Weather –

August 2009, Vol. 64, No. 8

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Meeting reportApplications of atmospheric science are

relevant to a range of themes within science

and society; application to entomology was

the main focus of this meeting organized

by Dr Curtis Wood (University of Reading),

which was held jointly with the Royal

Entomological Society. The talks were

designed to appeal to the broader scientific

community by showcasing topics near the

join of the two disciplines. The audience

heard about exciting topics within weather

and climate change, how they are applied to

entomological science and how insects can

be used to advance atmospheric science. The

meeting included the 2009 Margary Lecture

given by Prof. Philip Mellor (Figure 1) from the

Institute for Animal Health (IAH) at Pirbright.

First, one might question why one needs

to know about insect movements. Beyond a

more fundamental understanding of insect

ecology, there are impacts on many parts

of society. Dr Jason Chapman (Rothamsted

Research) highlighted that many insects

have well-developed migration strategies

that enable them to travel many hundreds

of kilometres in just a few days (e.g. the

diamond-back moth in Chapman et al.,

2002). This is important since many insects

can be pests for crops. In particular, Dr

Chapman discussed the detection and

understanding of the mass emigrations

at spring and autumn (northwards and

southwards respectively) observed in data

from UK entomological radar.

The research into insect-vectored

parasites and viral diseases (e.g. malaria

and bluetongue carried by mosquitoes and

midges respectively) was presented by Dr

Andrew Morse (University of Liverpool) and

Prof. Mellor (Mellor et al., 2000). Temperature

is a powerful determinant in the transmission

of viruses and other pathogens both within

vectors themselves and in their host animals,

in addition to strongly affecting insect

migration itself. UK media and politicians

have paid great attention in recent years

to the spread of bluetongue into northern

Europe via certain Culicoides midge species;

the first UK case was discovered on 21

September 2007. A quote was underlined

from the Prime Minister’s 2009 Romanes

Lecture in Oxford (Brown, 2009):

…when British scientists used

meteorological data to predict that

midges bearing bluetongue virus would

be carried to specific parts of the UK from

the continent – they enabled selective

vaccination of livestock and saved nearly

£500 million, together with 10 000 jobs.

Without doubt, society benefits from the

Met Office working with the Department

for Environment, Food and Rural Affairs

(Defra) and IAH in this integrated approach.

Laboratory work at Pirbright was empha-

sized since Pirbright is an international

reference laboratory for many viral diseases

(e.g. bluetongue, foot-and-mouth, African

horse sickness).

Classic entomological techniques of

ground-level trapping have been running for

many decades. For example, the Rothamsted

Insect Survey’s (www.rothamsted.ac.uk/

insect-survey) first trap started in 1933, and

netting studies have been operating for a

similar length of time (Chapman et al., 2004).

Recently, at Rothamsted Research, the flight

simulator technique (Mouritsen and Frost,

2002) is being used so that flight behaviours

– such as insect orientation phenomena –

can be studied under controlled conditions.

Since the development of radar for

entomological purposes in the 1960s, papers

on the detection of insects at high altitude

have developed into a large literature (see

the radar entomology website, www.pems.

adfa.edu.au/~adrake/trews). In particular,

vertical-looking entomological radars (VLRs)

have been operational in the UK since 2000

and are presently located at Rothamsted

and Chilbolton; an example of such VLR

output of aerial concentrations of macro-

sized insects is shown in Figure 2.

Dr Susan Rennie (University of Reading)

showed how understanding the movement

of insects detected by the UK network of

precipitation radars could be used to infer

information about winds and thus improve

short-term weather forecasts by including

this extra information in data assimilation

systems (Rennie et al., 2008; see also Wood

et al., 2009b for obtaining insect echoes

from cloud radars). Such information will

be most useful at short lead-times (of order

of minutes to hours) in the development of

convective precipitation.

John Gloster (IAH-Pirbright and the Met

Office) discussed the joint development by

the Met Office’s Atmospheric Dispersion

Group and IAH-Pirbright of the Numerical

Atmospheric-dispersion Modelling Environ-

ment (NAME) for use in the biological com-

munity (foot-and-mouth in Gloster et al.,

2003; bluetongue in Gloster et al., 2008)

(Figure 3). The NAME technique includes a

vital non-deterministic approach: since the

model is Lagrangian in nature, the numer-

ous trajectories show the breadth of path-

ways insects/particles could follow from a

given take-off location. Furthermore, the

need for a non-deterministic approach was

echoed by Dr Morse, who showed work from

Insects, weather and climate

Figure 1. Vice-president Philip Eden (right) presented Philip Mellor (left) with a certificate and gift for

giving the annual Margary lecture.

Figure 2. Macro-insect numbers per five-minute sampling period per range-gate (see colour key)

on 16/17 June 2000 at the Malvern radar. This diurnal cycle shows many of the features seen in the

vertical profile (see also Wood et al., 2009a). In the period shown the end of civil twilight and sunrise

were at 0259 and 0348 UTC respectively, sunset and the end of civil twilight were at 2031 and 2120 UTC

respectively. No data was available for heights below 150m above the radar.

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ECMWF weather prediction ensembles and

the resulting malaria forecasts (Thomson et

al., 2006).

A large range of spatial scales was

discussed at this meeting: (i) at larger spatial

scales, atmospheric flow and temperature

affect aerial insect migrations (Drake and

Farrow, 1988); (ii) at the scale of metres

to kilometres, micrometeorology and local

insect habitats were discussed by Prof.

Chris Thomas (York University, Thomas et

al., 2004) who emphasized the difficulty of

downscaling global climate-model data into

the effects at the microscale, and (iii) at the

molecular scale, Prof. Mellor talked about

the virus within the insect itself and the

effect of temperature on virus transmission.

Discussion

Much of the weather and climate change

work performed ultimately needs end-users.

The entomological community is one that

is a substantial user of many weather and

climate products (perhaps primarily because,

since insects are cold-blooded, many

entomological problems require temperature

data). Indeed, all research presented at this

meeting included atmospheric data that were

needed in order to conduct the research.

Dr Rennie’s work is part of the Flood Risk

from Extreme Events (FREE) programme,

where researchers are looking at the causes

and propagation of floods to help to forecast

and quantify flood risk, and inform society

about the likely effects of climate change.

FREE brings researchers in the hydrological,

meteorological, terrestrial and coastal

oceanography communities together in an

integrated research programme.

The presentations and subsequent

questions provoked interesting dialogue,

which included the long-standing debate on

the spectrum from passive-to-active flight.

In brief, at the lower end of the spectrum

dust/seeds/spores are often assumed

to be completely passive (or perhaps

with gravitational settling) and can be

transported hundreds of kilometres; next on

the spectrum are wingless arthropods (who

might be able to affect their movements

by curling their bodies or secreting silk

drag-lines); next are small insects (whose

flight strongly depends on atmospheric

conditions) and finally the self-propelled

flight of large insects and birds appreciably

affects their tracks. Reference was made

to Reynolds and Reynolds (2009), whereby

even small insects like aphids clearly are

not completely passive tracers of the wind.

As further evidence of the insects’ non-

passiveness, evidence of the common

orientation phenomenon was shown by Drs

Rennie and Chapman (in this effect most

insects’ bodies are not aligned with the wind

but they modify their flight path by flying at

an angle to the wind).

Further discussion took place around

posters that were presented by Laura Burgin

(Met Office), Rebecca Nesbitt (Rothamsted

Research) and Dr Wood. There was also an

interview with BBC Radio Berkshire, who

talked with Prof. Paul Hardaker (RMetS Chief

Executive) and Dr Wood on the highlights of

the meeting.

This report is not a full representation

of the meeting’s output, but merely

summarizes some of the work presented.

Copies of the speakers’ presentations can be

found on the RMetS website (at http://www.

rmets.org/events/abstract.php?ID=407).

References

Brown G. 2009. Romanes Lecture, Sheldonian Theatre in Oxford 27 February 2009. http://www.number10.gov.uk/Page18472. [Accessed 29 April 2009.]

Chapman JW, Reynolds DR, Smith AD, Riley JR, Pedgley DE, Woiwod IP. 2002. High altitude migration of the dia-mondback moth Plutella xylostella to the UK: a study using radar, aerial netting, and ground trapping. Ecol. Entomol. 27: 641–650.

Chapman JW, Reynolds DR, Smith AD, Smith ET, Woiwod IP. 2004. An aerial netting study of insects migrating at high-altitude over England. B. Entomol. Res. 94: 123–136.

Drake VA, Farrow RA. 1988. The influence of atmospheric structure and motions on insect migration. Annual Review of Entomology 33: 183–210.

Gloster J, Burgin L, Witham C, Athanassiadou M, Mellor PS. 2008. Bluetongue in the United Kingdom and northern Europe in 2007 and key issues for 2008. Vet. Rec. 162: 298–302.

Gloster J, Chamion HJ, Sorensen JH, Mikkelsen T, Ryall D, Astrup P, Alexandersen S, Donaldson AI. 2003. Airborne transmission of foot-and-mouth disease virus from Burnside Farm, Heddonon- the-Wall, Northumberland during the 2001 UK epidemic. Vet. Rec. 152: 525–533.

Mellor PS, Boorman J, Baylis M. 2000. Culicoides biting midges: their role as arbovirus vectors. Annual Review of Entomology 45: 307–340.

Mouritsen H, Frost BJ. 2002. Virtual migration in tethered flying monarch butterflies reveals their orientation mechanisms. Proc. Natl. Acad. Sci. USA 99: 10162–10166.

Rennie S, Illingworth A, Dance S, Ballard S. 2008. Utilization of Doppler radar wind measurements from insect returns. The fifth European conference on radar in meteorology and hydrology, 2008. http://erad2008.fmi.fi/proceed-ings/extended/erad2008-0123-extend-ed.pdf [Accessed 29 April 2009.]

Reynolds AM, Reynolds DR. 2009. Aphid aerial density profiles are consistent with turbulent advection amplifying flight behaviours: abandoning the epithet ‘pas-sive’. P. Roy. Soc. London B 276: 137–143.

Thomas CD, Cameron A, Green RE, Bakkenes M, Beaumont LJ, Collingham Y, Erasmus BFN, de Siqueira MF, Grainger A, Hannah L, Hughes L, Huntley B, van Jaarsveld AS, Midgley GF, Miles LJ, Ortega-Huerta MA, Townsend Peterson A, Phillips O,

Figure 3. Example of output from the Met Office’s NAME (Numerical Atmospheric-dispersion

Modelling Environment) issued to Defra on 7 August 2007 of the risk of virus vectors to the UK, taken

from Gloster et al., 2008.

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August 2009, Vol. 64, No. 8

Meeting report

Williams SE. 2004. Extinction risk from cli-mate change. Nature 427: 145–148.

Thomson MC, Doblas-Reyes FJ, Mason SJ, Hagedorn R, Connor SJ, Phindela T, Morse AP, Palmer TN. 2006. Malaria early warnings based on seasonal climate fore-casts from multi-model ensembles. Nature 439: 576–579.

Wood CR, Reynolds DR, Wells PM, Barlow JF, Woiwod IP, Chapman JW. 2009a. Flight

periodicity and the vertical distribution of high-altitude moth migration over south-ern Britain. B. Entomol. Res. DOI:10.1017/S0007485308006548. Published online 19 February 2009.

Wood CR, O’Connor EJ, Hurley RA, Reynolds DR, Illingworth IJ. 2009b. Cloud-radar observations of insects in the UK convective boundary layer. Meteorol. Appl. (in press). DOI:10.1002/met.146.

Correspondence to: Curtis Wood,

Department of Meteorology,

The University of Reading,

Earley Gate,

Reading, RG6 6BB,

UK.

Email: c.r.wood@reading.ac.uk

© Royal Meteorological Society, 2009

DOI: 10.1002/wea.431

LettersReaders are encouraged to submit letters for

possible publication. Letters can be submitted

either electronically through the system

used for articles, by email attachment to

weather@wiley.com or by post, as shown on

the Contents page. The Letters Editor reserves

the right to edit any letter.

Chamber’s Pillar

Unless the track has been upgraded – it was

for many years, and still may be, used for

an annual motor cycle race which ensured

that the surface remained loose, rough,

corrugated, and rutted – J. F. P. Galvin is to be

congratulated on having survived a bone-

shaking trip to Chamber’s Pillar and at the

end of it being steady enough of hand to

take such a splendid photograph (Weather,

April 2009). However, such forms – buttes

or small plateaus each with a maximum

crestal diameter that is greater than its

height above the adjacent plain – are not

restricted to arid lands. They occur in a range

of climates, including rainforests – as in the

Roraima Plateau of northern South America –

and monsoon Australia. Certainly they are

most spectacularly displayed in deserts or

semi-arid lands where the view is unimpeded

by vegetation. They develop wherever a

plateau of massive, flat-lying sandstone is

being dissected. They are ephemeral forms,

for the flanks gradually are undermined, so

that the bounding bluffs are worn back and

the diameter decreased. Eventually the last

slender remnant will collapse, as did the

well-known Mukarob (‘the Finger of God’) of

central Namibia, early in 1989.

C.R. Twidale

University of Adelaide, South Australia

DOI: 10.1002/wea.470

J. F. P. Galvin replies:

I thank C.R. Twidale for pointing out that

rock plateaux such as Chamber’s Pillar can

be seen in other than desert lands. Factors

such as the time that the eroding rock layers

have been exposed and their competence

must also be taken into consideration.

Buttes cannot, therefore, be considered

characteristic of arid lands or seen only

within them, but they are typical.

However, they are often observed in dry

lands and a degree of aridity is generally

associated with these landforms. This is even

the case in the example of the (ancient)

Roraima Plateau given in Rowl Twidale’s

letter. This area is one of savannah, despite

its proximity to the equator; not one of

tropical rainforest. Rainfall is seasonal,

amounting to less than 1600mm per annum

and photographs show the vegetation to

be characteristic of semi-arid lands. Heavy

convective rainfall predominates in the

wet season. Nevertheless, I am sure many

readers will know of pictures of lava flows

and remnant plateaux with steep slopes in

moist environments, in particular where the

feature has not long been exposed to the

elements.

Where rainfall is abundant and occurs

throughout the year, most mesas and

buttes soon assume rounded shapes. In

general, where frost is rare, rainfall is the

main (possibly the only) cause of erosion.

Dependent on the competence of the rock,

the difference in competence of layers

(typically more competent above less

competent, in the case of these plateaux)

and, of course, the orography, the more the

rainfall, the shallower the slope.

The near-vertical edges of Chamber’s

Pillar illustrate the arid environment of the

Australian desert, where erosion is slow

and due largely to ephemeral precipitation.

Erosion occurs largely due to run-off (often

from heavy downpours) washing away the

sides of the underlying, less competent

layer and undermining the rock layer above,

which preferentially breaks along near-

vertical joint surfaces. Whilst, of course, this

can happen elsewhere, the precipitation

characteristic of arid lands preferentially

forms these steep-sided formations.

ReferencesGalvin JFP. 2009. The weather and cli-mate of the tropics, Part 9 - Climate, flora and fauna. Weather 64: 100–107.

Jim Galvin

Met Office, RAF Akrotiri

DOI: 10.1002/wea.482