Monthly Archives: September 2014

Not all aphids have wings

Given that aphids are commonly known as green-fly or black-fly, it might be presumed that all aphids are capable of flight. Although this is almost certainly universal at the species level (but see Post script) it is not true within a species. As I have described in an earlier post aphids are possessed of extremely complex and fascinating (to me at least) life cycles. Depending on the species, either most stages of the life cycle are winged (alate) as adults, e.g. the sycamore aphid Drepanoisphum platanoidis

Holocyclic.png

Sycamore aphid

I couldn’t resist showing you this beautiful picture of an adult sycamore aphid borrowed from the best aphid web site that I know of (see http://influentialpoints.com/Gallery/Drepanosiphum_platanoidis_common_sycamore_aphids.htm)

 

Other aphid species, such as my favourite, the bird cherry-oat aphid, Rhopalosiphum padi, only produce alate morphs at specific times of year or in response to changes in host plant quality or crowding.

Heteroecious

 RhopalosiphumPadi  Rhopalosiphum padi on leaf

Winged (alate) and non-winged (apterous) morphs of Rhopalosiphum padi.

In species such as the sycamore aphid, the only apterous morph tends to be the sexual female or ovipara, which has no need to disperse and after mating lives only long enough to develop and lay its eggs on the bark of sycamore trees.

Sycamore ovip on bark

Ovipara of the sycamore aphid searching for an oviposition site

In those species such as the bird cherry-oat aphid, the winged forms are very different from the non-winged forms, not just in terms of their wings but in their physiology, behaviour and life history traits (Dixon, 1998). The role of the winged morphs is to find new host plants and to start new colonies. They have long antenna, long legs and well-developed and many, sensory organs (rhinaria). They are the dispersal stage, or in the case of winged males, the mate seekers. They respond more readily to host odours; they need to be able to find new host plants at a suitable physiological stage and preferably free of natural enemies. A well-developed olfactory system is thus called for.

If you cut them open (preferably anaesthetizing them first), and remove their ovaries, you will find that they have ovarioles with only a few embryos in each chain and that most of the embryos are not mature i.e. without eye spots. In addition, if you cut open a number of individuals from the same clone you will find that they will not all have the same number of ovarioles. For example, the alate exules (winged forms produced on the secondary host plants )of Rhoaplosiphum padi, the number of ovarioles can range from four to ten (Wellings et al, 1980). This variability of ovariole number in the dispersal morphs of aphids that spend much of their life cycle on ephemeral host plants is quite common (Leather et al 1988).  So why do so many aphid species have variable numbers of ovarioles in their alate morphs?

Shaw (1970), showed that there appeared to be three types of black bean aphid (Aphis fabae) alate exules; migrants, those that flew before depositing nymphs, flyers, those that deposited a few nymphs before flying, and non-flyers, those that stayed and reproduced on their host plant. He postulated that this was an adaptation in response to host quality, the worse state the plant was in the more likely the migrant morph would be produced. Many years later Keith Walters and Tony Dixon (Walters & Dixon, 1983) were able to show that there was a very strong relationship between reproductive investment (number of ovarioles) and flight willingness and ability. The more ovarioles an aphid had, the less likely it was to want to take off and fly, and in addition those with more ovarioles could not fly for as long or as far as those with fewer.

Ovarioles and flight

In other words a trade-off between fecundity and migration. As long distance aphid migration is very costly (very few survive, Ward et al, 1998) it makes sense to have members of your clone spreading the load (risk), from short-distance hops (trivial flights), with the chance that the next door plant might be just as bad as the one left behind and within easy reach of natural enemies, but with a higher chance of survival and reproduction, to long distance migratory flights, with the reduced probability of finding a host plant but with the chance that it will be high in nutrition and low in natural enemies.

What clever beasts aphids are 😉

 

References

Dixon, A.F.G. (1998) Aphid Ecology, Second edn. Chapman & Hall, London.

