Modelling the potential spread of Solenopsis invicta Buren (Hymenoptera: Formicidae) (red imported fire ant) in Australia

Quantifying the potential spread and density of an invading organism enables decision-makers to determine the most appropriate response to incursions. We present two linked models that estimate the spread of Solenopsis invicta Buren (red imported fire ant) in Australia based on limited data gathered after its discovery in Brisbane in 2001. A stochastic cellular automaton determines spread within a location (100 km by 100 km) and this is coupled with a model that simulates human-mediated movement of S. invicta to new locations. In the absence of any control measures, the models predict that S. invicta could cover 763 000–4 066 000 km2 by the year 2035 and be found at 200 separate locations around Australia by 2017–2027, depending on the rate of spread. These estimated rates of expansion (assuming no control efforts were in place) are higher than those experienced in the USA in the 1940s during the early invasion phases in that country. Active control efforts and quarantine controls in the USA (including a concerted eradication attempt in the 1960s) may have slowed spread. Further, milder winters, the presence of the polygynous social form, increased trade and human mobility in Australia in 2000s compared with the USA in 1940s could contribute to faster range expansion.

The first five days: field and laboratory investigations during the early stages of the equine influenza outbreak in Australia, 2007.

Until August 2007, Australia was one of only three countries internationally recognised to be free of equine influenza (EI). This report documents the diagnosis of the first cases of EI in Australian horses and summarises the investigations that took place over the next 5 days. During that time, a multifocal outbreak was identified across eastern New South Wales and south-eastern Queensland. The use of an influenza type A pan-reactive real-time reverse transcription polymerase chain reaction allowed rapid confirmation of suspect cases of EI.

Veneer Grade Analysis of Early to Mid-rotation Plantation Eucalyptus Species in Australia

Processing Australian hardwood plantations into rotary veneer can produce more acceptable marketable product recoveries compared to traditional processing techniques (e.g. sawmilling). Veneers resulting from processing trials from six commercially important Australian hardwood species were dominated by D-grade veneer. Defects such as encased knots, gum pockets, gum veins, surface roughness, splits, bark pockets, and decay impacted the final assigned grade. Four grading scenarios were adopted. The first included a change to the grade limitations for gum pockets and gum veins, while the second investigated the potential impact of effective pruning on grade recovery. Although both scenarios individually had a positive impact on achieving higher face grade veneer qualities, the third and fourth scenarios, which combined both, had a substantial impact, with relative veneer values increasing up to 18.2% using conservative calculations (scenario three) or up to 22.6% (scenario four) where some of the upgraded veneers were further upgraded to A-grade, which attracts superior value. The total change in veneer value was found to depend on the average billet diameter unless defects other than those relating to the scenarios (gum or knots) restricted the benefit of pruning and gum upgrading. This was the case for species prone to high levels of growth stress and related defects.

Inventories and significance of the genetic resources of an African mahogany species (Khaya senegalensis (Desr.) A. Juss.) assembled and further developed in Australia.

The forest tree species Khaya senegalensis (Desr.) A. Juss. occurs in a belt across 20 African countries from Senegal-Guinea to Sudan-Uganda where it is a highly important resource. However, it is listed as Vulnerable (IUCN 2015-3). Since introduction in northern Australia around 1959, the species has been planted widely, yielding high-value products. The total area of plantations of the species in Australia exceeds 15,000 ha, mostly planted in the Northern Territory since 2006, and includes substantial areas across 60-70 woodlots and industrial plantations established in north-eastern Queensland since the early-1990s and during 2005-2007 respectively. Collaborative conservation and tree improvement by governments began in the Northern Territory and Queensland in 2001 based on provenance and other trials of the 1960s-1970s. This work has developed a broad base of germplasm in clonal seed orchards, hedge gardens and trials (clone and progeny). Several of the trials were established collaboratively on private land. Since the mid-2000s, commercial growers have introduced large numbers of provenance-bulk and individual-tree seedlots to establish industrial plantations and trials, several of the latter in collaboration with the Queensland Government. Provenance bulks (>140) and families (>400) from 17 African countries are established in Australia, considered the largest genetic base of the species in a single country outside Africa. Recently the annual rate of industrial planting of the species in Australia has declined, and R&D has been suspended by governments and reduced by the private sector. However, new commercial plantings in the Northern Territory and Queensland are proposed. In domesticating a species, the strategic importance of a broad genetic base is well known. The wide range of first- and advanced-generation germplasm of the species established in northern Australia and documented in this paper provides a sound basis for further domestication and industrial plantation and woodlot expansion, when investment conditions are favourable

