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5 insects that have affected human history

Ozgur Kerem Bulur/Shutterstock.comdomestic-silk-moth_51436627623_o.jpgThe Domestic silk moth made the silk trade, and the web of Silk Roads, the major driver of economic change between east and west. Arkansas entomologists publish book about the impacts of 5 insects on human history.

Fred Miller, U of A System Division of Agriculture | Sep 24, 2021

If you’re happy about reading this story in English instead of French, thank a mosquito.

Specifically, thank Aedes aegypti, also known as yellow fever mosquitos.https://24de73fdce7fa5a61a718dfc331b7447.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

In 1802, Napoleon Bonaparte was trying to expand his holdings in the Americas when he was stopped short in Haiti. At least 30,000 troops fell to yellow fever and malaria, but mostly yellow fever, delivered by mosquitos. Faced with such devastating loss, the French decided to get out of the New World.

Napoleon and the French sold the Louisiana Purchase, which included Arkansas, to then-President Thomas Jefferson to recoup their investment. The rest is history…according to the perspective of entomologists Rob Wiedenmann and Ray Fisher.

Wiedenmann is a professor emeritus of entomology and a former entomology department head for the University of Arkansas System Division of Agriculture and the Dale Bumpers College of Agricultural, Food and Life Sciences at the U of A. Fisher is a post-doctoral research scientist in entomology for the Arkansas Agricultural Experiment Station, the research arm of the Division of Agriculture.ADVERTISINGthe-silken-thread_51435629327_o.jpg

Ray Fisher, left, and Rob Wiedenmann wrote “The Silken Thread, Five Insects and Their Impacts on Human History.” Fisher is a research scientist in entomology. Wiedenmann is a professor emeritus and former entomology department head.

The pair authored “The Silken Thread: Five Insects and Their Impacts on Human History,” published by Oxford University Press this month.

The book examines significant impacts on human history by domestic silk moths, human body lice, oriental rat fleas, yellow fever mosquitos and western honeybees. The silk moth and the honeybee spread economic benefits to civilizations. The other three spread devastating diseases that interrupted the course of western civilization.

Inspiration

The idea for a book was born from a class Wiedenmann taught called “Insects, Science and History.” Originally an undergraduate course that introduced students from other majors to entomology, he revised the class to include insects’ impacts on human life and culture.

After Wiedenmann retired in 2019, he and Fisher, friends since Fisher was working on his Ph.D. at the University of Arkansas, met for lunch regularly, usually at Hammontree’s. The Fayetteville restaurant gets a shout-out in the book’s acknowledgments. Their conversation frequently turned to stories about the impacts of insects on human history.

“Ray said, ‘You should write a book,’” Wiedenmann said.

They decided it was a two-person undertaking. Wiedenmann had what he refers to in the book as “zillions” of stories about the intersection of insect and human history. It was Fisher’s idea to trim those zillions down to five.

“He had way too many stories to fit in a book anyone would want to read,” Fisher said. “I had to rein him in.”

“We began with, ‘Can we write a cool history with these five insects?’” Fisher said. “Many insects have had diffuse impacts on history. But these five drove huge leaps in history. They have a very narrative story where they made these right-angle changes in the trajectory of human history.”

Just as they began working in earnest, the COVID-19 pandemic changed the course of human history in its own way. Wiedenmann and Fisher collaborated mostly by Zoom. Wiedenmann had the essential elements of history, but they knew they had to find clear historical records and biological evidence to support their narratives.

Fisher proved to be the Indiana Jones of historical and entomological research. “Ray would find these arcane references,” Wiedenmann said, adding that those were driving him crazy. Until they didn’t anymore. “The amoeba reference pushed me over the edge,” he said. “But it was perfect.”

Amoebae eat bacteria. But the bacteria that causes plague has a trick that keeps it from being digested and, instead, uses amoebae to survive under conditions it otherwise could not endure. The full story is in chapter 6. You’ll love it.

Relearning History

As Wiedenmann and Fisher dug deeper into the stories they wanted to tell, they discovered that much of what they thought they knew about history was wrong.

“Everyone knows that fleas carried on rats caused the Black Death plagues in Europe,” Fisher said. “Except they didn’t.”

Fisher said the oriental rat fleas took the plague bacteria out of Asia, but they didn’t cause the rapid spread, turning the plague into the Black Death. Another pest — human body lice are thought to be the culprits that rapidly spread the first two plagues.

“When we think about the Black Death, everything we thought we knew was wrong,” Fisher said.

Every discovery was like a revelation. Wiedenmann said, “I kept asking Luann (his wife), ‘Did you know this?’ Almost daily, we were learning that the history we thought we knew was wrong.”

Their book is also full of little stories that connected their insect subjects to big historical moments, like the plot to kill Abraham Lincoln with what may have been the first attempt at biological warfare.

Before anyone knew that Aedes aegypti mosquitos spread yellow fever, many people believed that clothes worn by the sick could spread the disease. Dr. Luke Pryor Blackburn, a fervent supporter of the Confederacy and hater of anything northern, collected clothing from yellow fever victims, packaged them up and shipped them to auction houses in northern cities, hoping to infect as many Yankees as possible. He even sent one load he claimed could kill at 60 yards to an auction house on Pennsylvania Avenue, a stone’s throw from the White House. He hoped Lincoln would pass by and die.

