Tetraplodon mnioides (deutsch Sternmoosartiges Vierzackmoos) ist eine Laubmoos-Art aus der Familie Splachnaceae.

Entireleaf Nitrogen Moss (Tetraplodon mnioides)

Insects don’t have noses and are not able to “smell” the roses in the familiar sense of the word. Instead, most odor molecules are detected by chemoreceptors that occur on an insect’s antennae. Using these chemical receptors, insects are capable of perceiving and differentiating between thousands of&nbsp;airborne compounds. They use these chemical signals to locate forage <a href="https://www.earth.com/news/some-plants-wont-survive-the-loss-of-seed-dispersing-animals/">plants</a> and mates, as well as to avoid predators.



But now, new research indicates that common air pollutants present in rural and urban environments may be hampering the ability of insects to detect the chemical signals so crucial to their activity as pollinators.&nbsp;



A team of scientists from the <a href="http://www.reading.ac.uk/">University of Reading</a> has conducted the first study to observe that common air pollutants, including diesel exhaust fumes and ozone, have a negative impact on the success of pollination by insects.&nbsp;



“We knew from our previous lab studies that diesel exhaust can have negative effects on insect pollinators, but the impacts we found in the field were much more dramatic than we had expected," said Dr. Robbie Girling, who led the project.



These previous laboratory studies by members of the Reading team showed that&nbsp;chemicals in <a href="https://www.reading.ac.uk/news-archive/press-releases/pr649662.html">diesel fumes react with and can change the scents of flowers such that the insects cannot locate the flowers. </a>The research suggested that pollution could contribute to the ongoing declines in pollinating insects, by making it harder for them to locate the pollen and nectar that form their food.



In the new study, the researchers aimed to gather evidence showing how air pollution affects different species of pollinating insects, some of which rely on scent more heavily than others.



The study, funded by the Natural Environment Research Council, used a purpose-built fumigation facility to regulate levels of nitrogen oxides (NOx) – present in diesel exhaust fumes – and ozone in an open field environment. They then observed the effects these pollutants had on the pollination of black mustard plants by free-flying, locally-occurring pollinating insects over the course of two summer field seasons.



Although the experiments made use of pollution levels that were way below the maximum acceptable levels considered as safe in the US, the results of the field experiments were dramatic. The researchers observed 62 to 70 percent fewer pollinator visits to the plants located in polluted air. This reduction was seen in seven different groups of pollinators, including bees, moths, hoverflies and butterflies.&nbsp;



There were also 83 to 90 percent fewer visits to flowers by these insects, and ultimately a 14 to 31 percent reduction in pollination success, based on the measurement of seed yield and other factors.



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



Insects are important pollinators of crops upon which we depend for food and so a reduction in pollinating activity could have far-reaching economic and social consequences. Around 70 percent of crop species rely on insects for pollination; these include apples, strawberries and cocoa.&nbsp;



In addition, pollination supports around eight percent of the total value of agricultural food production, worldwide. The pollinating activity of insects thus generates hundreds of billions of pounds worth of economic value each year.&nbsp;



Furthermore, far higher levels of air pollutants are found in many areas around the world where people and businesses breach the regulations. For example, a&nbsp;<a href="https://www.independent.co.uk/climate-change/news/air-pollution-england-defra-labour-who-nitrogen-dioxide-luke-pollard-b404484.html?r=55147">2019 analysis</a> recorded illegal levels of nitrogen dioxide present in local authorities, in large areas of northern England (including Cheshire and Gateshead), and in southern England (including Wiltshire, Chichester and rural areas such as the New Forest).



“This truly cross-disciplinary work demonstrated very clearly how atmospheric pollutants negatively impact on pollination with direct consequences for food production as well as the resilience of our natural environment," concluded study co-author Dr. Christian Pfrang.



Their results are published today in the <a href="https://doi.org/10.1016/j.envpol.2022.118847">&nbsp;journal&nbsp;</a><a href="https://www.journals.elsevier.com/environmental-pollution">Environmental Pollution</a>.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Air pollutants confuse pollinators and reduce food production

Insects don’t have noses and are not able to “smell”...

