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Archive for the ‘Control tactics’ Category

Scientific Reports volume 12, Article number: 15706 (2022) 

Abstract

Beauveria bassiana and Metarhizium anisopliae are two of the most important and widely used entomopathogenic fungi (EPFs) to control insect pests. Recent studies have revealed their function in promoting plant growth after artificial inoculation. To better assess fungal colonization and growth-promoting effects of B. bassiana and M. anisopliae on crops, maize Zea mays seedlings were treated separately with 13 B. bassiana and 73 M. anisopliae as rhizosphere fungi in a hydroponic cultural system. Plant growth indexes, including plant height, root length, fresh weight, etc., were traced recorded for 35 days to prove the growth promoting efficiency of the EPFs inoculation. Fungal recovery rate (FRR) verified that both B. bassiana and M. anisopliae could endophytically colonize in maize tissues. The recovery rates of B. bassiana in stems and leaves were 100% on the 7th day, but dropped to 11.1% in the stems and 22.2% in the leaves on the 28th day. Meanwhile, B. bassiana was not detected in the roots until the 28th day, reaching a recovery rate of 33.3%. M. anisopliae strains were isolated from the plant roots, stems and leaves throughout the tracing period with high recovery rates. The systematical colonization of B. bassiana and M. anisopliae in different tissues were further corroborated by PCR amplification of fungus-specified DNA band, which showed a higher detection sensitivity of 100% positive reaction. Fungal density comparing to the initial value in the hydroponic solution, dropped to be well below 1% on the 21st day. Thus, the two selected entomopathogenic fungal strains successfully established endophytic colonization rather than rhizospheric colonization in maize, and significantly promoted its growth in a hydroponic cultural system. Entomopathogenic fungi have great application potential in eco-agricultural fields including biopesticides and biofertilizers.

Read on: https://www.nature.com/articles/s41598-022-19899-7


Wednesday, 21 September 2022 00:51:45

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ENTOMOLOGY TODAY  

The Mexican fruit fly (Anastrepha ludens) is one of the world’s most damaging insect pests. A key method for managing them is the sterile insect technique, in which sterile male flies are mass-reared and released into the wild, whereupon they mate with wild females, which then fail to produce offspring. Determining the precise age of mass-reared fruit flies is a critical step in the sterile insect technique, and researchers in Mexico have applied machine-learning algorithms that can accurately measure the age of fruit fly pupae to properly time irradiation. (Photo by Andrés Diaz Cervantes)

By Diana Pérez-Staples, Ph.D., and Horacio Tapia-McClung, Ph.D.

Horacio Tapia-McClung, Ph.D.

Diana Pérez-Staples, Ph.D.

Two of the world’s most damaging pests are the Mediterranean fruit fly (Ceratitis capitata) and the Mexican fruit fly (Anastrepha ludens), causing billions of dollars in damage to agriculture. Fortunately, the sterile insect technique is currently used as part of area-wide integrated management programs to control these flies is certain regions of the world.

The sterile insect technique (SIT) is a type of birth control, consisting in rearing millions of these flies in factories, irradiating them with X or gamma rays to make them sterile, and then releasing them in areas where the pests are present. When the sterile males mate with wild females, the females will not have fertile eggs to lay in the fruits. Thus, population levels are decreased. The SIT has good green credentials because it only targets the pest species, it does not introduce foreign genetic material into the population, and it reduces the use of insecticides.

The irradiation process in SIT is key to its success. For tephritid flies, irradiation is usually carried out a couple of days before the pupae emerge as adults. If pupae are irradiated too soon or too late in their development process, this can lead to problems in mobility and behavior as adults. However, even during controlled conditions, pupae can vary in their development time. Thus, one of the tests that are carried out pre-irradiation is to determine the physiological age of the pupae.

Currently, at these fruit fly factories throughout the world, technicians must determine the correct time to irradiate by taking a sample of pupae, removing the pupal case to expose the eyes, and then checking the eye color against a color chart. This can be laborious and prone to human error, as it depends on the skill, experience, and expertise of the technician, as well as natural biases in color interpretation. The technicians can get tired from this repetitive work, while sick days and vision problems could also cause variations in the correct determination.

Mexican fruit fly (Anastrepha ludens) pupae
fruit fly pupae eye colors

Artificial Intelligence to the Rescue

At the Universidad Veracruzana, in collaboration with the Secretary of Agriculture of Mexico (Programa Operativo de Moscas, DGSV-SENASICA), we teamed up with experts in artificial intelligence to develop methods based on algorithms that can accurately determine the age of a pupa from a digital image captured with a common mobile device. We share our results in a new article published this month in the Journal of Economic Entomology.

Iván González-López

For this, and as part of his Ph.D. at the Facultad de Ciencias Agrícolas of the Universidad Veracruzana, Iván González-López, currently based at the IAEA-FAO Entomology Laboratory in Austria, took photographs of the exposed eyes of pupae of both Mediterranean fruit flies and Mexican fruit flies. We chose pupae that still had a few days to emerge and deliberately took rough photographs that did not have perfect lighting conditions or focus. In fact, they were taken quickly and with a mobile phone.

