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The world’s largest organism is slowly being eaten by deer

November 23, 2021 9.37am EST Updated November 24, 2021 6.47pm EST

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  1. Richard Elton WaltonPostdoctoral Research Associate in Biology, Newcastle University

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Richard Elton Walton is affiliated with Friends of Pando as a volunteer.

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In the Wasatch Mountains of the western US on the slopes above a spring-fed lake, there dwells a single giant organism that provides an entire ecosystem on which plants and animals have relied for thousands of years. Found in my home state of Utah, “Pando” is a 106-acre stand of quaking aspen clones.

Although it looks like a woodland of individual trees with striking white bark and small leaves that flutter in the slightest breeze, Pando (Latin for “I spread”) is actually 47,000 genetically identical stems that arise from an interconnected root network. This single genetic individual weighs around 6,000 tonnes. By mass, it is the largest single organism on Earth.

Aspen trees do tend to form clonal stands elsewhere, but what makes Pando interesting is its enormous size. Most clonal aspen stands in North America are much smaller, with those in western US averaging just 3 acres.

View across a valley with trees highlighted in green
Aerial outline of Pando, with Fish Lake in the foreground. Lance Oditt / Friends of Pando, Author provided

Pando has been around for thousands of years, potentially up to 14,000 years, despite most stems only living for about 130 years. Its longevity and remoteness mean a whole ecosystem of 68 plant species and many animals have evolved and been supported under its shade. This entire ecosystem relies on the aspen remaining healthy and upright. But, although Pando is protected by the US National Forest Service and is not in danger of being cut down, it is in danger of disappearing due to several other factors.

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Deer are eating the youngest ‘trees’

Overgrazing by deer and elk is one of the biggest worries. Wolves and cougars once kept their numbers in check, but herds are now much larger because of the loss of these predators. Deer and elk also tend to congregate in Pando as the protection the woodland receives means they are not in danger of being hunted there.

Three deer in an aspen forest
Well-disguised deer eating Pando shoots. Lance Oditt / Friends of Pando, Author provided

As older trees die or fall down, light reaches the woodland floor which stimulates new clonal stems to start growing, but when these animals eat the tops off newly forming stems, they die. This means in large portions of Pando there is little new growth. The exception is one area that was fenced off a few decades ago to remove dying trees. This fenced-off area has excluded elk and deer and has seen successful regeneration of new clonal stems, with dense growth referred to as the “bamboo garden”.

Diseases and climate change

Older stems in Pando are also being affected by at least three diseases: sooty bark canker, leaf spot and conk fungal disease. While plant diseases have developed and thrived in aspen stands for millennia, it is unknown what the long-term effect on the ecosystem may be, given that there is a lack of new growth and an ever-growing list of other pressures on the clonal giant.

The fastest-growing threat is that of climate change. Pando arose after the last ice age had passed and has dealt with a largely stable climate ever since. To be sure, it inhabits an alpine region surrounded by desert, meaning it is no stranger to warm temperatures or drought. But climate change threatens the size and lifespan of the tree, as well as the whole ecosystem it hosts.

Although no scientific studies have focused specifically on Pando, aspen stands have been struggling with climate change-related pressures, such as reduced water supply and warmer weather earlier in the year, making it harder for trees to form new leaves, which have led to declines in coverage. With more competition for ever-dwindling water resources (the nearby Fish Lake is just out of reach of the tree’s root system), temperatures expected to continue soaring to record highs in summer, and the threat of more intense wildfires, Pando will certainly struggle to adjust to these fast-changing conditions while maintaining its size.

The next 14,000 years

Yet Pando is resilient and has already survived rapid environmental changes, especially when European settlers began inhabiting the area in the 19th century or after the rise of 20th-century recreational activities. It has dealt with disease, wildfire, and grazing before and remains the world’s largest scientifically documented organism.

Trees at sunset
Pando has survived disease, hunting and colonisation. Lance Oditt / Friends of Pando, Author provided

Despite every cause for concern, there is hope as scientists are helping us unlock the secrets to Pando’s resilience, while conservation groups and the US forest service are working to protect this tree and its associated ecosystem. And a new group called the Friends of Pando aims to make the tree accessible to virtually everyone through 360 video recordings.

Last summer, when I was visiting my family in Utah, I took the chance to visit Pando. I spent two amazing days walking under towering mature stems swaying and “quaking” in the gentle breeze, between the thick new growth in the “bamboo garden”, and even into charming meadows that puncture portions of the otherwise-enclosed centre. I marvelled at the wildflowers and other plants thriving under the dappled shade canopy, and I was able to take delight in spotting pollinating insects, birds, fox, beaver and deer, all using some part of the ecosystem created by Pando.

It’s these moments that remind us that we have plants, animals and ecosystems worth protecting. In Pando, we get the rare chance to protect all three.


This article was updated on November 24 to correct a typo: Pando is estimated to weigh 6 million kilograms not 6 million tonnes. It now reads “6,000 tonnes”.

