Biosecurity Queensland Employment, Development Economic Innovation and Department of

Technical highlights Research projects 2010–11 CS0830 2/12

ISSN 1838-6350

© State of Queensland, Department of Employment, Economic Development and Innovation, 2012.

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Part 1 Integrated weed management 3

1. Understanding grader grass (Themeda quadrivalvis) ecology for improved management 3

2. Integrated management of bellyache bush (Jatropha gossypiifolia) in northern Queensland 6

3. Ecology of Captain Cook tree (Cascabela thevetia) in northern Queensland 8

4. Weed seed dynamics 11

5. Controlling calotrope (Calotropis procera) in northern Australia 12

6. Herbicide application research 14

7. Evaluating the effectiveness of the EZ‑Ject™ herbicide lance 17

8. Biological control of bellyache bush (Jatropha gossypiifolia) 19

9. Biological control of parthenium (Parthenium hysterophorus) 21

10. Biological control of prickly acacia (Acacia nilotica ssp. indica) 24

11. Biological control of Hudson pear (Cylindropuntia rosea) 27

12. Biological control of mother-of-millions (Bryophyllum spp.) 28

Part 2 Landscape protection and restoration 29

13. Biological control of cat’s claw creeper (Macfadyena unguis-cati) 29

14. Biological control of Madeira vine (Anredera cordifolia) 31

15. Biological control of lantana (Lantana camara) 33

16. Biological control of mikania vine (Mikania micrantha) in Papua New Guinea and Fiji 35

18. Ecology and control of national weed eradication targets 39

19. Class 1 weed control packages 42

20. Mimosa pigra research 44

21. Ecology and control of wet tropics weeds 45

22. Population viability analysis models for better management of lantana (Lantana camara) 48

23. Impacts of environmental weeds on soil processes 51

24. Cabomba (Cabomba caroliniana) ecology 55 Part 3 Pest animal management 58

25. Livestock guardian dog/wild dog (Canis lupus familiaris and C. l. dingo) interaction study 58

26. Assessing the role of harvesting in feral pig (Sus scrofa) management 62

28. Non-target impacts of 1080 meat baits for feral pigs (Sus scrofa) 66

29. Feral pig (Sus scrofa) best practice research in northern Queensland 68

30. Adaptive management of rabbits (Oryctolagus cuniculus) in south-eastern Queensland 69

31. Mapping the distribution and density of rabbits (Oryctolagus cuniculus) in Australia 71

32. Resistance to rabbit haemorrhagic disease virus in Australian rabbits (Oryctolagus cuniculus) 73

Part 4 Research services 75

33. Pest management chemistry 75

34. Chemical registration: providing tools for invasive pest control 76

Appendixes 77

1. Abbreviations 77

2. Species 78

2 Technical highlights: research projects 2010–11 Part 1 Integrated weed management

1. Understanding grader grass (Themeda quadrivalvis) ecology for improved management

Project dates Methods Progress in 2010–11 July 2006 – June 2015 Effect of fire frequency and timing Seed longevity Project leader In a replicated plot trial we impose each Artificial seed-bank trials were treatment (fire during dry season, fire completed in 2010. For the final results, Dr Wayne Vogler at start of wet season, fire at end of see Technical highlights 2009–10. Tropical Weeds Research Centre wet season) at yearly, two-yearly and Tel: (07) 4761 5707 four-yearly intervals. For comparison, Email: [email protected] we also apply the herbicide paraquat –1 –1 Other staff in 2010–11 (concentration of 250 g L ) at 2 L ha prior to seed set at yearly intervals. Laura Roden Changes in pasture species and biomass composition are measured using the Objectives Botanal methodology. • Examine the effect of fire frequency and timing on grader grass biomass and overall pasture composition. • Quantify the seed longevity of grader grass.

Rationale Management of invasive grasses has received little attention compared to research undertaken on other exotic weeds. There is a general lack of understanding of appropriate control options, particularly ones that are economical to apply over large areas of low-value land and in areas of high conservation value. Grader grass (Themeda quadrivalvis) has the potential to change biodiversity, Photo 1.1 Grader grass dominates a yearly burn plot at Undara National Park, 2011 reduce conservation values and reduce grazing-animal production over large areas of the tropical savannas. The Queensland Government Department of Environment and Resource Management (DERM) has identified this as a critical conservation issue threatening biodiversity in national parks. Also, the pest management plans of several local governments identify the weed as a significant threat both economically and environmentally; the Mitchell River Watershed Management Group classifies it as a significant weed species. This project aims to explain some basic ecological aspects of grader grass in response to management and natural conditions, so that management Photo 1.2 Perennial grass dominates a herbicide plot at Undara National Park, 2011 recommendations are based on science rather than anecdotal evidence.