Leather, S.R., Wellings, P.W., & Walters, K.F.A. (1988) Variation in ovariole number within the Aphidoidea. Journal of Natural History, 22, 381-393.

Shaw, M.J.P. (1970) Effects of population density on the alienicolae of Aphis fabae Scop.II The effects of crowding on the expression of migratory urge among alatae in the laboratory. Annals of Applied Biology, 65, 197-203.

Walters, K.F.A. & Dixon, A.F.G. (1983) Migratory urge and reproductive investment in aphids: variation within clones. Oecologia, 58, 70-75.

Ward, S.A., Leather, S.R., Pickup, J., & Harrington, R. (1998) Mortality during dispersal and the cost of host-specificity in parasites: how many aphids find hosts? Journal of Animal Ecology, 67, 763-773.

Wellings, P.W., Leather , S.R., & Dixon, A.F.G. (1980) Seasonal variation in reproductive potential: a programmed feature of aphid life cycles. Journal of Animal Ecology, 49, 975-985.

 

Post script

It is possible that there are some aphids that never fly – Aphids from the genus Stomaphis have incredibly long mouthparts (they all feed through tree bark), and as far as I can tell from perusal of

Stomaphis query aceris

Roger Blackman and Vic Eastop’s monumental work, alate morphs have never been described (or seen) and even males are apterous.

Blackman, R.L. & Eastop, V.F. (1994) Aphids on the World’s Trees. CABI, Wallingford.

 

Post post script

For a very detailed and thoughtful review of the ‘decisions’ and costs involved in aphid reproductive and dispersal biology see Ward, S.A. & Dixon, A.F.G. (1984) Spreading the risk, and the evolution of mixed strategies: seasonal variation in aphid reproductive strategies. Advances in Invertebrate Reproduction, 3, 367-386.

 

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Filed under Aphidology, Aphids

How do we save UK plant sciences?

At the beginning of this year (2014) the UK Plant Sciences Federation published an important report about the crisis facing plant sciences in the UK. This was not the first report of this type, for example in 2009 the BBSRC which ironically, is together with HEFCE perhaps one of the main culprits that caused the crisis in the first place, produced a report on vulnerable bioscience research skills, in which among others, they highlighted the vulnerability of plant sciences. The British Society for Plant Pathology produced a similarly gloomy report in 2012. All three reports basically said that UK plant sciences are in danger of extinction unless something is done sooner, rather than later.

Lawn dead 2014

To explain why I, an entomologist, am writing about this, I should explain that plant sciences encompasses plant pathology, plant nematology, plant entomology and pest management as well as agriculture, botany, horticulture, plant breeding etc.

In response to these findings the UKPSF set up four working groups, one of which, the Training and Skills Working Group, I was asked to chair. As if I hadn’t enough work to do already, I agreed.

Our Terms of Reference are:

To develop an implementation plan for the UKPSF and plant science community, outlining clearly defined actions and associated time scales. The plan should contain:

  • One or two short-term actions (achievable within six months to one year).
  • One to three medium to long-term actions (achievable within one to five years).

For each action the working group should specify realistic:

  • Mechanism(s).
  • Responsibility/responsibilities.
  • Timescale(s).
  • Rationale

The working group consists of

Simon Leather Professor of Entomology, Harper Adams University (Chair)

Mary Berry Curriculum Leader for Science, Woodlands Academy

Sarah Blackford Head of Education & Public Affairs, Society for Experimental Biology

Gary Foster Professor of Molecular Plant Pathology, University of Bristol; President-Elect, British Society of Plant Pathology

Alistair Griffiths Director of Science, Royal Horticultural Society

Jo Hepworth Postdoctoral Researcher, John Innes Centre

Jon Heuch Owner and Director, Duramen Consulting Ltd (Chartered Foresters and Arboricultural Consultants); Trustee/Director, Arboricultural Association

Emma Kelson Training Officer, Society of Biology (Minute Secretary)

Celia Knight Independent educational consultant (UKPSF Executive Committee)

Charles Lane Consultant Plant Pathologist, Food and Environment Research Agency (Fera)

