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Archive for the ‘Insects’ Category

The correct identification of insect pests and their natural enemies is critical for developing sound and sustainable pest management strategies: this is particularly so for rice. In the 1960’s, a comprehensive rice insect pest and natural enemy collection was established at the International Rice Research Institute (IRRI) in the Philippines, with the aim of helping those in national rice research programs to identify rice arthropods. 

A similar project was begun in West Africa in 1990, establishing a rice insect and natural enemy collection at WARDA (West African Rice Development Association), which subsequently became AfricaRice.

Associated with both of these collections, dichotomous keys were developed and published in the following books on rice arthropods:
Biology and Management of Rice Insects,
edited by E. A. Heinrichs (1994) and published by IRRI, and 
Rice Feeding Insects and Selected Natural Enemies in West Africa, authored by E. A. Heinrichs and Alberto Barrion (2002).

While the printed versions of both books have been out-of-print for several years, a recent upgrade of the Lucid software program, which makes it possible to convert paper-based, dichotomous keys to interactive pathway keys, means that both keys are now freely available to use on the Internet, courtesy of IAPPS (International Association for the Plant Protection Scientists) at: http://www.plantprotection.org

 Adding arthropod images: Note that the IRRI key now includes a large number of color images of important insect pests and natural enemies. E.A. Heinrichs (eheinrichs2@unl.edu) would appreciate any good resolution images that colleagues would be willing to submit for adding to the key – with due acknowledgement

IRRI arthropod key

West African arthropod key

© Copyright International Association for the Plant Protection Sciences. All rights reserved 2022.

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Amped-Up Ants: Caterpillars’ Sugary Treats Earn Carpenter Ant Care

ENTOMOLOGY TODAY  LEAVE A COMMENT

A new study finds that larvae of the endangered butterfly Cyclargus thomasi bethunebakeri, often known as the Miami blue butterfly, survive in greater numbers when protected by Florida carpenter ants (Camponotus floridanus), which fend off predators in exchange for the caterpillars’ sugary secretions. Shown here are two Florida carpenter ants tending to a Miami blue butterfly caterpillar. (Photo by Geena M. Hill)

By Carolyn Bernhardt

Since the 1960s, researchers have observed ants providing protection to various insects, a phenomenon called myrmecophily. And by creating a mix of chemical, acoustic, and other cues, certain butterfly species have long found ways to become frequent beneficiaries of ants’ dedicated services.

In a recent study led by Geena M. Hill, a research biologist at the Florida Natural Areas Inventory at Florida State University, researchers tested whether the Florida carpenter ant (Camponotus floridanus) provides protection to the highly endangered butterfly Cyclargus thomasi bethunebakeri, often known as the Miami blue butterfly. Their results were published this week in the open-access Journal of Insect Science.

The butterfly Cyclargus thomasi bethunebakeri, often known as the Miami blue butterfly, has been a federally listed endangered species since 2012. (Photo by Geena M. Hill)

“We found that ants provide significant protection to Miami blue larvae, with later instar larvae receiving a higher level of protection due to differences in tending frequencies,” Hill says. The ants tended to the late instar larvae more than twice as much as they did early instar larvae.

Geena M. Hill, a research biologist at the Florida Natural Areas Inventory at Florida State University, conducts fieldwork in central Florida. (Photo by John Lampkin)

Previous studies conducted by study co-author Matthew D. Trager, Ph.D., forest planner at the U.S. Forest Service, have shown that ant tending has sex-dependent benefits for female Miami blue butterflies. Ant-tended female Miami blue larvae grow into larger pupae and lay more eggs as adults. So, in this latest study, Hill and team conducted a series of timed observational trials in the lab to assess larval survival and ant protection from insect predators.

Ants were incredibly effective protectors for the larvae, but they seemed to provide greater protection over later instar larvae. Hill says she isn’t totally certain why this is, but she has a hunch that certain butterfly life stages influence ant tending behavior while some more vulnerable life stages do not as effectively stimulate ants to protect the larvae. She says she suspects this could be because each time the larvae molt they might develop and produce more secretions that signal to ants to help them as they increase in size.

At certain developmental stages, each caterpillar has a nectary organ tucked neatly into a slit in its back and flanked by tentacle-like organs on either side. When this organ emerges, it secretes a sugary substance packed with amino acids and other nutrients for ants. Hill and her colleagues watched in the lab as the ants’ energy levels soared whenever predators approached after the ants had ingested the substance. “They were all amped up!” she says. The carpenter ants would even drum their antennae on the back of the caterpillar to request a helping.