Wiedenmann and Fisher also show how IBM owes a debt of thanks to domestic silkworms for their role in inventing computers. Check out chapter three for that story.

Tie that binds

The common thread running through each of these insects’ stories is the web of ancient routes collectively called the Silk Roads, by which Chinese marketed silk to the world.

Silk became a major commodity that eventually bound eastern and western civilizations over the Silk Roads. “The history of silk is the history of humans,” Wiedenmann said. And the history of silk begins with the domestication of the silkworm, perhaps as long ago as 7,000 years, he said.

Those Silk Roads became major routes for many purposes, from trade to war. And the insect subjects of The Silken Thread found their way along those roads — both coming and going with the caravans that traveled them.

The human body louse and oriental rat flea, both carriers of the Black Death in their times, found their way to Europe, carried by the caravans that traveled the Silk Roads.

Aedes aegypti came to the Americas by a different and notorious route but was bound to the Silk Roads by external ties. Fisher said the connection was sugarcane, which originated in tropical regions of Asia and found its way to Europe over the Silk Roads. But Europeans, wanting to grow the crop for themselves found that the heat-loving plant thrived in the tropics of the New World. But they required a labor force.

The authors relate how the African slave trade originated on the Atlantic island of Madeira and eventually made its way to the Americas.

Yellow fever originated on islands near Madagascar and spread to and across the African continent. When slave traders began raiding western Africa to enslave the peoples there, Aedes aegypti and their deadly hitchhiker were waiting for them. The mosquitos and yellow fever were transported to the Caribbean on slave ships and eventually spread to the rest of the Americas.

Western honeybees, also known as European honeybees, traveled the Silk Roads in the opposite direction from the other four insects in the book. Honeybees provided a bountiful agricultural product — honey — sought in the east. Not to mention the bees’ gift of pollination for fruit and vegetable crops.

Back to Bonaparte

Poor Napoleon’s bad luck didn’t begin or end with his disastrous encounter with Aedes aegypti and yellow fever. He was defeated three times by the disease-carrying characters of Wiedenmann’s and Fisher’s book.

Before he ran out of luck in the New World, Bonaparte’s Egypt and Syria campaign was brought up short by oriental rat fleas. He set out with 13,000 troops on that mission. After losing some 2,000 of them to flea-borne plague, and being hampered by many more sick, Napoleon bailed out of that operation.

Finally, his Russian invasion was lost in 1812 when his Grand Armée of 650,000 French and allied troops was reduced to 20,000 who returned home healthy. Historians mostly attribute that defeat to the fighting spirit of the Russians and the intense cold of the Russian winter, and they’re not entirely wrong. But Wiedenmann said many died from typhus, spread when the shivering survivors put on the lice-infested coats of those who died from the disease.

Point of view

Wiedenmann and Fisher concede that modern historians may not entirely share their perspectives on history. “We’re not historians,” Wiedenmann said. “We’re just entomologists who have a love for history.”

Wiedenmann and Fisher say the book was a delightful journey of discovery for its authors.

“The wonderful things we learned along the way had everything to do with how much we enjoyed writing this book,” Wiedenmann said.

Wiedenmann and Fisher will hold book signings at the University of Arkansas Bookstore on Oct. 5 from 11 a.m. to 1 p.m. and at Pearl’s Books in downtown Fayetteville on Nov. 9 from noon to 1 p.m.Source: University of Arkansas System Division of Agriculture, 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.TAGS: EDUCATIONRELATED

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A new approach for simulating potential impacts of fungal, insect and mammal pests on European forest ecosystems Global forest disturbance patterns — or events which disrupt the structure and composition of forests — are altering as a result of climate change. Changes, such as more severe insect outbreaks, can negatively impact forests and the ecosystem services they provide to society. This study presents a new model that simulates the impacts of forest disturbance from biotic agents such as fungi, insects or large mammals. Click here to read more A new approach for simulating potential impacts of fungal, insect and mammal pests on European forest ecosystems

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This tiny insect spreads a disease for which there’s no cure — and it’s coming for our citrus

Landline / 

by Kerry StaightPosted Fri 10 Sep 2021 at 9:21pmFriday 10 Sep 2021 at 9:21pm

Photo of citrus psyllid
The Asian citrus psyllid, at just 3-4mm long, poses a massive problem for healthy citrus orchards across the globe.((creative commons))

Help keep family & friends informed by sharing this articleabc.net.au/news/hlb-citrus-greening-biosecurity-australia-psyllid-finger-limes/100452594COPY LINKSHARE

Australia is ramping up biosecurity for an incurable disease that has crippled citrus-producing regions around the world and is posing a growing threat to the local industry.

Key points:

  • Huanglongbing (HLB) outbreaks are appearing in Timor-Leste, Indonesia, and Papua New Guinea.
  • HLB is a bacterial disease that originated in China and is largely spread by insects called citrus psyllids.
  • The citrus industry is ramping up its trapping program for the bacteria spreading bugs.

Huanglongbing (HLB), commonly called citrus greening, locks the arteries that transport nutrients in trees.