Then, as a part of her master’s research at the Laboratorio Nacional de Informática Avanzada in Xalapa Veracruz, Georgina Carrasco processed the images with a program that was trained to detect the eye area in the photograph and crop it. Afterward, using the correct answers from a technician at the factory, another algorithm was trained through a supervised machine-learning method known as transfer learning, to accurately determine the age of the pupae.

We found that algorithms based on a neural network architecture known as Inception v1 correctly identified the physiological age of maturity at two days before emergence, with a 75 percent accuracy for the Mexican fruit fly and 83.16 percent for Mediterranean fruit fly, respectively. This method is not perfect for sure, and it still requires a technician to dissect the pupae and take photographs, but it is a promising approximation of how supervised machine learning and artificial intelligence can be used to help uncertainty in decisions about when to irradiate. The level of accuracy may also be improved as more pictures are taken and provided for the algorithm to learn from.

The next steps will be to develop software that could easily be used by technicians as well as to train these algorithms with other tephritid pest species currently controlled through SIT. Certainly, it highlights that there can be some exciting collaborations between entomologists and artificial intelligence researchers.

Read More

Determination of the Physiological Age in Two Tephritid Fruit Fly Species Using Artificial Intelligence

Journal of Economic Entomology

Diana Pérez-Staples, Ph.D., is a research professor at the Institute of Biotechnology and Applied Ecology at the Universidad Veracruzana, in Xalapa, Veracruz, Mexico. Email: diperez@uv.mxHoracio Tapia-McClung, Ph.D., is a research professor at the Artificial Intelligence Research Institute at the Universidad Veracruzana also in Xalapa. Email: htapia@uv.mx.

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Wednesday, 28 September 2022 08:23:46

Grahame Jackson posted a new submission ‘Sugary poo could be used to lure destructive plant pests to their doom’

Submission

Sugary poo could be used to lure destructive plant pests to their doom

Newswise

Male spotted lanternflies are strongly attracted to smell of honeybee produced by male conspecifics
by Frontiers

Spotted lanternflies communicate through their smelly excretions  ̶  called honeydew, reports a new study in Frontiers in Insect Science. This invasive species has been impacting crops in the northeastern US, but little is known about how these insects locate each other for reproduction or feeding. According to this latest research, the insects’ honeydew emits several airborne chemicals that attract other lanternflies. Surprisingly, these effects are sex-specific, which may be the first known case of such signals in insects known as planthoppers.

“This research is important because the first step to managing any pest is to understand their biology and behavior,” said Dr Miriam Cooperband of the United States Department of Agriculture Animal and Plant Health Inspection Service, Plant Protection and Quarantine Division (USDA APHIS PPQ) in the US. “As we learn more about the behavior of the spotted lanternfly, we hope to find a vulnerability that we can use to develop pest management tools to reduce its population and spread.”

Attractive scents

Although these insects are known to leave their excretions throughout the understory, they have the peculiar habit of coming together in huge numbers on only select tree trunks. Other tree trunks are mysteriously left untouched. These multitudes of lanternflies can secrete so much honeydew that the surface of the tree becomes white and frothy, as well as emitting a smell of fermentation.

To study the signals sent by these excretions, Cooperband and her collaborators collected honeydew samples separately from male and female lanternflies in the field, to test in the lab. The researchers then gave lanternflies a choice between areas with or without the different types of honeydew to see what attracted them. 

Surprisingly, males were strongly attracted to male honeydew, while both males and females were only slightly attracted to female honeydew. Although it’s still unclear what would cause this behavior, this is consistent with observations of how these insects behave in the field.

The team went on to analyze the different components of the honeydew to determine which produced the strongest signals. Five molecules were tested for attraction and found to have specific sex-attractant profiles. Two molecules called benzyl acetate and 2-octanone attracted both sexes, one molecule called 2-heptanone attracted only males, one molecule 2-nonanone attracted only females and one molecule, 1-nonanol, repelled females, but not males.

Pest control

These findings are just the beginning for better understanding how to potentially control this invasive pest. There are many more questions, such as whether there are seasonal variations in this behavior, and whether there are interactions with microbes in the honeydew that produce the necessary chemicals.

“Spotted lanternfly behavior and communication is quite complex, and this is only the tip of the iceberg. In addition to our work studying chemical signals, such as those in honeydew, we are also interested in the role of substrate vibrations in their communication system,” said Cooperband. “Future research might focus on understanding how they locate each other when they gather and find mates using multiple types of signals.”

Original paper: https://www.frontiersin.org/articles/10.3389/finsc.2022.982965/full


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UAF VC Urges Scientists To Discover New Biological Control For Parthenium

 Sumaira FH  Published September 09, 2022 | 07:48 PM

UAF VC urges scientists to discover new biological control for Parthenium

University of Agriculture Faisalabad (UAF) Vice Chancellor Prof Dr Iqrar Ahmad Khan has urged agricultural scientists to discover new biological control for Parthenium as it is spreading at an alarming rate across the country

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FAISALABAD, (UrduPoint / Pakistan Point News – 9th Sep, 2022 ) :University of Agriculture Faisalabad (UAF) Vice Chancellor Prof Dr Iqrar Ahmad Khan has urged agricultural scientists to discover new biological control for Parthenium as it is spreading at an alarming rate across the country.