Part 1 Integrated weed management 3 Effect of fire frequency and timing late dry-season fires early wet-season fires Grader grass biomass was generally late wet-season fires herbicide maintained in yearly and two-yearly fire treatments applied at any time of control 100 year (Figures 1.1 and 1.2), except for the 90 two-yearly late wet-season fire treatments 80 in 2009 and 2011, where biomass was 70 similar to that of the control and herbicide 60 treatments (Figure 1.2). It is unclear at 50 this stage why these reductions in grader 40 grass biomass occurred, but they may be (%) grass Grader 30 caused by the previous late wet-season 20 fires (applied in 2008 and 2010) killing 10 a large proportion of grader grass seed, 0 resulting in lower populations in 2009 2006 2007 2008 2009 2010 2011 and 2011. Grader grass populations have Year then recovered in intervening years due to the disturbance caused by the 2008 Figure 1.1 Grader grass response to yearly fires at Undara National Park and 2010 fires (Figure 1.2). In contrast, where disturbance was minimal (such as late dry-season fires early wet-season fires in the control and herbicide treatments), late wet-season fires herbicide grader grass biomass continued to decline following the fourth year of treatment. control 100 Where fire was excluded for four years 90 following treatment, grader grass 80 biomass declined to levels similar 70 to those of the control and herbicide 60 treatments in 2010 (Figure 1.3). 50 Following application of the four-yearly 40 fires in 2010, grader grass biomass in the 30 late dry-season and early wet-season fire (%) grass Grader 20 treatments in 2011 increased markedly; 10 levels were similar to those in 2007 0 2006 2007 2008 2009 2010 2011 following the application of the first fire treatments in 2006 (Figure 1.3). Grader Year grass biomass in the late wet-season fire treatment remained similar to that in the Figure 1.2 Grader grass response to two-yearly fires at Undara National Park control and herbicide treatments, as the four-yearly fire in this treatment was applied only after biomass measurements late dry-season fires early wet-season fires were conducted in the late wet season. late wet-season fires herbicide The effect of late wet-season fires will be control seen in following years. 100 These results continue to confirm that 90 grader grass invasion and dominance 80 is inherently related to the frequency 70 of fire or other disturbances within 60 pasture systems. They also suggest that 50 minimising disturbance is a critical 40 factor in reducing the presence and 30 impact of this invasive grass. (%) grass Grader 20 10 0 2006 2007 2008 2009 2010 2011 Year

Figure 1.3 Grader grass response to four-yearly fires at Undara National Park

4 Technical highlights: research projects 2010–11 Funding in 2010–11 More information Queensland Government Key publications Collaborators Vogler, WD 2009, Grader grass management guide, Burdekin Dry Tropics • DERM, Undara National Park Natural Resource Management, Northern • Northern Gulf Resource Management Gulf Resource Management Group, Group Southern Gulf Catchments, 8 pp. • Southern Gulf Catchments Vogler, WD & Owen, NA 2008, • Landholders ‘Grader grass (Themeda quadrivalvis): changing savannah ecosystems’, in RD van Klinken, VA Osten, FD Panetta & JC Scanlan (eds), Proceedings of the 16th Australian Weeds Conference, Queensland Weeds Society, Brisbane, p. 213. Keir, AF & Vogler, WD 2006, ‘A review of current knowledge of the weedy species Themeda quadrivalvis (grader grass)’, Tropical Grasslands 40(4): 193–201. For further information on this research project and access to key publications, visit the invasive plant and animal science pages on the Biosecurity Queensland website at www.biosecurity.qld.gov.au

Part 1 Integrated weed management 5 2. Integrated management of bellyache bush (Jatropha gossypiifolia) in northern Queensland