A new study finds that larvae of the endangered butterfly Cyclargus thomasi bethunebakeri, often known as the Miami blue butterfly, survive in greater numbers when protected by Florida carpenter ants (Camponotus floridanus), which fend off predators in exchange for the caterpillars’ sugary secretions. (Video by Chris Johns and Geena M. Hill)

For the most part, Hill says she thinks the substance itself is enough motivation for the ants to protect the larvae from threats. However, it’s also possible that the chemical makeup of the secretions affects the dopamine levels in the ants. “We already know other species can trick the ants by using different chemicals,” she says. “So, it is interesting to think maybe they could have a chemical in the secretions that affects the dopamine levels [in the ants] and makes them more aggressive toward predators.”

Whatever the reason, this research shows that, for Miami blue butterfly caterpillars, Florida carpenter ants are effective protectors against attacks and help improve butterfly larvae survivorship. But while the Florida carpenter ant is the Miami blue’s most common associate, 16 other species of ants also tend the Miami blue caterpillars. Hill says she wants to test those other species to measure how effective each species is at promoting survival for the federally listed, critically endangered butterfly species. This information can help inform conservation efforts for rehabilitating the endangered Miami blue. “Hopefully with this work, we will see increases within the Miami blue population,” Hill says. “As our lab conducts butterfly releases, it will be important to select release sites that have Florida carpenter ants present.

While the Florida carpenter ant (Camponotus floridanus) is the most common associate with the endangered butterfly Cyclargus thomasi bethunebakeri, often known as the Miami blue butterfly, 16 other species of ants also tend the Miami blue caterpillars, such as Camponotus planatus, sometimes known as the compact carpenter ant, shown here. Geena M. Hill, a research biologist at the Florida Natural Areas Inventory at Florida State University, says she wants to test those other species to measure how effective each species is at promoting survival for the federally listed, critically endangered butterfly species. (Photo by Geena M. Hill)

Historically, the Miami blue was found throughout coastal Florida. But, with climate change and the effects of human-driven land development, the species’ numbers have long dwindled. “Predators are not the sole driver for the decline of the Miami blue, but with such low population numbers, they can have a big impact,” says Hill.

For a long time now, the Miami blue has been limited to a few islands in the Florida Keys. It mainly lives in the Key West National Wildlife Refuge. Still, over the last several decades, researchers have successfully reestablished the species into the ecosystem in Bahia Honda State Park—35 miles east of Key West and that much closer to mainland Florida. And work is underway to reintroduce the species in mainland Florida.

“Insect declines are being observed worldwide,” says Hill, “and it’s imperative to study these insects and their interactions so we best know how to protect them. There are so many species that will go extinct without us knowing. By protecting one species, we [could be] protecting others within the habitat as well.”

Read More

Protective Benefits of Tending Ants to a Critically Endangered Butterfly

Journal of Insect Science

Carolyn Bernhardt, M.A., is a freelance science writer and editor based in Portland, Oregon. Email: carolynbernhardt11@gmail.com.

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Entomologists issue warning about effects of climate change on insects

by University of Maryland

<img src="https://scx1.b-cdn.net/csz/news/800a/2022/entomologists-issue-wa-1.jpg&quot; alt="Entomologists issue warning about effects of climate change on insects" title="Climate change impacts on insects can be categorized into two major categories: Gradual long-term change and extreme events that will increase in frequency and severity, while interventions include formal mitigation of change through policy and public approaches which in turn help to reduce impacts in various ways. Credit: <i>Ecological Monographs
Climate change impacts on insects can be categorized into two major categories: Gradual long-term change and extreme events that will increase in frequency and severity, while interventions include formal mitigation of change through policy and public approaches which in turn help to reduce impacts in various ways. Credit: Ecological Monographs (2022). DOI: 10.1002/ecm.1553

In a new scientific review, a team of 70 scientists from 19 countries warned that if no steps are taken to shield insects from the consequences of climate change, it will “drastically reduce our ability to build a sustainable future based on healthy, functional ecosystems.”

Citing research from around the world, the team painted a bleak picture of the short- and long-term effects of climate change on insects, many of which have been in a state of decline for decades. Global warming and extreme weather events are already threatening some insects with extinction—and it will only get worse if current trends continue, scientists say. Some insects will be forced to move to cooler climes to survive, while others will face impacts to their fertility, life cycle and interactions with other species.

Such drastic disruptions to ecosystems could ultimately come back to bite people, explained Anahí Espíndola, an assistant professor of entomology at the University of Maryland and one of the paper’s co-authors.

“We need to realize, as humans, that we are one species out of millions of species, and there’s no reason for us to assume that we’re never going to go extinct,” Espíndola said. “These changes to insects can affect our species in pretty drastic ways.”

Insects play a central role in ecosystems by recycling nutrients and nourishing other organisms further up the food chain, including humans. In addition, much of the world’s food supply depends on pollinators like bees and butterflies, and healthy ecosystems help keep the number of pests and disease-carrying insects in check.