The story goes that, in 1820, a farmworker in the fields around Debenham in Suffolk, spotted a spectacular ear of barley. John Andrews picked the ear and planted the seeds at home in his <a href="https://www.earth.com/news/urban-gardens-provide-a-reliable-food-supply-for-pollinators/">garden</a>. When his landlord, Charles Chevalier, saw the remarkable barley that grew from these seeds, he was impressed and wished to grow more of it. He harvested it and began to propagate more plants, calling the new variety “Chevalier.”



At the time, barley was very important in the malting process used in the brewing of beer and very soon the new variety was being grown widely. In fact, by the end of the 19th century more than 80% of all malting barley in England was of the Chevalier type. The properties of this variety were considered so superior that the name Chevalier became synonymous with malting barley.&nbsp;



The variety became popular around the world, including in Sweden, where it was cultivated and improved, using breeding techniques, during the second half of the 19th century.&nbsp; Today, Chevalier is part of the lineage of many modern malting barley varieties and beer brewers have begun to consider returning to the use of this type, as well as other classic varieties of barley.



This has led Swedish researchers from the universities of Linköping and Stockholm to investigate whether the Chevalier variety of barley did indeed originate from a single plant, as described anecdotally. They wished to clarify how this cultivar was spread and adopted to Nordic seed systems of the time, and used molecular genetic analysis to establish whether the early Chevalier variety was used for selective breeding purposes to produce today’s varieties of malting barley.



“When we started this study, we were primarily curious about whether Chevalier barley had been discovered and used in the same way as today’s modern varieties, with a genetic signature unique to Chevalier, and where the name is a sort of brand name for a certain kind of product,” said Jenny Hagenblad, associate professor of population genetics at the Department of Physics, Chemistry and Biology (IFM) at Linköping University.



The researchers tested seeds from two different sources. Firstly, seeds were obtained from museum specimens of historical grains labeled “Chevalier.” These samples had been collected and stored at various times during the 19th century, with the oldest sample dating from 1865. Secondly, the researchers used seeds from current Chevalier accessions preserved in genebanks. In total, 282 individual seeds, representing 47 accessions, were used in the study.&nbsp;



Genetic analysis of the seeds revealed that many of them did indeed belong to a specific variety – Chevalier, and that this variety had been bred and kept pure for its superior malting qualities. From the very beginning, Chevalier was considered a premium malting barley and sold at higher prices than other cultivars. Farmers may have gone to great lengths to keep this cultivar pure, long before they knew the details of Mendelian inheritance or genes. In the light of these samples of pure Chevalier seeds, researchers were tempted to think it possible that a single plant may have given rise to all successive generations of this type of barley.&nbsp;



However, not all the sample jars marked “Chevalier” contained true Chevalier barley seeds.&nbsp;



Some of the samples contained unimproved landrace barley, representing the varieties that were present in Nordic countries before the introduction of the Chevalier cultivar. Other samples contained mixtures of Chevalier and landrace seeds, while a few samples also had seeds that were, hybrids (crosses) between Chevalier and other varieties.&nbsp;



From these results it was clear that the designation “Chevalier” was applied rather loosely in the 19th century. The seed mixtures indicated that, after the Chevalier variety was brought to Sweden, local farmers mixed it – deliberately or accidentally –with seeds from local landraces.&nbsp;



Although barley is usually self-fertilizing, there is a small incidence (2%) of cross-fertilization. This can lead to the development of a hybrid variety which would then have characteristics of both the Chevalier parent and the local landrace parent. The result would be a Chevalier-type malting barley that was also adapted to local environmental conditions. Not only did this generate new diversity from which farmers could obtain their future seeds, but hybrids often give increased yield as well.



According to the authors of the study, their findings indicate that farmers were practicing plant improvement methods long before there was an understanding of genetics. The processes used during the 1800s by farmers in Sweden were not very different from the plant improvement methods developed in the early 20th century, when genotypes superior in yield or quality were combined with locally adapted material to create the first modern cultivars.



“We can see signs of how people, long before the development of modern plant breeding, were already unwittingly using the very methods that became the foundation for the revolution in Swedish farming during the early 20th century,” said study co-author Matti Leino, a researcher in crop history at Stockholm University.



The results of the study have been published in the journal&nbsp;<a href="https://acsess.onlinelibrary.wiley.com/journal/14350653">Crop Science</a>.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Barley was bred for exceptional qualities in the 19th century

The story goes that, in 1820, a farmworker in the...