“I’ve been working on citrus diseases for 21 years now, and this is the worst,” said citrus pathologist Dr Nerida Donovan, who is part of a team trying to keep the disease out of Australia while also preparing for its arrival.

“It is marching across the globe, and it’s getting closer to our shores in the countries to our north.”

“So it’s in Timor-Leste. It’s in Indonesia. It’s in the corner of PNG.”

Photo of Dr Nerida Donavan inspecting a citrus tree
Citrus pathologist Dr Nerida Donovan is part of a team trying to keep the disease out of Australia.(Landline: Kerry Staight)

Florida in the United States has been one of the worst-hit regions.

Citrus producer Kyle Story said almost all the orchards were infected.

“We had roughly 12,000 growers when greening first came into the state of Florida in 2005,” said Mr Story.

“The most recent counts that we can go by is about 2,500 growers.”

What is Huanglongbing (HLB)?

HLB is a bacterial disease that originated in China and is largely spread by insects called citrus psyllids.

It shows itself in several ways, from uneven, yellow, blotchy marks and raised veins on leaves to misshapen and sour fruit.

Photo of discoloured leaf
Citrus greening locks the arteries of trees, blocking nutrients.(Landline: Kerry Staight)

“Pre-greening, you could easily see a grove that was between 50 and 100 years old,” said Kyle Story.

 “Today, most people plant an orange grove with a lifespan of 20 to 30 years.”

While Kyle Story and his team have learned to adapt management of their infected trees to get the best out of them and stay in business, local growers say Australia must do everything to keep the disease out.

“It was scary what I saw in Florida,” said Riverland grower Ryan Arnold.

“It just looked like an orchard in Australia that we’d be pushing it out and starting again, and they were trying to live with that and get some production out of it.”

“I didn’t want my beautiful green trees looking like that.”

Photo of citrus trees being removed
The lifespan of Florida’s citrus trees has fallen from 50-100 years to as low as 20 years. (Landline)

Operation ‘citrus watch’

To protect Australian growers’ trees, the citrus industry is ramping up surveillance for the bacteria-spreading bugs, in particular the Asian citrus psyllid.

As part of a new biosecurity program dubbed “citrus watch” about 1,000 sticky traps are distributed each year.

The traps are sent to vulnerable urban areas as well as commercial citrus properties because it’s not just fruit trees the psyllids are attracted to.

Photo of Ryan Arnold checking psyllid trap
Citrus psyllid traps are being sent to vulnerable urban areas as well as commercial citrus properties in Australia. Pictured: Riverland grower, Ryan Arnold.(Landline: Kerry Staight)

They’re fans of murraya, a common hedge plant also known as orange jasmine.

“In most countries where they’ve found the disease and the psyllid, it’s been found in the urban areas first,” said Nerida Donovan

“So that’s why our biosecurity system is so important and educating people not to bring in plant material from other countries.”

If the disease does spread to Australia, there’s another safeguard.

At Dareton, in the far west of NSW, there’s a bank of every commercial citrus variety grown in the country.

Photo of workers in a greenhouse
Mother trees are tested for disease annually and are used to produce budwood for commercial nurseries.(Landline)

These mother trees are tested for disease annually and are used to produce budwood for commercial nurseries.

They’re also protected from citrus psyllids by a giant screen.

“The facility has been built to grow around a million buds per year,” said manager Tim Herrmann.

“We’ve got plans in place to double that to about two million buds per year, which we predict will be enough to get the industry through an incursion.”

One of the biggest challenges with HLB is there’s no cure.

Growers in the US have been using antibiotics and heat treatments to try and slow the reproductive cycle of the psyllid.

“We do actively, and have for the last 15 plus years, tried to control the Asian citrus psyllid, but we have not had a tremendous amount of success,” said Mr Story.

Could finger limes be the answer?

In a surprise twist, with a decidedly Australian flavour, a promising new treatment is being developed.

Researchers at the University of California in Riverside have discovered a peptide in native finger limes that attacks the bacteria and protects healthy plants.

Red coloured finger limes inside the bush, some have scratches on their skin.
Researchers have discovered a peptide in native finger limes that attacks the bacteria and protects healthy plants.(ABC Rural: Jennifer Nichols)

“Our data show that our antimicrobial peptide is much more effective than those antibiotics,” said lead researcher Hailing Jin.

“We can use a much less concentration and that can kill bacteria much faster.”

Hailing Jin says the peptide also isn’t heat sensitive, like antibiotics.

Photo of Florida University conducting field trials
Florida University has been conducting field trials of finger lime peptides to combat the disease.(Landline)

After successful greenhouse trials, the new treatment is now being tested in the field by the University of Florida.

“There is a very long history of things looking pretty good in a greenhouse and failing in the field,” said Dr Megan Dewdney, who is running the trials over a couple of years.

“I have high hopes that this one will not, but one never knows.”

See more about this story on ABC TV’s Landline at 12:30pm on Sunday, or on iview.Posted 10 Sep 2021

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Science News

Body parts reinforced with zinc and manganese make impossible cuts possible, a study suggests

a leaf-cutting ant, with sharp mandibles visible
Leaf-cutting ants (Atta cephalotes) have jaws lined with “teeth” kept razor sharp by interspersing zinc atoms among proteins.RYAN GARRETT

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Science News

By Jake Buehler

SEPTEMBER 8, 2021 AT 9:00 AM

If you’ve ever felt the wrath of a biting or stinging insect, it may seem incredible that something so small can so easily slice or puncture human skin. 