These are just a few of the ecosystem services that could be compromised by climate change, the team of scientists cautioned. Unlike mammals, many insects are ectotherms, which means they are unable to regulate their own body temperature. Because they are so dependent on external conditions, they may respond to climate change more acutely than other animals.

One way that insects cope with climate change is by shifting their range, or permanently relocating to places with lower temperatures. According to one study cited by Espíndola and other scientists, the ranges of nearly half of all insect species will diminish by 50% or more if the planet heats up 3.2°C. If warming is limited to 1.5°C—the goal of the global Paris Agreement on climate change—the ranges of 6% of insects will be affected.

Espíndola, who studies the ways in which species respond to environmental changes over time, contributed to the sections of the paper that address range shifts. She explained that drastic changes to a species’ range can jeopardize their genetic diversity, potentially hampering their ability to adapt and survive.

On the other hand, climate change may make some insects more pervasive—to the detriment of human health and agriculture. Global warming is expected to expand the geographical range of some disease vectors (such as mosquitoes) and crop-eating pests.

“Many pests are actually pretty generalist, so that means they are able to feed on many different types of plants,” Espíndola said. “And those are the insects that—based on the data—seem to be the least negatively affected by climate change.”

The team noted that the effects of climate change are often compounded by other human-caused impacts, such as habitat loss, pollution and the introduction of invasive species. Combined, these stressors make it more difficult for insects to adapt to changes in their environment.

Though these effects are already being felt by insects, it is not too late to take action. The paper outlined steps that policymakers and the public can take to protect insects and their habitats. Scientists recommended “transformative action” in six areas: phasing out fossil fuels, curbing air pollutants, restoring and permanently protecting ecosystems, promoting mostly plant-based diets, moving towards a circular economy and stabilizing the global human population.

The paper’s lead author, Jeffrey Harvey of the Netherlands Institute of Ecology (NIOO-KNAW) and Vrije Universiteit Amsterdam, said in a statement that urgent action is needed to protect insects and the ecosystems they support.

“Insects are tough little critters, and we should be relieved that there is still room to correct our mistakes,” Harvey said. “We really need to enact policies to stabilize the global climate. In the meantime, at both government and individual levels, we can all pitch in and make urban and rural landscapes more insect-friendly.”

The paper suggested ways that individuals can help, including managing public, private or urban gardens and other green spaces in a more ecologically-friendly way—for instance, incorporating native plants into the mix and avoiding pesticides and significant changes in land usage when possible.

Espíndola also stressed the value of encouraging neighbors, friends and family to take similar steps, explaining that it’s an easy yet effective way to amplify one’s impact.

“It is true that these small actions are very powerful,” Espíndola said. “They are even more powerful when they are not isolated.”

Their paper was published in Ecological Monographs.

More information: Jeffrey A. Harvey et al, Scientists’ warning on climate change and insects, Ecological Monographs (2022). DOI: 10.1002/ecm.1553

Provided by University of Maryland 


Explore further

We need to stop thinking of insects as ‘creepy crawlies’ and recognise their keystone role in ecosystems, say scientists

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“Coconut Leaf Wilt Disease could have been controlled sooner if there was cooperation”

Monday, December 5, 2022 – 01:00

Print Edition

Local

Priyan de Silva

Dr. Nayani Arachchige

Fourteen years after being first detected in Sri Lanka, over 340,000 coconut palms identified as diseased, over 313,000 coconut palms cut down and destroyed, and billions of rupees spent on disease control, coconut growers in the Southern Province continue to be plagued by the Weligama Coconut Leaf Wilt Disease (WCLWD)

Coconut Research Institute (CRI) Deputy Director (Research) Dr. Nayani Arachchige said that the CRI together with Coconut Cultivation Board (CCB) and other related stakeholders including law enforcement authorities have managed to contain the disease to the Southern Province and added that if the coconut growers and the community on the whole had been more cooperative, the disease could have been controlled sooner.

The Weligama Coconut leaf Wilt disease is caused by phytoplasmas and transmitted by infective insect vectors, vegetative propagation or grafting of infected planting material to healthy plants, by vascular connections made between infected and uninfected host plants by parasitic plants, and by seed or embryo transmission. Once infected, a coconut palm will die within two years. There is no known cure and cutting down infected trees and incinerating the crowns is the only practical solution to arrest the spread of the disease.

Dr. Arachchige said that at the initial stage of infection, a coconut tree would bear profusely and growers have second thoughts of cutting down the tree even after they have been noticed to do so by the authorities. The delay causes greater harm as more trees in the vicinity are prone to infection and was one reason that containing the disease has taken so long.

The WCLWD was first detected in the Weligama area in 2008, but had spread from Galle to Tangalle. To prevent the disease spreading further, the CRI demarcated a buffer zone three kilometres wide on either side of the A17 trunk road from Galle running through Angulugaha, Henegama, Akuressa, Kamburupitiya, Kirinda – Puhulwella, Hakmana, Walsmulla, Beliatta and ending in Tangalle.