A new study from the <a href="https://www.ubc.ca/">University of British Columbia</a> has taken a closer look at the ultraviolet "bullseye" patterns found on sunflowers. The ultraviolet (UV) <a href="https://www.earth.com/news/dragonfly-wing-colors-driven-by-climate-and-sexual-selection/">colors</a> are invisible to humans, yet clearly visible to many insects.&nbsp;



The bullseye patterns were already known to make the flowers more attractive to bees, but scientists have now discovered that they do much more. The researchers found that chemicals in the UV markers also help the plants respond to stress from drought and extreme temperatures.&nbsp;&nbsp;&nbsp;&nbsp;



“Unexpectedly, we noticed that sunflowers growing in drier climates had flowers with larger UV bullseyes, and found that those flowers are able to retain water more efficiently. This suggests that these larger UV bullseyes help plants adapt to these drier environments,” said study lead author Dr. Marco Todesco, a research associate in the UBC Department of Botany.



Dr. Todesco and colleagues grew nearly 2,000 individual sunflowers of two different species in a lab in 2016 and 2019. Measuring the UV patterns and examining the genome of the plants, the researchers found that sunflowers growing in different regions of North America had differently sized bullseye patterns. Bees were better able to see the larger bullseyes.&nbsp;



The experts also found that the same gene that controlled the bullseye pattern was used in the production of UV-absorbant flavonoids, which help the plants survive stresses from things like drought and high temperatures.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;



“Floral UV patterns appear therefore to play at least a dual role in adaptation; besides their well-known effect on enhancing pollination, they also regulate water loss from flowers,” said study senior author Dr. Loren Rieseberg. “That’s not something you would necessarily expect a flower color to do, and it exemplifies the complexity and efficiency of adaptation - solving two problems with a single trait.”



The scientists feel more research into this adaptation could help improve the resilience of sunflower crops in the future.&nbsp;



The research is published in the journal <a href="https://elifesciences.org/">eLife</a>.



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

"Invisible" colors in sunflowers do more than just attract bees

A new study from the University of British Columbia has...

When plants grow, their stems, roots and <a href="https://www.earth.com/news/caterpillars-spotted-for-the-first-time-on-alpine-rose-leaves/">leaves</a> increase in size and abundance in a coordinated manner. The changes in one type of organ keep pace with the changes in the other types. Dividing cells need to communicate with one another in order to achieve this, and previous research has identified that plants package important messages into molecules of RNA, which are sent from cell to cell.&nbsp;



New research, published today in the journal <a href="https://www.science.org/">Science</a>, adds to this understanding by identifying a special protein in the cells of plants that acts as an escort and helps the RNA molecules to travel to where they are needed.&nbsp;



By studying the mustard-like plant&nbsp;Arabidopsis thaliana, Cold Spring Harbor Laboratory (CSHL) Professor&nbsp;<a href="https://www.cshl.edu/research/faculty-staff/david-jackson/">David Jackson</a>&nbsp;and his team found that without this escort protein, known as AtRRP44a, the plant cells cannot communicate or coordinate the growth of the plant.&nbsp;



While all animal and plant cells are surrounded by a membrane, plant cells alone have an additional wall around each cell. Chemical messages can cross this cell wall through tiny holes called plasmodesmata.&nbsp;



Munenori Kitagawa is a postdoc in the Jackson lab who led the study. He explained that plasmodesmata are nanochannels embedded in the cell wall. "They mediate [the transport of various signals] from cell to cell, including protein, RNA, hormones, ions, and nutrients.”



Kitagawa investigated exactly how plasmodesmata regulate the movement of chemical messages from one cell to the next. He and his colleagues discovered that the protein AtRRP44a is involved in the transport of RNA molecules through the nanochannels in the cell wall. Decreasing the amount of AtRRP44a available slowed down the movement of RNA messages between cells and, because they then lacked the right messages, the plants failed to develop properly.&nbsp;



A protein similar to this escort protein is present in other plants, yeasts, and animals. The researchers were able to swap out part of the&nbsp;Arabidopsis thaliana&nbsp;signaling system and replace it with a part from&nbsp;<a href="https://www.cshl.edu/corn-2-0/">corn</a>;&nbsp;this restored normal development, showing that many kinds of plants share this signaling system.&nbsp;



“Plants are very sophisticated," said Jackson. "We think of them just sitting in their environment, not moving, but really they’re processing a lot of information. The different parts of the plant are talking to each other, sharing whether they have some pathogen attack or if they need some nutrients.”