He was addressing an international seminar on “Biological Control of Parthenium hysterophorus in Pakistan using stem boring weevil (Listronotus setosipennis)”, organised by the university in collaboration with the CABI Regional Bioscience Centre Pakistan.

He said that Parthenium was spreading rapidly both in rural and urban landscapes in the country after crossing continents. It was highly-invasive due to its prolific seed production, flower production within four weeks of germination, tolerance to varying climatic conditions, and the production of allelochemicals that affect the growth of nearby plants.

He said that agri scientists were duty bound accelerate their efforts for control Parthenium in addition to creating awareness among the farming community about destructive effects of this weed so that it could be controlled at maximum extent.

Dr. Philip Weyl, Weed Biocontrol Specialist from CABI Switzerland during his address said that Listronotus was a natural enemy of Parthenium, from the weed’s native range of Central America. Listronotus was a nocturnal weevil that layed its eggs primarily in the flowers of Parthenium where newly hatched larvae tunnel into the stem and continue to feed, eventually exiting at the base of the stem to pupate in the soil. Several larvae feeding in the stem can kill Parthenium rosettes and mature plants.

Pro-Vice Chancellor UAF Prof Dr Anas Sarwar Qureshi also addressed the seminar and called for innovative approaches to address the issues of the agricultural sector.

He said that excessive usage of chemicals on crops was creating health and environmental hazards. He said that adoption of latest scientific trends was need of the hour to cope with agricultural challenges at national level because this sector was directly linked to poverty alleviation.

Chairman Entomology UAF Prof Dr Sohail Ahmad highlighted the importance of research needed around the biocontrol of parthenium and other invasive weeds.

He said that the country faced the catastrophe due to heavy floods in which we had lost vast range of agriculture. The university had also mapped out a comprehensive plan to rehabilitate this sector in flood hit areas, he added.

Abdul Rehman from CABI said that keeping in view the destructive impacts of Parthenium weed, CABI initiated a biological control programme in Pakistan in 2017. For this purpose, CABI’s established a new quarantine laboratory at its Rawalpindi centre in Pakistan to enhance its capabilities to manage Parthenium weed.

The new quarantine facility allowed scientists to investigate a range of biological control options including the stem boring weevil Listronotus setosipennis.

Dr. Ijaz Ashraf from UAF shared updates on an awareness campaign for control of Parthenium hysterophorus in Pakistan and said that university students were on front foot to sensitize stakeholders and communities on negative impacts of Parthenium.

He vowed that such awareness-raising interventions around invasive species management and other agricultural challenges would be continued in close collaboration with CABI.

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Biopesticides and Biocontrols 

Could biocontrol solve the papaya mealybug problem for Ugandan farmers?

   Delhi Bureau  0 Comments CABI  4 min read

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14 September 2022, Uganda: Papaya mealybug, Paraccous margniatus, is native to Central America but has spread rapidly in invaded countries. It was detected in Uganda in 2021 where it has the potential to affect the production and quality of papaya and other host crops.

Typically, mealybugs are not pest problems in the countries they are native to because naturally occurring parasitoids and predators keep their numbers in check. The most serious outbreaks occur when mealybugs are introduced accidentally to new countries without natural enemies.

Papaya mealybug spread

The trade in live plant material, such as papaya fruits and seedlings, has accidentally accelerated the spread of papaya mealybug outside its native range. This pest threatens food and nutrition security and adversely affects the safe trade and competitiveness of the agricultural sector for many countries.

Without natural enemies to manage outbreaks, farmers often turn to pesticides. The lack of registered pesticides results in farmers using highly hazardous chemicals that are not only ineffective but can negatively impact native insect biodiversity such as pollinators and natural enemies of pests. A more ecologically sound approach to management is the use of biological control.

Rapid Rural Appraisal of papaya mealybug

As part of the PlantwisePlus programme, CABI in collaboration with the National Agricultural Research Organisation (NARO, Uganda), conducted a Rapid Rural Appraisal (RRA) of papaya mealybug in Uganda. The appraisal sought to gain an understanding of the presence, distribution, and impact of papaya mealybug in Uganda as well as farmers’ management practices. The evaluation also assessed farmers’ willingness to adopt and use biocontrol and their information requirements around biocontrol products.

Information from the appraisal will be used to design an integrated management strategy for papaya mealybug as well as help target community-level communications.

A major cash crop

The seventeen focus group discussions brought together papaya growers from four districts: North District (Lira), Central District (Kayunga, Luwero and Mukono). The districts captured a diversity of farming systems, agro-ecological zones, and agricultural potential. Papaya is a major cash crop for farmers in these districts, in addition to pineapple and traditional cash crops such as coffee. The average farmer cultivates the crop on 0.75-2.5 acres.