The Government, by gazette notification No. 1542/7 of 24 March 2008, prohibited the transport of any palm species and their live parts out of the demarcated boundary. Although the prohibition was not strictly adhered to due to various restraints, it was fortunate that the disease did not spread to other coconut growing areas.

The Matara district where WCLWD was first detected has borne the brunt of the disease. Figures obtained from the Coconut Cultivation Board show that up to September 30, 2022, 313,857 diseased trees have been identified in the Matara district.

Growers who complied with the order given by the CCB authorities and cut down the diseased trees were paid Rupees 3,000 per tree more as an initiative to cut and destroy the tree rather than compensation as the cost incurred by a grower to tend to a plant until it starts bearing and the loss of produce is very much more.

Due to WCLWD and other factors such as eating of the coconut by Grizzled Giant Squirrels and the Toque macaque, the annual yield in the Matara district had dropped from 121 million nuts in 2011 to 96 million nuts in 2019 and to 73 million nuts in 2020.

Some growers have been compelled to destroy their whole plantation and plant alternate crops as provisions of the Plant Protection Act prohibits planting any type of palm trees in the areas where WCLWD has been detected.

According to the CCB, WCLWD could be fully eradicated in the near future if the growers and public were more cooperative and if the Government would continue to provide adequate funds.

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New Executive Board of the Entomological Federation of Latin America (FELA)

The Entomological Federation of Latin American (FELA) is integrated by nine entomological societies: Sociedad Entomológica de Brasil (SEB), Sociedad Entomológica Argentina (SEA), Sociedad Boliviana de Entomología (SBE), Sociedad Colombiana de Entomología (SOCOLEN), Sociedad Chilena de Entomología (SCHE), Sociedad Entomológica Ecuatoriana (SEE), Sociedad Mexicana de Entomología (SME), Sociedad Panameña de Entomología (SEPAM), and Sociedad Entomológica del Perú (SEP). During the XI Argentinian Congress of Entomology and the XII Latin American Congress of Entomology (La Plata, Buenos Aires, Argentina, October 24–28), FELA held its first ordinary assembly, where representatives of the member societies voted the new Executive Board. Welcomed members of the Board are Juana María Coronado Blanco (President), Bruno Zachrisson (Vice-President), Lucía Claps (Secretary), Norma Nolazco (Vocal), and María Stella Zerbino (Past President). The city of Uberlandia (Minas Gerais, Brazil) was designated to host the XIII Latin American Congress of Entomology (CLAE), that will be held in 2024.

New Executive Board of FELA: Bruno Zachrisson, Lucía Claps, Norma Nolazco, Juana María Coronado Blanco, and María Stella Zerbino.

Submitted by:

Dr. Nora Altier

IAPPS Coordinator Region XV, South America

E-mail: naltier@inia.org.uy

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Feel the Vibe: Study Shows Spotted Lanternflies Sense Acoustic Stimuli

ENTOMOLOGY TODAY  LEAVE A COMMENT

In a new lab study, spotted lanternflies moved toward the source of a nearby 60-hertz vibration. Further field experiments could reveal whether “vibrational trapping” might be a new tool for managing the invasive pest. Spotted lanternflies are known for massing on tree trunks and other surfaces. Chemicals released by the insects’ honeydew may help trigger these conventions. The new research suggests that vibrations may also play a role. (Photo by Richard Gardner, Bugwood.org)

By Ed Ricciuti

Ed Ricciuti

The world of insects is filled with communicative vibrations, some good, some bad. The sound of a male cricket rubbing its wings together, carried through the night air, is good news to females in the mood to mate. Not so the vibrations of an ant struggling in the sandy trap of a hungry antlion larva—for the ant, at least. Like the antlion, an estimated 200,000 species of insects can sense vibrational messages traveling though the ground, water, plants, and other substrates. And, according to new research published in October in the Journal of Economic Entomology, the invasive spotted lanternfly (Lycorma delicatula) may also be one of them.

Researchers at the United States Department of Agriculture (USDA) have found that spotted lanternflies actively respond to substrate-borne vibrational signals broadcast during laboratory experiments. That may be good news for pest managers, who increasingly see acoustic signals as a way to control pests while reducing the use of chemical agents. Research into the role of substrate vibrations on behavior of lanternflies could enable scientists to “develop better tools that rely on modulating their behaviors (attraction, repulsion) for survey, detection, and control,” says Miriam F. Cooperband, Ph.D., entomologist at the USDA Forest Pest Methods Laboratory in Buzzards Bay, Massachusetts, who designed the experiment.