“This paper represents an important step towards understanding how information is exchanged between cells to control development and other processes,” said John McDowell, a program officer in the&nbsp;<a href="https://nsf.gov/">U.S. National Science Foundation</a>’s Directorate for Biological Sciences. “By revealing a new component of cell-to-cell communication, this research opens the door for further investigation that could allow us to harness this process.”



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Plant cells message each other using RNA and escort proteins

When plants grow, their stems, roots and leaves increase in...

In the past, when climates changed, forests became distributed more to the north or to the south of their previous locations. This is not to say that the trees, themselves, moved. Rather, the ranges of the tree species changed. For example, fossil plant and pollen records show that the ranges of tree species shifted northward at a rate of 50km per century as the climate warmed after the retreat of the North American ice cap.&nbsp;



Tree range migration is facilitated by the movement of seeds. When the climate changes, trees begin to form more seeds; these get spread around by dispersal agents and may germinate in areas that are more favorable for growth. Although wind and water may carry some seeds, the vast majority of trees depend on animals to disperse them to new areas. But now, many of these seed-dispersing animals are themselves threatened, as climate changes and habitats are lost.



In&nbsp;<a href="http://www.science.org/doi/10.1126/science.abk3510?adobe_mc=MCMID%3D84587913426847399401258317155412422308%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1641994662">a study</a>&nbsp;featured on the cover of this week’s issue of&nbsp;<a href="https://www.science.org/">Science</a>, U.S. and Danish researchers consider how the loss of species of birds and animals will impact the ability of plants to adapt to human-induced climate change in future. While animals can often fly, walk, run or swim to more suitable areas, trees cannot escape the heat. Tree species that need to move their offspring away from warmer temperatures will only be able to do so via the activities of seed-dispersal agents, such as mammals and birds.&nbsp;



“Some plants live hundreds of years, and their only chance to move is during the short period when they're a seed moving across the landscape,” said <a href="https://www.rice.edu/">Rice University</a> ecologist&nbsp;<a href="https://www.evanfricke.com/">Evan Fricke</a>, the study's first author. “If there are no animals available to eat their fruits or carry away their nuts, animal-dispersed plants aren’t moving very far."



In collaboration with researchers from the University of Maryland, Iowa State University and Aarhus University, the Rice team used machine learning and data from thousands of field studies to map the contributions of seed-dispersing birds and mammals worldwide. They compared maps of seed dispersal today with maps showing what dispersal would look like if there were no human-caused extinctions or species range restrictions.



The experts also used data synthesized from field studies around the world to train a machine-learning model for seed dispersal, and then used the trained model to estimate the loss of climate-tracking dispersal caused by animal declines.



Fricke explained that developing estimates of seed-dispersal losses due to animal and bird extinctions or changes in their ranges required two significant technical advances: “First, we needed a way to predict seed-dispersal interactions occurring between plants and animals at any location around the world."



For this, they used data on species interactions from over 400 field studies that detailed how many seeds are dispersed by particular species of birds and mammals, how far they are dispersed and how well those seeds germinate. Based on this data, the researchers could predict interactions between plants and seed dispersers.



“Second, we needed to model how each plant-animal interaction actually affected seed dispersal,” said Fricke. “For example, when an animal eats a fruit, it might destroy the seeds or it might disperse them a few meters away or several kilometers away.”



The results of the study showed that many seed-dispersing mammals and birds have already been lost, particularly in temperate regions across North America, Europe, South America and Australia. In addition, if currently endangered species go extinct, tropical regions in South America, Africa and Southeast Asia would be severely affected.&nbsp;&nbsp;



“We found regions where climate-tracking seed dispersal declined by 95%, even though they’d lost only a few percent of their mammal and bird species,” said Fricke.&nbsp;



The findings showed that the ability of animal-dispersed plants to keep pace with climate change has been reduced by 60% due to the loss of mammals and birds that help such plants adapt to environmental change.&nbsp;



“In addition to the wake-up call that declines in animal species have vastly limited the ability of plants to adapt to climate change, this study beautifully demonstrates the power of complex analyses applied to huge, publicly available data,” said Doug Levey, program director of the National Science Foundation’s (NSF) Directorate for Biological Sciences, which partially funded the work.