The participants confirmed papaya mealybug is already widespread in all four districts where it causes damage to several crops, not just papaya. Farmers started observing the pest between 2017 and 2019 with most saying it is a serious pest that can cause up to 100% crop loss. The official pest reporting to IPPC took place in 2021.

Papaya mealybug management

Farmers mainly attributed the papaya mealybug outbreaks to low productivity and poor-quality fruits. They observed that trees take longer to bear fruit and when they do, they only last one season compared to an average of 4 before. It was estimated that before the pest invaded, farmers obtained UGX 6-8 million/acre each season (£1,800), but currently only obtain UGX 1 million/acre each season (£230).

Regarding management options, commercial farmers reported using pesticides to deal with outbreaks. However, managing papaya mealybugs with pesticides is not always successful due to the pest’s waxy covering. In addition, misuse and/or improper use of these pesticides exacerbate pest problems by reducing beneficial organisms and natural enemies and negatively impacting biodiversity, human health and environmental safety. Further, some farmers don’t observe pre-harvest intervals, thus toxic substances are likely to enter the human food chain posing long-term health risks to consumers and the environment.

Sustainable options

Biological control represents a sustainable and effective management option, however, the farmers interviewed had mixed views on the method and the efficacy of the parasitoid in Uganda’s agroecologies. This highlights the importance of proper testing and community-level communications before the introduction of exotic natural enemies. Farmer and community engagement, and mass awareness are key in pest identification and management, especially with the promotion of unfamiliar pest management options. Extension in particular plays a vital role in the research and advancement of low-risk options.

However, one of the main takeaways from the appraisal was farmers’ papaya problems extend beyond papaya mealybug. Farmers reported other associated viral and bacterial diseases causing challenges, including bunchy top disease and leaf necrosis. As such, it is important that researchers assess the economic damage, effect and losses due to papaya mealybug and the associated pests and diseases before releasing biological control parasitoids.

Implementing a biocontrol programme

The PlantwisePlus programme is now looking at the activities required for the implementation of the biocontrol programme in Uganda. In particular, they are developing extension and farmer training manuals to cover papaya crop integrated pest management. These will include papaya mealybug as well as other pests affecting papaya production in the country. In addition, continuous community engagement and mass awareness campaigns will help farmers and their communities manage this highly destructive pest in a more sustainable way. 

PlantwisePlus is working to reduce the reliance on high-risk farm inputs that have adverse effects on human health and biodiversity. By implementing biological control programmes, PlantwisePlus is responding to the challenge and working to improve livelihoods through sustainable approaches to crop production.

Also Read: Tractor sale in India lowest in two months; 32 percent down in August 2022

(For Latest Agriculture News & Updates, follow Krishak Jagat on Google News)

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Could biocontrol solve the papaya mealybug problem for Ugandan farmers?

Papaya mealybugParaccous margniatus, is native to Central America but has spread rapidly in invaded countries. It was detected in Uganda in 2021 where it has the potential to affect the production and quality of papaya and other host crops.

Papaya
Papaya fruit

Typically, mealybugs are not pest problems in the countries they are native to because naturally occurring parasitoids and predators keep their numbers in check. The most serious outbreaks occur when mealybugs are introduced accidentally to new countries without natural enemies.

Papaya mealybug spread

The trade in live plant material, such as papaya fruits and seedlings, has accidentally accelerated the spread of papaya mealybug outside its native range. This pest threatens food and nutrition security and adversely affects the safe trade and competitiveness of the agricultural sector for many countries.

Without natural enemies to manage outbreaks, farmers often turn to pesticides. The lack of registered pesticides results in farmers using highly hazardous chemicals that are not only ineffective but can negatively impact native insect biodiversity such as pollinators and natural enemies of pests. A more ecologically sound approach to management is the use of biological control.

Rapid Rural Appraisal of papaya mealybug

As part of the PlantwisePlus programme, CABI in collaboration with the National Agricultural Research Organisation (NARO, Uganda), conducted a Rapid Rural Appraisal (RRA) of papaya mealybug in Uganda. The appraisal sought to gain an understanding of the presence, distribution, and impact of papaya mealybug in Uganda as well as farmers’ management practices. The evaluation also assessed farmers’ willingness to adopt and use biocontrol and their information requirements around biocontrol products.

Information from the appraisal will be used to design an integrated management strategy for papaya mealybug as well as help target community-level communications.

Papaya mealybug on fruit
Papaya mealybug on a papaya fruit

A major cash crop

The seventeen focus group discussions brought together papaya growers from four districts: North District (Lira), Central District (Kayunga, Luwero and Mukono). The districts captured a diversity of farming systems, agro-ecological zones, and agricultural potential. Papaya is a major cash crop for farmers in these districts, in addition to pineapple and traditional cash crops such as coffee. The average farmer cultivates the crop on 0.75-2.5 acres.

