CHARUDATTAN, R. (University of Florida, USA)
Plant Pathogens – An Underexploited Resource to Counteract Invasive Weeds.

Pathogens are under-utilised in the global efforts to counter invasive weeds. Past successes and our recent discovery of a virus-induced herbicidal action in the Tobacco mild green mosaic tobamovirus-Solanum viarum system provide the basis to argue for intensified efforts to discover, develop, and use pathogens as weed-control agents.

SHAW, R.H.¹, GREATREX, R.² (¹CABI Bioscience, UK, ²Syngenta Bioline, UK)
Why is biological control so difficult in the UK?

Developing and implementing UK classical weed biocontrol programmes has proven challenging. Biocontrol in the glasshouse is more established but not without its own hurdles. This paper compares the theory and reality facing both practitioners and suggests improvements to bring the UK situation closer to that of more experienced countries.

DJEDDOUR, D.H. SHAW, R.H. TANNER, R.A. (CABI Bioscience, UK)
The biological control of Japanese knotweed (Fallopia japonica): the story so far.

This programme, the first of its kind in the UK, began in earnest in 2003 after 13 years of development. We present the weed's profile, including its original source, the findings of Japanese field surveys and introduce the natural enemies so far studied in quarantine, highlighting those still under consideration.

KIRK, A.A.¹, WIDMER, T.¹, DUDLEY, T.², CAMPOBASSO, G.¹ (¹United States Department of Agriculture, Montpellier, France, ²University of Nevada, Reno, USA)
Biological control of Arundo donax; a practical solution.

Arundo donax is an invasive weed in the southwestern USA. It replaces native vegetation causing flooding and wildfires. In its native Mediterranean natural enemies such as Diptera and Hymenoptera reduce its invasiveness. Biological control of Arundo may be a practical solution.

EVANS, H.C.¹, TOMLEY, A.J.² (¹CABI Bioscience, UK, ²Alan Fletcher Research Station, UK)
Towards successful management of the Madagascan rubber-vine weed in Australia: an integrated approach underpinned by classical biological control.

Rubber-vine weed (Cryptostegia grandiflora) covers over 40,000 km² of Queensland, Australia. The purposeful introduction of the coevolved rust Maravalia cryptostegiae has resulted in sustained defoliation of the target weed and the regeneration of indigenous grasses. It also permits the integration of more traditional fire management practices that were previously impossible.

GERBER, E. HINZ, H.L. (CABI Bioscience, Switzerland Centre)
Impact of two potential biological control agents on Alliaria petiolata and the interactions between them.

We investigated the individual and joint effects of two weevils, Ceutorhynchus scrobicollis and C. alliariae, which are currently studied for biological control of Alliaria petiolata in North America. Results indicate that both species could be released together but preference should be given to C. scrobicollis due to its stronger impact.

MUELLER-SCHAERER, H.¹, SCHAFFFNER, U.², STEINGER, T.¹ (¹University of Fribourg, CH, ²CABI Bioscience Centre, CH)
Evolution in invasive plants and implications for biological control.

Evidence is mounting that invasive plants can undergo rapid adaptive evolution during the process of range expansion. Here, we argue that evolutionary change during invasions will affect plant-antagonist interactions and thus have important implications for biological control programmes targeted at invasive plants.

UYGUR, S.¹, SMITH, L.², UYGUR, F.N.¹ (¹Cukurova University, Turkey, ²USDA-ARS Western Regional Research Center, USA)
Biological Control Studies on Centaurea solstitialis L. (Yellow starthistle) in Turkey.

Centurea solstitialis L. which is native to southern Europe and western Eurasia.It was accidentally introduced to western USA and became an alien weed.It occurs throughout Turkey as an annual weed especially in pastures.Our ongoing studies starting from 1999 were conducted to understand occurance of C. solstitialis, to determine natural enemies, to study on its promising agents and population growth towards its biological control. Ceratapion spp. were the most common natural enemies. Our previous studies show that C. basicorne was the most promising biocontrol agents against to control of C. solstitialis.