Fricke explained that the study is the first to quantify the scale of the seed-dispersal problem globally and to identify the regions most affected. He emphasized that declines in the populations of seed dispersers highlight an important intersection between the climate and biodiversity crises impacting natural environments today.



“Biodiversity of seed-dispersing animals is key for the climate resilience of plants, which includes their ability to continue storing carbon and feeding people,” he said, adding that restoration of ecosystem connections in natural habitats could counteract some declines in seed dispersal, but not all of them. People also rely, both economically and ecologically, on seed-dispersing birds and mammals to ensure the supply of important resources.&nbsp;



“Large mammals and birds are particularly important as long-distance seed dispersers and have been widely lost from natural ecosystems,” said Svenning, the study’s senior author. “The research highlights the need to restore faunas to ensure effective dispersal in the face of rapid climate change.”&nbsp;



“When we lose mammals and birds from ecosystems, we don’t just lose species. Extinction and habitat loss damage complex ecological networks," said Fricke. "This study shows animal declines can disrupt ecological networks in ways that threaten the climate resilience of entire ecosystems that people rely upon.”



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Some plants won't survive the loss of seed-dispersing animals

In the past, when climates changed, forests became distributed more...

Replacing butter, mayonnaise and dairy fat with olive oil on a regular basis can literally save your life, according to a new study from the <a href="https://www.acc.org/">American College of Cardiology</a>. The experts report that consuming more than half a tablespoon of olive oil per day is associated with a reduced risk of death from cardiovascular disease, <a href="https://www.earth.com/news/meat-eating-animals-are-more-susceptible-to-cancer/">cancer</a>, neurodegenerative disease, or respiratory disease.



Study lead author Dr. Marta Guasch-Ferré is a senior research scientist at the Department of Nutrition at Harvard T.H. Chan School of Public Health.&nbsp;



“Our findings support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils,” said Dr. Guasch-Ferré&nbsp;



“Clinicians should be counseling patients to replace certain fats, such as margarine and butter, with olive oil to improve their health. Our study helps make more specific recommendations that will be easier for patients to understand and hopefully implement into their diets.”



Based on data from the Nurses’ Health Study and the Health Professionals Follow-up Study, the researchers analyzed the dietary habits and health outcomes of 60,582 women and 31,801 men. At the beginning of the study period in 1990, the participants were free of cardiovascular disease and cancer. 



Based on 28 years of follow-up, the researchers compared individuals who regularly consumed olive oil to those who rarely or never consumed olive oil. The study revealed that participants in the highest consumption category, had a lower risk of cardiovascular mortality by 19 percent and a lower risk of cancer mortality by 17 percent. These individuals also had a 29-percent lower risk of neurodegenerative mortality and an 18-percent lower risk of respiratory mortality. 



According to the study, substituting 10 grams of olive oil (daily) for other fats such as margarine, butter, and mayonnaise lowers the risk of mortality from all causes by up to 34 percent.



“It’s possible that higher olive oil consumption is a marker of an overall healthier diet and higher socioeconomic status. However, even after adjusting for these and other social economic status factors, our results remained largely the same,” said Dr. Guasch-Ferré.&nbsp;



“Our study cohort was predominantly a non-Hispanic white population of health professionals, which should minimize potentially confounding socioeconomic factors, but may limit generalizability as this population may be more likely to lead a healthy lifestyle.”



The study is published in the <a href="https://www.jacc.org/">Journal of the American College of Cardiology</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Regular olive oil consumption can literally save your life

Replacing butter, mayonnaise and dairy fat with olive oil on...

Ecological interactions are often not simple or straightforward in nature. Instead, they commonly represent trade-offs between different processes so that the best compromise is reached in the end.&nbsp;This is exactly what scientists from the <a href="https://www.ice.mpg.de/">Max Planck Institute for Chemical Ecology</a> found when they investigated the choices made by female tobacco hawkmoths (Manduca sexta) when laying their eggs. 