Jonathan Mitchley Lecturer in Plant Community Ecology, University of Reading; Senior Botanist, RSK Group Ltd

Ginny Page Director, Science and Plants for Schools (SAPS) (UKPSF Executive Committee)

Dawn Sanders Docent/Associate Professor, Gothenburg University; Gardens for Learning

Phil Smith Coordinator, Teacher Scientist Network (TSN)

Mimi Tanimoto Executive Officer, UKPSF (Coordinator)

Eleanor Walton PhD Student, University of York

So a fairly wide range of interests and hopefully representative of the plant science community.

I began by asking each member of the group to highlight their greatest concern about plant science training and skills: In no particular order these were our thoughts and concerns

  • we seem to have lost people who can identify things.
  • what do we understand plant science to be, what plant scientists do and what are the skills and opportunities for the future? These need to be understood to communicate professions to young people.
  • the perception that plants are boring. There is a lack of general respect for plant scientists and this needs to be tackled to attract young people into the sector.
  • Even within the academic world, there is a lack of respect for plant scientists, and this stems from a wider society perspective. Plant scientists are underappreciated at all levels.
  • lack of curriculum knowledge at lower level e.g. NVQs.
  • Government does not see plant science as connected with culture. There is big strength in relation to food production but we are failing to explain the wealth of ecosystems services that plants give us. Fusing technology with functionality and health and wellbeing will allow people to understand that plant science is worthwhile and valuable.
  • lack of funding: securing more funding for plant science will entail getting greater public support and more people interested in plants. Increasing awareness of plant science in schools will therefore allow more of a cultural change.
  • lack of trained people within schools to deliver effective plant science education. Making teachers confident and well equipped to teach plant science is a challenge. Few biology teachers in schools have a plant science background. Biology content of the secondary school curriculum is fractured and does not tell a sensible story, so it does not entice or engage students sufficiently. At ‘A’ level, the main focus is on human physiology and not enough on the physiology of plants. Students do not understand the life cycle of plants because they are taught in random chunks.
  • the university sector is just as bad; many biology departments are moving towards animal, human and biomedical sciences because they tend to bring in more funding. Plant pathologists are a dying breed in UK universities and if plant science is not made a core part of biology degrees, it could lead to a major skills gap.
  • a behavioural change is needed to get people involved with plant science and plant health. Funding initiatives, although welcome, tend to be short-lived so how do we sustain a significant long term improvement?
  • it is important to inspire young people to study plant science and demonstrate the types of careers available. We also need to make sure that employers have people with the right kinds of skills but universities often struggle to put on plant sciences courses because of a lack of student interest.

For a similar overview and some possible solutions, see http://cairotango.wordpress.com/2014/04/03/the-trouble-with-plant-science-education/

The main concerns are a lack of understanding of what plant science is, a lack of respect for whole organism plant science and plant scientists in universities, and a huge problem at pre-university level with children and young people not understanding how important plants are and why they are exciting. There is a huge skills shortage in areas such as plant nematology and in basic whole organism biology including the ability to identify organisms, be they plants, fungi, insects and the damage they cause. Students do not understand that there are careers in plant science and related areas such as integrated pest management. In summary the UK has a big educational and resourcing problem in plant sciences.

Why this post?

Think of this as a crowd-sourcing exercise. As a group we want your opinions and most importantly, your suggestions about what the best way forward is. Please engage.

 

If we do nothing

Without a well-trained cadre of plant scientists that are able to recognise whole organisms and are able to interact with industry we will see more problems arising with invasive species, our crop production industry will be severely compromised and biodiversity loss will accelerate. The current crisis in the Forest Health sector for example, is a direct result of lack of investment in plant and allied sciences.

 

What can we do?

Degree accreditation

The Society of Biology and their degree accreditation scheme is one way to restore whole organism plant science teaching to universities. Rachel Lambert-Forsyth of the Society of Biology told us that the key learning outcomes for the three-year programme are general skills such as teamwork, project management, maths and statistics, demonstrating technical skills and familiarity with a practical environment. The final component is specific skills and knowledge appropriate to the degree title. The Society expects to be able to accredit across the breadth of the biosciences but they will need to make sure that they have the relevant expertise to assess this.

We noted that in chemistry and experimental psychology, external bodies specify what should be taught in universities for a course to be accredited. Perhaps to be accredited a biology course should contain a minimum specified number of hours of plant science teaching. Apparently however, the academics involved in the development of the criteria are very against being too specific in case they stifled innovation. The criteria do, however, specify that biology courses should contain the breadth of biosciences so accreditation assessors would look for this. On the plus side, a number of large companies have stated that during their recruitment processes they will actively be looking for students with accredited degrees. This will hopefully encourage universities, including Russell Group ones, to accredit their degrees.

Named plant science degrees at the moment are in decline, Imperial College infamously reduced their plant science provision in 2010 despite having opened new facilities two years earlier. Bristol University used to run a botany degree but this was stopped recently with full support from the plant biologists in the department. The reason given was that instead of studying plants in isolation, plant science should be studied in relation to ecology, animals/insects etc. This may sound a reasonable argument but the problem is that once these subjects are taken out of courses, biochemistry and biomedicine begin to take over and basic whole organism plant science is invariably the loser. This had already happened to the Imperial plant sciences degree before its closure.

We therefore felt that the only way to prevent this happening was to ask the Society of Biology specify that core parts of whole organism plant science must be included in biology degrees, as this would force departments to make plant science appointments and to teach it in a unified way.
Inspiring the next generation of plant scientists

The high level priorities from the UKPSF report include inspiring the next generation of plant scientists and ensuring that employers’ skills needs are met through appropriate training and education.

A recent report from the Aspires project at King’s College, London, highlights that children make important decisions about what is not for them at around the age of 10 to 12 (start of KS3 in the UK). http://www.kcl.ac.uk/sspp/departments/education/research/aspires/ASPIRES-final-report-December-2013.pdf

It is therefore important to get the message across to children that plant sciences are exciting before this. There are a number of initiatives run by national learned and public societies already in existence e.g. the Bug Club for, Nature Detectives, Science and Plants for Schools, RSPB and Plantasia at Kew. See the links below for some examples

http://www.amentsoc.org/bug-club/

http://jointhepod.org/campaigns/campaign/31 Big Bumblebee Discovery

http://www.pestival.org/

http://nationalinsectweek.co.uk/

http://www.saps.org.uk/

http://www.gatsby.org.uk/en/Plant-Science/Projects/Science-and-Plants-for-Schools.aspx

http://www.naturedetectives.org.uk/club/ run by the Woodland Trust

http://www.opalexplorenature.org/ has a Kid Zone

The problem is that whilst it is “relatively” easy, given the right resources and parental and teacher support, to get pre-secondary school interested in the wonders of nature, once they get to secondary school the demands of the school curriculum and expertise available, tend to deter all but the most ‘nature-struck’ children. Those that still retain an interest in whole organism plant biology then find that at university level, options are still very much restricted. This is due to the composition of university teaching staff in biology departments which for the last twenty years or so, has been determined by fashions in research funding and not by the needs of teaching. Courses and modules available have, due to lack of suitable staff, been steadily drifting away from the much-maligned area of natural history and whole organism biology to the much-lauded, and very well-funded, bio-molecular sciences, despite the plethora of articles highlighting the dangers of this attitude, and not all by me 😉

At university level the Gatsby Foundation runs summer schools to encourage undergraduates to consider plant sciences as a career option. This is much-needed, as Ginny Page from SAPS reports that of all the resources SAPS produces, they struggle the most to get teachers using the careers resources. She said this is probably because traditionally, subject specialist teachers are not responsible for delivering careers advice so it is not a standard part of lessons.

There are still a few postgraduate programmes currently available in the UK that are plant science based, such as that run by Reading University in Plant Identification or the MSc in Plant Pathology at Harper Adams University to mention just one of our applied plant science degrees. The problem is, that although jobs await graduates form these courses, particularly those in the pest management area, it is increasingly difficult to get undergraduates to take up the places. Again pointing to the fact that there is a dearth of plant science teaching in current undergraduate courses.

There is of course the Field Studies Council who do a fantastic job, and are, with funding from the Esmée Fairbairn Trust also seeking ways to train trainers and to enthuse future generations of field biologists, so it is worth looking at their priority areas and considering linking up with them.

The UKPSF is developing an online outreach toolkit to collate information on the types of activities that plant scientists can get involved with and how they can get involved, as well as some downloadable resources. They are hoping to launch the toolkit later in 2014. There are also a number of passionate advocates for the plant sciences such as Jonathan Mitchley and his Dr M Goes Wild site.

We agreed that there needs to be greater clarity of signposting to schools or anyone thinking about future careers in plant science, about how and where they can study plant science. This could perhaps be achieved by setting up a young plant science ambassador scheme for students and postdocs to go into schools to teach children about plants and talk about careers. It is likely that the Gatsby Summer School would be a good source of ambassadors.

In conclusion, we agreed that there is a need to highlight the educational opportunities and the career paths to the very many varied, and well-paid jobs in the plant science sector.

The problem is that although there are a number of organisations and individuals promoting plant science that they are not yet all centrally coordinated. We see this as a job for the UKPSF. Funding for these initiatives might then become easier and perhaps more available and generous.

 

Inspiring the teachers

We noted that there is a shortage of plant scientists teaching in schools.

At the moment trainee teachers in physic, maths, chemistry and computing are awarded £25,000 but nothing is provided to trainee biology teachers[1] as a lot of biology graduates already go on to do PGCEs (Postgraduate Certificate of Education); however a large proportion of them are molecular biologists, microbiologists, biochemists and some zoologists. Many have little or no field experience and prefer to remain in the laboratory so this reinforces the idea that plants are boring

We need to get more time for plant science into school curricula and make children interested in it because this would help to fill the spaces on plant science degrees. To do this we need to get more plant science students to take up teaching so once again we are back to the supply problem.

As there is so much to fit into a PGCE, it might be worth looking at what training could be provided for Newly Qualified Teachers during their first year of teaching. SAPS already run two day events for those who train teachers, where they have practicals and talks from plant scientists.

A few universities already have schemes such as INSPIRE, which encourage PhD students and postdocs to go into schools but this is for physics, chemistry and engineering students. The STEM Ambassador scheme provides similar opportunities but very few of the students involved are plant scientists.

Getting more plant scientists into schools is, I think, a government responsibility and will involve yet more adjustment of the school science curriculum nationally. Over to you whichever Minister is in charge this week.

 

“Our vision

At the end of our first meeting as a working group, we came up with a vision of where we would like to see plant science in the future, hopefully near rather than distant.

  • Raised awareness and appreciation of the importance of plant science to UK plc and globally.
  • Better industry and government support for plant science, including appropriate legislation.
  • Plant science seen as a well-paid and respected profession, with clarity over the variety of attractive career paths.
  • Universities valuing the impact of plant science and adjusting their recruitment priorities accordingly.
  • Biology degrees at UK universities with a clear thread of plant science throughout.
  • Accreditation and QAA benchmarks that require the inclusion of plant sciences in biology degrees.
  • Education and training covering a wide range of plant sciences that equips students with a variety of skills.
  • Stronger training links between academia and industry ensuring that HE courses are fit for purpose in industry.
  • Greater awareness and interest in plant science at all levels of education.
  • More plant scientists going into professional teaching, and more researchers engaging with schools.

The next hurdle to overcome is to implement the actions that will help us to achieve our vision. Easier said than done, but we did come up with some concrete suggestions.

 

What we decided

Short term

  • Establishment of a young plant scientist group/ambassador scheme.
  • Collation of resources providing information on plant science careers, training opportunities, courses and provisions, and depositing them on suitable websites.
  • Engagement with employers to find out what skills/training provisions they need.
  • Communication to funders/BBSRC that more support is needed for field based work, not just molecular biology.

Medium term

  • Degree accreditation and QAA benchmark engagement.

Long term

  • Getting more plant scientists into universities.

 

All very laudable but will it bear fruit? At present it is all very much dependent, certainly for the short-term and medium term objectives on the UKPSF finding the wherewithal to fund and manage our proposed initiatives. I think the bottom line is that unless universities are forced to teach a well-rounded plant science degree we are unlikely to see much positive change in the future. The onus may be on the government to change the way it funds universities.

 

Please feel free to comment and disseminate.

Lawn 2014 with fungi

 

Post script

Too much talking not enough action?

Note that in 2009, the Biotechnology and Biological Sciences Research Council (BBSRC) and the then Biosciences Federation held a public consultation to identify strategically important and vulnerable areas of UK bioscience expertise. “Plant and agricultural sciences were highlighted by more respondents (76%) than any other discipline as strategically important capabilities that were already vulnerable or liable to become so. According to the 47 organisations surveyed, the UK still has major skills shortages. We need improved training in-house, as well as through degree, postgraduate and specialised courses”. The following areas were identified as priorities: general plant science, taxonomy and identification, crop science, horticultural science, plant pathology, plant physiology, field studies, plant entomology, nematology, genetics, weed science and pest management.

Interestingly enough when given the chance to fund the only MSc in Entomology in the UK, the Training & Awards Committee failed to take it, and one reviewer (a molecular biologist at a leading Russell Group university) even cited the course area as being outwith the remit of the BBSRC despite  the call specifically mentioning entomology as an area that should be funded at MSc level. The mind boggles at such a narrow-minded view. I suggested at the time that funds should be ring-fenced to ensure funding in these vulnerable areas but was told that this was impossible.

Disturbingly, the BBSRC and MRC are once again conducting a survey to identify vulnerable skills areas and again, due to the composition of the various committees within the BBSRC and MRC (heavily biomedical and molecular biased), I suspect that the only way in which plant sciences and whole organism biology will be saved is by enforcing ring-fencing. We can only hope that someone has the courage and vision to implement it.

 

Post postscript

For those of you who remain unconvinced that plants are exciting I refer you to this remarkable footage from the Private Life of Plants

Private Life of Plants – Bramble Scramble

 

References

Campen, R. (2012) The great outdoors. Biologist, 59, 30-34.

Cheeseman, O.D. & Key, R.S. (2007). The extinction of experience: a threat to insect conservation? In Insect Conservation Biology (ed. by A.J.A. Stewart, T.R. New & O.T. Lewis), pp. 322-348. CABI, Wallingford.

Dayton, P.K. (2003) The importance of the natural sciences to conservation. American Naturalist, 162, 1-13.

Greene, H.W. (2005) Organisms in nature as a central focus for biology. Trends in Ecology & Evolution, 20, 23-27.

Leather, S.R. & Quicke, D.L.J. (2009) Where would Darwin have been without taxonomy? Journal of Biological Education, 43, 51-52.

Leather, S.R. & Quicke, D.L.J. (2010) Do shifting baselines in natural history knowledge threaten the environment? Environmentalist, 30, 1-2.

Noss, R.F. (1996) The naturalists are dying off. Conservation Biology, 10, 1-3.

Tewksbury, J.J., Anderson, J.G.T., Bakker, J.D., Billo, T.J., Dunwiddie, P.W., Groom, M., Hampton, S.E., Herman, S.G., Levey, D.J., Machinicki, N.J., Del Rio, C.M., Power, M.E., Rowell, K., Dsalomon, A.K., Stacey, L., Trombulak, S.C., & Wheeler, T.A. (2014) Natural History’s place in science and society. Bioscience, 64, 300-310.

 

[1] Source: http://www.education.gov.uk/get-into-teaching/funding/postgraduate-funding

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