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IAPPS Region X Northeast Asia Regional Center (NEARC)

Present committee members

Dr. Izuru Yamamoto, Senior Advisor

Dr. Noriharu Umetsu, Senior Advisor

Dr. Tsutomu Arie, a representative of the Phytopathological Society of Japan, the chair of Region X

Dr. Tarô Adati, a representative of Japanese Society of Applied Entomology and Zoology

Dr. Hiromitsu Moriyama, a representative of Pesticide Science Society of Japan, the secretary general of Region X

Dr. Rie Miyaura, a representative of The Weed Science Society of Japan

The Phytopathological Society of Japan and Pesticide Science Society of Japan became official partners of IYPH2020 by FAO of UN and Ministry of Agriculture, Forestry and Fisheries (MAFF) of Japan and endeavored to educate the society on plant protection. https://www.maff.go.jp/j/syouan/syokubo/keneki/iyph/iyph_os.html

Annual activities related to IAPPS especially to IPM of plant diseases, insects and weeds, and plant regulation (from April 2020 to March 2021)

The Phytopathological Society of Japan (PSJ)

2020 Kanto District Meeting, Online; Sep 21–22, 2020

2020 Kansai District Meeting, Online; Sep 21–22, 2020

2020 Tohoku District Meeting, Online; Oct 12–14, 2020

2020 Hokkaido District Meeting, Online; Oct 15, 2020

2020 Kyushu District Meeting, Online; Nov 24–26, 2020

2021 Annual Meeting, Online; Mar 17–19, 2021

Japanese Society of Applied Entomology and Zoology (JSAEZ)

65th Annual Meeting, online, March 23-26, 2021

28th Annual Research Meeting of the Japan-ICIPE Association, online, March 25, 2021

Pesticide Science Society of Japan

37rd Study Group Meeting of Special Committee on Bioactivity of Pesticides, online, Sep 18, 2020

40th Symposium of Special Committee on Agricultural Formulation and Application, Yokohama, Kanagawa; Oct 15–16, 2020 (Cancelled due to the spread of COVID-19)

43th Annual Meeting of Special Committee on Pesticide Residue Analysis, online, Nov. 5–6, 2020

46th Annual meeting, Fuchu, Tokyo and Online, March 8–10, 2021

The Weed Science Society of Japan (WSSJ)

2020 Annual Meeting, The Weed Science Society of Kinki, Online; Dec 5, 2020

35th Symposium of Weed Science Society of Japan, Online; Dec 12, 2020

2020 Annual Meeting, Kanto Weed Science Society, Online; Dec 22, 2020

22th Annual Meeting, The Weed Science Society of Tohoku, Japan, Online; Feb 25, 2021

2020 Study Group Meeting of Weed Utilization and Management in Small Scale Farming, Online; Feb 26, 2021

Hono-Kai (means, Meeting who are appreciating agriculture)

35th Hono-Kai Symposium was cancelled due to the epidemic of COVID-19

Japan Biostimulants Association

rd Symposium, Online; Nov 2–30, 2020

Nodai Research Institute

2020-1 Biological Control Group Seminar, Setagaya; Tokyo; Jun 16, 2020 (Cancelled due to the epidemic of COVID-19)

2020-2 Biological Control Group Seminar, online, Nov 13, 2020

2021-1 Biological Control Group Seminar, online, Jun 15, 2021

2021-2 Biological Control Group Seminar, online, Nov 9, 2021

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Aspen trees affected by invasive insect

Oregon State UniversityWFP-OSU-aspens.jpg

Aspen trees grow in Yellowstone National Park.Quaking aspen is the most widely distributed tree species in North America.

Julene Reese | Nov 17, 2021

Oystershell scale, an invasive insect that can weaken and kill aspen trees, has recently been confirmed in native forests in Utah.

The insect has been a common urban plant pest in the United States since the 1700s and has likely been affecting trees and shrubs in Utah landscapes for decades. However, the USDA Forest Service’s Forest Health Protection program only recently confirmed its presence in the Uinta-Wasatch-Cache National Forest in Pole Canyon, east of the Provo area.https://4ff46bf5974d951b8089e0c653f785cf.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

“Quaking aspen is the most widely distributed tree species in North America, and it adds an important component of biodiversity, wildlife habitat, and fall color to Utah landscapes,” said Darren McAvoy, Utah State University Extension assistant professor of forestry. “This pest is a significant threat to the health of our Utah forests, and management options for dealing with it are limited and need more research.”

McAvoy said young trees are particularly susceptible to oystershell scale, which is especially challenging since young trees are important for stand replacement, and many Utah forests already lack younger aspen trees.

“Historically, other invasive species have practically wiped out certain species of trees in the U.S., including the American chestnut and western white pine,” he said. “Oystershell scale is known to have killed large groups of native forest tree species in several eastern states. It is currently causing significant damage to aspens in northern Arizona, where it has been active over the past decade, weakening and killing aspen trees below 8,200 feet in elevation.”

Sap-sucking insect

McAvoy said oystershell scale is a tiny sap-sucking insect that matures over the summer and develops a waxy outer shell that looks like a tiny oyster or mussel shell attached to the bark of the tree. Insects tend to congregate on the shady side of trees and branches, avoiding direct sunlight. Initially they will affect a small portion of a tree but can eventually encrust whole branches and cause branch dieback, leading to tree death.

“For this reason, it’s important to be extremely careful not to move firewood that is infected with the insects into a forest,” he said.

While there are more than 100 known host species of oystershell scale, it is best known for its effects on ash, aspen, willow, cottonwood, and boxelder trees in Utah. Although strategies for management are limited, the first step is to monitor its spread.

“Applying fire to the affected landscape appears to be the most promising management strategy for controlling the spread of oystershell scale, but we are just starting to learn about it, so more research is needed to understand this relationship,” McAvoy said.

Managers can help with monitoring efforts by sending confirmed sightings of oystershell scale, including a GPS location, photo, and affected host species, to Justin Williams, USDA Forest Service, Forest Health Protection Ogden Field Office, justin.williams3@usda.gov.

Click here to see a journal article preview on oystershell scale by Conner Crouch of the Northern Arizona University School of Forestry.Source: Utah State University, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.

