and the industry lost a lot of money.

Spotted Wing Drosophila is a fruit fly that, unlike many of our native fruit flies, will attack undamaged fruit and has many generations in a short period of time. They infest cherries and berries mainly. Also a pest we have to spray for even if we don’t see it because one fly can cause the whole field to be kicked out of an export program.

How do these pest move around? Well, mostly by human activity but also changing climate patterns are opening up new habitats in locations where these pests can move to as well. I mentioned that the European Grapevine moth came in by way of some grapevine cuttings that were transported from France to Napa. They did not go through legal import procedures, otherwise the pests would have been detected. Plants and fruit travel to and from places all the time but if they go through airports or border stations, they can generally be intercepted. But it they do not, hitchhiking pests are never far. This local story is about smuggled fruit being sold by roadside vendors and some had invasive pests on them.

We can all help in the fight against these pests. The USDA’s Hungry Pest website has good information on “What Can You Do“.