The participants confirmed papaya mealybug is already widespread in all four districts where it causes damage to several crops, not just papaya. Farmers started observing the pest between 2017 and 2019 with most saying it is a serious pest that can cause up to 100% crop loss. The official pest reporting to IPPC took place in 2021.

Papaya mealybug management

Farmers mainly attributed the papaya mealybug outbreaks to low productivity and poor-quality fruits. They observed that trees take longer to bear fruit and when they do, they only last one season compared to an average of 4 before. It was estimated that before the pest invaded, farmers obtained UGX 6-8 million/acre each season (£1,800), but currently only obtain UGX 1 million/acre each season (£230).

Regarding management options, commercial farmers reported using pesticides to deal with outbreaks. However, managing papaya mealybugs with pesticides is not always successful due to the pest’s waxy covering. In addition, misuse and/or improper use of these pesticides exacerbate pest problems by reducing beneficial organisms and natural enemies and negatively impacting biodiversity, human health and environmental safety. Further, some farmers don’t observe pre-harvest intervals, thus toxic substances are likely to enter the human food chain posing long-term health risks to consumers and the environment.

Papaya on a farm infected with papaya mealybug
Papaya on a farm infected with papaya mealybug

Sustainable options

Biological control represents a sustainable and effective management option, however, the farmers interviewed had mixed views on the method and the efficacy of the parasitoid in Uganda’s agroecologies. This highlights the importance of proper testing and community-level communications before the introduction of exotic natural enemies. Farmer and community engagement, and mass awareness are key in pest identification and management, especially with the promotion of unfamiliar pest management options. Extension in particular plays a vital role in the research and advancement of low-risk options.

However, one of the main takeaways from the appraisal was farmers’ papaya problems extend beyond papaya mealybug. Farmers reported other associated viral and bacterial diseases causing challenges, including bunchy top disease and leaf necrosis. As such, it is important that researchers assess the economic damage, effect and losses due to papaya mealybug and the associated pests and diseases before releasing biological control parasitoids.

Implementing a biocontrol programme

The PlantwisePlus programme is now looking at the activities required for the implementation of the biocontrol programme in Uganda. In particular, they are developing extension and farmer training manuals to cover papaya crop integrated pest management. These will include papaya mealybug as well as other pests affecting papaya production in the country. In addition, continuous community engagement and mass awareness campaigns will help farmers and their communities manage this highly destructive pest in a more sustainable way. 

PlantwisePlus is working to reduce the reliance on high-risk farm inputs that have adverse effects on human health and biodiversity. By implementing biological control programmes, PlantwisePlus is responding to the challenge and working to improve livelihoods through sustainable approaches to crop production.

About PlantwisePlus

PlantwisePlus is supported by contributions from the UK Foreign, Commonwealth and Development Office, the Swiss Agency for Development and Cooperation, the Netherlands Ministry of Foreign Affairs and the European Commission (DG INTPA).

PapayaPapaya mealybugParaccous margniatusUgandaplant healthplant pestsplantwiseplus

Agriculture and International DevelopmentCrop healthInvasive species

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Sky Islands: Isolated Mountaintops Teem With Unique Insect Communities

ENTOMOLOGY TODAY  LEAVE A COMMENT

For a study of the communities of parasitic wasps on mountains in the Interior Highlands of Arkansas, one of the sites chosen was Mount Magazine State Park in Arkansas, which rises 709 meters (2,326 feet) above sea level. With cooler, wetter climates than lowlands nearby, such each feature their own communities of parasitic wasps—and likely other insects—that differ from the insect fauna found on other mountains and in the surrounding valleys, according to a new study published in August in Environmental Entomology. (Photo courtesy of Allison Monroe)

By Ed Ricciuti

Ed Ricciuti

It’s not quite Sir Arthur Conan-Doyle’s Lost World of dinosaurs, but the insect life found by scientists atop so-called “sky islands” in Arkansas ranks as truly unique.

“Sky island” is a term popularized in the 1960s to describe isolated mountains with environments markedly different than that of surrounding lowlands. Conan-Doyle prefigured such environments in his story about an expedition that explored a plateau rising above jungle, where prehistoric dinosaurs, reptiles and “ape men” had survived the ages.

Although not as dramatic as dinosaurs, isolated endemic populations of animals of any size excite scientists. According to a study published in August in Environmental Entomology, such distinct assemblages of insects in the order Hymenoptera (sawflies, bees, wasps, and ants) live atop uplands in Oklahoma, Arkansas, Missouri, and Illinois called the Interior Highlands.

The study, by student researchers at Hendrix College in Conway, Arkansas, focused on parasitic wasps inhabiting three mountains, but the results can be extrapolated to other sky islands in the region and their insects in general, the researchers say.

