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This research aims to determine whether weed biological control agents attack non-target plants that supported some development in host specificity testing. Field surveys were conducted for agents released to control six major Australian weeds: ragwort (Jacobaea vulgaris Gaertn.) English broom (Cytisus scoparius (L.) Link), gorse (Ulex europaeus L.), alligator weed (Alternanthera philoxeroides (Mart.) Griseb.), Montpellier broom (Genista monspessulana (L.) L.A.S.Johnson), and St John’s wort (Hypericum perforatum L.). A total of 10 agents, including mites and insects, previously released for biological control were examined, and host specificity checks were conducted. Overall, 15 potential alternative host plants were examined for agent attack as well as the target plants. All agents are well established in Australia and had been released from 12 to 44 years earlier. There was no evidence that the non-target species included in this survey were able to support full development of the agents, although an incidental finding of non-target host use requires further survey effort.

Gestational Trophoblastic Disease (GTD) is a rare complication of pregnancy that can develop into cancer. Medical outcomes are well researched but evidence is required on the impact of GTD on health-related quality of life (HRQoL) to improve care. The review was conducted to determine the impact of GTD and its treatment on HRQoL and identify how HRQoL is measured and appropriateness of these measures. Quantitative studies found HRQoL in long-term survivors to be at or above population norms. GTD appeared to have a negative impact on HRQoL where patients experience physical, psychological and social sequelae related to the condition. Clinically significant levels of anxiety, depression, sexual dysfunction and fertility-related distress were found. The results should be treated with caution because the evidence base was limited to small heterogeneous samples, retrospective data and the wide range of measures used. Within the qualitative data, new themes emerged including nerve damage, fatigue, amenorrhea, and grief. Currently, these areas are not captured in patient reported outcome measures (PROMs) and the content may not be valid for this population. Further qualitative research could lead to development of a GTD specific PROM providing reliable, meaningful and valid assessments and allowing longitudinal data to be obtained.

Mike Day and colleagues recently published their paper 'Factors influencing the release and establishment of weed biocontrol agents' in Proceedings of the 16th Australian Weeds Conference. The CRC for Australian Weed Management facilitated an investigation into the factors influencing the release and establishment of weed biological control agents on a wide variety of Australian weeds. The investigation improved the understanding of post-release ecology of biocontrol agents and generated recommendations for best practice. Factors affecting successful establishment on the weed include host plant characteristics, size of releases, dispersal power of the agent, predation and parasitism, and climate. A best practice guide was produced by the CRC to assist practitioners in designing robust release strategies to increase rates of establishment.

Weeds are serious threats to Australia's primary production and biodiversity conservation. For example, a recent Australia Bureau of Statistics survey found that 47% of farmers across Australia have a significant weed problem. A literature review revealed that legumes represent a significant proportion of the national weed problem and most serious Australian legume weeds are exotic thicket-forming species that were deliberately introduced for their perceived beneficial properties, such as for shade and fodder, or even quite trivial reasons, such as garden ornamentals. The low economic value of the rangelands most of these species infest, compared with control costs, hinders chemical and mechanical control of these weeds, such that biological control, which takes time, is expensive to implement and has no guarantee of success, may represent the only economically viable alternative to abandoning vast tracts of land. We argue that, because the behaviour of an introduced species in a novel environment is so hard to forecast, better predictive techniques should be developed prior to further introductions of plant species into novel environments. We also discuss the potential of legumes currently being promoted in Australia to become weeds and suggest the recent trend of exporting Australian Acacia spp. to semiarid regions of Africa risks history repeating itself and the development of new weed problems that mirror those posed by Australian Acacia spp. in southern Africa.

A replicated field experiment was conducted in Tasmania, Australia to assess the impact of Tetranychus lintearius on the growth and reproductive capacity of gorse. The dry weight of gorse shoots collected from T. lintearius attacked bushes and miticide-treated controls were compared over a two and a half year period. Over this period, T. lintearius underwent approximately five generations and caused a significant reduction in dry matter production of approximately 36% compared to the miticide-treated control. The reduction could have been greater as this figure was calculated after control plants sustained damage by T. lintearius. Predicted mean shoot dry weights of control plants in the absence of T. lintearius damage were calculated by solving a regression equation on the proportion of non-infested shoots per plant and mean final shoot dry weight. Using this method, it is predicted that a reduction in dry matter production caused by T. lintearius would have been approximately 44% had no damage to controls occurred. Two specialist predators of Tetranychus spp., Phytoseiulus persimilis and Stethorus sp., were both found at the site within the first year of the trial. Tetranychus lintearius was not found to negatively affect the damage caused by an established gorse biocontrol agent, the seed feeding weevil, Exapion ulicis. The use of T. lintearius as a biological agent for gorse in Australia, the interaction between agents and the impact of predators are discussed.

It has been estimated that weeds cost Australian agriculture about $4 billion annually (Sinden et al 2004), In Tasmania, about 1.8 million ha is used for production agriculture (Australian Bureau of Statistics 2001). In 1996, the cost of weeds to Tasmanian primary producers in terms of lost production and the cost of control was estimated at $33 million annually (Anon 1996). The primary aim of this technical bulletin is to provide a revised assessment of the cost of weeds to Tasmanian pastures and field crops as well as identifying the weeds that are having the most significant impact on Tasmanian agriculture. It also reviews the current status of all weed biological control programs that have been conducted in Tasmania against some of the major weeds and provides a case study of the successful biological control program on ragwort. The document should serve as a useful reference for those involved in weed control both within the state and nationally.

Water-logged soil could be a major factor affecting populations of the ragwort biological control agent, Longitarsus flavicornis , in Australia. Survival of L. flavicornis larvae in potted ragwort plants after inundation with water for up to 264 h (11 days) was compared to larval survival in control plants not exposed to inundation. Probit analysis indicated that 35.6% mortality of the larval population occurred after 24 h inundation and 50.4% after 72 h. As high mortality was recorded at periods of inundation known to occur in the field, it is concluded that winter flooding is likely to be detrimental to populations of L. flavicornis.