The hawkmoths did not always make the obvious choice when placing their eggs on the leaves of <a href="https://www.earth.com/news/invasive-plants-cause-a-global-loss-of-floristic-uniqueness/">plants</a> that would provide food for the larvae, once they hatched. Previous research had shown that tobacco hawkmoths avoid laying their eggs on plants where they smell the feces of other hawkmoths. “This is apparently their way of avoiding food competition. Therefore, we wondered whether the moths also avoid plants infested by other herbivorous insects,” explained study first author Jin Zhang.



In the lab, the researchers gave female hawkmoths a choice between laying their eggs on sacred Datura plants (Datura wrightii) that were infested with three-lined potato beetles (Lema daturaphila) or Datura plants that had no potato beetles. Both adult and larval potato beetles feed on the leaves of this plant, and the researchers hypothesized that the hawkmoths would avoid plants where potato beetles were present in order to ensure the maximum supply of food for their offspring.&nbsp;



But the hawkmoth females surprised the researchers by laying their eggs, preferentially, on the leaves of Datura plants that already hosted numerous potato beetles.&nbsp;&nbsp;



“To be honest, we were a little frustrated at first because we had expected the experiments to confirm our initial hypothesis, namely that egg-laying tobacco hawkmoths avoid food competitors,” explained study leader Markus Knaden.



“In our case, however, the unexpected observation suddenly made sense when we realized that beetle-infested plants smell quite differently and that parasitoid wasps, which often use plant odors to find their host insects, are less efficient at detecting tobacco hornworms on beetle-infested plants."



Tobacco hornworms, the larvae or caterpillars of tobacco hawkmoths, are heavily parasitized by the wasp&nbsp;Cotesia congregate, which lays its eggs in the caterpillars. Up to 90 percent of these caterpillars are parasitized by wasps and die shortly after the wasp larva hatches. Female hawkmoths therefore need to consider not only the available food supply for their larvae, but also their potential exposure to this parasitic wasp species.



The experts analyzed the odor given off by Datura&nbsp;plants when they carry an infestation of three-lined potato beetles compared to the odor emitted when there is no infestation. They found that infested plants produce more alpha-copaene in the in their odor when the beetles and their larvae are present. Interestingly, these three-lined potato beetles coat themselves with their own feces, possibly as a means of deterring would-be predators and parasites.&nbsp;



The research team then tried to establish how exactly the tobacco hawkmoth females detect the presence of the molecular substance alpha-copaene. Of the 70 potential chemical receptors present in the hawkmoths, the researchers identified a single one, Or35, as the odorant receptor activated by alpha-copaene. They suggest that this receptor is probably involved in the moth’s choice of where to deposit its eggs.



Next, the experts tested the choices made by the wasps (Cotesia congregate) that parasitize tobacco hawkmoth caterpillars. They found that the wasps preferred the odor of plants on which tobacco hornworms were feeding, but they also avoided the odor of plants that were infested with potato beetles. These results were confirmed by assays in an experimental tent containing&nbsp;Datura&nbsp;plants infested by tobacco hawkmoths only, or by tobacco hawkmoths and potato beetles together. Wasps also avoided plants with beetles in this setting.



The findings indicate that female tobacco hawkmoths, when choosing where to lay their eggs, weigh up the benefit for their larvae of having no food competition against the disadvantage of being parasitized by the wasps. Although tobacco hornworms develop more slowly on plants that are additionally infested by beetles, the mother moths accept this disadvantage when laying their eggs. The advantage of protecting their offspring from parasitic wasps must therefore outweigh the disadvantage of food competition. Such cost-benefit trade-offs play a significant role in many ecological interactions.&nbsp;



“Our results show that in nature, simple explanations are often not sufficient. Tobacco hawkmoths do not only have to take into account whether a plant is a good food substrate for their offspring, but also whether potential competitors are already present, and whether the presence of these competitors could even help to hide [their offspring] from predators,” concluded study co-author Bill Hansson.



The researchers will focus future studies on the reasons why&nbsp;Datura&nbsp;plants emit different odors depending on the insects that feed on them. They plan to use interdisciplinary approaches that also consider, for example, the role of microorganisms in these complex interactions, and hope to uncover further exciting aspects of the multifaceted interactions between living organisms.



The study is published in the journal <a href="https://www.cell.com/current-biology/home">Current Biology</a>.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Complex factors determine where hawkmoths lay their eggs

Ecological interactions are often not simple or straightforward in nature....

Entireleaf Nitrogen Moss

Description

Taxonomic tree: