Hawkmoth losing flower attraction

Surveys undertaken by researchers from the Max Planck Institute of Chemical ecology and the University of Virginia had investigated whether the scent altered by ozone pollutants still attracted their specialist pollinators. Ozone is a reactive oxidant believed to modify the flowers scent. The model species that was used was the tobacco hawkmoth because of it's innate attraction to the floral scent and their visualization. In natural environments  the floral scent is altered when the scent migrates downwind of the flower and mixes with the ozone pollutant. 

 

Investigating the hawk moth's attraction to the ozone altered scent was undertaken in a wind tunnel where they had been exposed to both the original and alteredfloral scent. The response exhibited by the hawkmoth was 'shocking' that the strong attraction initially formed between the hawkmoth and floral scent had been lost after it had been ozone altered. 

 

Researchers then assesed numerous ways in which these hawkmoth may learn to recognize the sugar source as a reward whenever they smelt the ozone altered scent. The lead author had discussed  "While we anticipated that Manduca sexta could learn new floral scents and hoped that they would be able to learn the polluted floral scent of their host flower, we were amazed to see that Manduca sexta could learn the polluted floral blend in a number of different ways, including learning a polluted scent that was decoupled from a sugar reward. This type of learning, which we were surprised to find in Manduca sexta, could be very important in insects' ability to use learning to cope with their rapidly changing environments,"

 

A major concern is that these pollinators will take a significant amount of time to learn these altered scents provided a sugar reward where many will die of starvation and birth rates would decline due to these intense pressures. This will then in turn result in a reduction in genetic diversity where they will struggle to form genetics change during harsh conditions. It is likely that other pollinators that rely less on visualization than the hawk moth, will lead to the extinction of the species. 

 

Brynn Cook, Alexander Haverkamp, Bill S. Hansson, T’ai Roulston, Manuel Lerdau, Markus Knaden. Pollination in the Anthropocene: a Moth Can Learn Ozone-Altered Floral Blends. Journal of Chemical Ecology, 2020; DOI: 10.1007/s10886-020-01211-4 

Max Planck Institute for Chemical Ecology. "Pollination: Air pollution renders flower odors unattractive to moths." ScienceDaily. ScienceDaily, 4 September 2020. <www.sciencedaily.com/releases/2020/09/200904101806.htm>.

 

US EPA. 2020. Ground-Level Ozone Basics | US EPA. [online] Available at: <https://www.epa.gov/ground-level-ozone-pollution/ground-level-ozone-basics> [Accessed 10 September 2020].

Queen bee failures

8th September, 2020 (University of British Columbia)- Researchers from the University of British Columbia (UBC) have been investigating aspects which may be responsible for colony collapse disorder (CCD) where it had been thought that queen bee failures is a significant factor. CCD is when the majority of worker bees disappear from the colony leaving the Queen, nursebees and juveniles.

It was discovered by the Canadian Association of professional apiarists that the queen could no longer produce sufficient fertilized eggs. To asses this, protein markers are examined. These proteins are activated within a queen bee when put under significant stress ie. heat shock, pesticide exposure, malnutrition etc. 

During this research, the protein markers of the queen bee from a hive experiencing CCD was compared to a queen's from a healthy hive. It was discovered that queen's from hives experiencing CCD had higher levels of heat shock and pesticide exposure which creates detrimental effects on sperm viability. This has negative implications on the genetic diversity which makes it more difficult for offspring to survive, adapt to change etc. It also causes there to be a lack of worker bee population where the worker bees that were produced work themselves to death sooner as each worker bee had more work in sustaining the hive. 

These bees are subject to heat shock due to climate change but the primary reason is the transport of bees from differing climate ie New Zealand to Canada. The high climate fluctuation puts the bees under serious strain due to evolution over millions of years in a completely different climate.

 

Alison McAfee, Joseph Milone, Abigail Chapman, Leonard J. Foster, Jeffery S. Pettis, David R. Tarpy. Candidate stress biomarkers for queen failure diagnostics. BMC Genomics, 2020; 21 (1) DOI: 10.1186/s12864-020-06992-2

US EPA. 2018. Colony Collapse Disorder | US EPA. [online] Available at: <https://www.epa.gov/pollinator-protection/colony-collapse-disorder> [Accessed 22 September 2020].

Moths are the overlooked pollinator.

University College London (UCL), 12th May 2020 - Moths are important pollen transporters in English farmlands and play a significant role in the maintenance of crop yields. Although they may not receive as much media coverage as daytime pollinators but research led by (UCL) showed that nocturnal moths have a larger, more complex pollination network and will often compliment the pollination done by the daytime pollinators. Moths will commonly visit the same flowers already visited and will visit flowers that hasn't been pollinated during the day. They serve as a form of back-up for biodiversity, which in turn supports crop yields.

Lead author, Dr Richard Walton (UCL Geography researcher) had stated that moths have a vital, yet often overlooked pollinators which play vital ecological functions being responsible to a certain degree of floral diversity and abundance. He also makes a bold statement that many species including bats, mammals, birds etc would be put under significant pressure without the moth. 

Moths uniquely pollen with their chest instead of their tongue optimizing the volume of pollen being transported. This essentially means more pollen from a single interaction will be introduced to higher numbers of flower individuals. While feeding, the moth's distinctly hairy body comes into contact with the male floral reproductive parts where higher quantities of pollen will attach to these hairs.  

While investigating the importance of moths, they monitored ponds in agricultural regions in Norfolk where it was noted that 45% of the moths were transporting pollen derived from 47 different floral species. Moths are seen as generalists where they can pollinate/ feed on a wide range of floral species, meanwhile, bumble/ honeybees will target the most prolific nectar and pollen sources.

This study has come at a pivotal period in our climate crisis as moths are suffering from serious decline with a 28% decline in the UK since 1968. Interstingly, the southern portion of England have suffered from a 40% reduction, meanwhile, the northern proportion has displayed no significant decline. This is likely to be due to the higher abundance of urban centers along the south. Street lights have had detrimental effects on nocturnal species which confuses them on when to feed. Some individuals may feed during the day time where they're out competed by diurnal species. Chemical pesticides are also responsible where they reduce floral diversity and will often be toxic to moths when consumed.

Dr Walton (UCL Geography) concluded: “While bumblebees and honeybees are known to be super pollinators they also preferentially target the most prolific nectar and pollen sources.

“Moths may appear to be less effective pollinators by comparison, but their high diversity and abundance may make them critical to pollination in ways that we still need to understand. Our research sheds light on a little known world of nocturnal plant-insect interactions that might be vital to the look and smell of our precious countryside and to the crops that we grow.”

• Walton, R., 2020. Moths Have A Secret But Vital Role As Pollinators In The Night. [online] UCL News. Available at: <https://www.ucl.ac.uk/news/2020/may/moths-have-secret-vital-role-pollinators-night> [Accessed 8 August 2020].
• Butterfly-conservation.org. 2020. The State Of Britain's Moths. [online] Available at: <https://butterfly-conservation.org/moths/the-state-of-britains-moths> [Accessed 8 August 2020].

Roadside verges a pollinators paradise?

University of Exceter, 9th -August-2020-  Research that had been led by the University of Exceter had discovered that roadside verges can provide suitable refuge for pollinators despite high  levels of pollution and risk of getting hit by oncoming traffic. It has been urged the positives significantly outweigh the negatives. 

It has been said in this study that all verges won't have the exact same benefits as one another. It was found that verges along quieter stretches of road showed the best results. This study states that less cutting throughout the year and leaving it until later in the year to cut will have signifficant benefits to the pollinator population. 

Regular cutting of grass will result in loss of shelter and nectar source and this will be amplified if done in peak summer periods where the pollinators are most active. Wildflowers are most prevalent during this period and the removal of these wildflowers will reduce many pollinator's opportunity for pollination leading to increased risk of starvation  and less flowers pollinated leading to less flowers. 

It has been emphasized that cuttings should be altered from peak flowering periods to Autumn, a period were pollinators are notably less active reducing the impact. The only section that should be considered being cut is the area 2m in from the roadside. This is the case as these sections were recorded to have the lowest abundance in pollinator populations and are the most important zone for visibility for road users. 

These road verges creates a network of corridors providing sufficient food sources to sustain this population. These verges pose many negative aspects including pollution, collision but it has been stressed that the positive effects remarkably outweigh these negative aspects which may somewhat help the 97% decrease of meadow wildflowers since the 1930's. 

Street lights cause great confusion to nocturnal insects and the University of Exceter have stated these verges can be dramatically improved through limiting the amount of street lights used.“This new research shows the potential that road verges have to help to reverse insect declines.

