Archive for the ‘Insects’ Category


Moth pest fall armyworm found in Hamilton, growers asked to watch for pest

29 Apr, 2022 05:20 PM2 minutes to read

Biosecurity New Zealand and primary sector partners are asking maize and corn growers to keep an eye out for the moth pest fall armyworm. Photo / Crop Science Australia, Ted C. Macrae

Biosecurity New Zealand and primary sector partners are asking maize and corn growers to keep an eye out for the moth pest fall armyworm. Photo / Crop Science Australia, Ted C. Macrae

Waikato Herald

The moth pest fall armyworm has been discovered at two properties on the outskirts of Hamilton so Biosecurity New Zealand and primary sector partners are asking Waikato maize and corn growers to keep an eye out and report any signs of caterpillars on their plants.

The fall armyworm is a plant pest that can cause damage to crops. It is native to the Americas and can feed on more than 350 plant species, including corn, beans, capsicum, onions, kumara and tomatoes.

The moth’s larvae particularly feed on stems and leaves which causes crop damage. They can skeletonise the leaves and severe infestation can cause unwanted defoliation.

On corn, larvae attack the ear, silks, cob and kernels which reduces leaf mass, fruit, pods, seeds and the overall plant health.

Adult moths are between 16 and 18mm long, and have a wingspan of 38mm. The forewings are a brown-grey colour and the hind wings a cream colour.

Larvae change from a green-brown to a brown-black colour as they mature and are almost black in the “armyworm” phase. Eggs are only about 0.4mm and laid on leaf surfaces in masses of between 150 and 200, covered with a protective layer of scales.

The fall armyworm was introduced to Africa, Asia and parts of Australia in 2016, but because it usually thrives in very warm climates, it was thought unlikely the pest would spread into colder climate zones like New Zealand. However, in March this year, egg mass belonging to the moth was found in Tauranga.

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Fall Armyworm Control in Action March 2022 – Issue #8

The Kingdom of Saudi Arabia reported fall armyworm (FAW) infestations in fields in Najran Governorate, with in Al-Kora Governorate of Al-Baha Province illustrating continuous spread of FAW in NENA region. The Ministry of Environment, Water, and Agriculture announced the insect pest was detected on maize plants. In response, authorities have implemented phytosanitary measures, destroyed infested maize crops, installed traps around infested sites, and is managing FAW populations in neighbouring crops.
In Zambia, FAW has reportedly reached concerning population levels in ten provinces and in 96 out of 116 districts, illustrating the need for continuous capacity development in FAW management. FAO,
under the aegis of the Global Action for Fall Armyworm Control (GA), will support the government of the Republic of Zambia in improving capacities for FAW management among farmers and extension workers. FAW has reportedly affected 129 517 households and 96 222 hectares of maize fields.
Based on lessons learned during the work conducted by the International Plant Protection Convention (IPPC) technical working group on FAW quarantine and phytosanitary measures, a new work programme on banana Fusarium wilt (TR4) is under way. The IPPC Secretariat is holding a virtual workshop series on Fusarium TR4
diagnostic, surveillance, inspection and simulation exercises. The first of three sessions is scheduled for 24 March 2022, followed by sessions on 19 April 2022 and 10 May 2022. The three sessions
will be held in English, and two of the sessions will have simultaneous interpretation in French and Spanish through an in-kind contribution from the Comité de liaison Europe ACP (COLEACP).
The Cameroon workshop discussed the use of biological control, botanicals, and farmer trainings. It was opened by the Secretary General of the Ministry of Agriculture and Rural Development, Mbong Epse Bambot Grace Annih.

FAW was named as top national priority for key pest control in the People’s Republic of China for 2022 in February as the National Agricultural Technology Extension and Service Center (NATESC) renewed the annual strategy for FAW control. This followed a national expert working group meeting organized by NATESC to analyse FAW data and control measures that had been implemented in 2021. The working group also presented conclusions to facilitate the delivery of early warning messages with regard to FAW at the national level.
Resource mobilization training was conducted on 28 February 2022 for 30 people including national focal points and FAO focal points in country offices. A general overview of the resource mobilization situation with regard to the Global Action was provided during the session. The training was based on the new GA resource
mobilization guide and was also interpreted in the French language.
In the Republic of Cameroon, a three-day training workshop began on 28 February 2022 to enhance capacity of national focal points from central Africa countries in FAW monitoring, early warning and sustainable management of the pest. The workshop also aimed to strengthen coordination between GA demonstration
and pilot countries through theory as well as farm-level practical sessions. The 25 participants, including including leaders of farmer organizations, extension officers, researchers and FAO facilitators,
were asked to validate the strategy document at the central Africa geo-zone level. The workshop included participants from the Republic of Cameroon, Central African Republic, Republic of Equatorial Guinea, Equatorial Guinea, the Gabonese Republic, Republic of the Congo, Democratic Republic of the Congo, and the Democratic Republic of Sao Tome and Principe.
The Republic of the Philippines Bureau of Plant Industry hosted seven geo-zone webinar training events in January and February 2022 covering multiple topics, including monitoring and early warning, host plant resistance, biological control, biopesticide and pesticide application.

Contact information:
Plant Production and Protection – Natural Resources and Sustainable Production
Email: Fall-Armyworm@fao.org
Food and Agriculture Organization of the United Nations
Rome, Italy
Some rights reserved.
This work is available under a
CC BY-NC-SA 3.0 IGO licence
Communications and Partnerships
A GA resource mobilization guide has been finalized and will be
available for public download. These guidelines provide a framework for mobilizing essential resources to support the work of the
GA and the FAW Secretariat.1
New Technical Cooperation Programmes have been initiated,
including a USD 500 000 emergency response to strengthen the
management and preparedness capacities of five North African
countries – the People’s Democratic Republic of Algeria, the State of
Libya, the Islamic Republic of Mauritania, the Kingdom of Morocco,
and the Republic of Tunisia – to mitigate the impact and risk of FAW.
New Developments
By comparing genetic characteristics of FAW populations collected
from 22 sub-Saharan countries between 2016 and 2019, Nagoshi
et al. (2022) inferred that the strain preferring maize as the host
plant predominated the FAW populations in Africa. Additionally,
a broad grouping of genetic characteristics of FAW collected in
East and West Africa seem to indicate limited natural migrations
of FAW at a continental scale. The authors suggested that smallerscale movement through trade probably contributed to the initial
spread of the pest across Africa. Nagoshi, R.N., Goergen, G., Koffi, D.
et al. Genetic studies of FAW indicate a new introduction into
Africa and identify limits to its migratory behavior. 2022. Sci Rep
12, 1941.2
A study led by icipe and NIBIO showed that FAW density levels
could be predicted using host availability as well as climatic data.
The study utilized FAMEWS data, among others, to validate the
predictions. The authors suggested that further detailed data on
the natural enemies of FAW, their occurrence and efficiency in
regulating FAW populations, will further strengthen the predictive
mode. Harnessing data science to improve integrated management
of invasive pest species across Africa: An application to Fall
armyworm (Spodoptera frugiperda) (J.E. Smith) (Lepidoptera:
Noctuidae) – ScienceDirect.
©FAO, 2022
1 https://www.fao.org/3/cb8910en/cb8910en.pdf
2 https://www.nature.com/articles/s41598-022-05781-z
3 https://www.sciencedirect.com/science/article/pii/S2351989422000580?via%3Dihub
Field stories
In Burkina Faso, field work by two university partners of the
GA – Université Nazi Boni (UNB) and Université Joseph Ki Zerbo
(UJKZ) – has included trials to evaluate a number of potential
FAW control measures including: production of Telenomus remus
parasitoid; selection of maize varieties for FAW tolerance; the
efficacy of several types of FAW traps; efficacy of local strains of
entomopathogens; biological control potential of local arthropod
natural enemies; and effectiveness of combining other crops with
maize (herbs, pigeon peas and other species) on FAW.
In the Republic of Cameroon, a field visit was organized following
the training workshop that began on 28 February 2022. The field
visit included the area around Ntui in central Cameroon, and around
Foumbot in the western region, with the goal of identifying sites
for large-scale demonstrations of integrated pest management
(IPM) technology. Foumbot holds particular significance because
it is also the first site where FAW was reported in Cameroon.
During the field visit, members of a young farmers cooperative, local leaders and
extension agents were consulted to discuss collaborations for successful
implementation of the GA in the Republic of Cameroon as the demonstratio

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Insect wingbeats will help quantify biodiversity

Date:February 22, 2022 Source:University of Copenhagen – Faculty of Science Summary: Insect populations are plummeting worldwide, with major consequences for our ecosystems and without us quite knowing why. A new AI method is set to help monitor and catalog insect biodiversity, which until now has been quite challenging.Share:


Insect populations are plummeting worldwide, with major consequences for our ecosystems and without us quite knowing why. A new AI method from the University of Copenhagen is set to help monitor and catalogue insect biodiversity, which until now has been quite challenging.

Insects are vital as plant pollinators, as a food source for a wide variety of animals and as decomposers of dead material in nature. But in recent decades, they have been struggling. It is estimated that 40 percent of insect species are in decline and a third of them are endangered.

Therefore, it is more important than ever to monitor insect biodiversity, so as to understand their decline and hopefully help them out. So far, this task has been difficult and resource-intensive. In part, this is due to the fact that insects are small and very dynamic. Furthermore, scientific researchers and public agencies need to set up traps, capture insects and study them under the microscope.

To overcome these hurdles, University of Copenhagen researchers have developed a method that uses the data obtained from an infrared sensor to recognize and detect the wingbeats of individual insects. The AI method is based on unsupervised machine learning — where the algorithms can group insects belonging to the same species without any human input. The results from this method could provide information about the diversity of insect species in a natural space without anyone needing to catch and count the critters by hand.

“Our method makes it much easier to keep track of how insect populations are evolving. There has been a huge loss of insect biomass in recent years. But until we know exactly why insects are in decline, it is difficult to develop the right solutions. This is where our method can contribute new and important knowledge,” states PhD student Klas Rydhmer of the Department of Geosciences and Natural Resource Management at UCPH’s Faculty of Science, who helped develop the method.

Advanced artificial intelligence

The researchers have already developed an algorithm that identifies pests in agricultural fields. But instead of identifying insects as pests, the researchers have been able to develop this new algorithm to identify and count various insect populations in nature based on the measurements obtained from the sensor.

“The sensor is a bit like the wildlife surveillance cameras used to monitor the movements of larger animals in nature. But instead of snapping a photo, the sensor measures insects that have has flown into the light source. The algorithm then uses the insect’s wingbeat to identify them into different groups,” explains Assistant Professor Raghavendra Selvan of the Department of Computer Science, who led the development of the artificial intelligence used in the sensor.

The algorithm distinguishes insects by their silhouettes when their wings are folded out, as it is only then that their physical differences become most apparent. It then compares the silhouettes of different insect recordings, and puts similar silhouettes into the same group which can then be used to determine the insect that most likely flew through the light beam.

Prototype to be released in spring

When insects emerge in full force come spring, scientists will be using the initial prototype to venture out into nature and collect real-world data.

Until now, researchers have tested the algorithm and artificial intelligence using a large image database of insects recordings obtained in controlled conditions and some real-world data, where results have been promising.

“We will test the sensor in different landscapes, including heathland, forests and agricultural areas, to see how it works out in the real world. But also, to feed the algorithm more data, so that it can become even more accurate,” says Raghavendra Selvan.

According to the researchers, their invention makes it possible to monitor many geographical areas more thoroughly than has been possible in the past. At the same time, the invention makes it less resource-intensive to keep a close eye on insects, which make up 80 percent of all terrestrial animal species.

“Today, it is impossible to afford the kind of monitoring needed to gain a more precise overview of how our insects are doing. This sensor only needs humans to place it out in the wild. Once there, it begins collecting data on local insect populations,” concludes Klas Rydhmer.


  • Insects are the largest, most diverse group of described animal species on Earth. They make up about 80% of all terrestrial animal species on the planet.
  • It is the first time that this artificial intelligence method, known as Variational Auto Encoder (VAE), is being used to take inventory of insect biodiversity.
  • Using an optical signal from an infrared sensor, the algorithm is able to decode insects flying through a light beam.

Story Source:

Materials provided by University of Copenhagen – Faculty of ScienceNote: Content may be edited for style and length.

Journal Reference:

  1. Klas Rydhmer, Raghavendra Selvan. Dynamic β-VAEs for quantifying biodiversity by clustering optically recorded insect signalsEcological Informatics, 2021; 66: 101456 DOI: 10.1016/j.ecoinf.2021.101456

Cite This Page:

University of Copenhagen – Faculty of Science. “Insect wingbeats will help quantify biodiversity.” ScienceDaily. ScienceDaily, 22 February 2022. <www.sciencedaily.com/releases/2022/02/220222135250.htm>.

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Student’s device enables researchers to easily track elusive insects

Date:February 24, 2022Source:Florida Museum of Natural HistorySummary:With some home security software and a little ingenuity, researchers have developed an inexpensive device that will allow them to study the behavior and activity of insects in regions of the world where they’re most diverse.Share:


With some home security software and a little ingenuity, researchers have developed an inexpensive device that will allow them to study the behavior and activity of insects in regions of the world where they’re most diverse.

Insects are easily the largest group of organisms on the planet, and with species inhabiting every continent, including Antarctica, they’re also ubiquitous. Yet compared to birds and mammals, scientists know very little about when most insects are awake and active, which is especially true of nocturnal species that fly under the obscuring veil of darkness.

“Most of what we know regarding insect behavior is from species that are active during the day,” said Akito Kawahara, curator of the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History and co-author of a new study describing the device. “We study butterflies, bees and ants because we can see them, but there are hundreds of thousands of nocturnal insects out there, all of which have been nearly impossible to track until now.”

Knowing when organisms are most active is the foundation for understanding their behaviors and circadian rhythms — patterns that determine when they look for food, reproduce, pollinate flowers and more. Without this basic information for insects, it’s harder to predict or determine how changes in the environment, like an increase in light pollution, might impact them.

But the tinier the animal, the harder it is to track. Insects are generally too small to carry around tracking devices that would cue in biologists to their movements. Instead, researchers have to lure them in with baits or lights, which only paint a partial picture of their activity.

“You might think a moth is nocturnal because it’s only been seen at night, but that doesn’t mean it’s not out during the day. It just might not have been seen,” said lead author Yash Sondhi, a Ph.D. student at Florida International University co-advised by Kawahara. “We wanted to look past the standard nocturnal or diurnal categories that could be an oversimplification.”

For years, Kawahara tried to find a portable device that would allow him to track insects while working in the field with his collaborator Jesse Barber at Boise State University, at times even attempting to outsource the work to companies in the hopes they could build it for him. But equipment sensitive enough to measure the delicate movements of the smallest moths while being durable enough to hold up in harsh environments and remote locations without electricity or internet proved difficult to engineer.

So when Sondhi offered to try creating it himself, Kawahara was thrilled. “We had put the project aside, but Yash was able to come along and build the device we’d always envisioned,” he said.

Sondhi gathered a microcomputer, open-source motion tracking software, sensors, a camera and all-important infrared lights that don’t disturb or confuse insects. He housed all of this in a mesh cage that looks like a laundry hamper, and the portable locomotion activity monitor, called pLAM, was born.

It can be built for under $100, a tiny fraction of the lab-based technology that cost anywhere between $1,000 to $4,000.

After using pLAM to monitor insect activity in the lab to ensure the equipment was running smoothly, Sondhi and Kawahara tested it on a research trip to Costa Rica. They collected 15 species, placing between four and eight moths of each into the activity monitors.

Sondhi says one of the most interesting examples was a species of tiger moth. It’s assumed these brightly colored, toxic moths are exclusively out during the day, because predators steer clear of them and they can move about without fear of being eaten. However, data from the activity monitors revealed they’re also active at dusk. After all, they have to escape other predators who come out at nightfall, like bats.

“It was so cool to see the different activity patterns,” Sondhi said. “Not everything is as black and white as we think. Now, we can predict and better understand what’s driving when insects fly. The goal is to quantify when they are active and then associate that with their traits — for example, if a moth is dull-colored, beige, does that mean it’s strictly nocturnal?”

Kawahara is optimistic that the new device will help inform efforts to stave off the recent global trend of insect decline and extinction. “The baseline data that we need to understand the activity of small insects and other organisms is so limited,” he said. “We talk about how light pollution, noise pollution and climate change impact insects, but we don’t know anything about how it affects their activity because we haven’t been able to monitor activity for most insect species. This device will allow us to collect that information.”

This year, Sondhi will be using this new tool to continue his National Geographic-funded research on how moths respond to light pollution. He’s collected data on the differing light levels at several field sites in India. Now, he can examine how light pollution could be confusing moths, interfering with their natural circadian patterns and impacting when they are active.

The research was published in Methods in Ecology and Evolution.

Funding for the study was provided by the Florida International University Graduate School, the National Science Foundation, a Tropical Conservation Grant from the Susan Levine Foundation, a Lewis Clark Exploration Grant from the American Philosophical Society, a National Geographic Explorer Grant and the Centers for Disease Control, Southeastern Center of Excellence in Vector-borne Disease.

make a difference: sponsored opportunity

Story Source:

Materials provided by Florida Museum of Natural History. Original written by Angela Nicoletti and Jerald Pinson. Note: Content may be edited for style and length.

Journal Reference:

  1. Yash Sondhi, Nicolas J. Jo, Britney Alpizar, Amanda Markee, Hailey E. Dansby, John Paul Currea, Samuel T. Fabian, Carlos Ruiz, Elina Barredo, Pablo Allen, Matthew DeGennaro, Akito Y. Kawahara, Jamie C. Theobald. Portable locomotion activity monitor ( pLAM ): A cost‐effective setup for robust activity tracking in small animalsMethods in Ecology and Evolution, 2022; DOI: 10.1111/2041-210X.13809

Cite This Page:

Florida Museum of Natural History. “Student’s device enables researchers to easily track elusive insects.” ScienceDaily. ScienceDaily, 24 February 2022. <www.sciencedaily.com/releases/2022/02/220224120640.htm>.

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Collecting Insects: Tricks of the Trade


New to insect collecting? Whether you’re a student just getting started in entomology or a hobbyist exploring your own backyard, entomology graduate student Elizabeth Bellow offers a primer on tools and tactics for gathering a variety of insects and arthropods. For example, malaise traps are an easy and passive way to collect a variety of insects. (It’s also important to wear proper gear like the permethrin-treated coverall, as Bello shows here.)

By Elizabeth Bello

Editor’s Note: This post is part of a series contributed by the ESA Student Affairs Committee. See other posts by and for entomology students here at Entomology Today.

Elizabeth Bello

Humans have most likely collected insects since the beginning of our civilizations. Our earliest records indicate that Chinese civilizations used silkworms in 4700 BC, honey bees by the 5th century, and scale insects by the 13th century. Insects have been collected for a multitude of reasons, everything from food production to dye creation to scientific study. This trend continues today, and many more people have become involved in insect collections, not just for science, but as a hobby, and even for art.

Perhaps the most avid insect collectors are—you guessed it—entomologists. As with most things, insect collecting is a skill that can be learned and honed over time, but in the beginning it can be quite difficult. In this article, I will outline some tips and advice on how, when, and where to collect insects as well as a few other things to keep in mind while you’re out collecting.

Know Your Insects

The first step is to figure out what insects you’re trying to collect and why. Are you taking your first entomology course and need to create an insect collection? Are you a researcher who needs to find that one species of pollinator for your study? Are you a hobbyist looking for big flashy beetles to display? Knowing what you’re looking for will help inform how to go about collecting what you need. Researching the life history of your insect(s) will tell you what they eat, where to find them, when to find them, and most likely the best way to capture them. Insects are virtually everywhere, so if you’re looking to catch anything and everything you should have no problem; but, if you’re looking for something specific, you’ll need to tailor your hunting strategy and your gear.

Know Your Gear

There are two main types of insect collecting: active and passive. Active collection requires more energy and the physical effort to capture insects, while passive collecting often involves traps that can be checked and monitored on a regular basis.

For active collecting, the three most popular tools are nets, beat sheets, and aspirators. Nets can come in a wide variety, including lightweight mesh aerial nets for collecting flying insects, aquatic mesh nets for collecting aquatic insects (this is often paired with using a white bottomed container in which to place the insects for easy visibility), and sweep nets, which are made of a sturdier fabric for sweeping insects off vegetation. Beat sheets are used by placing a sheet under vegetation and shaking or disturbing the plant above to capture any falling insects. Aspirators are another popular collecting tool and can be electric or manual. They are great for sucking small insects off natural and artificial surfaces.

Blacklight traps like the one pictured here are a great way to collect or photograph nocturnal insects.

The traps involved in passive collection will also depend on the insect you’re after. Malaise traps will catch a wide variety of insects, whereas funnel traps baited with specific pheromones can be aimed at collecting a particular species of beetle, for example. Pitfall traps are another common trap and involve placing a container filled with soapy water in soil, rim level with the ground. This will capture any insects that fall into it but will need to be periodically replaced, especially if it rains. Blacklight or UV traps are tailored to attract nocturnal insects but need a little more work in that they require the use of an aspirator or net to collect the insects off the trap.

Another important thing to remember is that traps can also be baited, which will greatly improve your success. Mosquitos for example, are attracted to carbon dioxide, so their traps often will be baited with dry ice. Berlese funnels aren’t exactly traps but are a very effective tool used to extract arthropods from soil and leaf litter samples and can easily be made at home with common supplies. Please note there are many, many more insect traps than what I’ve mentioned here.

Aside from what you’re using to collect the insects, you’ll need different equipment to store your insects. This means jars, containers, and lots of them in all different sizes, plus something to carry them in. I’ve seen people recommend multipocketed cargo pants, fly fishing vests, backpacks, and fanny packs. For soft bodied or aquatic insects, you’ll need ethanol in a leak-proof container; for lepidopterans you’ll need wax envelopes; and, for most other insects, plastic or glass containers will do. I am particularly fond of repurposing 33-millimeter film canisters as a storage container. Many entomologists will also often bring a kill jar, which is a glass jar equipped with either hardened plaster or some cotton balls at the bottom soaked with acetone. Be careful, though, when using acetone, as it can disturb the color of your insects and cause damage to any plastic materials.

If you are collecting insects for research purposes, a handheld GPS or smartphone will come in handy for recording your location. It is also vital that you write your collection information as soon as possible, because a freezer full of unlabeled specimens are practically useless, and I can guarantee you’ll never remember when or where you got them from.

Know Your Environment

Knowing where you will be collecting will influence not only what insects you’ll be able to catch but also other gear you might need. If you’ll be searching hard or rocky landscapes, you might want knee pads and elbow pads. If you’re in a hot, arid environment, you’ll need protective clothing, sunscreen, and a lot of water. On the other hand, if you’re in a wet environment you’ll need waterproof clothing.

Additionally, you’ll want to know if you even can collect there. Is it private or public land? Do you need a permit? Are you going to be in the woods during hunting season? These are all important details to understand while planning your collecting trip. Finally, knowing your environment will help you to identify the potential hazards you may face.

Know the Hazards

Rolling duct tape around a pen will lighten your load and come in handy for tick removal, broken equipment, or other emergencies.

The three main hazards to your health while insect collecting fall under the categories of weather, wildlife, and terrain. Always, always plan for the weather and keep an eye out for any signs of quickly approaching storms. It’s also good to keep in mind how the weather might negatively affect your more delicate gear and electronics.

As for wildlife, we often pose more of a threat to wildlife than it does to us, but that doesn’t mean we’re invincible. Being prepared for unexpected wildlife encounters could include wearing bug spray, leech socks, or boot gaiters, or it could mean carrying a pocketknife or a can of bear spray. Remember, if you’re in the wilderness, you’re invading their space, not the other way around, so it’s important be respectful.

Just as with weather, the terrain will also influence what you wear. A good pair of shoes that are right for the occasion can make all the difference in the world, and wearing long pants instead of shorts can save your legs from scratches and exposure to poisonous plants. Make sure you keep in mind the obstacles you might be faced with when you’re out collecting, as well. Depending on where and how long you’ll be collecting for, it might not be a bad idea to bring some emergency supplies and let at least one other person know the details of your route. A great tip I learned from one of my friends is to roll some duct tape around a pen. It’s much lighter than carrying around a whole roll and can be used in a variety of ways, including removal of ticks or repairing tears in clothing and gear.

A Note on the Ethics of Collecting

While there are many benefits of collecting insects, there may also be numerous consequences. Many entomologists see the value in collecting insects for research, monitoring, and record-building purposes, but some people are opposed to it, and their perspective is equally valid. We must ask ourselves about the ethics of insect collecting: Are we negatively impacting insect populations? Are we contributing to the steady decline in biodiversity? Is it right or just of us to take the life of another living creature? How can we better our collecting practices to minimize our negative impacts and maximize the benefits? “The Insect Collectors’ Code,” a fantastic article by Carolyn Trietsch and Andrew R. Deans in the Fall 2018 issue of American Entomologist, discusses these points and is well worth the read.

A Note From the Author

Finally, some of the material in this paper was crowdsourced from users on Twitter, and there is additional information I was not able to include in this article. You can find other tips and tricks of the trade in the replies to this tweet below.


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FEBRUARY 18, 2022

‘Super pest’ Colorado potato beetle has the genetic resources to sidestep our attacks

by Eric Hamilton, University of Wisconsin–Madison

‘Super pest’ Colorado potato beetle has the genetic resources to sidestep our attacks
The Colorado potato beetle’s rapid spread, hardiness, and recognizable tiger-like stripes have caught global attention since it began infesting potatoes in the 1800s. Credit: Zach Cohen

The Colorado potato beetle has evolved resistance to more than 50 different kinds of insecticides, making the insect a “super pest” that wreaks havoc on potatoes around the world.

New research finds that the beetle achieved this feat largely by turning to a deep pool of diversity within its genome, which allowed different populations across the U.S. to quickly evolve resistance to nearly anything humans have thrown at it.

The pest’s wealth of diversity and arsenal of existing resistance genes will likely make it hard to control in the future, regardless of what new insecticides researchers develop. But the new understanding of the pest’s genomic resources could help scientists design management systems that keep it in check.

“This beetle was one of the first to be attacked with chemicals in the modern era, and it’s been very successful at evolving past those attacks,” says Sean Schoville, a University of Wisconsin–Madison professor of entomology who led the new analysis. “For other insects we’re hoping to control, there’s lessons to be learned from studying this pest. What mechanisms does this insect use to get past these insecticides?”

Along with his collaborators at UW–Madison and other institutions, Schoville published his findings Jan. 19 in the journal Molecular Biology and Evolution.

Schoville’s team first sequenced the Colorado potato beetle’s genome in 2018. Since then, they’ve probed the genome to understand how the insect can overcome new insecticides as quickly as it does. To do so, they sequenced several dozen beetles from across the U.S. These regional populations vary in what pesticides they are resistant to and where they came from, which can give clues to the evolutionary history of the pest.

The scientists discovered that these different regional groups evolved so quickly because their parent populations already had the genetic resources necessary to overcome insecticides.

“The genes that evolve are well known to be involved in insect resistance. But what’s interesting is that different populations are altering different parts of genes or different genes in the same pathway,” says Schoville. This similar, but not identical, pathway to resistance across different populations is known as repeated evolution.

This rapid evolution based on a wealth of existing genetic diversity is at odds with an older model of evolution that assumed rare mutations have to slowly arise in a population. While new mutations do develop and can contribute to insecticide resistance, the potato beetle’s rapid response to new chemicals in different parts of the country can be explained only by its existing diversity.

The findings are unwelcome news for farmers and scientists hoping to turn the tide on the potato beetle’s attacks. It seems unlikely, Schoville says, that even a brand-new insecticide would keep the pest in check for long.

But armed with the knowledge of how the Colorado potato beetle has sidestepped our attacks, future research might help produce creative strategies to keep pace with this nemesis.

“More sophisticated models might help us learn how different management techniques affect the beetle’s evolution. That might allow us to change our management style to slow it down,” says Schoville.