“Given that each sky island in our study showed unique community characteristics of Hymenoptera, it is reasonable to predict that other insects follow the same pattern,” the authors write. Mountains studied were Petit Jean Mountain at 253 meters (830 feet) in elevation, Mount Magazine at 709 meters (2,326 feet) and Rich Mountain at 747 meters (2,451 feet).

overlook
field site

Parasitic Hymenoptera are a multitudinous group, with 50,000 or so identified species and perhaps millions in all. Typically, they parasitize other insects by laying their eggs in host eggs, larvae, or pupae. They are of immense ecological importance because they are fine-tuned to specific hosts, including many pest species, which they can regulate, like natural pest control managers. “We chose parasitic Hymenoptera as our focal group because they are considered bioindicators of broader diversity patterns, especially those of other insects,” the authors write.

The Interior Highlands, centered in Missouri and Arkansas and including the Ouachita Mountains and Ozark Plateau, were chosen as a study site because they have been above sea level for 320 million years, likely serving as a refuge for ecological communities avoiding the impact of the Pleistocene glaciers. The region is the only major mountainous area between the Appalachians and the Rockies, covering much more area than the Black Hills of South Dakota. Typical of the Interior Highlands, Mount Magazine is 10 degrees Fahrenheit cooler than normal temperatures in the landscape down below and wet, with an annual rainfall of 54 inches. Crowned with upland hardwood and upland pine-hardwood forests, these mountains rise from grasslands, with vegetation ranging from tallgrass prairie to lowland pine-hardwood and bottomland hardwood forests.

Much of the area where the research was conducted lies in state and federal lands. Sweating in the hot summer sun, the research team trekked along hiking trails from grasslands into woodlands. They set up traps, then collected insects from them.

“Though evidence is accumulating that the Interior Highlands host unique species relative to other areas of the North American continent, there is less known about how mountaintops within the region compare in terms of biodiversity,” the researchers write. “We used parasitic Hymenoptera to explore biodiversity patterns across high elevation areas in Arkansas to determine whether these patterns are similar to those exhibited by other sky island regions.”

malaise trap
research team

Each mountaintop had its distinct community of parasitoid species, indicating that the same applies to Hymenoptera in general and even to other groups of insects. On a given mountaintop, communities differed stratigraphically, with those on the ground distinct from those in the forest canopy.

The results of the study suggest the need for additional research. “Our study suggests that these highland areas are important regions of North American biodiversity and that they should be evaluated individually for conservation efforts in order to preserve their distinctive community structure,” the authors write.

Elaborating on the study, lead author Allison Monroe, says, “This study is important for a variety of reasons. Parasitic wasps are deeply important to our environment but are often overlooked if not deeply hated.”

Monroe, now a Ph.D. candidate at the Oregon State University College of Forestry, says, “Arkansas is an incredibly biodiverse state with high rates of agricultural production, yet little research exists on insect biodiversity trends and their applied impacts on diverse land management strategies within this system. We hope that this paper brings to light the extraordinary diversity housed in Arkansas, the importance of insect biodiversity more broadly, and the significance of parasites in our pursuits of nature conservation.”

Read More

Biodiversity of Parasitic Hymenoptera Across Sky Islands of Arkansas, United States

Environmental 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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Researchers just made it easier—and cheaper—to confuse crop pests

Plant that helps produce behavior-changing pheromones could boost environmentally friendly pest control

A diamondback moth on a leaf
The antennae of the diamondback moth are hypersensitive to airborne mating hormones, which makes them vulnerable to nontoxic pest control. HUANGLIN/ISTOCK

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Each year, pests eat more than one-fifth of the crops grown around the world. Many farmers turn to insecticides to protect their harvest, but some opt for a gentler approach: They perfume their crops with behavior-influencing chemicals called pheromones that can confuse insects and prevent them from finding mates.

But the high price of pheromones—commercial products can cost $400 per hectare—has prevented the widespread adoption of the tactic. Now, a new, cheaper method of manufacturing artificial pheromones could allow more farmers to add this weapon to their arsenals.

“It could revolutionize how pheromones are produced for crop protection,” says Lukasz Stelinski, an entomologist at the University of Florida, Gainesville, who was not involved in the work. “I expect that it’s going to catch on and make pheromone disruption much cheaper and easier to apply in practice.”

Farmers worldwide use more than 400,000 tons of insecticide annually. These pesticides can harm farm workers and cause collateral damage to pollinators and other wildlife. Meanwhile, insects have already evolved resistance to many pesticides, forcing farmers to apply even more.

For some growers, pheromones provide an attractive alternative. Female insects naturally emit pheromones that attract males to mate. By flooding their fields and orchards with fake pheromones designed to appeal to specific insects, farmers can overwhelm these signals and prevent reproduction. Females then lay sterile eggs, which don’t hatch into hungry caterpillars.

The pheromone mating call is usually a mixture of compounds. Traps are designed to attract a particular species—to monitor for the presence of a pest, for example—so a precise cocktail is usually needed. But to sabotage mating, a broad-spectrum component can work because many related species use the same basic compounds as pheromone components.

Synthesizing this chemical smokescreen is nevertheless a complex, expensive proposition. It can cost anywhere from $1000 to $3500 to produce just 1 kilogram of artificial pheromones. Deploying it can cost between $40 and $400 per hectare, depending on the type of pest.