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Learnings From Latin America: Potential Risk of Helicoverpa armigera to U.S. Soybean Production (entomologytoday.org)

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From PestNet

[Citrus greening (CG) is one of the most damaging diseases of the crops, affecting leaves and fruit. It is caused by fastidious phloem-inhabiting bacteria classified as _Candidatus_ Liberibacter asiaticus (CaLas; Asian greening; huanglongbing), africanus (including a subsp. capensis; African greening), or americanus (South American greening). The 3 pathogens can only be distinguished by molecular methods. Several phytoplasma species have been reported to cause symptoms similar to greening disease in citrus; coinfections of phytoplasmas with CaLas have also been recorded (see ProMED posts 20180214.5629251, 20190329.6392077). Further research is needed on symptomatology, epidemiology, and host impact of both single and mixed infections of these pathogens.

Symptoms include blotchy mottling and yellowing of leaves, as well as small, irregularly shaped fruits with a thick, pale peel and bad taste. Early symptoms may be confused with nutrient deficiencies. Affected trees become stunted, bear multiple off-season flowers, and may live for only a few years without ever bearing usable fruit. CG is restricted to _Citrus_ and close relatives because of the narrow host range of their psyllid vectors. The pathogens can also be spread by grafting and possibly by seed from infected plants or transovarially in the vectors. Both pathogens and vectors can be spread with plant material.

Disease management requires an integrated approach including use of clean planting and grafting stock, elimination of inoculum, use of pesticides for vector control in orchards, as well as chemical or biological control of vectors in non-crop reservoirs. Control using cultural methods, such as interplanting with non-host crops, is being trialled. In areas where a pathogen has not yet been detected, biological control of vectors has been used successfully to reduce insect numbers and, therefore, the risk of greening outbreaks (for example, see ProMED post 20090601.2034).

Antibiotics as leaf sprays, seed treatments, or trunk injections are being used occasionally to treat CG (see for example, ProMED posts 20181119.6154764, 20190320.6377319), but are subject to strict regulations in most countries due to their associated risks of facilitating the emergence of antibiotic resistances in other crop, animal, and human pathogens. Furthermore, beneficial soil microbes may be killed off as collateral damage, making the plants weaker and more susceptible to other diseases. Residues of antibiotics may also lead to rejection of exported produce by some countries.

In neighbouring India, CaLas was shown to be present in most states and widespread in all commercial citrus species and hybrids (ProMED post 20150409.3285806). While molecular diagnosis is often not obtained for local outbreaks, like the one reported above, CaLas seems to be the most likely CG pathogen involved in the region.

In South America, citrus in colder areas has been found less affected by CG (ProMED post 20201207.7999673), possibly due to vector insects in colder temperatures being less active or their numbers remaining lower. On the other hand, in Nepal, citrus psyllids have been found at increasing altitudes (ProMED post 20161129.4660906), potentially due to increasing overall temperatures there. This reflects similar effects observed for other pathogens and pests (for example, ProMED posts 20160902.4459660, 20160622.4302098, 20160509.4211696) migrating to new areas in many regions due to warming climates.

Maps
Bhutan:
https://i.infopls.com/images/mbhutan.gif
Bhutan districts:
http://www.maps-of-the-world.net/maps/maps-of-asia/maps-of-bhutan/color-administrative-map-of-bhutan.jpg

Pictures
Citrus greening symptoms:
http://www.citrusalert.com/wp-content/uploads/2012/10/GreenIslandsOfColor.jpg,
https://geneticliteracyproject.org/wp-content/uploads/2016/10/citrus_greening.jpg and
http://www.abc.net.au/reslib/200904/r362894_1677317.jpg
Citrus greening, symptoms and vector photo galleries:
http://www.invasive.org/browse/subinfo.cfm?sub=4695 (Asian) and
https://gd.eppo.int/taxon/LIBEAF/photos (African)

Links
Citrus greening information:
http://www.pestnet.org/fact_sheets/citrus_huanglongbing_greening_230.htm (with pictures),
https://www.aphis.usda.gov/aphis/resources/pests-diseases/hungry-pests/the-threat/citrus-greening/citrus-greening-hp,
http://cisr.ucr.edu/citrus_greening.html and
http://ecoport.org/ep?SearchType=slideshowViewSlide&slideshowId=197
Asian greening, information and distribution:
http://www.cabi.org/isc/datasheet/16565 and
http://www.planthealthaustralia.com.au/pests/huanglongbing-or-citrus-greening-asiatic-strain/
African greening, information and distribution:
http://www.cabi.org/isc/datasheet/16564
Taxonomy of Liberibacter species via:
http://www.uniprot.org/taxonomy/34019
Taxonomy and information for psyllid vectors (with pictures) via:
http://www.psyllids.org/index.htm

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Sarpang farmers worry about drying orange trees 

November 3rd, 2021 Post Views: 438

Gelephu gewog cannot produce any orange this year

Nima Gelephu

Farmers in Nubgang, Dekiling are cutting down orange trees for firewood and vegetable stalks. They are abandoning the cash crop and venturing into commercial farming or planting areca nut trees.

Oranges were the main source of income for the farmers in Nubgang. It was widely grown until citrus greening, one of the most serious citrus plant diseases in the world, emerged in the village, wiping out entire orchards. The dried orange trees remain abandoned in the orchards that were earlier filled with healthy fruiting trees.

Farmers say the problem became worse in the past three years.

Leki from Nubgang said that it was worrying to see all of the orange orchards fail in three years, as his family depended on the oranges for their livelihood.

“Living is becoming more difficult by the year. We lived a comfortable life because there were good returns from the oranges. Nothing is left now. There are no orange trees near home, or in the orchards,” he said.

He added that the family sold the orchard on contract to exporters. “We used to earn at least Nu 90,000 in a year. Exporters complained of a decreasing yield. We are not sure if they will pay us this time,” said Leki.

Most farms in Nubgang were filled with orange trees and the farmers owned separate orange orchards a few kilometres away from the village in the past. No orange trees can be seen today except for a few leafless and drying orange trees at a few homes.

Farmers said that there was no fruiting at all this time. A study was done and farmers were trained in managing orchards. However, the disease couldn’t be wiped out, as not all infected trees could be destroyed.

“The orange trees have started to die naturally. We have got no solution to this. It might also be because of soil fertility. The nature of the soil is different here. If we dig deep, we find sand and clay,” said Leki.

The farmer said that the officials from the agriculture sector have encouraged growing other cash crops. “It is equally discouraging when we don’t get the expected yield. It’s because of the poor soil quality. The orange trees might have died because of the soil,” said the farmer.

Another farmer from Nubgang said that they could replace the old trees with new seedlings, but it was not advisable because not all infected trees in the gewog have been destroyed.

“Now everyone has started growing areca nuts. Growing vegetables on a commercial scale is a challenge without a reliable water supply. We don’t have enough of a drinking water supply,” he said.

Former tshogpa from Nubgang, Dumber Singh Dahal, said that orange trees started to die in large numbers in 2014. “It will be difficult to earn income now. Some might choose to work as labourers for a living and move towards towns,” he said.

He added that the change in weather patterns could have also worsened the problem.

“There was no fruiting on time. Leaves started to drop and the whole tree dried up in two years. We tried to control the disease by spraying insecticides,” said Damber Singh.

Dekiling gewog agriculture extension officer, Sarita Rai said that the number of orange trees in the gewog fell every year. “It’s a nationwide problem caused mainly by poor orchard management. Farmers have to attend to other work and there are no good management practices,” she said.

She added that the agriculture sector, in collaboration with the agriculture research development centre (ARDC) in Samtenling, destroyed infected trees. It was not possible to cut down all of the trees because farmers were disappointed,” said Sarita Rai.

The farmers are encouraged to grow cash crops such as dragon fruit, ginger, and vegetables that are equally profitable. Orange production in Dekling has dropped every year, according to the official.

The gewog extension official said that it is challenging to procure insecticides, as it takes over six months to reach the farmers. The gewog also conducts awareness exercises on orchard management annually.

The official said that the gewog does not have the technical expertise to study the impact of the disease and works in collaboration with ARDC, Samtenling for technical supports and research.

Officials from the dzongkhag agriculture said that the citrus canopy management that focuses on improving orchard management practices and enhancing soil nutrients proved successful in Gakiling gewog.

While the disease couldn’t be wiped out without an advanced rehabilitation programme, the farmers were asked to replace orange trees with other fruit trees today.

Edited by Tshering Palden

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grasshopper sunset

A grasshopper adult admires the sunset on a New Mexico rangeland. Myriad variables influence when and where outbreaks of pest grasshoppers will occur in the western United States, but researchers are making strides in developing models to try to predict the swarms. (Photo by Lonnie R. Black, USDA)

By Erica Kistner-Thomas, Ph.D.; Derek A. Woller, Ph.D.; Sunil Kumar, Ph.D.; and Larry Jech, Ph.D.

Setting the Stage

The battle between humans and grasshoppers has been going on in the western United States for over 100 years. These insects are major pests of rangeland habitats as well as adjacent croplands, and cyclical population outbreaks have the potential to cost the economy millions of dollars in annual damages.

Despite this risk, these native pests (mainly 12 to 15 species out of hundreds) are often overlooked in terms of their economic and ecological impacts compared to novel invasive insect pests. Ranchers annually seek technical assistance and treatment options for managing grasshopper outbreaks from the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) Rangeland Grasshopper and Mormon Cricket Suppression Program.

In addition to these duties, the program also conducts bi-annual population surveys, in spring and early summer for nymphs, and in late summer and fall for adults. The primary goal of these surveys is to identify areas of outbreak potential and provide very limited population predictions for the next season using a statistical methodology known as “empirical Bayesian kriging.” We say “limited” because, from a modeling standpoint, grasshopper outbreaks are notoriously difficult to predict due to the myriad and complex variables that are involved, such as species complexes, weather patterns, soil type and moisture level, and many more.

In a new open-access article published in June in the Journal of Economic Entomology, we developed a grasshopper population density forecasting model using the most complete APHIS population survey data set (10 years) we could find that focused on four counties in north central Wyoming. To the best of our knowledge, this is the first model of this type for grasshoppers to incorporate both geographic information system-based climate variables as well as landscape variables.

Incredible Diversity and Complex Variables

The diversity of grasshopper species at the 56 survey sites was staggering: A total of 99 species was recorded over 10 years, from 2007 to 2017. That’s a lot of hoppers! The two most abundant species sampled consistently were Melanoplus sanguinipes and Ageneotettix deorum, both of which are major rangeland pests and are part of the top 14 grasshopper pests in Wyoming. In fact, across the time period, all of these species shown in the graphic below were represented, with some far more abundant than others.

A team of researchers used historical grasshopper outbreak data, combined with geographic information system-based climate variables and landscape variables, to develop a model for forecasting grasshopper outbreaks. The map here shows observed versus predicted (outbreak risk) mean grasshopper density levels in north central Wyoming for July from multiple regression modeling for 2012–2016. (Image originally published in Kistner et al. 2021, Journal of Economic Entomology)

Since no one had ever developed a predictive geospatial model for U.S. grasshoppers, we were not even sure which environmental variables would be good predictors for future population densities. Past research suggests that climate, topography, soil properties, land cover and land use types, historical grasshopper densities, and remotely sensed enhanced vegetation index are correlated with grasshopper population densities. Plus, as noted earlier, the presence of species complexes also presented a unique challenge because it is far more common to focus predictive models on a single species.

We ended up examining 72 biologically relevant environmental variables as potential predictors of grasshopper density in north central Wyoming. Using these predictor variables, we created several regression models and tested their robustness using the survey data from the years 2012 to 2016 as our response variable. The best-fit model included a handful of the predictor variables (some monthly weather variables and corresponding past mean grasshopper density) and was able to explain 35 percent of the variation, which we were pleased with, all things considered. In fact, when we compared this model’s population predictions to the actual (observed) survey data, we had a pretty good match overall (see map below).