The introduction and release of Chiasmia inconspicua and C. assimilis (Lepidoptera: Geometridae) for the biological control of Acacia nilotica in Australia

Two geometrid moths Chiasmia inconspicua and Chiasmia assimilis, identified as potential biological control agents for prickly acacia Acacia nilotica subsp. indica, were collected in Kenya and imported into quarantine facilities in Australia where laboratory cultures were established. Aspects of the biologies of both insects were studied and CLIMEX® models indicating the climatically favourable areas of Australia were developed. Host range tests were conducted using an approved test list of 74 plant species and no-choice tests of neonate larvae placed on both cut foliage and potted plants. C. inconspicua developed through to adult on prickly acacia and, in small numbers, Acacia pulchella. C. assimilis developed through to adult on prickly acacia and also in very small numbers on A. pulchella, A. deanei, A. decurrens, and A. mearnsii. In all experiments, the response on prickly acacia could be clearly differentiated from the responses on the non-target species. Both insects were approved for release in Australia. Over a three-year period releases were made at multiple sites in north Queensland, almost all in inland areas. There was no evidence of either insect's establishment and both colonies were terminated. A new colony of C. assimilis was subsequently established from insects collected in South Africa and releases of C. assimilis from this new colony were made into coastal and inland infestations of prickly acacia. Establishment was rapid at one coastal site and the insect quickly spread to other infestations. Establishment at one inland area was also confirmed in early 2006. The establishment in coastal areas supported a CLIMEX model that indicated that the climate of coastal areas was more suitable than inland areas.

Diversity in the sunflower: Puccinia helianthi pathosystem in Australia

Sunflower rust caused by Puccinia helianthi is the most important disease of sunflower in Australia with the potential to cause significant yield losses in susceptible hybrids. Rapid and frequent virulence changes in the rust fungus population limit the effective lifespan of commercial cultivars and impose constant pressure on breeding programs to identify and deploy new sources of resistance. This paper contains a synopsis of virulence data accumulated over 25 years, and more recent studies of genotypic diversity and sexual recombination. We have used this synopsis, generated from both published and unpublished data, to propose the origin, evolution and distribution of new pathotypes of P. helianthi. Virulence surveys revealed that diverse pathotypes of P. helianthi evolve in wild sunflower populations, most likely because sexual recombination and subsequent selection of recombinant pathotypes occurs there. Wild sunflower populations provide a continuum of genetically heterogeneous hosts on which P. helianthi can potentially complete its sexual cycle under suitable environmental conditions. Population genetics analysis of a worldwide collection of P. helianthi indicated that Australian isolates of the pathogen are more diverse than non-Australian isolates. Additionally, the presence of the same pathotype in different genotypic backgrounds supported evidence from virulence data that sexual recombination has occurred in the Australian population of P. helianthi at some time. A primary aim of the work described was to apply our knowledge of pathotype evolution to improve resistance in sunflower to sunflower rust. Molecular markers were identified for a number of previously uncharacterised sunflower rust R-genes. These markers have been used to detect resistance genes in breeding lines and wild sunflower germplasm. A number of virulence loci that do not recombine were identified in P. helianthi. The resistance gene combinations corresponding to these virulence loci are currently being introgressed with breeding lines to generate hybrids with durable resistance to sunflower rust.