“By making small changes to the management of our road verge network, local authorities and others involved in road verge management can make a significant difference to support nature’s recovery.”

References

• Phillips, B., 2019. Research News - Road Verges Provide Refuge For Pollinators - University Of Exeter. [online] Exeter.ac.uk. Available at: <https://www.exeter.ac.uk/news/research/title_728484_en.html> [Accessed 22 July 2020].

• Phys.org. 2020. Road Verges Could Be Havens For Pollinators. [online] Available at: <https://phys.org/news/2020-07-road-verges-havens-pollinators.html> [Accessed 22 July 2020].

Bees going to war for almonds

80% of global almond cultivation can be found in the state of California. Due to a decline in pollinator populations there are too many many flowers with any of the flowers will go unpollinated. As of 2006, due to high levels of colony collapse disorder it appeared almond cultivation was in trouble, however, due to the growing market for almonds, it had become feasible to make it worthwhile for beekeepers to rent out their hives to these almond growers for the blooming months. Many of these beekeepers heavily rely on renting out their hives during bloom season. This is the case as it costs $100 per year for maintenance of these hives yet the bees will only generate roughly $50-$80 in honey. Almond growers offer an enticing $160 per month for each hive to both the commercial and hobbyist beekeepers from across the United States. 

This is a mutualistic relationship for all involved...... except for the bees. Record numbers of honey bees had declined following their transport back from California with beekeepers recording average losses of 38% of their colonies (50 billion within 3 months in Winter of 2018/2019). The main reason  believed as to why this strategy of cultivation is detrimental to the honeybee populations is that bee colonies from different regions of the United States are associated with different parasites which have built up partial immunity due to years of exposure. Individuals foreign to these pathogens had no form of immunity. California has been described as a 'chemical soup' due to high levels of pesticides such as clothianidin and dicamba. These pesticides have detrimental effects on a bees immunity and reproductive cycles. When these major implications are exposed to bees in conjunction to one another it will cause a population to seriously decline. 

Organic bee keepers blame this decline on the over reliance of heavy mechanization, meanwhile, others believe a lack of preparation is responsible. Almond growers rented a diverse range of bee breeds and it is theorized that the European honeybee would out compete the less diverse bees and limiting the growth of these bees. Less common ideas for this decline is said to be a result of being out competed by Africanized bee strains. Africanized bees had been accidentally introduced to Brazil and are known to migrate northwards. California is one of the few areas in the US that these bees may reside due to the temperature and so it satisfies their fundamental niche. The Africanised bees would colonize new hives by killing the hive's Queen and would replace it with their Queen. 

Finally, it is possible that the ecology of California may be unsuitable for bee survival due to the high abundance of animals (bears, honeybadgers etc) that feed off honey and will kill the bees in the process. As the rapid decline has only gained significant attention in the last few years, there is a lack of research done with only hypothesis formed. These educated guesses must be investigated greater so that it can be prevented. Due to the large revenue almond production generates it is unlikely that renting bees will halt and so research is vital so almond growers and beekeepers may help silence the decline we have recently seen. 

Reference

• McGinvey, A., 2020. 'Like Sending Bees To War': The Deadly Truth Behind Your Almond Milk Obsession. [online] the Guardian. Available at: <https://www.theguardian.com/environment/2020/jan/07/honeybees-deaths-almonds-hives-aoe> [Accessed 9 July 2020].
•  Jacobsen, R., 2009. Fruitless fall: the collapse of the honeybee and the coming agricultural crisis. Choice Reviews Online, 46(08), pp.46-4440-46-4440.
• Schumann, D., 1993. Income Opportunities in Special forest products. 1(1), p.134.

Who's guilty for the murder of pollinators?!?!?!?!?!?!?

Pollinators play a key role in the production of seeds and almost all food we eat. Pollination is a process involving the transfer of pollen from the male part of a plant to the female .The pollen attached to the pollinator will enter the female component. This pollen will enter through the stigma and travel down the style where it will come into contact with the egg and will eventually turn into a seed. This seed will germinate into a plant. This process is obviously vital for sustaining the human population that is growing exponentially. Between 1947-2005 beekeepers have recorded a 50% loss of their hive populations and up to 90% decrease following 2006.





https://edition.cnn.com/2020/01/28/us/best-flowers-for-bees-conservation-study-scn/index.html