In a data set used to model rangeland grasshopper outbreaks, a total of 99 species was recorded over 10 years in four Wyoming counties, from 2007 to 2017. Shown here is the relative abundance of grasshopper species recorded, with the 15 most abundant identified by name. Asterisks denote species that are one of the 14 major pest species in Wyoming. (Figure originally published in Kistner et al. 2021, Journal of Economic Entomology)

What’s Next?

While our forecasting models provided moderate predictive power, there was still a lot of unexplained variation that traditional statistical models could not account for. Therefore, we have decided to start incorporating machine learning techniques, which can better-handle the complex ways in which biotic factors (like past population densities) and abiotic factors (like monthly precipitation) appear to be driving grasshopper population densities. To enhance our new modeling abilities even further, we are also now focusing on specific grasshopper species (12 of the most economically important pests in the west) and across the known geographic range for each.

Read More

Modeling Rangeland Grasshopper (Orthoptera: Acrididae) Population Density Using a Landscape-Level Predictive Mapping Approach

Journal of Economic Entomology

Erica Kistner-Thomas, Ph.D. is a national program leader at the USDA National Institute of Food and Agriculture’s Institute of Food Production and Sustainability. Email: erica.kistnerthomas@usda.govDerek A. Woller, Ph.D. is a supervisory entomologist and team leader of the Science & Technology Rangeland Grasshopper and Mormon Cricket Management Team at the USDA Animal and Plant Health Inspection Service (APHIS). Email: derek.a.woller@usda.govSunil Kumar, Ph.D. is an ecologist and quantitative risk analyst at USDA-APHIS. Larry Jech, Ph.D. is retired from the USDA APHIS. Email: larryjech@gmail.com.

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Functions of Grasshopper Genitalia Revealed, in 3D, Via Correlative Microscopy

April 4, 2017

The Eastern Lubber Grasshopper: Hard to Miss, But Only an Occasional Pest

March 22, 2018

Building a Better Grasshopper Trap: New Design Offers Safer, More Efficient Harvest

March 19, 2021 Research NewsAgeneotettix deorumAPHISDerek WollerErica Kistner-ThomasforecastinggrasshoppersJournal of Economic EntomologyLarry JechMelanoplus sanguinipesmodelingrangelandSunil Kumarusda

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UTA to use tiny sensors to track bugs and combat infestations

The University of Texas at Arlington is helping develop tiny sensors that attach to insects, tracking their movements and life cycles in an effort to combat infestations and increase farm production.

The project is led by computer science Professor Gautam Das and electrical engineering Professor Wei-Jen Lee, working with the U.S. Department of Agriculture (USDA). The $122,057, USDA grant runs through June 2023.

“This is a unique approach to the problem of infestations, and we hope to produce results that will allow us to expand our research later,” Das said. “The use of artificial intelligence in agriculture is a growing field, and this is just one small example of how it can make an impact.”

Das will work to develop a sensor that can be attached to the tarnished plant bug, a plant-feeding insect known to ruin crops of small fruits and vegetables. The sensors would relay information to a base station that tracks the insect’s coordinates and movements. Das and Jianzhong Su, professor and chair of mathematics, will perform data analysis to find patterns.

Lee will work on a radio-frequency identification (RFID) tag for the insects and use multiple readers to pinpoint their locations. A wireless sensor network will transmit data for analysis.

Wei-Jen Lee
The researchers must also develop a way to provide power to the sensor, possibly by tapping into the insect’s movements. The team is working with University of Central Florida mechanical engineering Assistant Professor Wendy Shen.

“Insects can positively or negatively affect agricultural quality and production,” Lee said. “Understanding their behavior is an important step to taking advantage of their benefits and mitigating potential damages. Applying advanced sensor technologies and artificial intelligence will have a profound impact on the future development of agriculture.”

Jianzhong Su
The insects will be released into special rooms maintained by the USDA that have large spaces where plants are grown, and insects can fly around in a controlled environment. This way, the team can test its technology without worrying about negative impacts on actual crops.

Since 2020, the USDA and the National Science Foundation have poured millions of dollars into artificial intelligence research in agriculture. Su has led a university-wide research collaboration with the USDA since 2018 with researchers from the Colleges of Science and Engineering, through funding from an earlier USDA Hispanic Serving Institution grant focused on agriculture data and Internet of Things.

“We have built a good relationship with the USDA, and we are happy that they have provided funding for this project,” Das said. “Hopefully, this is the beginning of a series of opportunities.” 

Source: www.uta.edu

Publication date: Fri 17 Sep 2021

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Rice Scientists,

About 5 months ago the US AGRONOMY journal invited me to write a review. Since it is pandemic time I thought it will be a nice mental challenge. After peer reviews, corrections, editing etc, it is finally published. Those interested the online version is available for those interested. https://www.mdpi.com/2073-4395/11/11/2208/pdf

KL Heong

klheong@yahoo.com

Ecological Engineering for Rice Insect Pest Management: The Need to Communicate Widely, Improve Farmers’ Ecological Literacy and Policy Reforms to Sustain Adoption

by Kong-Luen Heong 1,*,Zhong-Xian Lu 2,Ho-Van Chien 3,Monina Escalada 4,Josef Settele 5,Zeng-Rong Zhu 1 andJia-An Cheng 11Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China2Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China3Department of Plant Protection, Mekong University, Vinh Long 890000, Vietnam4Department of Development Communication, Visayas State University, Baybay City 6521, Philippines5Helmholtz Centre for Environmental Research—UFZ, 06120 Halle, Germany*Author to whom correspondence should be addressed.Academic Editor: George G. KennedyAgronomy202111(11), 2208; https://doi.org/10.3390/agronomy11112208Received: 20 September 2021 / Revised: 24 October 2021 / Accepted: 29 October 2021 / Published: 30 October 2021(This article belongs to the Special Issue Crop Pest Management Based on Ecological Principles)
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Abstract