Achievements in forest tree genetic improvement in Australia and New Zealand 2: Development of Corymbia species and hybrids for plantations in eastern Australia

This paper describes the establishment of provenance seedling seed orchards of three spotted gums and cadaga (all species of Corymbia ex Eucalyptus). It also discusses the limitations of growing the spotted gums as pure species including: lack of mass flowering, susceptibility to a fungal shoot blight and low amenability to vegetative propagation. These limitations, together with observation of putative natural hybrids of the spotted gums with cadaga, and the early promise of manipulated hybrids, led to an intensive breeding and testing program. Many hybrid families have significant advantages in growth and tolerance to disease, insects and frost, and can be vegetatively propagated. They also exhibit broad environmental plasticity, allowing the best varieties to be planted across a wider range of sites than the spotted gums, resulting in more land being suitable for plantation development.

A method for mapping the distribution and density of rabbits and other vertebrate pests in Australia

The European wild rabbit has been considered Australia’s worst vertebrate pest and yet little effort appears to have gone into producing maps of rabbit distribution and density. Mapping the distribution and density of pests is an important step in effective management. A map is essential for estimating the extent of damage caused and for efficiently planning and monitoring the success of pest control operations. This paper describes the use of soil type and point data to prepare a map showing the distribution and density of rabbits in Australia. The potential for the method to be used for mapping other vertebrate pests is explored. The approach used to prepare the map is based on that used for rabbits in Queensland (Berman et al. 1998). An index of rabbit density was determined using the number of Spanish rabbit fleas released per square kilometre for each Soil Map Unit (Atlas of Australian Soils). Spanish rabbit fleas were released into active rabbit warrens at 1606 sites in the early 1990s as an additional vector for myxoma virus and the locations of the releases were recorded using a Global Positioning System (GPS). Releases were predominantly in arid areas but some fleas were released in south east Queensland and the New England Tablelands of New South Wales. The map produced appears to reflect well the distribution and density of rabbits, at least in the areas where Spanish fleas were released. Rabbit pellet counts conducted in 2007 at 54 sites across an area of south east South Australia, south eastern Queensland, and parts of New South Wales (New England Tablelands and south west) in soil Map Units where Spanish fleas were released, provided a preliminary means to ground truth the map. There was a good relationship between mean pellet count score and the index of abundance for soil Map Units. Rabbit pellet counts may allow extension of the map into other parts of Australia where there were no Spanish rabbit fleas released and where there may be no other consistent information on rabbit location and density. The recent Equine Influenza outbreak provided a further test of the value of this mapping method. The distribution and density of domestic horses were mapped to provide estimates of the number of horses in various regions. These estimates were close to the actual numbers of horses subsequently determined from vaccination records and registrations. The soil Map Units are not simply soil types they contain information on landuse and vegetation and the soil classification is relatively localised. These properties make this mapping method useful, not only for rabbits, but also for other species that are not so dependent on soil type for survival.

Diseases of fruit crops in Australia.

Diseases of Fruit Crops in Australia is the new standard reference in applied plant pathology in Australia covering important diseases affecting the broad range of fruit and nut crops grown throughout Australia. It is an essential tool for growers, horticulturists, crop consultants, research scientists, plant pathologists, quarantine officers, agribusiness representatives, pest management personnel, educators and students. The book is generously illustrated with high quality colour images to help diagnose diseases. It explains how to identify and manage each disease, describing the symptoms, its importance, the source of infection and spread, and control measures. Based on the highly regarded 1993 edition of Diseases of Fruit Crops, this new work updates management practices that have evolved since then. Importantly, it contains the latest information on diseases that have recently emerged in Australia as well as exotic diseases that are biosecurity threats to Australian fruit and nut production.

