News in Brief

Postgraduate Research

Many students undertake some or all of their Ph.D research at Kew. Recently, a number of Ph.D. projects have started on biological control while several students ahve gained Ph.D.'s in orchid research.
Biological Control

Until 1985, pest management in Kew's glasshouses was dominated by the use of pesticides. Now, more reliance is placed on the use of biological control agents such as predatory beetles, mites and parasitic wasps. The dynamics of pest and control agent populations in high plant diversity situations are considerably more complex than in glasshouse monocultures. For example, predators show varying degrees of effectiveness in controlling pests on different plant species. To improve the effectiveness of these controls, Dr Monique Simmonds, in collaboration with Prof. Wally Blaney (Birkbeck College, London), is leading investigations on how plant diversity in the glasshouses influences the interactions between pests and beneficial agents.

Thrips are a major pest in the Temperate House and cause a great deal of damage. So far the use of the predatory mite, Amblyseius cucumeris, or the predatory bug, Orius laevigatus, has met with limited success and Alison Town is attempting to find out why, as part of a PhD project. She is monitoring populations of the western flower thrip and the glasshouse thrip, and early indications are that the present use of A. cucumeris is not preventing the build- up of the spring populations.

Alison Town monitoring thrip emergence in the Temperate House.

The presence of mealy-bugs is very apparent in some areas of the glasshouses as the copious quantities of honey dew they produce become infected with fungi which appear as sooty deposits on the plants. Steve Belmain, as part of his PhD, is mapping the distribution of mealy-bugs in the Princess of Wales Conservatory. He is monitoring how plants influence the behaviour of the control agents, Cryptolaemus montrouzieri and Leptomastix dactylopii. Similar studies on aphid population dynamics are being undertaken by Fiona Dennis (Living Collections, Kew) in collaboration with Dr Sarah Gardner (Birkbeck College).

First stage nymph of a western flower thrip (SEM x240).

Two students, John Manlove and Asham Ahmad, are investigating how plant- based insecticides, such as Neem, influence the predators and parasitoids of mealy-bugs and whitefly. Whitefly can also be controlled by entomopathogenic fungi, and another PhD student, Pasco Avery, is examining whether fungi affect the foraging behaviour of the parasitoid, Encarsia formosa. The chemical, behavioural or morphological factors involved in these tritrophic interactions will be the subject of future studies.

Contact: Dr Monique Simmonds (0181-332 5328)

Email: Dr Monique Simmonds

PhDs in Orchid Research

Four students studying orchid biology at Kew gained their PhDs recently from the University of Reading: Elizabeth Dauncey and Antonio Toscano de Brito worked on revisions of Dendrobium section Pedilonum and the subtribe Ornithocephalinae, respectively; Tony Cox studied the molecular systematics of Cypripedium; and Guo Yi did research on the breeding systems in Coelogyne and related genera. Sheena McKendrik (University of Cambridge), who studied orchid reintroductions at Wakehurst Place as part of her project, has also gained her PhD.

Tony Cox and Elizabeth Dauncey

  • Dr Colin Clubbe is the new Co-ordinator of Graduate Studies. He took over from Dr Brian Schrire who was appointed to the Herbarium in October 1994.

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