Ecological engineering (EE) involves the design and management of human systems based on ecological principles to maximize ecosystem services and minimize external inputs. Pest management strategies have been developed but farmer adoption is lacking and unsustainable. EE practices need to be socially acceptable and it requires shifts in social norms of rice farmers. In many countries where pesticides are being marketed as “fast moving consumer goods” (FMCG) it is a big challenge to shift farmers’ loss-averse attitudes. Reforms in pesticide marketing policies are required. An entertainment education TV series was able to reach wider audience to improve farmers’ ecological literacy, shifting beliefs and practices. To sustain adoption of ecologically based practices organizational structures, incentives systems and communication strategies to support the new norms and practices are needed. View Full-TextKeywords: ecological engineeringentertainment-educationadoptionsustainabilityrice insect pest managementrice farmerspesticide marketingpolicy reformecosystem services▼ Show Figures

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Possible tool in the war on resistant weeds

Wallaces Farmer

Prashant JhaRedekop Seed Control Unit harvesting soybeans

NO RESISTANCE TO STEEL: Iowa State University is among the leading places in the U.S. to put the Redekop Seed Control Unit to the test — including on a field in Story County, Iowa, and in Harrison County, Iowa, on a field owned by Iowa Pest Resistance Management Program participant Larry Buss.For the second year, ISU is testing a Redekop Seed Control Unit on Iowa farm fields to determine the economic feasibility of harvest weed-seed control.

Tyler Harris | Oct 25, 2021

Larry Buss often says, “I haven’t seen any weeds yet that are resistant to steel.” Steel can refer to preplant tillage, cultivation — or in more recent cases, mechanical control of harvested weed seed.

Ever since Palmer amaranth was identified in Harrison County, Iowa, in 2013, Buss has been vigilant in doing his part to slow the spread of herbicide resistant weeds in Iowa and across the continent — spreading the word with national organizations like the Weed Science Society of America and Entomological Society of America, and at international events like the Manitoba Agronomists Conference and the Soil and Water Conservation Society’s Annual Conference.

A Redekop unit being tested on 500 acres of soybeans in Story County last year to kill waterhemp seed at harvest
REDUCED WEED SEED BANK: A Redekop unit was tested on 500 acres of soybeans in Story County last year to kill waterhemp seed at harvest. “We had about 90% or more kill efficacy for waterhemp — and that was a multiple herbicide-resistant waterhemp population in soybean,” says Prashant Jha, ISU associate professor and Extension weed specialist. (Photo by Prashant Jha)

These efforts grew with the launch of the Iowa Pest Resistance Management Program in 2017. Since then, Buss has collaborated with Iowa State University researchers, agronomists, landowners, crop consultants, ag lenders and commodity organizations to monitor the spread of resistance on farms in Harrison County, and test different practices and herbicide programs to control weeds like Palmer amaranth, waterhemp, marestail and giant ragweed.

Most recently, this involves harvest weed-seed techniques — more specifically, using a Redekop Seed Control Unit. Designed to be used with a John Deere combine, the Redekop unit uses high-impact mills to break the seed through physical destruction as it comes out of the back of the combine, killing the seed and preventing germination. According to Saskatoon, Saskatchewan-based Redekop, the unit can destroy as much as 98% or more of weed-seed germination during harvest. The unit also allows the operator to turn it on and off on the go.

“I have a few weeds at a field by Dunlap, so we’re going to test it up there,” Buss says. “Then, we are going to get a sample of the weed seed behind the combine to see if the unit helps with germination destruction.”ADVERTISING

Off to a good start

Iowa is one of the first states the unit has been tested in the U.S. — it was tested by Prashant Jha, an ISU associate professor and Extension weed specialist in 2020 at a farm in Story County.

Jha notes one Redekop unit was tested on 500 acres of soybeans in Story County last year, with promising results for controlling waterhemp seed at harvest. However, he notes the study is ongoing.

“We had about 90% or more kill efficacy for waterhemp — and that was a multiple-herbicide-resistant waterhemp population in soybean,” Jha says. “We don’t know what level of resistance those waterhemp plants had, but they had survived multiple applications, and that’s why it made perfect sense to do some harvest weed-seed control. The same is true in Harrison County — they have populations resistant to Group 9 as well as Group 2 [herbicides] and most likely PPO and HPPD inhibitors.”

This year, after running the seed destructor in soybean fields, Jha will monitor the changes in weed seed bank density over time by collecting soil core samples in the fall, and then counting weed emergence in the following spring.

“We will estimate how much of the initial weed-seed bank has emerged and how much has survived herbicide applications, and how many weeds are present at harvest and the weed-seed-kill efficacy of the Redekop seed unit,” Jha says.

Economic feasibility

Of course, one of the big questions to be answered is: At what point does it become economically feasible to use harvest weed-seed control? Jha notes while the Redekop unit costs about $70,000, it will take time to determine how long it takes to pay for the machine by reducing the weed-seed bank.

Waterhemp
PROBLEM WEEDS: Since 2017, growers, agronomists, Extension educators and other stakeholders in Harrison County have studied herbicide resistance in weeds as part of the Iowa Pest Resistance Management Program. This includes some key problem weeds in the area: Palmer amaranth (pictured), waterhemp, giant ragweed and marestail. (Photo by Bob Hartzler)

“It won’t happen in one year, but we expect at least a 90% reduction in the seed bank,” he says. “There will be some header/thresher loss — probably close to 25% to 30%. Kevin Bradley at the University of Missouri has seen close to 25% header loss, and some of the weed seeds are getting shattered. We had close to 30% to 33% header loss last year. It’s not stand-alone, but we expect that, of the remaining 67% to 70% seed going inside the unit, 95% will be killed.”