Efficacy of herbicides on weedy Sporobolus grasses in the glasshouse in Australia

Twenty three herbicides including the current registered herbicides were screened for activity on pre-emergent, juvenile and mature plants of the weedy Sporobolus grass species Sporobolus pyramidalis P.Beauv. and Sporobolus fertilis (Steud.) Clayton. No new herbicides trialled effectively controlled mature plants. Propaquizafop, fluazifop-P-hutyI, flupropanate, haloxyfop-R-methyl ester, glyphosate-ipa and clethodim + haloxyfop-R-methyl ester mix showed good activity on juvenile plants while atrazine, flupropanate, dithiopyr and imazapyr where effective as pre-emergent herbicides. Further work needs to be done to define the recommended application rates for juvenile and pre-emergent plant stages and to determine the selectivity of these herbicides on native and exotic pasture grasses.

Detection of Polymyxa graminis in a barley crop in Australia.

Polymyxa graminis was detected in the roots of barley plants from a field near Wondai, Queensland, in 2009. P. graminis was identified by characteristic sporosori in roots stained with trypan blue. The presence of P. graminis f. sp. tepida (which is hosted by wheat and oats as well as barley) in the roots was confirmed by specific PCR tests based on nuclear ribosomal DNA. P. graminis is the vector of several damaging soil-borne virus diseases of cereals in the genera Furovirus, Bymovirus and Pecluvirus. No virus particles were detected in sap extracts from leaves of stunted barley plants with leaf chlorosis and increased tillering. Further work is required to determine the distribution of P. graminis in Australian grain crops and the potential for establishment and spread of the exotic soil-borne viruses that it vectors.

Tilapia in Australia – Development of management strategies for the control and eradication of feral tilapia populations in Australia

This report presents a culmination of different research projects on two species of tilapia (Oreochromis mossambicus and Tilapia mariae) and provides recommendations for the future management and research of these pest fish. Feral populations of O. mossambicus and T. mariae are now widely distributed in tropical northeastern Queensland, with O. mossambicus also occurring in southeastern Queensland and river systems of Western Australia. O. mossambicus is known to have existed in impoundments in southeastern Queensland, as well as urban drains and ornamental ponds in the Townsville region of north Queensland from about the late 1970s, while T. mariae became established in some easternflowing tropical streams by the early 1990s. In Australia, feral stocks of tilapia are widely regarded as pests that potentially threaten both native fish stocks and biodiversity.

: Parasitoids of the painted apple moth Teia anartoides Walker (Lepidoptera: Lymantriidae) in Australia.

Painted apple moth Teia anartoides Walker (Lepidoptera: Lymantriidae), a native to Australia, was discovered in Auckland, New Zealand in late 1999 and eradicated by 2006. It was recognised in 2002 that biological control would be the most effective long-term control strategy if eradication was unsuccessful, and a search was initiated for potential biocontrol agents in Australia. In 2003, autumn and spring surveys were undertaken in Victoria, Tasmania and South Australia of the guild of parasitoid natural enemies of T. anartoides. Eggs, larvae and pupae were collected and held to rear out any parasitoids. In addition, localised searches were made in Queensland in late 2003 early 2004 and laboratory-reared juvenile stages of T. anartoides were released for recapture in both Victoria and Queensland. Acacia dealbata Link (Fabales: Fabaceae) was the main plant from which T. anartoides was recovered, followed by apple. Most T. anartoides samples were collected from Victoria and Tasmania. Eighteen species from 13 genera of egg, larval and pupal parasitoids were reared and included Diptera (Tachinidae) and Hymenoptera (Braconidae, Encyrtidae, Eulophidae and Ichneumonidae). Of the seven Hymenopteran genera recovered from the larval stage, the most common in Victoria and Tasmania was a previously unidentified larval parasitoid Cotesia Cameron (Hymenoptera: Braconidae) sp. Echthromorpha intricatoria (Fabricius) (Hymenoptera: Ichneumonidae) was the dominant pupal parasitoid. The survey showed that the parasitoid complex associated with T anartoides is structurally very similar to that on other pest Lymantriidae in the northern hemisphere such as gypsy moth (Lymantria dispar L.) (Lepidoptera: Lymantriidae). Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) was recorded for the first time in Australia.

Water and thermal regimes for field pea in Australia and their implications for breeding.