Some insects deliberately produce vibrations, like the cricket’s chirp. Others, like those from a trapped ant, are incidental. Either way, substrate-borne messages can trigger aspects of insect behavior such as mating, predation, avoiding predators, or foraging. Understudied, the role of vibrations that use substrates as a channel for insect communication is receiving increasing interest from researchers, including its potential to modify insect behavior for integrated pest management (IPM).

Pest control researchers are working feverishly to come up with effective IPM for the spotted lanternfly. Since its arrival in Pennsylvania in 2014, the lanternfly (really a planthopper in the infraorder Fulgoromorpha) has spread to more than a dozen other states. With its piecing-sucking mouthparts, it can reach and swill the sap out of more than 100 different plant species, from grapes to hardwoods. The feeding damage significantly stresses the plants, which can lead to decreased health and potentially death.

As the lanternfly feeds, it excretes sugary glop called honeydew, which makes a gooey mess, attracts bees and wasps, and promotes the growth of sooty mold, a gross blanket over ornamental plants, patio furniture, cars, and anything else on which it grows. The honeydew problem is aggravated when lanternflies congregate, as they commonly do.

In a study of how spotted lanternflies (Lycorma delicatula) respond to acoustic stimuli, individuals were placed at the center of a circular surface with a 60-hertz tone broadcast nearby. In these charts, open circles show where the individual lanternflies moved and reached the edge of the circle, and red lines indicate the average direction of all individuals observed. (Length of the red lines indicates magnitude of the average direction as a proportion of the circle radius; the maximum magnitude of the full radius would be obtained if all insects exited the test circle at the same angle.) (Image originally published in Rohde et al 2022, Journal of Economic Entomology)

Spotted lanternflies are becoming famous—or, rather, infamous—for gathering like flash mobs, massing on tree trunks and backyard furniture, even ending up in people’s clothing and entering buildings. Chemicals released by honeydew may help trigger these lanternfly conventions. The new research suggests that vibrations may also play a role in these get-togethers, which occur prior to mating. Their egg masses, which adhere even to the tires of vehicles, enable the spotted lanternfly to travel well.

After hatching, a lanternfly goes through four instars, or stages in nymph development. Nymphs as well as adults attack plants. The USDA experiments were conducted on fourth instars and adults, both of which have receptors on their bodies that sense substrate vibration. Results showed that both were attracted to and walked purposefully toward broadcasts of 60-hertz (Hz) vibroacoustic stimulus. This frequency, the so-called “60-cycle hum,” can interfere with audio equipment. During the experiments, volume was set below the range of human hearing.

The nuts-and-bolts experiments were conducted by USDA technician Isaiah Canlas, alone in a room due to pandemic precautions, with equipment designed by Cooperband, who with the other authors analyzed the results. Lanternflies were placed in an arena floored by white paper atop a plywood platform covered by tulle fabric. The observer was hidden. When the vibrations were broadcast, the insects clustered toward the signal, dispersing when it stopped.

Based on their findings, the USDA team suggests next conducting field studies to monitor vibrations in trees where lanternflies are congregating and mating. Eventually, such studies could perhaps lead to development of what pest control managers call “vibrational trapping.”

Read More

Evidence of Receptivity to Vibroacoustic Stimuli in the Spotted Lanternfly Lycorma delicatula (Hemiptera: Fulgoridae)

Journal of Economic Entomology

Ed Ricciuti is a journalist, author, and naturalist who has been writing for more than a half century. His latest book is called Bears in the Backyard: Big Animals, Sprawling Suburbs, and the New Urban Jungle (Countryman Press, June 2014). His assignments have taken him around the world. He specializes in nature, science, conservation issues, and law enforcement. A former curator at the New York Zoological Society, and now at the Wildlife Conservation Society, he may be the only man ever bitten by a coatimundi on Manhattan’s 57th Street.

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Insects have a weak capacity to adjust their critical thermal limits. Sam England, Author provided (no reuse)

Insects will struggle to keep pace with global temperature rise – which could be bad news for humans

Published: October 3, 2022 11.01am EDT

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  1. Hester WeavingPhD Candidate in Entomology, University of Bristol

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Animals can only endure temperatures within a given range. The upper and lower temperatures of this range are called its critical thermal limits. As these limits are exceeded, an animal must either adjust or migrate to a cooler climate.

However, temperatures are rising across the world at a rapid pace. The record-breaking heatwaves experienced across Europe this summer are indicative of this. Heatwaves such as these can cause temperatures to regularly surpass critical thermal limits, endangering many species.

In a new study, my colleagues and I assessed how well 102 species of insect can adjust their critical thermal limits to survive temperature extremes. We found that insects have a weak capacity to do so, making them particularly vulnerable to climate change.

The impact of climate change on insects could have profound consequences for human life. Many insect species serve important ecological functions while the movement of others can disrupt the balance of ecosystems.

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How do animals adjust to temperature extremes?