And there are other factors — like the potential savings on herbicide application costs in the future.

“There are millions of dollars right now going into managing herbicide resistance in corn and soybeans,” Jha adds.

“If you calculate the cost of three applications in a season — burndown, pre- and postresidual — can we cut that cost by reducing the weed-seed bank in a three- to four- year time frame, and increase the longevity of the herbicide? More importantly, we are quickly running out of herbicide options because of multiple-herbicide-resistant waterhemp and Palmer amaranth populations,” Jha says.

Last-resort option

Larry Buss notes that for the time being, the best method for weed control is to keep them from competing with crops during the growing season, by controlling them upfront and preventing them from going to seed and expanding the weed-seed bank.

Larry Buss speaks at a field day
SPREADING THE WORD: Larry Buss speaks at a field day as part of a Weed Science Society of America and Entomological Society of America event in this 2019 photo. Buss notes that growers in Harrison County and across Iowa are getting the message that weeds must be controlled early on with a full rate and multiples modes of action. (Photo by Ethan Stoetzer)

“I’m not going to spend money on it yet, because I would prefer to invest it in a better sprayer or a more robust herbicide program. If herbicide resistance continues to get worse, we can use harvest weed-seed methods to significantly reduce the weed-seed bank, because it’s going to wipe out the weed mechanically,” he adds. “Weeds won’t be resistant to steel, so you can kill it with preplant tillage, cultivation — or you kill the seed with the Redekop Seed Control Unit. But before we do that, I think farmers will look to control weeds upfront so they don’t compete with the crop.”

And, Buss notes the outreach efforts of the Pest Resistance Management Program are paying off — while herbicide resistance continues to be a challenge, people are aware it’s a problem and are taking steps to slow its spread.

“I’m going to pat ourselves, in Harrison County and the Iowa Pest Resistance Management Program, on the back,” he says. “Because I think we’re getting the message out that we’ve got to control weeds early on with a full rate of herbicide, and multiples modes of action.”

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Why Augmentative Biological Control Holds Promise for Advancing Agriculture in Developing Countries

ENTOMOLOGY TODAYLEAVE A COMMENT

Parasitoid wasps in the genus Trichgramma are often used in augmentative biological control efforts to manage crop pests. Here, a female Trichogramma dendroliti wasp lays an egg of its own inside an armyworm egg. (Photo by Victor Fursov, Ph.D.CC BY-SA 4.0, via Wikimedia Commons)

By Anamika Sharma, Ph.D.

Anamika Sharma, Ph.D.

A sustainable agricultural system could make the economies of developing countries more stable and self-dependent, and augmentative biological control provides such an opportunity. The aim of augmentative biological control is to manage a crop pest through inoculation and inundation of biological control agents, or natural enemies of the pest. These can include predator or parasitoid insects or microbial organisms. A focused effort and investment to enhance the commercial production of biocontrol agents can improve the human and institutional capacity of developing countries.

The establishment of augmentative biological control requires extensive dissemination of appropriate information and capacity building. One of the major priorities of the Feed the Future Innovation Lab for Integrated Pest Management—located at Virginia Tech’s Center for International Research, Education, and Development and funded by the U.S. Agency for International Development—is improving the human and institutional capacity of its host countries in Africa and Asia.

Muni Muniappan, Ph.D., director of IPM Innovation Lab, says there is a general misperception among scientists that the production and augmentative release of natural enemies is unfeasible and not cost-effective, especially in developing countries.

“This is because usually the cost of production of natural enemies (parasitoids, predators, and microbials) in the laboratories is compared to the cost of available synthetic chemical pesticides,” he says. “However, the establishment of the production units in developing countries builds the human and institutional capacity of the country, and all the money spent on production and use of the natural enemies remain in the country, which in turn makes the food production sustainable and economical. Moreover, about 80 percent of the amount spent on chemical pesticides in developing countries goes to the developed country that produces the chemical, and only a small amount of money stays in the developing countries applying them.”

Augmentative Biological Control in the Realm of Pest Management

The three major types of biological control are classical, conservation, and augmentative. Classical biological control (also identified as inoculation of an exotic natural enemy) involves importing a natural enemy of a pest to the infested region and working to establish a sustained local population. Conservation biological control focuses on maintaining conditions favorable to native natural enemies. Augmentative biological control involves mass rearing of natural enemies and actively releasing or dispersing them to control a pest.

Each approach has its limitations and strengths. For instance, while classical biological control requires longer implementation periods and provides lasting control of a pest, augmentative approaches are comparatively quicker and can control targeted nuisance organisms (insect pests, diseases, weeds) for an extended period but certainly not permanently.

In Niger, farmers are provided gunny sacks with grains, rice moth (Corcyra cephalonica) larvae, and two pairs of the parasitoid wasp Habrobracon hebetor in them. This low-cost process enables farmers to release the parasitoids easily and economically. A bucket is usually used to avoid the sack getting drenched during the rainy season.

Within augmentative biological control, an inoculative approach uses only living organisms (biocontrol agents), including predators, parasites, and microbials (fungus, bacteria, nematodes, and virus), whereas an inundative approach uses living organisms as well as non-living components extracted from living organisms such as neem products, pyrethrins, and Bacillus thuringiensis. The non-living components that are extracted from living organisms are known as biologically based pesticides and function by inundating the system. Currently, highly potent synthetic biochemical pesticides are also available in the market, such as pyrethroids. Since synthetic biochemical and chemical pesticides also require a repetitive application, therefore they can also be identified as an inundative augmentative approach.