That’s why pheromones are typically only used to protect crops that require relatively little land to turn a decent profit, such as fruits and nuts. Farmers who grow crops that don’t sell for as much per hectare, such as corn or soybeans, often can’t afford to use pheromones to defend their vast fields. It also requires some experience to deploy pheromones effectively. “You’re talking about razor-thin profit lines for a family farm and then asking them to invest not only in the product, but in the labor it takes to get the product in the field,” says Monique Rivera, an entomologist at Cornell University. “It’s a tough ask.”

In a bid to lower costs, Christer Löfstedt, a chemical ecologist at Lund University, and his collaborators in several countries have for the past decade been modifying plants to produce the chemical building blocks needed for synthesizing pheromones. Their crop of choice is Camelina, a flowering plant related to canola with seeds rich in fatty acids—key ingredients in coaxing plants to produce these raw materials.

Löfstedt and colleagues relied on genetic engineering to outfit Camelina with a gene from the navel orangeworm which causes Camelina seeds to produce a fatty acid called (Z)-11-hexadecenoic acid. In insects, this fatty acid is a precursor to mating pheromones. The researchers began to grow their genetically modified Camelina in experimental plots in Nebraska and Sweden in 2016, selectively cultivating the plants that produced the highest amounts of this critical molecule.

After three generations, 20% of the fatty acid content of the seeds consisted of (Z)-11-hexadecenoic acid—enough to suggest the crop could be an efficient source of the raw materials needed to produce pheromones. Next, the researchers purified the oil and converted it into a liquid cocktail of pheromone molecules designed to appeal to the diamondback moth (Plutella xylostella), a pest that presents a particular problem in the Brassica, a group of plants including cabbage, kale, and broccoli.

In 2017, the team tested this pheromone blend in China. They put pheromone traps on sticks about 10 to 15 meters apart in a plot of the leafy Brassica choy sum. The traps worked just as well as commercial synthetic pheromones, the team reports today in Nature Sustainability. Another test in bean fields in Brazil revealed that a single plantmade pheromone could disrupt the mating patterns of the destructive cotton bollworm (Helicoverpa armigera) just as well as a synthetic pheromone.

ISCA Inc., a pest control company in Riverside, California, that participated in the research, estimates it would cost between $70 and $125 per kilogram to grow the Camelina and make the pheromones, less than half the cost of current synthesizing methods. That would put the costs on par with pesticides. The authors note that a liquified version of these pheromones could be dripped on fields, which would require less labor than manually placing traps.

A lower price might make the pheromones accessible to farmers in the developing world, says entomologist Muni Muniappan at the Virginia Polytechnic Institute and State University, who was not involved in the research. But because these pheromones work best when applied to large areas and most farmers in developing regions work small fields, farmers would likely need to work together to see the benefits, he says. “You need to have farmer education and outreach in order to make that successful.”

Getting regulatory approval to grow the genetically modified Camelina on commercial farms would take several years, the researchers note. But existing experimental permits already enable researchers to grow more than enough engineered Camelina to meet the current worldwide demand for pheromone control of diamondback moths and cotton bollworms, says Agenor Mafra-Neto, CEO of ISCA.

Several hurdles remain to applying the approach to other kinds of pests, such as beetles and leafhoppers. Doing so will likely require finding and adding other genes to Camelina. Still, says Junwei Zhu, a chemical ecologist with the U.S. Department of Agriculture, the new work “is a very good start.”


doi: 10.1126/science.ade6979

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PLANTS & ANIMALS

ABOUT THE AUTHOR

Erik Stokstad

Erik Stokstad

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Erik Stokstad is a reporter at Science, covering environmental issues. 

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Bioengineered plants help produce moth pheromones for pest control

Pheromones are often used by farmers for controlling pest insects but the chemical process for producing them is expensive. A method for making them using bioengineered oil plants could be cheaper

ENVIRONMENT 1 September 2022

By James Dinneen

camelina oilseeds
The camelina oilseed plant can be used to make insect pheromones Kurt Miller

A bioengineered oilseed plant can produce a moth sex pheromone molecule used to control insect pests.

Pheromones are chemical signals that cause a behavioural response in members of the same or closely related species. For decades, farmers have used pheromones to keep pest insects away from high-value crops like apples and grapes, for instance by baiting traps with the chemicals or saturating fields with them to make it difficult for the insects to find mates. But the chemical process for making pheromones is too expensive to use for lower-value row crops like maize, soybeans and cotton.

Hong-Lei Wang at Lund University in Sweden and his colleagues bioengineered plants to produce a sex pheromone molecule secreted by two damaging pest species: female diamondback moths (Plutella xylostella) and cotton bollworms (Helicoverpa armigera).

The team used the bacterium Agrobacterium tumefaciens to introduce two genes into the oilseed plant Camelina sativa.