Explore further

Colorado potato beetle genome gives insight into major agricultural pest

More information: Benjamin Pélissié et al, Genome Resequencing Reveals Rapid, Repeated Evolution in the Colorado Potato Beetle, Molecular Biology and Evolution (2022). DOI: 10.1093/molbev/msac016

Journal information: Molecular Biology and Evolution 

Provided by University of Wisconsin–Madison

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Tobacco Thrips: Tiny Insects With a Big Impact on Georgia Peanut Production


Tobacco thrips (Frankliniella fusca) also have a taste for peanut, and they spread the plant virus causing spotted wilt disease. A new guide in the open-access Journal of Integrated Pest Management details the biology and management of tobacco thrips in peanut crops. (Photo by Jena Johnson, University of Georgia Department of Entomology)

By Gabrielle LaTora

Gabrielle LaTora

Few people other than farmers think about the toll that insect-transmitted viruses have on crop yields. Tomato spotted wilt orthotospovirus (TSWV)—the virus that causes spotted wilt disease in peanut—caused over $27 million (US) in financial losses during the 2020 peanut season in the state of Georgia. Although TSWV infects several crops, it can be devastating for Georgia’s peanut growers, who produce more peanuts than any other state in the U.S.

Peanut plants with spotted wilt disease develop discolored leaflets and abnormal pods and kernels. Often, whole plants become stunted. The primary vector of TSWV in Georgia peanuts is the tobacco thrips (Frankliniella fusca). Besides transmitting TSWV, larvae and adults directly injure peanut plants when feeding, causing additional foliar symptoms and yield losses.

Thrips can be difficult to identify. Life stages of Frankliniella fusca on peanut are shown here: (A) egg; (B) first instar larva; (C) second instar larva; (D) prepupa; (E) pupa; (F) brachypterous adults, female (left) and male. (Scale bar = 0.5 millimeters). (Photos by Yi-Ju Chen and Pin-Chu Lai, Ph.D.)

In “Frankliniella fusca (Thysanoptera: Thripidae), the Vector of Tomato Spotted Wilt Orthotospovirus Infecting Peanut in the Southeastern United States,” published this month in the open-access Journal of Integrated Pest Management, my colleagues at the University of Georgia Vector-Virus Interactions Lab and I provide an overview of F. fusca‘s biology and pest status, including its morphology, life cycle, vector biology, management, and economic impact. Our hope is that this article can be used as a go-to for researchers, extension professionals, farmers, and anyone who wants to learn more about F. fusca. Thrips can be difficult to identify, so we have provided photos and descriptions of each F. fusca life stage and photos of short-winged and long-winged morphs.

Because peanut is an annual crop, F. fusca overwinter in weed hosts surrounding peanut fields until peanuts are planted again in the spring. Many of these plants are also TSWV hosts—F. fusca acquire TSWV as first- and second-instar larvae most likely by feeding on infected weeds before peanuts are available, then moving into croplands and inoculating peanuts in the late spring.

Using TSWV-resistant peanut cultivars has been the most common and successful non-chemical management strategy to date. Resistant cultivars are not immune to the virus, but they exhibit milder symptoms and higher yields than susceptible cultivars. Many growers employ avoidance and disruption strategies, too—they may shift planting dates to avoid peak thrips populations or modify planting patterns to disrupt thrips’ landing cues. Most growers also head off TSWV outbreaks by controlling thrips with prophylactic applications of insecticides, like phorate and imidacloprid. In addition to controlling thrips, phorate—an organophosphate—can actually suppress spotted wilt disease by inducing peanut defenses.

stunted peanut growth
spotted wilt disease foliar symptoms in peanut

Peanut Rx, a disease risk index developed by researchers and extension specialists from southeastern land-grant universities, is a tool used by growers to evaluate the risks of peanut diseases, including spotted wilt, on their farms. Peanut Rx uses individual farm and management characteristics, like plant density, row pattern, irrigation, pesticide programs, and prior disease incidence, to predict disease risks each year.

Although most Georgia peanut growers use a variety of methods to manage F. fusca and TSWV, there are still opportunities to diversify IPM programs. At this time, there are no standardized monitoring protocols or economic thresholds for F. fusca in peanuts. Very few studies have evaluated biological control agents, like thrips-parasitic nematodes and generalist predators, against F. fusca. Although TSWV-resistant cultivars are common, resistance to thrips themselves is not a targeted trait for peanut breeding programs. By “stacking” TSWV and thrips resistance traits, peanut cultivars can become even more resilient.

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Frankliniella fusca (Thysanoptera: Thripidae), the Vector of Tomato Spotted Wilt Orthotospovirus Infecting Peanut in the Southeastern United States

Journal of Integrated Pest Management

Gabrielle LaTora is a research professional and lab manager at the Srinivasan Lab at the University of Georgia Griffin Campus in Griffin, Georgia. Twitter: @Gab_LaTora. Email: gabrielle.latora@uga.edu.


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 Frankliniella fuscaGabrielle LaTorageorgiaintegrated pest managementJournal of Integrated Pest Managementpeanuttobacco thripstomato spotted wilt orthotospovirus

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Minimizing Further Insect Pest Invasions in Africa

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Esther Ngumbi

Jun 20, 2018

Photo: Tamzin Byrne/ICIPE

This was written by Esther Ngumbi, and appeared on Sci Dev Net

USAID recently offered prize money for the best digital tools that can be used to help combat the fall armyworm (FAW), an invasive pest that has spread across Africa. The winners will be announced in the coming months.
Identified in over 35 African countries since 2016, the FAW is expected to continue to spread, threatening food security and agricultural trade in African countries.

Map of areas affected by Fall Armyworm (as of January 2018)

Map of areas affected by Fall Armyworm (as of January 2018) Credit: FAO

But this is not the first invasive pest the African continent is dealing with. Just a few years ago, African smallholder farmers battled the invasive South American tomato moth, Tuta absoluta. According to recent research, five invasive insect pests including T. absoluta cost the African continent US$ 1.1 billion every year.
Around the world, invasive pests are causing US$ 540 billion in economic losses to agriculture each year despite the fact that many countries are doing their best to prevent insect invasions now and into the future.

Tackling invasive pests reactively

To deal with invasive insects, African countries assisted by other stakeholders, including aid agencies such as USAID, research institutions such as the International Center for Insect Physiology and Ecology, the Center for Agriculture and Bioscience International (CABI, the parent organization of SciDev.Net) and the United Nations Food and Agriculture Organization (UN FAO) have repeatedly taken a reactive rather than a proactive approach in tackling the invasive pests only after they have established a foothold and caused considerable damage.
Ghana, for example, established a National Taskforce to control and manage FAW after the worms had invaded local fields. This taskforce mandate includes sensitizing farmers and making them aware of the symptoms of armyworm attacks so they can report infestations to authorities and undertake research aimed at finding short and long term solutions to combat the spread of FAW.

“While many of these strategies are working, one cannot help but wonder what it would take for African governments to get ahead of this problem.”

Esther Ngumbi, University of Illinois

Malawi’s government prioritized the use of pesticides as an immediate and short-term strategy to fight the FAW after many of their smallholder farmers lost crops to this invasive insect. Further, the government intensified training and awareness campaigns about this pest and installed pheromone traps to help monitor the spread only after the pest had established a foothold.
The FAO, a leader in the efforts to deal with invasive pests in Africa, has spearheaded many efforts including bringing together experts from the Americas, Africa and other regions to share and update each other on FAW. The FAO has launched a mobile phone app to be used as an early warning system tool. But again, many of these efforts happened after the first detection of the FAW.
While many of these strategies are working, one cannot help but wonder what it would take for African governments to get ahead of this problem. How can aid agencies such as USAID, UN FAO and other development partners that are currently spending billions to fight the invasive FAW help Africa to take the necessary steps to ensure that it is better prepared to deal with invasive insects now and into the future?

Anticipate and prepare

Recent research predicts that threats from invasive insects will continue to increase with African countries expected to be the most vulnerable. African governments must anticipate and prepare for such invasions using already available resources.
Early this year, CABI launched invasive species Horizon Scanning Tool (beta), a tool that allows countries to identify potential invasive species. This online and open source tool supported by United States Department of Agriculture and the UK Department for International Development allows countries to generate a list of invasive species that are absent from their countries at the moment but present in “source areas,” which may be relevant because they are neighboring countries, linked by trade and transport routes, or share similar climates. Doing so could allow African countries to prepare action plans that can be quickly rolled out when potential invaders actually arrive.

Learn from other regions

Africa can learn from other regions that have comprehensive plans on dealing with invasive insects and countries that have gone through similar invasions. The United States and Australia are examples of countries that have comprehensive plans on preventing and dealing with insect invasions, while Brazil has gone through its own FAW invasion.

“African governments must learn to be proactive rather than reactive in dealing with invasive insects.”

Esther Ngumbi, University of Illinois

Through workshops and training programs that help bring experts together, African countries can learn how to prevent and deal with future insect invasions. Moreover, key actors should help organize more workshops and training programs to enable African experts to learn from their counterparts overseas. At the same time, the manuals, and all the information exchanged and learned during such workshops, could be stored in online repositories that can be accessed by all African countries.   

Strengthen African pest surveillance

A recent Feed the Future funded technical brief, which I helped to write, looked at the strength of existing African plant protection regulatory frameworks by examining eight indicators including the existence of a specified government agency mandated with the task of carrying out pest surveillance.
It reveals that many African countries have weak plant protection regulatory systems and that many governments do not carry out routine pest surveillance which involves the collection, recording, analysis, interpretation and timely dissemination of information about the presence, prevalence and distribution of pests.
The International Plant Protection Convention offers a comprehensive document that can help African countries to design pest surveillance programs. Also, the convention offers other guiding documents that can be used by African countries to strengthen their plant protection frameworks. African countries can use these available documents to strengthen national and regional pest surveillance abilities.

Set up emergency funds

Invasive insects know no borders. Thus, African countries must work together. At the same time, given the rapid spread of invasive insect outbreaks, the African continent must set up an emergency fund that can easily be tapped when insects invade. In dealing with the recent FAW invasion, it was evident that individual African countries and the continent did not have an emergency financing plan. This must change.

By anticipating potential invasive insects and learning from countries that have comprehensive national plant protection frameworks, Africa can be prepared for the next insect invasion. African governments must learn to be proactive rather than reactive in dealing with invasive insects.
Doing so will help safeguard Africa’s agriculture and protect the meaningful gains made in agricultural development. Time is ripe.
Esther Ngumbi is a distinguished postdoctoral researcher with the Department of Entomology at the US-based University of Illinois at Urbana Champaign, a World Policy Institute Senior Fellow, Aspen Institute New Voices Food Security Fellow and a Clinton Global University Initiative Agriculture Commitments Mentor and Ambassador. She can be contacted at enn0002@tigermail.auburn.edu 
This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk. 


[1] USAID: Fall Armyworm Tech Prize (USAID, 2018). 
[2] Briefing note on FAO actions on fall armyworm in Africa (UN FAO, 31 January 2018) 
[3] Corin F. Pratt and others  Economic impacts of invasive alien species on African smallholder livelihoods (Global Food Security, vol 14, September 2017).
[4] Abigail Barker Plant health-state of research (Kew Royal Botanic gardens, 2017).
[5] US Embassy in Lilongwe United States assists Malawi to combat fall armyworm. (US Embassy, 13 February 2018).
[6] Joseph Opoku Gakpo Fall armyworm invasion spreads to Ghana (Cornell Alliance for Science, 19 May 2017). 
[7] Kimberly Keeton Malawi’s new reality: Fall armyworm is here to stay (IFPRI, 26 February 2018).
[8] Malawi’s farmers resort to home-made repellents to combat armyworms (Reuters, 2018). 
[9] Fall Armyworm (UN FAO, 2018). 
[10] FAO launches mobile application to support fight against Fall Armyworm in Africa (UN FAO, 14 March 2018).
[11] Dean R. Paini and others Global threat to agriculture from invasive species (Proceedings of the National Academy of Sciences of the United States of America, 5 July 2016).
[12] CABI launches invasive species Horizon Scanning Tool (CABI, 2018).
[13] United States Department of Agriculture Animal and Plant Health Inspection Service(USDA APHIS, 2018).
[14] Australia Government Department of Agriculture and Water Resources (Australia Government, 2018).
[15] Plant protection EBA data in action technical brief (USAID FEED THE FUTURE, 26 January 2018).
[16] Guidelines for surveillance (International Plant Protection Convention, 2016)FILED UNDER:AGRICULTURAL PRODUCTIVITYMARKETS AND TRADEPOLICY AND GOVERNANCERESILIENCE

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A monarch butterfly sits on an orange flower
There were up to 70% fewer pollinators for plants in polluted air in the study. Image © Nikola Bilic/Shutterstock


Bees, butterflies and moths ‘confused’ by air pollution

By James Ashworth

First published 24 January 2022

Bees and butterflies are ‘confused’ by air pollution, making them less able to seek out the crops that both humans and insects depend upon.

In some cases, the presence of pollutants such as nitrogen oxides and ozone resulted in as much as a 90% decline in flower visits by pollinators.

Air pollution obscures the sweet smell of flowers, making it much harder for pollinators to find them.

Research led by the University of Reading found that insects including bees, flies, moths and butterflies were being impaired by air pollution, reducing pollination rates by as much as 31%. 

With 70% of the world’s crops, including apples, strawberries and cocoa, relying on insect pollination, scientists are concerned that the impact of common air pollutants goes far beyond impacts on human health.

Lead author Dr James Ryalls, says, ‘The findings are worrying because these pollutants are commonly found in the air many of us breathe every day. We know that these pollutants are bad for our health, and the significant reductions we saw in pollinator numbers and activity shows that there are also clear implications for the natural ecosystems we depend on.’

The findings of the study were published in the journal Environmental Pollution.

Cars in a queue with exhaust fumes rising around them
Common air pollutants include ground-level ozone, nitrogen oxides and sulphur oxides. Image © LanaElcova/Shutterstock

What is air pollution?

Air pollutants are commonly found across the world and include any substance that contaminates the environment by modifying the normal characteristics of the atmosphere.

After fuels are burnt, the waste products (as well as their impurities) can react in the atmosphere to produce a variety of harmful products. Common air pollutants include nitrogen oxides, ozone, sulphur oxides and particulates.