SALZMANN, D. HANDLEY, R.J. MÜLLER-SCHÄRER, H. (University of Fribourg, CH)
Effect of reduced photosynthetic rate in Senecio vulgaris on resistance and tolerance to the rust fungus Puccinia lagenophorae.

Isonuclear triazine herbicide resistant (with reduced photosynthetic capacity) and susceptible biotypes of Senecio vulgaris were compared to: (1) examine the role of photosynthetic rate and its compensatory increase (a potential tolerance mechanism) after damage imposed by the rust fungus Puccinia lagenophorae; (2) find potential negative cross resistance.

HINZ, H.L.¹, SCHWARZLAENDER, M.² (¹CABI Bioscience Switzerand Centre, Switzerland, ²University of Idaho, USA)
Comparing invasive plants in their native and exotic range: what can we learn for biocontrol?

This paper reviews and summarizes data sets that attempt to compare performance, population dynamics, and herbivory of invasive plant species at field sites in their native and exotic range and under standardized conditions. We will discuss how such studies can benefit biological control programs and suggest future research.

BUCKLEY, Y.M.¹, REES, M.¹, PAYNTER, Q.², LONSDALE, M.² (¹NERC Centre for Population Biology, Imperial College London, UK, ²CSIRO Entomology, Australia)
An integrated approach to managing invasive weeds.

The giant sensitive plant (Mimosa pigra) is the worst invasive weed in tropical Australia. We use experimental data to parameterise an integrated weed management model and predict optimal management incorporating biocontrol, herbicides, fire and mechanical control. The model includes much of the basic ecology of mimosa while retaining a simple framework.

INGLESE, S.J. CACHU, Y. PAUL, N.D. (Lancaster University, UK)
Tolerance of Senecio vulgaris attacked by a native and alien rust fungus.

It is generally accepted that plants are more vulnerable to the effects of alien pathogens due to a lack of resistance. We are testing the hypothesis that tolerance of disease is also lower in the face of alien pathogens using Senecio vulgaris attacked by native and introduced rust fungi.

ROSE, K.E.¹, LOUDA, S.M.², REES, M.¹ (¹Imperial College, UK, ²University of Nebraska, USA)
Demographic and evolutionary impacts of native and invasive insect herbivores: a case study with Platte thistle, Cirsium canescens.

We quantify evolutionary effects of herbivory by native and invasive insects on monocarpic thistles. Models specified how demographic rates varied with individual size and herbivore damage. These were used to parameterise integral projection models (IPMs) investigating the effects of herbivory on lamba, equilibrium population size and evolutionary stable flowering strategy.

ODURO, C.¹, HATCHER, P.¹, NEWMAN, J.² (¹University of Reading, UK, ²Centre for Aquatic Plant Mgt., Sonning, UK)
Control of red water fern (Azolla filiculoides) using tarragon (Artemisia dracunculus) and mugwort (Artemisia vulgaris) leaf extracts.

Effect of tarragon and mugwort leaf extracts on Azolla growth was examined. Leaves were extracted sequentially with methylene chloride, ethanol, and water. Extracts were introduced into growth medium. Tarragon and mugwort aqueous extracts and mugwort ethanol extract inhibited Azolla growth whilst methylene chloride and ethanol extracts of tarragon were lethal.

REEDER, R.H. SHAW, R.H. (CABI Bioscience, UK)
Innundative biocontrol of Azolla filiculoides using a specialist weevil.

The non-native fern, Azolla filiculoides, causes problems in many aquatic habitats. Fortunately, the monophagous weevil, Stenopelmus rufinasus, has also become naturalised in the UK but has failed to emulate its spectacular South African performance. The reasons are examined and the potential for early inundative releases of overwintered weevils is explored.

Many thanks to the British Ecological Society for allowing us to publish these abstracts, which first appeared in their ‘Annual Meeting and AGM, Programme and Abstracts’.