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Country Matters: Tiny but brilliant creatures are better than pesticides

Ants are incredible, hard-working creatures

Ants are incredible, hard-working creatures

Joe Kennedy

August 28 2022 02:30 AM


Patiently I have watched ants for lengthy periods at their agricultural practices, endlessly busy cutting and ferrying vegetation to maintain the farms producing their fungal livelihood. Leaning over cliff top fences on Portugal’s Atlantic coast, I have looked at endless processions of insects moving along rutted tracks to disappear underground and reappear to collect more leaf fragments from a far source. Such lives of endless toil appear to be never-ending.

This leaf-cutting species works continuously to keep its fungal farms in production. The ants live on fungi that grows in their formicaries, or colonies, nurtured by leaf fragments which are further reduced by a separate team of stalk cutters before being laid out in ‘gardens’ to be tended by yet another crew.

There is careful husbandry: if a leaf source is found to be toxic, the ants promptly move to another. Source sites may be up to 300m away but, like slugs, the insects follow a scent trail laid down by the original surveyors. Individual ‘soldiers’, separate from the constantly moving lines, are on the lookout for intruders who might steal the crops. Colonies can also be raided and resident insects enslaved. Within the formicaries, reigning queen ants — who can live for up to 15 years — preside over colonies of between 100,000 and 500,000. The largest was found in Switzerland in 1977 with 300 million living in 1,200 anthills crossed by 60km of paths in the Jura Mountains.

Most of us have had unpleasant encounters with ants, red and black, in this country.

In Africa there is a species called Matabele which have remarkable human-like traits in that they save wounded comrades on termite battlefields. If an ant can stand on just one leg after a fight, it is carried off to have its wounds tended to by triage ‘doctors and nurses’ to fight another day. Prone casualties, however, are left where they fall.

A scientific report recently suggested that ‘ant power’ in crop production can be more efficient than chemicals. The ants are better at disposing of pests, thereby reducing damage and increasing yields. An analysis published in Proceedings of the Royal Society looked at 17 crops in several countries and found some ant species with proper management had similar or higher efficacy than pesticides — and at lower cost.

However, ants can also be a problem where meal bugs, aphids and whiteflies are concerned. They produce a sugary substance called honeydew to which ants are attracted and which they ‘farm’ like livestock. But researchers say alternative sugar sources may be used to distract the ants so they continue to attack the other pests.

There are more ants than any other insects in the world, about 14,000 known species, making up about half of the earth’s biomass. They are incredible creatures.

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Using pheromones and mating disruption to fight Tuta absoluta

Tuta absoluta is a pest found in many greenhouses around the world. “Due to the climate change and the movement of goods, Tuta absoluta can now be found in many parts of the world,” says Irina Caraeva from Eco Center. “Generally speaking, if you see mining on the leaves  or the pests themselves – there might be a chance of an infestation.” And this can get quite nasty, not only because they inevitably weaken the plants but also because these get more susceptible to other pathogens.

The risk of using chemical products
Usually, a good practice to prevent that is to use insecticides, but they come with a downside. “The main issue has to do with the beneficial insects present in the greenhouse,” Irina points out. “Insecticides tend to affect those too, which is something growers definitely don’t want.” Another disadvantage of the use of insecticides to counter Tuta absoluta is the residue levels. “First of all, most of the insecticides are quite toxic, and residues can then be found on the produce. You can perhaps use them before the planting, but not during the entire growing season, it’s really not advisable. Additionally, Tuta absoluta develops resistance to most insecticides available on the market, even if there are products that can control the pest, they contain highly concentrated substances that cannot be used immediately before collection since the degradation period is too high.”

Pheromones
That is why Eco Center has devoted its efforts to developing solutions to control greenhouse pests in the most natural and environmentally friendly way. “Pheromones,” Irina points out. “These are species-specific, which means that they will affect only a given insect. In this way, a grower can be sure that beneficial insects don’t get harmed. At Eco Center, we have developed many pheromone products, with the most recent addition of the Tuta Protect – a mating disruption product.” The Eco Center also makes pheromone lures for monitoring tomato leaf miner to go together with their Delta Traps. “These are designed specifically to monitor the insect population in a cost-efficient and environmentally friendly way. They will help the growers to make decisions on further application of other pest management actions.”

Mating disruption
Irina continues to explain that before planting, a grower should start the monitoring process by installing a couple of Delta traps with pheromone lures. At the same time, if traps indicate the need for control of pests, Eco Center has come up with another solution. “Mating disruption,” she says. “These pheromone dispensers contain 170-180 milligrams of pheromone. Bluntly put, the mating disruption dispensers create “false pheromone trails” that affect Tuta absoluta males, which interferes with their mating finding behavior.”

Irina says that Eco Center is constantly working to include more insects in their pheromones catalog. “Right now, we are testing our products for the pink bollworm, which are mainly asked by our customers from the Middle East and Africa. At the same time, we are in the process of figuring out the best pheromone solution for the most common cannabis pests. Hopefully, we’ll get into that market soon,” she concludes.

For more information:
Eco Center
MD-2005, Moara Rosie 5E str.
Chisinau, Republic of Moldova
+373 68979696
info@ecocenter.md 
ecocenter.md

Publication date: Mon 29 Aug 2022
Author: Andrea Di Pastena
© HortiDaily.com

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