Colony Collapse Disorder (CCD) is when all worker bees and juveniles disappear from the hive with just a single queen remaining. CCD has been predicted to be responsible for up to a 50% loss of wild honeybee species within the last 120 years. As far back as 1868, the Commissioner of Agriculture were noting a reduction in the honey bee population and yet there is still insufficient studies  performed to determine the cause for this decline.  It is likely climate change has been a major factor for this decline especially in boreal regions where climates are warmer due to greenhouse emmisions. Warmer climates increases the melting of ice. This increased water availability and warmer environment causes flowers to bloom earlier. Conditions at this time ie high rainfall are unsuitable for pollinators and so synchrony that took thousands of years to form is lost. This causes alterations to the phenology of  pollinators and flowers at different rates. This leaves many of the plants to go unpollinated and will lower the floral diversity and so will reduce food availability and variety. It has been predicted that specialist pollinators will decrease in population and pollinators that don't discriminate will survive.

The increased use of pesticides is thought to be a major reason for this population decline. This has further reduced the floral diversity available to these pollinators. Neonicotonoids are a class of chemicals that act as a pesticide and are seen as the most responsible for the death of these pollinators out of other pesticides. These chemicals are fatal when consumed and even at non- fatal doses, it commonly causes the loss in the ability for bees to communicate and to successfully forage. The EU have banned pesticides similar to these chemical classes.

As a result of a lack of variety to the pollinators food source and exposure to pesticides has resulted in a reduction in the immune system and have made them more susceptible to infections, viruses, parasites etc. The spread of these parasites are catalyzed through the buying and selling of bees. These bees are fitted into small, enclosed boxes commonly transported from other countries who have developed partial immunities to certain diseases that the native populations are yet to establish. Blood sucking mites (Varroa destructor) is a parasite that will shorten the lifespan of the bee. These parasites are responsible for the spreading of viruses which are associated with the death of larvae. Infection of these mites are also correlated to deformities of the offspring or paralysis of infected bees. Paenibacillus  are bacteria that target larvae and will often kill the larvae and decompose which will turn the larvae into liquid. Ascarpis  woodi will then lay their larvae into the bee's breathing tubes which will cause suffocation. Some bees are resistant to these infections and scientists are examining the genome makeup responsible for this resistance. They are determining ways they can breed offspring containing this gene.

It is widely believed that not just a single one of these factors are responsible for such a decline in the honey bee population but instead a host of these factors commonly decrease the immunity which will then result in the death of these populations and shorten their life span (Goulson. D, et al 2015)

Trading Food for Profit

'Money makes the world go round'. This phrase couldn't be any more true than when it's observed from the point of view of the environment. Despite a healthy ecosystem being crucial for the survival of our species, the greed of our society is jeopardizing future generation's survival. As a result of human activity through urbanization, habitat loss, climate change etc has caused a serious decline in pollinator species. 

About 75% of global crops consumed is dependent on animal pollination and are responsible for half a trillion dollars each year globally. The human population is exponentially growing (there has been an increase in demand for crops by 300% within the last 50 years) in conjunction with a simultaneous decline in arthropod pollinators and subsequently a severe decline in crop production. As there is a greater demand for these crops but less supply, the earth will no longer be able to maintain it's carrying capacity and so a global famine is likely to ensue if we don't make alterations to our human activities. Animal pollinated species is responsible for much of vitamin A, C & E and so if we continue to observe this trend of decline of arthropods it will significantly restrict much of the nutrients and vitamins we require  and so we will become more susceptible to environmental changes, diseases etc. 

Pollinators plays an integral role in the health of an ecosystem because 80-95% of all plant species are reliant on animal mediating pollination. It is likely that specialist floral species will display the greatest decline due to a lack of synchrony between plant and pollinator as described in a previous blog. These plants make up the foundation of the food web and so a reduction in floral diversity will result in less energy transferred through the trophic levels. It is predicted that floral communities will become homogeneous and so herbivores that consume primarily on these plants will decrease. This will make all trophic levels more homogeneous causing many niches essential for our survival unoccupied.

The most productive ecosystem on planet earth is heavily reliant on pollination with over 95% of their floral composition depending on this process. These habitats play a significant role in climate control preventing many nations (especially the Americas) from experiencing desertification and reduction in carbon in the atmosphere. These habitats host almost half of all species on earth and with the reduction of pollinators responsible for the reproduction of the floral individuals in conjunction with deforestation, this will put a serious strain onto our planet.