An animal can extend its critical thermal limits through either acclimation or adaptation.

Acclimation occurs within an animal’s lifetime (often within hours). It’s the process by which previous exposure helps give an animal or insect protection against later environmental stress. Humans acclimate to intense UV exposure through gradual tanning which later protects skin against harmful UV rays.

One way insects acclimate is by producing heat shock proteins in response to heat exposure. This prevents cells dying under temperature extremes.

A ladybird drinking a speck of water on a narrow leaf.
Insects in warmer environments develop fewer spots to reduce heat retention. mehmetkrc/Shutterstock

Some insects can also use colour to acclimate. Ladybirds that develop in warm environments emerge from the pupal stage with less spots than insects that develop in the cold. As darker spots absorb heat, having fewer spots keeps the insect cooler.

Adaptation occurs when useful genes are passed through generations via evolution. There are multiple examples of animals evolving in response to climate change.

Over the past 150 years, some Australian parrot species such as gang-gang cockatoos and red-rumped parrots have evolved larger beaks. As a greater quantity of blood can be diverted to a larger beak, more heat can be lost into the surrounding environment.

A colourful red-rumped parrot perched on a branch.
The red-rumped parrot has evolved a larger beak to cope with higher temperatures. Alamin-Khan/Shutterstock

But evolution occurs over a longer period than acclimation and may not allow critical thermal limits to adjust in line with the current pace of global temperature rise. Upper thermal limits are particularly slow to evolve, which may be due to the large genetic changes required for greater heat tolerance.

Research into how acclimation might help animals survive exceptional temperature rise has therefore become an area of growing scientific interest.

A weak ability to adjust to temperature extremes

When exposed to a 1℃ change in temperature, we found that insects could only modify their upper thermal limit by around 10% and their lower limit by around 15% on average. In comparison, a separate study found that fish and crustaceans could modify their limits by around 30%.

But we found that there are windows during development where an insect has a greater tolerance towards heat. As juvenile insects are less mobile than adults, they are less able to use their behaviour to modify their temperature. A caterpillar in its cocoon stage, for example, cannot move into the shade to escape the heat.

Exposed to greater temperature variations, this immobile life stage has faced strong evolutionary pressure to develop mechanisms to withstand temperature stress. Juvenile insects generally had a greater capacity for acclimating to rising temperatures than adult insects. Juveniles were able to modify their upper thermal limit by 11% on average, compared to 7% for adults.

But given that their capacity to acclimate is still relatively weak and may fall as an insect leaves this life stage, the impact is likely to be limited for adjusting to future climate change.

What does this mean for the future?

A weak ability to adjust to higher temperatures will mean many insects will need to migrate to cooler climates in order to survive. The movement of insects into new environments could upset the delicate balance of ecosystems.

Insect pests account for the loss of 40% of global crop production. As their geographical distribution changes, pests could further threaten food security. A UN report from 2021 concluded that fall armyworm populations, which feed on crops such as maize, have already expanded their range due to climate change.

A damaged corn crop following an attack by fall armyworms.
The fall armyworm is a damaging crop pest which is spreading due to climate change. Alchemist from India/Shutterstock

Insect migration may also carry profound impacts on human health. Many of the major diseases affecting humans, including malaria, are transmitted by insects. The movement of insects over time increases the possibility of introducing infectious diseases to higher latitudes.

There have been over 770 cases of West Nile virus recorded in Europe this year. Italy’s Veneto region, where the majority of the cases originate, has emerged as an ideal habitat for Culex mosquitoes, which can host and transmit the virus. Earlier this year, scientists found that the number of mosquitoes in the region had increased by 27%.

Insect species incapable of migrating may also become extinct. This is of concern because many insects perform important ecological functions. Three quarters of the crops produced globally are fertilised by pollinators. Their loss could cause a sharp reduction in global food production.

The vulnerability of insects to temperature extremes means that we face an uncertain and worrying future if we cannot curb the pace of climate change. A clear way of protecting these species is to slow the pace of climate change by reducing fossil fuel consumption. On a smaller scale, the creation of shady habitats, which contain cooler microclimates, could provide essential respite for insects facing rising temperatures.

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With Xsect Xtra, Inveragro eliminates pepper pests

Inveragro, located in the valley of San Felipe, Guanajuato, and known for its tradition of producing and drying chili peppers, was having problems with pest control and humidity levels inside the greenhouse. With Xsect Xtra, they were able to reduce the entry of thrips by 50% while increasing their humidity by 15%, resulting in an ideal climate that promotes pepper growth.

Inveragro is a 10-hectare pepper greenhouse that started operations three years ago in the valley of San Felipe, Guanajuato, an area with different challenges for pepper growers due to its semi-arid climate and the presence of insects and pests such as whitefly, thrips, and weevils.