Scientists already knew that some small animals’ piercing and slashing body parts are infused with metals such as zinc and manganese, making the parts tough and durable. Now, a study published September 1 in Scientific Reports shows how these toollike appendages form hard and extremely sharp cutting edges.

Robert Schofield, a physicist at the University of Oregon in Eugene, and colleagues used a special microscope to examine the sharp “teeth” that line the jaws of leaf-cutting ants called Atta cephalotes, revealing the teeth’s atomic structure (SN: 11/24/20). The team found that zinc atoms were dispersed homogeneously, rather than in chunks, throughout a single tooth. This uniformity allows the ants to grow much thinner, sharper blades, since “chunks of mineral limit how sharp the tool can be,” Schofield says.

The team also tested a suite of properties of these metal-infused materials, known as heavy element biomaterials, in ant teeth, spider fangs, scorpion stingers and marine worm jaws, among others. These structures are stiffer and more damage resistant than biomineralized materials, like the calcium phosphate typically found in teeth or the combination of calcium carbonate and the protein chitin in many arthropod shells, the team found. The metal-fortified body parts have “the kinds of properties that you want in a knife or needle,” Schofield says.

The team estimates that the zinc-infused teeth of A. cephalotes allow it to puncture and cut using only about 60 percent of the energy and muscle mass it would otherwise. 

By making these sharp, precisely sculpted tools, ants and other small animals can make up for their tiny muscles, allowing them to acquire and process foods that would normally be beyond their reach.

Questions or comments on this article? E-mail us at feedback@sciencenews.org

CITATIONS

R.M.S. Schofield et alThe homogenous alternative to biomineralization: Zn- and Mn-rich materials enable sharp organismal “tools” that reduce force requirementsScientific Reports. Published September 1, 2021. doi: 10.1038/s41598-021-91795-y.

About Jake Buehler

Jake Buehler is a freelance science writer, covering natural history, wildlife conservation and Earth’s splendid biodiversity, from salamanders to sequoias. He has a master’s degree in zoology from the University of Hawaii at Manoa.

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From PestNet

Palm tree disease in Florida transmitted by traveling bug from Jamaica

Phys.Org

by American Phytopathological Society

What began as a curious survey of an insect in Florida revealed a much larger network of movement across the Caribbean basin. Haplaxius crudus, commonly known as the American palm cixiid, transmits phytoplasmas (bacteria that cause plant diseases) in palm. The American palm cixiid is known to transmit lethal yellowing disease and lethal bronzing disease, both of which are lethal to a variety of palm species, especially coconut and date palms.

While many scientists have assumed these pathogens migrated to Florida in infected plants, Brian Bahder at the University of Florida wondered if the real culprits were the insects themselves. To test this suspicion, Bahder and his colleagues began by categorizing the insect’s DNA in Florida, where they found four distinct groups.

Next they looked beyond the United States and tested populations in Costa Rica, Colombia, and Jamaica, three places that were distinct and relatively isolated. They found different insect DNA in Costa Rica and Colombia. In Jamaica, however, they found an exact match to one of the groups in Florida.

Read on: https://phys.org/news/2021-09-palm-tree-disease-florida-transmitted.html Haplaxius_crudus

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What a warmer, wetter world means for insects, and for what they eat

August 30, 2021 11.28am EDT

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  1. Esther Ndumi NgumbiAssistant Professor, Department of Entomology; African-American Studies, University of Illinois at Urbana-Champaign

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Esther Ndumi Ngumbi is a senior Food Security Fellow with the Aspen Institute New Voices.

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new report has been released by the Intergovernmental Panel on Climate Change (IPCC) – the UN’s authority on climate change – which revealed the latest research on how the Earth is changing and what those changes will mean for the future.

The report shows there’s been a dramatic increase in carbon dioxide (CO2) levels and temperatures, stating that Earth is likely to reach the crucial 1.5℃ warming limit in the early 2030s. There are also dramatic changes in precipitation – water that’s released from clouds, such as rain, snow, or hail.

As an entomologist, I study insects and how climate change stressors – such as flooding and drought – affect what insects eat. I’m also a food security advocate.

The report’s projections caused me to reflect on the many direct and indirect impacts that a warmer and wetter world will have on insects, their natural enemies, plants and African food security.


Read more: How changes in weather patterns could lead to more insect invasions


Across the African continent, recent years brought out some of these extremes, showing what a serious issue this is.

For instance, in southern Africa, the 2016 outbreak of the fall armyworm has continued to spread because of increased rainfall and elevated temperatures – perfect conditions for them to breed and grow quickly. These conditions also supported the growth of over 70 host plants that are fed upon by the fall armyworm.

There’s also a major desert locust outbreak in eastern Africa which started in 2019. It spread due to unusually heavy rainfall that created the perfect environment for locusts to breed and increase in numbers and size. The rains also support the growth of vegetation to feed them.

Here I present a closer look at some of the report’s key findings and show how changes could affect insects and, indirectly, us.