These have a diverse range of impacts, from causing acid rain to harming health. Air pollution has both short and long-term health impacts, from shortness of breath and exacerbating asthma to increasing the risk of heart failure.

As a result, the World Health Organisation (WHO) estimates that these pollutants cause around four million deaths a year, and suggest that 91% of the global population live in areas where air pollution exceeds recommended limits.

Aside from its impact on people, air pollution also impacts the natural world. In vertebrates, air pollution can cause similar issues as in humans, while pollutants like ozone and particulate matter can impair the ability of plants to photosynthesise.

The scents that plants produce to attract their insect pollinators are also affected by air pollution. While there are a number of ways insects find plants to pollinate, scent is one of the most important. However, air pollution can react with the compounds in these scents, making them much less recognisable to the insects they are supposed to be attracting.

The researchers wanted to investigate how this impacted pollinators in practice, by running an experiment testing their ability to find plants to pollinate.

Dr Robbie Girling, one of the paper’s co-authors, described the findings as ‘much more dramatic than we had expected.’

Bees landing on a yellow flower
Pollution reduced the visits of pollinators to the plants by up to 90% in some cases. Image © RUKSUTAKARN studio/Shutterstock

Pollinators in peril

The researchers used a purpose-built facility to regulate the levels of nitrogen oxides and ozone in a field environment, looking at the impacts these pollutants had on free-flying local pollinators and the pollination of black mustard.

They found that there up to 70% fewer pollinators for plants in polluted air, which led to a reduction in pollination of up to 31%.

With 8% of the value of agricultural food production worldwide dependent on pollinators, productivity declines from pollution could be causing billions of pounds worth of economic damage each year.

Furthermore, the levels of pollution used in the study were below the average maximum levels known from the real world, with scientists using concentrations around half of that deemed safe by the US government. 

These higher levels of air pollution in the real world could mean that the impacts on pollinators and other insect life are more severe than demonstrated in this study.

The UK Government says that it intends to tackle air pollution through a variety of techniques, including the consideration of an SMS air pollution alert scheme and aiming to set new targets for particulates and other pollutants. 

To find out levels of air pollution in your area, visit DEFRA’s forecasting site here.

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How Can Ant and Termite Queens Live So Long?

Scientists are working to understand the matriarchs, who can survive decades while investing huge amounts of energy into reproduction


Tim Vernimmen, KnowableJanuary 21, 2022

Queen Ant
A queen Oecophylla smaragdina ant Didier Descouens via Wikimedia under CC BY-SA 4.0

Small animals don’t usually grow very old. Since they’re always at risk of becoming another critter’s quick snack, the best way to ensure that their genes will make it into the next generation is having a bunch of young as soon as possible. This is certainly true for insects, which, with some famous exceptions like cicadas, often have a life expectancy best expressed in days, weeks or months.

In contrast, animals like elephants and humans raise only a few offspring and have bodies that survive for decades: If your size or lifestyle offers protection, you can afford to take your time.

This contrasting pattern is so common it suggests that because reproduction and maintenance are both costly, animals simply can’t maximize both. So the more energy and nutrients an individual invests in producing offspring, the faster it will probably age, and the shorter its life will be.

Yet in social insects such as termites, ants, bees and wasps, the queens appear to have found a way to have their cake and eat it.

In many colonies, queens that lay hundreds of eggs every day can stay alive for years or even decades, while workers that never lay a single egg in their life will die after a few months. Apparently, these species have found a route that allows at least some of their kind to escape the constraints that force other animals to choose between longevity and lots of offspring.

A few years ago, an international team of biologists set out to study how the creatures pull it off — and though there’s a lot still to learn, the first results of the project are starting to offer up clues.

Fruit flies offer aging clues

Differences in the genetic code can’t explain the unusual longevity of queens compared to workers. All workers are daughters of the queen and, in many cases, any of those daughters could have grown up to become queens themselves had they received the appropriate royal treatment when they were larvae.

This close genetic relatedness is why it makes sense that workers dedicate their lives to caring for the queen and her offspring, maintaining and protecting the colony’s nest and foraging for food. By keeping the queen safe and providing her with the plentiful resources she needs to produce eggs for years on end, each worker helps in the spread of its own genes.

And since the queen is the only one in a colony laying eggs, colonies with long-lived queens are likely to grow larger and send forth more young queens to start new nests, as well as males to fertilize them.

In other words, many scientists reason, there must have been strong selective pressure to keep the queen alive for as long as possible by evolving delayed aging.

But how might that be achieved? Other insects offer some possible leads.

Researchers Moving Ants With Brush
Because ants are so small, researchers (here in the lab of evolutionary biologist Romain Libbrecht) use brushes to move them around. Roman Libbrecht

Some species, it turns out, can tilt their investment in body maintenance and reproduction one way or the other, depending on circumstances. Studies have found, for example, that when the fruit fly Drosophila melanogaster is fed a restricted diet, it can significantly extend its lifespan, but will produce fewer eggs.

Researchers have also shown that an entire network of genes involved in sensing the presence of nutrients such as amino acids and carbohydrates is responsible for this effect. When food is scarce, this network will transmit signals that delay reproduction while increasing the animal’s longevity and investment in processes such as tissue repair — perhaps enabling the individual to wait for better days to come. Some scientists have also shown that the lifespans of flies can be prolonged when some of the key genes involved in this nutrient-sensing network are inactivated.

This fruit fly work suggests that the rate of aging is not set in stone. Instead, it can be adapted to some extent as part of an evolved strategy to invest resources in the best possible way — on reproduction when they are plentiful, and on maintenance when they’re not.

“When we talk about the mechanisms of aging, we usually only talk about the way things deteriorate,” says evolutionary biologist Thomas Flatt of the University of Fribourg in Switzerland, who has worked mainly with fruit flies and is coauthor of an article about insect aging in the Annual Review of Entomology. “What we often seem to forget about is the flip side of aging: the key mechanisms that slow down the deterioration.”

Getting workers to lay eggs

Might social insects be using some of the same genes that Drosophila uses to tweak the rate of aging — in their case, to delay aging in queens?

Studying aging in queens is difficult, because there is usually only one queen in every colony, and it takes many years, often decades, for them to age. To get around that, researchers can remove the queen, which often triggers some of the workers to start producing eggs of their own.

Acorn Ants
The acorn ant Temnothorax rugatulus is so small that an entire colony fits in one acorn—or in a tiny container in the lab. The larger ant in the middle is the queen. Megha Majoe

This certainly doesn’t fully turn workers into queens, but experiments have shown that it does result in health benefits similar to those enjoyed by the long-lived queens. In a study published in 2021, for example, researchers at the University of North Carolina Greensboro found that worker bees that reactivated their ovaries were more resilient against a virus that can cause lethal infections.

Worker bees with active ovaries were also more likely to survive an injection with paraquat, a herbicide that causes oxidative damage to proteins, DNA and other components of cells. Damage of this kind is also caused more slowly by the waste products of normal metabolism and is widely thought to be an important contributor to aging.

Scientists at two German universities saw something similar in the workers of three ant species. In two of the species, resistance to oxidative stress went up when the queen was removed, almost doubling the workers’ chance of surviving treatment with paraquat. In one of those species, the workers activated their ovaries in response. In the other, they did not — but in this case, a longer life might buy workers time to raise a new queen, reasons Romain Libbrecht, an evolutionary biologist at Johannes Gutenberg University of Mainz, a coauthor of the study.

Lessons from termites

Clues about the antiaging tricks of social insects may also be gleaned from various termite species, creatures that are essentially social cockroaches, says evolutionary biologist Judith Korb of the University of Freiburg in Germany.

One of the termite species she studies, the dry-wood termite Cryptotermes secundus, never leaves the nest — it just holes up in dead trees, feasting on the wood from within. The workers don’t have to work very hard, and they maintain their ability to reproduce, always ready to move out to try to start their own colony elsewhere when food runs out.

Korb and colleagues found that when the workers are younger and not reproducing, genes involved in combating oxidative damage are more active. But when they get older and become reproductively mature, the activity of such genes goes down: The focus is now largely on reproduction.

Termite Queen and King
A termite queen (left), which is about 2 inches long, and a termite king (right), which is about a third of an inch long. The queen continually produces eggs out of its massive abdomen. China Photos / Getty Images

In this species, workers can live for several years, while kings and queens may last for a decade or more. But in most other termite species, the social structure is more complicated, and in some species, workers are completely sterile and will never have a chance to lay eggs of their own. This is where really large lifespan differences between worker and queen are seen.

“These workers will often live only a few months, while their kings and queens are very long-lived,” says Korb. In Macrotermes bellicosus, the largest known termite species, queens can live for more than 20 years.

Only when colony members lose all hope of ever having their own offspring, it seems, does “Long live the queen” truly become the colony’s creed.

Every insect does it differently

To try to learn more about what enables the long life of queens in social insects, a team of researchers including Korb, Libbrecht and Flatt decided to compare the activity levels of various genes in termites, ants and bees — two species of each. In all, they studied 157 individuals, including insects of different ages as well as different castes.

Unsurprisingly, the team found that genes that are known to play crucial roles in reproduction showed different activity patterns in queens than they did in sterile workers. Some of these genes, which carry instructions for making proteins called vitellogenins, were active in queens of all species.

The main role of vitellogenins is to support the production of yolk for the eggs. But some scientists suspect that vitellogenins may be doing more than that: In honeybees, at least, research has found that vitellogenins also function as antioxidants. If vitellogenins do the same thing in other social insects, they might contribute to the resistance of queens to oxidation.

The team also found differences in the activity of genes involved in the prevention of oxidative damage or the repair of such damage, between queens and egg-laying workers compared with sterile workers. But the precise genes involved differed strongly from one species to another. Apparently, each species has evolved its own way of keeping its queens alive longer, says Korb, who led the study.

The scientists also checked the nutrient-sensing gene network that can increase lifespan when manipulated in fruit flies and didn’t find obvious patterns across ages and castes. But they did find something else: differences in the activity of genes involved in the production and effects of a substance called juvenile hormone, a molecule involved in reorganizing the bodies of most maturing insects.

Perhaps the same hormone that allows insects to become full-grown adults can also help them to delay aging, the scientists speculate. But again, precisely how these juvenile hormone-related genes were tuned up or down varied from species to species.

To Korb, this somewhat bewildering variety across species reveals an important lesson about the nature of aging: There isn’t one button or switch that allows a species to invest more, or less, in maintenance or reproduction, but a whole dashboard of them that is set up slightly differently in each species.

“The tradeoff between lifespan and reproduction is clearly not hardwired — it is much more flexible than people thought,” she says. “Species have evolved different solutions,” depending on their own social and natural environments.

And though it is obviously useful to know a few species through and through, these findings are also a warning to not assume that one or two intensively studied creatures — like the famous fruit fly Drosophila melanogaster — can teach us everything, Flatt says. “There is tremendous diversity to be discovered out there that we don’t even know about yet.”

Knowable Magazine is an independent journalistic endeavor from Annual Reviews.



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Zombie plants, witches’ brooms and the cauldron of curious science

27th October 2021

Carrots, ants, snails, strawberries, mice, and major cereal crops are just a few of the many organisms that can be turned into zombies: kept alive on life support under the manipulating spell of parasites.

This is not a Halloween horror tale; it is a fascinating area of research that is bubbling away at the John Innes Centre.

Delving into the mechanisms behind host manipulating parasites may offer new clues to protecting disease-threatened food crops in using biological control methods rather than chemicals which damage the environment.

Until recently there was little understanding of what guides these bizarre relations on a molecular and mechanistic level. Research from the Hogenhout group at the John Innes Centre and collaborators has identified a manipulation molecule produced by phytoplasma bacteria to hijack plant development.

When inside a plant this protein causes key growth regulators to be broken down, triggering abnormal growth. Phytoplasma bacteria are often responsible for the witches’ brooms seen in trees where an excessive number of branches grow close together. These bushy outgrowths are the result of the plant being stuck in a vegetative “zombie” state, unable to reproduce and providing a longer-lasting environment for the parasite within.

Plant parasites such as phytoplasma bacteria, and also other bacteria and plant viruses, are spread by insect vectors such as aphids, plant lice and leafhoppers.

These insects feed on the vascular tissue of plants and may be referred to as the ‘mosquitoes of the plant world’, because they transmit a wide range of plant parasites.

The research conducted by the Hogenhout group focuses on the interactions among plants, pathogens and insects and has generated unique insights into the fascinating world of plant defence and immunity.

Professor Saskia Hogenhout, explains: “Our work on the phytoplasma has revealed how a parasite modulates plant defences and turn plants into better hosts for insect vectors. This information can be turned around and used to better understand what plants need to become more resilient to insect attack.

“Understanding these interactions is especially important because pesticides are being taken off the market for environmental reasons and there are not a lot of control methods to protect against the insects. It’s important that we understand the plant defence and immune system so that we can engineer durable resistance of crops to phytoplasmas and their insect vectors.”

Phytoplasmas affect food production worldwide. They cause devastating crop diseases, such as Aster Yellows that often badly affect vegetable crops such as lettuce and carrots, and also oilseed rape, and the grain crop wheat.

The wine industry in France, Italy, and Croatia regularly experiences losses, because it is challenging to reduce phytoplasma outbreaks in grape vines without using chemical pesticides to control the phytoplasma insect vectors.

There is much to be gained from finding innovative biological solutions to replace chemical pesticides, which require carbon-intensive resources for their production and are damaging to biodiversity.

Human health may also benefit from our improved knowledge of the mechanisms by which parasites manipulate hosts.

The phytoplasmas that the Hogenhout group are studying are related to the human and animal mycoplasma pathogens, which may use similar mechanisms to modulate cells.

Professor Hogenhout said: “Parasites are often excellent puppeteers, as they excel at manipulating their hosts to become more attractive to other organisms the parasite needs to spread. However, how the parasites do this is largely unknown. As such, our work on the phytoplasma parasites is relevant to other parasites, such as the insect-vectored malaria and virus parasites that jeopardise human and animal health.”

The research on phytoplasmas presents spectacular examples of how single genes can turn parasites into excellent puppeteers of other organisms and take control of the surrounding environments: this cauldron of curious science may contain a cure for major diseases of plants and humans.



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