Germán Sandoval Barba, grower at Inveragro, was looking for a climate solution that would help him face these challenges. A year ago, he decided to try Xsect Xtra.

Ideal humid climate = healthier peppers
The pepper is a tropical crop that likes high humidity levels. Ideally the humidity inside a pepper greenhouse should be between 60% and 80%.

During the summer months, humidity inside Inveragro was between 45% and 50%, and it was necessary to keep the windows closed as a way to conserve humidity inside the greenhouse.

“Before installing Svensson’s insect control nets, I was worried that the temperature would rise too much and that it would affect the humidity. Once we tested the nets, the truth is that it was a very positive surprise the results that we had in terms of temperature and humidity”, says Germán Sandoval

Unlike last year when the windows were practically closed, now with Xsect Xtra, the windows are open between 20% and 30%, having a maximum temperature between 32 and 33 degrees. In addition, with Xsect Xtra, the humidity inside the greenhouse increased between 10% and 15%, compared to last year, achieving an ideal humidity between 60% and 75%, which benefits the growth of peppers.

“I thought that I was going to experience disadvantages with this insect control net because, for me, it was more important to sacrifice climate in order to reduce the entry of pests and insects. But to my surprise, I now have a better climate and fewer insects inside the greenhouse,” said Germán Sandoval.

Greenhouses with 50% fewer thrips
One of the biggest challenges for Germán is the entry of pests, and one way to control this problem is through hermeticity. Inveragro has four full-time employees dedicated exclusively to supervising any failure in the hermeticity of the greenhouses. “When I started looking for options to improve our hermeticity, I discovered the Svensson insect control nets, which would help us to improve our conditions,” says Germán Sandoval.

Before installing Xsect Xtra, during the fifth week of the production cycle, thrips were already seen inside the greenhouse, and it was necessary to apply pesticides and/or agrochemicals prior to the release of the biological control. “Now I can release the biological control we use Orius to control thrips, without pesticides and/or agrochemicals applications that could damage the biological control program,” says Germán, “since the installation of Xsect Xtra, 50% fewer thrips have entered the greenhouse”.

Powdery mildew was another climate problem at Inveragro, and it was necessary to apply agrochemicals at least once a week. During the first year with Svensson’s insect control net, Germán continued with the same program, but no powdery mildew was found inside the greenhouse.

“I’ve already modified my program for this year. I’m only going to apply preventive products every 15 days, which reduces by 50% the cost of powdery mildew throughout the year because now I have better climate conditions in terms of humidity, which is more controllable and promotes pepper growth”.

Germán has also noticed improvements in the beneficial program used to control thrips. He used to have 4 Orius per square meter, and this year he only has three orius per square meter, which means savings in this year’s beneficials budget.

“What Xsect Xtra has given me is improved humidity, fewer pests, and reduced phytosanitary diseases.”
 
Finally, Germán shared the following advice for all pepper growers: “I would tell growers who are afraid to try these nets not to be afraid. In the beginning, I hesitated, but it is something that will help them. What it can generate in the climate is minimal and what it can help them in the phytosanitary issue is very broad. The net pays for itself”.

For more information:
Ludvig Svensson

info@ludvigsvensson.com www.ludvigsvensson.com    

Publication date: Mon 14 Nov 2022

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HLB and Canker Incidence Increasing in Brazil

 SEPTEMBER 27, 2022 BRAZIL DISEASES

The average incidence of HLB rose from 22.37% in 2021 to 24.42% in 2022 in Brazil’s citrus belt, an annual survey by Fundecitrus shows. That’s an increase of 9.16%.

HLB
Inadequate psyllid control is a major reason that HLB is on the rise in Brazil.

In the regions of Brotas, Limeira and Porto Ferreira, where the incidence was already high in previous years, HLB increased to even more worrying levels of 49.41%, 70.72% and 74.05%, respectively. HLB is also commonly called greening disease.

“We are seeing the disease grow at a worrying speed,” said Fundecitrus General Manager Juliano Ayres. “However … the results obtained in properties in regions that have registered a decline or stabilization of the disease reinforce our confidence that the measures to combat greening are effective. This has always been the way and always will be, until we manage to reach plants resistant to the disease. However, we need more efforts” to control HLB.

REASONS FOR HLB INCREASE

Fundecitrus reported that most regions have a favorable climate for HLB. Additionally, most regions have a high density of orchards and a large number of medium and small properties. Those factors make it difficult to coordinate joint actions for the regional management of the disease.

Most importantly though, Fundecitrus stated, in most orchards in production, diseased trees are not being eliminated, and control of HLB-spreading psyllids has been inadequate. Inefficient spraying has also contributed to the increase in HLB.

“This work has not been done with the necessary frequency, especially in the sprouting seasons,” said Fundecitrus researcher Renato Bassanezi. “Failures in spray coverage have also been observed, mainly at the top of the canopy of adult trees and in dense orchards.”

Also impairing the effectiveness of psyllid control is the repetitive use of insecticides from the pyrethroid group without adequate rotation with insecticides with other modes of action, Fundecitrus stated. That has led to the detection of psyllid resistance to the pyrethroid group in some places.

BIG JUMP IN CANKER

The Fundecitrus survey also showed growth in the incidence of canker in orchards. According to the new survey, the disease is present in 18.77% of the trees, an increase of 74.44%.

Canker accounts for just 0.21% of fruit drop across the citrus belt. The low rate is related to studies carried out by Fundecitrus that adjust the use of copper in the management of the disease. That adjustment doesn’t impact the effectiveness of the treatment and generates savings of 56% in the amount of product used per hectare.

CVC REMAINS LOW

The incidence of CVC remains low throughout Brazil’s citrus industry, with an incidence of just 0.80% in 2022. About 20 years ago, the disease was present in 46% of the trees. The significant reduction is mainly due to the evolution of research and management practices disseminated by Fundecitrus.

Source: Fundecitrus

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New Extension website helps solve pest and disease problems

November 10, 2022

CORVALLIS, Ore. – A new Oregon State University Extension Service website provides a trove of science-based solutions for garden pests, weeds and disease problems in one easy-to-navigate place.

The project was shepherded by Weston Miller, an OSU Extension community horticulturist who got the ball rolling six years ago when collaborators expressed interest and provided funds for what would become the Solve Pest and Weed Problems website.

“Our stakeholders – Metro, the East and West Multnomah Soil and Water Conservation Districts and the city of Gresham – challenged OSU to create a user-friendly pest management resource for the public. Part of my job was to figure out the resources Extension has and pull them together in one place,” Miller said.

Solve Pest and Weed Problems focuses specifically on the Pacific Northwest and prioritizes low-risk approaches. Based on feedback, Miller incorporated household pests, invasive plants, pesticide safety and pollinators, as well as pests and diseases.

“We did extensive planning, including community involvement, user testing, feedback from agencies, nonprofits and many more,” Miller said. “We were able to hire a professional to design the website and do graphic design. Gradually, we kept improving it and building on it.”

The peer-reviewed content is presented in categories with information presented below photos. Clicking on the photo takes you to another page that offers information about identification, look-alikes and specific information on control. High-quality, color photos illustrate each subject.

After compiling Extension resources from sources like the Pacific Northwest Pest Management Handbooks, entries are written by Miller with help from Signe Danler, OSU Extension Master Gardener online horticulture instructor, and other OSU experts. The content is peer reviewed by the OSU Department of Horticulture in the College of Agricultural Sciences. Miller edits the content and posts it on the website. More entries will be added in the future.

To provide more information, the website features links to other OSU Extension resources, as well as to other university-level, science-based sources.

“We hope that people both public and private property managers find practical pest management and prevention,” Miller said. “We want people to use it to make informed decisions for their gardens and public spaces.”

To do that, users will find sections on using less pesticides, pesticide safety, organic pesticides and preventive measures like planting in the right place for the size, water needs, exposure and soil for each plant. Using good selection criteria keeps plants healthy and a healthy plant can fend off pests and diseases, Miller said. The hope, he added, is that people will use less pesticides – or if they do, in a safe manner.

Weeds – from both sides of the Cascades and from throughout the state – get attention. Examples include cheatgrass in eastern and western Oregon; pampas grass on the coast; and tree of heaven, a species of concern statewide. The website includes guides about how to manage landscapes without pesticides or herbicides and 20 pages of pesticide safety guidance.

“We’re putting together material that’s not available in one place with such complete information,” Miller said. “We are super grateful to our partnerships in the broader community who were looking to have a durable information service to meet a fairly defined need. I’m proud of what we’ve accomplished.”

About the OSU Extension Service: The Oregon State University Extension Service shares research-based knowledge with people and communities in Oregon’s 36 counties. OSU Extension addresses issues that matter to urban and rural Oregonians. OSU Extension’s partnerships and programs contribute to a healthy, prosperous and sustainable future for Oregon.

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NZ: Stink bugs at the border

As well as fruit flies, we are currently in the high-risk season for Brown Marmorated Stink Bug (BMSB). The season started in September and to date there have been two BMSB finds, compared to six for the same period last season. Both finds were at the border, by Quarantine Officers at Auckland Airport.

One of the finds was at a search bench where passengers from multiple fights from the USA were being processed; and the other was on an aircraft which had just arrived from South Korea.

More detail can be read in the latest KVH risk update for BMSB.

The risk period for BMSB stretches throughout the summer so remember to be on the lookout and report anything unusual. Information and videos about the risks this bug poses are available on the KVH website.

Publication date: Thu 10 Nov 2022

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