Elevated carbon dioxide levels

Global levels of CO₂ are already high, and they’re expected to continue rising. While elevation in CO₂ does not directly impact insects, it can alter plants’ nutritional quality and chemistry. This will indirectly affect insect herbivores.

For instance, according to recent research, elevated CO₂ reduces the nutritional quality of plant tissues by reducing protein concentrations and certain amino acids in the leaves. To compensate, insect herbivores eat more.

Elevated CO₂ levels can also affect an insect’s development, driving down their numbers – as seen in this study of dung beetles.

Rising temperatures

The report says that global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in CO₂ and other greenhouse gas emissions occur in the coming decades.

Temperature regulates insects’ physiology and metabolism. An increase in temperature increases physiological activity and, therefore, metabolic rates. Insects must eat more to survive and it’s expected that insect herbivores will consume more and grow faster.

This will lead to increases in the population growth rate of certain insects. Because they grow fast they’ll reproduce more. Their numbers will multiply and this will ultimately lead to more crop damage.


Read more: What changes in temperature mean for Africa’s tsetse fly


Previous research projected that with every increase in one degree of global warming, losses of crops to insects will increase from 10% to 25%.

Drought and flooding

The changing climate is expected to change precipitation patterns – such as rainfall. The report anticipates increased and frequent drought and flooding incidences across the world. These environmental stressors will have an impact on plant productivity, plant chemistry, defences, nutritional quality, palatability, and digestibility.

Consequently, insects eat more plants and this can result in more crop damage.

On the other hand, increased precipitation can support fresh vegetation (food for insects) and can facilitate population buildup of insects. As seen with the desert locust, for example, prolonged rain allowed them to have food, multiply in numbers and spread. This was also the case for the fall armyworm; plentiful rains supported the growth of their host plants. When food for the insects is no longer a limiting factor, their populations continue to build up.


Read more: A new model shows where desert locusts will breed next in East Africa


Reducing effectiveness of natural enemies

All insects have natural enemies or predators. For example, the maize stem borer – a significant insect pest of maize across Africa – has several natural enemies, such as Cotesia flavipes. These predators reduce the populations on insects and further reduce the need to use pesticides to control insect pests.

Predators can be affected by climate changes in many ways. For instance, they can be sensitive to increases in temperature and precipitation, ultimately reducing their numbers. Fewer natural enemies could result in more insect pests. One study, which modelled temperature changes on stem borers in East Africa, showed an increase in their numbers and a decrease in impact by natural enemies.

In addition, because of climate change, both crop distribution ranges and insects will shift. As they seek out conditions that suit them, insects move to new areas that lack their natural enemies. This will cause their populations to grow, resulting in more crop damage.

More palatable food

Because of climate change, weather extremes are likely to happen together.

According to researchplants exposed to double stresses may become even more palatable to insects. This is because when two stressors (say drought and insect herbivory, flooding and insect herbivory, or elevated carbon dioxide and elevated heat) happen together, their impact on crops can be additive or synergistic. This would lead to increased crop damage and reduced crop yields.

What can be done?

Climate change will affect agricultural plants and the insects associated with them. These effects are complex, but it is certain pest pressures will increase. There is a need for more insect monitoring and forecasting and modelling so that we can develop adaptation strategies.

In addition, countries should continue to monitor, share information, and use historical data and modelling to predict and prepare for an uncertain future that is expected to have hungrier insect pests, with impacts on crop productivity and food security.

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Entomology Today

P.M. Pollinators: Study Shines Light on Nocturnal Insects’ Role in Apple Production

ENTOMOLOGY TODAY1 COMMENT

A study on apple pollination, published in July 2021 in the Journal of Economic Entomology, highlights the valuable role that moths and other nocturnal insects play in pollinating crops and other plants. “What happens at night—where we’ve been somewhat ignoring it, somewhat dismissing it—there’s actually something going on. It’s potentially highly valuable input to fruit production,” says the University of Arkansas’ Stephen Robertson, Ph.D., lead author on the study. Shown here is an armyworm moth (Mythimna unipuncta) on an apple flower. (Photo by Stephen Robertson, Ph.D.)

By Paige Embry

Paige Embry

Insects are indispensable members of the world. They serve as breakfast, lunch, and midnight snack for a host of other animals. They chow down on everything from poop to wood, freeing up the nutrients for re-use. Some even prey on other insects, helping prevent pests from running amok. And, of course, insects also help pollinate 80 percent or more of the world’s flowering plants, including around three-quarters of agricultural crops that we humans value.

This last insect job has received a lot of attention and research dollars, but most of the focus has been on daytime pollinators. Pollinators that fly at night—and, yes, there are a lot of them—have gotten much less scrutiny. A study published in July in the Journal of Economic Entomology took a look at nighttime pollinators, in particular at their impact of both on apple tree pollination in Arkansas as compared with their daytime counterparts. The results were illuminating—both for how much pollination happened at night and who was responsible.

Stephen Robertson, Ph.D.