The categorizations for all these different approaches may overlap in different ecosystems and circumstances. For instance, Pediobius foveolatus, an introduced parasitoid of the Mexican bean beetle (Epilachna varivestis) in the northeastern United States, does not overwinter and hence does not provide permanent management. It is released every summer in the crop fields as a source of “inoculative augmentation,” a combination of classical and augmentative forms of biological control.

Augmentative Biological Control in Action

Numerous examples throughout history give evidence to the success, sustainability, and viability of biological control in a variety of ecosystems. For just one example, the papaya mealybug (Paracoccus marginatus), is a native of Mexico and feeds on several crops such as papaya, cassava, and mulberry, causing substantial damage to these crops around the globe. Endoparasitoid wasps Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana have single-handedly managed this pest wherever they are released, including in Africa and Asia.

Meanwhile, release of the native parasitoid Habrobracon hebetor at the onset of summer in the Sahelian region of Africa, coinciding with the emergence of the pearl millet head miner Helicochilus albipunctella, is an example of inoculative biological control. Malick Niango BaPh.D., principal scientist at the International Crops Research Institute for the Semi-Arid Tropics in Niger, found this approach immensely effective in managing H. albipunctella populations.

“When you have natural enemies that are easy to multiply in mass at a cheap cost, augmentative biological control is easy to implement,” says Ba. “It works well in settings with functional infrastructure and enabling policies (incentives for biological control and reduced use of chemical pesticides). One of the challenges we faced in West Africa was how to pass on the technology to the private sector. We overcame that by working with farmer cooperatives to enable them to produce the natural enemies and sell them to fellow farmers. This requires a lot of capacity building and engagement from farmers.”

Trichogramma is a genus of tiny polyphagous wasps, measuring about 0.3 millimeters in length, and are endoparasitoids of insect eggs. Several species of Trichogramma are employed as biological control agents as part of an inundative approach and have managed key lepidopteran pests of several crops worldwide.

While sharing a success story of inundative approach using Trichogramma, Chandish R. Ballal, Ph.D., former director, of the Indian Council of Agricultural Research’s National Bureau of Agricultural Insect Resources, mentioned that an inundative approach using Trichogramma for management of rice pests in India resulted in substantial savings in plant protection costs and restoration of rice biodiversity.

collection of parasitoids in Tanzania
mass rearing of parasitoids in Niger
Trichogramma cards in Kenya
Habrobracon hebetor mass rearing

“Rice crop in wetlands or Kole lands of Kerala state in India were earlier subject to as many as six rounds of chemical pesticide sprays during a crop season,” she says, “leading to significant deleterious effects on the ecosystem and biodiversity, as the wetlands are interspersed by a network of canals, besides being home to a large number of migratory birds. Two egg parasitoids, Trichogramma japonicum, and T. chilonis, for managing stem borer and leaf roller infestations were promoted by the local department of agriculture. This intervention was so successful that not a single spray of insecticide was required in rice during the entire season.”

When the effectiveness and benefits of augmentative biological control (both inoculative and inundative) are compared with conventional chemical pesticides, safety and sustainability are always emphasized. Nevertheless, crucial aspects—including efficacy, ease of application, and availability and viability of the commercially available organisms/products—are required to develop an economically viable augmentative biocontrol program. Similar to synthetic chemical pesticides, a successful augmentative biocontrol program requires timely release/application and repetitive use. For the purpose of ease of application, like chemical pesticides, both microbial and botanical biological control agents are currently available in various forms, such as flowable concentrates or wettable powders.

Challenges and Opportunities in Augmentative Biological Control

T. M. Manjunath, Ph.D., who established India’s first commercial insectary, says “mass production, supply, and utilization of parasitoids and predators are beset with several challenges. Being living entities, they have definite life cycles and shelf-life, and their productions require a great deal of pre-planning to match and balance the timely demand, as otherwise the valuable products may go waste.” Based on his long experience, he says, “mass-production and marketing of biological control agents should be treated as a passionate scientific adventure. Although the entire process could be challenging to initiate and function, careful training and promotion could lead to profitable commercial production of biological control agents in developing countries.”

Big challenges often create big opportunities. Commercial production of biocontrol agents has immense growth potential. Collaboration of public and private sectors and involvement of small-scale industries is the key to the successful commercialization of biological control agents in developing countries. Currently, chemical pesticides are the most commonly used method around the world to manage pests because of the rapid results and easy availability; however, they carry a breadth of health and environmental hazards. Moreover, chemical pesticides also need repeated applications similar to inundative biological control agents, and, unlike synthetic chemical methods, the use of natural enemies is compatible with all other pest control methods and does not create resistance in pest populations.

The establishment of production and rearing units of biological control agents in developing countries enable local technicians and scientists to be trained, making institutes and universities of these countries equipped with appropriate skills and facilities. Production of the beneficial fungus Trichoderma spp., which is used as a seed treatment to protect crops from soil-inhabiting fungal pathogens, and mass rearing and releasing Trichogramma spp. for control of pestiferous species of Lepidoptera (for example, Spodoptera spp.,) are examples of some of the IPM Innovation Lab’s most effective capacity-building programs.

Appropriate scaling and pricing as well as active networks of communication among businesses, research institutions, government extension agents, farmer organizations, and farmers can all increase the chances of success of this venture. Augmentative biological control creates opportunities for the local population, small- and large-scale farmers, and industries to work together and harvest monetary benefits, besides human and environmental safety. It is indeed money well spent.

Anamika Sharma, Ph.D., is a research associate at the Feed the Future Innovation Lab for Integrated Pest Management, housed at Virginia Tech’s Center for International Research, Education, and Development. Email: anamika@vt.edu.

All photos courtesy of Anamika Sharma, Ph.D., Feed the Future Innovation Lab for Integrated Pest Management, unless otherwise noted.

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