There is a large gap between the refined approaches to characterise genotypes and the common use of location and season as a coarse surrogate for environmental characterisation of breeding trials. As a framework for breeding, the aim of this paper is quantifying the spatial and temporal patterns of thermal and water stress for field pea in Australia. We compiled a dataset for yield of the cv. Kaspa measured in 185 environments, and investigated the associations between yield and seasonal patterns of actual temperature and modelled water stress. Correlations between yield and temperature indicated two distinct stages. In the first stage, during crop establishment and canopy expansion before flowering, yield was positively associated with minimum temperature. Mean minimum temperature below similar to 7 degrees C suggests that crops were under suboptimal temperature for both canopy expansion and radiation-use efficiency during a significant part of this early growth period. In the second stage, during critical reproductive phases, grain yield was negatively associated with maximum temperature over 25 degrees C. Correlations between yield and modelled water supply/demand ratio showed a consistent pattern with three phases: no correlation at early stages of the growth cycle, a progressive increase in the association that peaked as the crop approached the flowering window, and a progressive decline at later reproductive stages. Using long-term weather records (1957-2010) and modelled water stress for 104 locations, we identified three major patterns of water deficit nation wide. Environment type 1 (ET1) represents the most favourable condition, with no stress during most of the pre-flowering phase and gradual development of mild stress after flowering. Type 2 is characterised by increasing water deficit between 400 degree-days before flowering and 200 degree-days after flowering and rainfall that relieves stress late in the season. Type 3 represents the more stressful condition with increasing water deficit between 400 degree-days before flowering and maturity. Across Australia, the frequency of occurrence was 24% for ET1, 32% for ET2 and 43% for ET3, highlighting the dominance of the most stressful condition. Actual yield averaged 2.2 t/ha for ET1, 1.9 t/ha for ET2 and 1.4 t/ha for ET3, and the frequency of each pattern varied substantially among locations. Shifting from a nominal (i.e. location and season) to a quantitative (i.e. stress type) characterisation of environments could help improving breeding efficiency of field pea in Australia.

African mahogany (Khaya senegalensis) plantations in Australia - status, needs and progress

The Australian African mahogany estate comprises over 12,000 ha of industrial plantations, farm-forestry plots and trials, virtually all derived from Africa-sourced wild seed. However, the better trees have given high-value products such as veneers, high-grade boards and award-winning furniture. Collaborative conservation and improvement by the Northern Territory (NT) and Queensland governments since 2000 realised seed orchards, hedge gardens and genetic tests revealing promising clones and families. Private sector R&D since the mid 2000s includes silvicultural-management and wood studies, participatory testing of government material and establishing over 90 African provenances and many single-tree seedlots in multisite provenance and family trials. Recent, mainly public sector research included a 5-agency project of 2009-12 resulting in advanced propagation technologies and greater knowledge of biology, wood properties and processing. Operational priority in the short term should focus on developing seed production areas and ‘rolling front’ clonal seed orchards. R&D priorities should include: developing and implementing a collaborative improvement strategy based on pooled resources; developing non-destructive evaluation of select-tree wood properties, micropropagation (including field testing of material from this source) to ‘industry ready’ and a select-tree index; optimising seed production in orchards; advancing controlled pollination techniques; and maximising benefits from the progeny, clone and provenance trials. Australia leads the world in improvement and ex situ conservation of African mahogany based on the governments’ 13-year program and more recent industry inputs such that accumulated genetic resources total over 120 provenances and many families from 15 of the 19 African countries of its range. Having built valuable genetic resources, expertise, technologies and knowledge, the species is almost ‘industry ready’. The industry will benefit if it exploits the comparative advantage these assets provide. However the status of much of the diverse germplasm introduced since the mid 2000s is uncertain due to changes in ownership. Further, recent reductions of government investment in forestry R&D will be detrimental unless the industry fills the funding gaps. Expansion and sustainability of the embryonic industry must capitalise on past and current R&D, while initiating and sustaining critical new work through all-stakeholder collaboration.