The study took place over two years, and the researchers used four treatments: closed (flowers bagged day and night), open (no bag), diurnal (bagged at night, to allow only daytime pollinator visits), and nocturnal (bagged during the day, to allow only nighttime visits). Stephen Robertson, Ph.D., just completed his doctorate at the University of Arkansas and is the lead author of the paper. Every day during bloom (except during thunderstorms) he went out to the orchard at sunrise and sunset to take bags off some branches and put them on others. After bloom was over, Robertson and his colleagues counted fruit set, prodding each baby fruit with a finger to see if it was truly set or would fall off. They removed the set fruits and counted the seeds. “Seed set,” the authors write, “is a direct proxy of the level of pollination.”

Last, they looked to see if at least one flower per cluster had set fruit. Growers would rather have one pollinated flower each in five different clusters instead of five flowers in one cluster because, the authors write, “Growers typically reduce the number of developing fruit to one per cluster to ensure tree resources are devoted to fewer apples, thus generating higher quality and more valuable fruit.”

Changes in research design between the two years (e.g., different trees used, changes in methods) means each year needs to be looked at separately. In 2017 the clusters that were bagged both day and night (closed) showed nearly 30 percent pollination which can be put down to the potential self-fertility of some of the trees or problems with the mesh bags used that year. Nocturnal pollination rates in 2017 were 57.5 percent, while both diurnal and un-bagged clusters showed pollination rates in the mid-eighties. In 2018, 3.4 percent of closed clusters were pollinated, while the nocturnal, diurnal, and open treatments came out nearly the same (11.3 percent, 12.8 percent, and 10.8 percent, respectively). The vastly different pollination rates between years could be because different trees were used, natural variation in pollinators, or a late freeze in 2018 that killed most of the nearby blooms that acted as pollinizers for the trees being tested.

Atalantycha bilineata on apple flower
armyworm moth (Mythimna unipuncta) on apple flower
Eupithecia sp. moth on apple flower
Chrysopid lacewing on apple flower
Culex sp. mosquito on apple flower
Galgula partita moth on apple flower
Udea rubigalis moth on apple flower
Eupithecia sp. moth on apple flower

However, in both years, similar seed sets show that nocturnally pollinated fruit had similar pollination levels to those pollinated during the day. Although the results were quite varied between the years, they nevertheless show that nocturnal pollinators have the power to contribute to pollination services in apple production—and potentially other crops as well. Robertson says part of why he conducted this study was because he’d learned that moths were visiting both blackberries and a peach tree in the area. Robertson says, “What happens at night—where we’ve been somewhat ignoring it, somewhat dismissing it—there’s actually something going on. It’s potentially highly valuable input to fruit production.”

This study also shows that one grower’s bane may be another’s gift. The dominant night-time visitors were moths in the family Noctuidae, and the two most common have larvae that are considered pests: armyworm (Mythimna unipuncta) and variegated cutworm (Peridroma saucia). In a time where insect declines are increasingly well documented, it may be useful to realize that “pest” insects are not all bad.

Robertson says, “Insects don’t fall into these categorizations [good, bad] so neatly. … There’s more to the story.” In other words: Pest, pollinator, food source, balance keepers—insects—even the same insect—perform a variety of jobs.

“Let’s not dismiss [an insect] based on previous classifications and just hang our hats on this is a bad guy,” Robertson says. “There’s duality associated with this. There’s mutuality associated with all these things.”

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Nocturnal Pollinators Significantly Contribute to Apple Production

Journal of Economic Entomology

Paige Embry is a freelance science writer based in Seattle and author of Our Native Bees: North America’s Endangered Pollinators and the Fight to Save Them. Website: www.paigeembry.com.

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Science News

Viruses can kill wasp larvae that grow inside infected caterpillars

A new study is a take on the adage, “The enemy of my enemy is my friend.”

picture of a green caterpillar-like creature walking across a leaf
A group of proteins found in some insect viruses as well as some insects (such as this beet armyworm) can kill the larvae of parasitic wasps, protecting the caterpillars that those wasps exploit to lay eggs.JOHN CAPINERA, UNIVERSITY OF FLORIDA/BUGWOOD.ORG (CC BY-NC 3.0 US)

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By Erin Garcia de Jesús

JULY 29, 2021 AT 2:00 PM

When parasitic wasps come calling, some caterpillars have a surprising ally: a viral infection. 

Insects called parasitoid wasps lay their eggs inside young moth larvae, turning the caterpillars into unwitting, destined-to-die incubators for possibly hundreds of wasp offspring. That’s bad news for viruses trying to use the caterpillars as replication factories. For the caterpillars, viral infections can be lethal, but their chances of survival are probably higher than if wasps choose them as a living nursery.

Now, a study shows how certain viruses can help caterpillars stymie parasitoid wasps. A group of proteins dubbed parasitoid killing factor, or PKF, that are found in some insect viruses are incredibly toxic to young parasitoid wasps, researchers report in the July 30 Science.

The new finding shows that viruses and caterpillars can come together to fight off a common wasp enemy, says study coauthor Madoka Nakai, an insect virologist at Tokyo University of Agriculture and Technology. A parasitoid wasp would kill a host that the virus needs to survive, so the virus fights for its home. “It’s very clever,” Nakai says.

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What’s more, some moth caterpillars make the wasp-killing proteins themselves, the team found. It’s possible that in the distant past, a few moths survived a viral infection and “got some presents” in the form of genetic instructions for how to make the proteins, says study coauthor Salvador Herrero, an insect pathologist and geneticist at the University of Valencia in Spain. Those insects could have then passed the ability down to offspring. In this case, “what doesn’t kill you makes you stronger,” Herrero says.

Previous studies had shown that viruses and insects, including moths, can swap genes with each other. The new finding is one of the latest examples of this activity, says Michael Strand, an entomologist at the University of Georgia in Athens who was not involved in the work.

“Parasite-host relationships are very specialized,” he says. “Factors like [PKF] are probably important in defining which hosts can be used by which parasites.” But whether caterpillars stole the genetic instructions for the proteins from viruses or if viruses originally stole the instructions from another host remains unclear, Strand says.  

Researchers discovered in the 1970s that virus-infected caterpillars could kill parasitoid wasp larvae using an unknown viral protein. In the new study, Herrero and colleagues identified PKF as wasp-killing proteins. The team infected moth caterpillars with one of three insect viruses that carry the genetic blueprints to make the proteins. Then the researchers either allowed wasps to lay their eggs in the caterpillars or exposed wasp larvae to hemolymph — the insect equivalent of blood — from infected caterpillars.  

Virus-infected caterpillars were poor hosts of the parasitoid wasp Cotesia kariyai; most young wasps died before they had the chance to emerge from the caterpillars into the world. Hemolymph from infected caterpillars was also an efficient killer of wasp larvae, typically destroying more than 90 percent of offspring.

C. kariyai wasp larvae also didn’t survive in caterpillars, including the beet armyworm (Spodoptera exigua), that make their own PKF. When the researchers blocked the genes for the proteins in these caterpillars, the wasps lived, a sign that the proteins are key for the caterpillars’ defenses.

Some parasitoid wasps, including Meteorus pulchricornis, weren’t affected by PKF from the viruses and also beet armyworms, allowing the wasp offspring to thrive inside caterpillars. That finding suggests that the wasp-fighting ability is species-specific, says Elisabeth Herniou, an insect virologist at CNRS and the University of Tours in France who was not involved in the work. Pinpointing why some wasps aren’t susceptible could reveal the details of a long-held evolutionary battle between all three types of organisms.  

The study highlights that “single genes can interfere with the outcome of [these] interactions,” Herniou says. “One virus may have this gene and the other virus doesn’t have it,” and that can change what happens when virus, caterpillar and parasitoid all collide.

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Kenya’s first crop of GMO Bt insect-resistant cotton ready for harvest

Irungu Mwangi | Kenya News | August 27, 2021

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Credit: Kenyan Ministry of Industrialization, Trade and Enterprise Development
Credit: Kenyan Ministry of Industrialization, Trade and Enterprise Development

This article or excerpt is included in the GLP’s daily curated selection of ideologically diverse news, opinion and analysis of biotechnology innovation. It is posted under Fair Use guidelines.

After waiting for nearly two decades for the commercialisation of BT cotton, there is finally some light at the end of the tunnel, as the farmers prepare for the harvest before the end of the year.

Once harvested, the cotton is expected to spur economic development by creating jobs in the dormant textile sector and free Kenyans from dependence on second-hand clothes also known as Mitumba.

Charles Waturu, the Principal Researcher on the BT cotton said the government has already trained 50,000 youths and women who are being involved in the production of the crop and consequently, establish five million square feet of industrial sheds.

“Successful implementation of this measure is expected to increase revenue from Sh 3.5 million to Sh 200 billion, create 500,000 cotton related jobs and other 100,000 from the apparel sector by 2022,’’ Waturu stated.Follow the latest news and policy debates on agricultural biotech and biomedicine? Subscribe to our newsletter.SIGN UP

Farmers in the lower Mwea have been able to produce yields, three times more than the conventional varieties and has taken shorter time of between 130 to 180 days to mature.

For the traditional variety, a farmer if lucky can harvest 250 kilograms per acre of the crop while BT cotton yields stand 7000 kilograms per acre.

Read the original postRelated article:  GM, insect-resistant, Bt corn could reach Kenyan farms in 2021 — and may help double crop yields

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Science News from research organizations


Urban lights keep insects awake at night

Scientists reveal how the urban-related increase in nighttime light and heat postpones natural hibernation periods of flesh flies

Date:August 18, 2021Source: Osaka City University Summary: New research sheds light on the effect urbanization has on the flesh fly species Sarcophaga similis. Through a series of laboratory and in-field experiments, scientists show that an increase in nighttime illumination and temperature, two of the major characteristics of urbanization, can postpone S. similis hibernation anywhere from 3 weeks to a month.Share: FULL STORY


A new study shows how an increase in nighttime lighting (light pollution) and heat from urban areas disturbs the hibernation periods of insects.

“The study looks at a species of flesh fly called Sarcophaga similis, but the results could be applicable to any animal species that relies on predictable environmental signals for biological processes like growth, reproductive behavior, sleep, and migration,” said Assistant Professor Ayumu Mukai of Setsunan University and lead author of the study. In collaboration with Professor Shin Goto of Osaka City University, their findings were published in Royal Society Open Science.

A common way of exploring the ecological effects of urbanization is to investigate changes in life cycles of species in the urban and surrounding area. Urban warming and artificial light at night are two of the most influential factors in this regard. As urban warming can increase surface temperatures anywhere between 5 — 9°C, species with lower critical thermal optima, i.e. biological processes such as growth and development that occur at lower environmental temperatures, are disproportionately affected. Due to large fluctuations throughout the day and year, temperature can be an unreliable cue for species to determine when to sleep, breed, migrate, etc., rendering this cue supplemental to a biological response to seasonal changes by monitoring day length — an ability called photoperiodism. Increased nighttime light can throw off an insect’s photoperiodism, yet few studies have focused on the effect urban warming and artificial light at night have had on insects in their natural habitat.

“Recognizing the conditions urbanization brings upon insects where they actually live would be a great step forward in mitigating any negative effects,” Shin Goto said. To understand this, the team conducted experiments indoors and outdoors. As S. similis typically enters hibernation during autumn, laboratory hibernation was induced in flies under two average October temperatures (20°C and 15°C), with varying levels of illuminance to mimic bright urban to dark rural areas. They found that the percentage of flies entering hibernation decreased as illumination increased and as the temperature increased from 15°C to 20°C — suggesting the higher temperatures found in urban areas are associated with higher nighttime illumination.

In the field, the team measured when the insects entered hibernation in two city locations: a site with nighttime lighting at around 0.2 lux (the brightness of a full moon in a clear sky), and another with nighttime lighting at around 6 lux, which is equivalent to a residential area or street at night. At sites with dark nights, most flies enter hibernation between October and November while at sites with increased nighttime light, they did not enter hibernation until after November. The team also compared urban areas with illumination of about 0.2 lux with rural areas of almost 0 lux. The percentages of flies entering hibernation in rural areas increased from late September, around 3 weeks earlier than their urban counterparts. Temperatures were also 2.5°C higher in the cities, which is thought to be the cause for the delay in hibernation.

While these findings do suggest that nighttime lighting, which supports our daily lives, is disrupting the seasonality of insects, “urban environments are complex, with nighttime illumination and temperatures varying within the same neighborhood and between different cities,” Ayumu Mukai pointed out, “and our work on a single flesh fly does not elucidate the photoperiodic response of other insects.”

To understand the extent to which our cultural life influences other organisms, Shin Goto continued, “Future studies with a variety of insect species at different sites, in cities with different climatic regions would clarify what levels of light pollution and urban warming affect insect seasonal adaptation”


Story Source:

Materials provided by Osaka City UniversityNote: Content may be edited for style and length.


Journal Reference:

  1. Ayumu Mukai, Koki Yamaguchi, Shin G. Goto. Urban warming and artificial light alter dormancy in the flesh flyRoyal Society Open Science, 2021; 8 (7): 210866 DOI: 10.1098/rsos.210866

  • Osaka City University. “Urban lights keep insects awake at night: Scientists reveal how the urban-related increase in nighttime light and heat postpones natural hibernation periods of flesh flies.” ScienceDaily. ScienceDaily, 18 August 2021. <www.sciencedaily.com/releases/2021/08/210818130525.htm>.

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APHIS expands the Mexican Fruit Fly (Anastrepha ludens) quarantine areas in Cameron County, Texas

Effective July 14, 2021, USDA’s Animal and Plant Health Inspection Service (APHIS) and the Texas Department of Agriculture (TDA) expanded the Mexican fruit fly (Mexfly) quarantines in the cities of Brownsville and Harlingen, Cameron County, Texas. APHIS is applying safeguarding measures and restrictions on the interstate movement or entry into foreign trade of regulated articles from this area.

Between June 25 and July 14, 2021, APHIS confirmed the detections of 87 adult Mexflies in Brownsville and Harlingen. Although the detections were within the Brownsville and Harlingen quarantines, some detections were close enough to the perimeters of the quarantines to trigger expansion of the quarantines. Traps in residential areas, in a variety of dooryard citrus (grapefruit, key lime, lemon, sour orange and sweet orange) and stone fruit trees (mango and peach), accounted for 69 of the 87 detections. The remaining 18 detections were from traps in commercial grapefruit and sweet orange groves.

With these detections, the Brownsville quarantine expanded from 229 square miles with 888 acres of commercial citrus to approximately 446 square miles with 1,412 acres of commercial citrus. This is an expansion of the Brownsville quarantine of approximately 217 square miles with 524 acres of commercial citrus. The Harlingen quarantine expanded from 192 square miles with 2,079 acres of commercial citrus to approximately 231 square miles with 2,095 acres of commercial citrus. This is an expansion of the Harlingen quarantine of 39 square miles with 16 acres of commercial citrus.

APHIS and TDA established the original Cameron County quarantine following the confirmed detections, between January 14 and February 3, 2020, of 80 adult Mexflies and 14 Mexfly larval sites in citrus from various residential areas and two commercial groves. By establishing the quarantine, APHIS and TDA restricted interstate movement of regulated articles from this area to prevent the spread of Mexfly to non-infested areas of the United States. APHIS has worked cooperatively with TDA to eradicate the transient Mexfly population through various control actions per program protocols.

The following website contains a description of all the current Federal fruit fly quarantine areas:

http://www.aphis.usda.gov/plant-health/ff-quarantine

For more information:
Richard Johnson
APHIS
Tel: 301-851-2109.

Publication date: Wed 18 Aug 2021

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