Project dates slashing, stick-raking and chemical declined with burial depths except for treatments for controlling bellyache bush. ant-discarded seeds, where it remained July 2000 – June 2011 (completed) nearly constant over all burial depths Weed ecology Project leader under natural conditions. Intact seeds appear to be more sensitive to burial Dr Faiz Bebawi Seed longevity (initiated in conditions and burial depth than ant- Tropical Weeds Research Centre March 2001) discarded seeds. Tel: (07) 4761 5716 We bury two types of bellyache bush Email: [email protected] seeds (intact and ant-discarded) at six Pasture management research depths (0 cm on mulched ground; 0 cm Other staff in 2010–11 There were significant interactions on bare ground; depths of 5 cm, 10 cm, between treatment duration and Chris Crowley 20 cm and 40 cm) under two rainfall simulated grazing regimes impacting on regimes (natural rainfall and rainfall- bellyache bush mortality (Figure 2.3). Objectives excluded). After 9 years, 55% of original bellyache • Develop an integrated management bush plants died in areas void of pasture. Pasture management research strategy for bellyache bush. In contrast, 73%, 77%, 77% and 79% (initiated in September 2002) mortality occurred in simulated regimes • Evaluate the efficacy of combinations with no grazing, low grazing, medium of fire, slashing and foliar herbicides In a competition trial we determine grazing and high grazing, respectively. on the mortality, seedling recruitment the impact of five simulated grazing regimes: and survival of bellyache bush. Funding in 2010–11 1. no grazing (uncut pasture) • Better understand the ecology of Queensland Government bellyache bush and its implications 2. low grazing (cut at 40 cm height) for timing and effectiveness of 3. medium grazing (cut at 20 cm height) Collaborator control strategies. 4. high grazing (cut at 10 cm height) Ralph Woodard (Branmore Station) • Promote changes in management 5. no pasture (pasture removed). practices that will lead to sustainable More information levels of production. These are applied to four plant densities: 1. control (no bellyache bush) Key publications Rationale 2. low density (2 plants m–2) Bebawi, FF, Vitelli, JS, Campbell, SD Bellyache bush (Jatropha gossypiifolia), & Mayer, RJ 2011, ‘Impact of control 3. medium density (6 plants m–2) a native of tropical America, is a major strategies on bellyache bush (Jatropha –2 weed of the Burdekin and Palmer 4. high density (12 plants m ). gossypiifolia L.) mortality, seedling River catchments in Queensland. It is recruitment, population dynamics, also starting to spread in the Fitzroy Findings pasture yield and cost analysis’, The catchment and other areas of central and Rangeland Journal 33(3): 277–86. northern Queensland. Dense infestations Integrated weed control Randall, A, Campbell, S, Vogler, W, generally form along river flats, creek Field trials were completed in June Bebawi, F & Madigan, B 2009, banks and disturbed roadsides. 2006. For the final results, see Technical Bellyache bush (Jatropha gossypiifolia) This project helps to fill gaps in our highlights 2005–06. A scientific paper management manual: control options and knowledge about the seed ecology, on the results has now been published in management case studies from across competitive ability under different The Rangeland Journal. Australia, Department of Employment, grazing pressures and population Economic Development and Innovation, dynamics of bellyache bush. It also Weed ecology Brisbane, 104 pp. assesses the impact of integrated control Seed longevity Bebawi, FF, Vitelli, JS, Campbell, SD, techniques; this will help in developing Vogler, WD, Lockett, CJ, Grace, BS, strategies for best practice management. Under natural rainfall conditions, intact seeds exhumed were all expired after Lukitsch, B & Heard, TA 2007, ‘The Methods 36 months, compared with 72 months biology of Australian weeds 47. Jatropha for ant-discarded seeds. At the rainfall- gossypiifolia L.’, Plant Protection This project includes two areas of excluded site, all intact seeds expired Quarterly 22(2): 42–58. research—integrated weed control and 84 months after burial. However, ant- weed ecology of bellyache bush. Bebawi, FF, Cooper, AP, Brodie, GI, discarded seeds showed some signs of Madigan, BA, Vitelli, JS, Worsley, KJ & Integrated weed control viability (average 1%) even 120 months Davis, KM 2007, ‘Effect of microwave after burial (Figure 2.1). There were radiation on seed mortality of rubber We trial individual and integrated significant interactions between burial vine (Cryptostegia grandiflora R Br.), control techniques to determine the conditions, seed types and burial depths parthenium (Parthenium most effective combination of burning, (Figure 2.2). Generally seed viability hysterophorous L.) and bellyache

6 Technical highlights: research projects 2010–11 bush (Jatropha gossypiifolia L.)’, Plant 100 natural rainfall Protection Quarterly 22(4): 136–42. rainfall-excluded 90 Bebawi, FF, Mayer, RJ & Campbell, SD standard error 80 2005, ‘Flowering and capsule production of bellyache bush (Jatropha 70 gossypiifolia L.)’, Plant Protection 60

Quarterly 20(4): 129–32. 50

Bebawi, FF, Mayer, RJ & Campbell, SD 40

2005, ‘Phenology of bellyache bush (%) viability Seed 30 (Jatropha gossypiifolia L.) in northern Queensland’, Plant Protection Quarterly 20 20(2): 46–51. 10 Bebawi, FF & Campbell, SD 2004, 0 0 3 6 9 12 24 36 48 60 72 84 96 108 120 0 3 6 9 12 24 36 48 60 72 84 96 108 120 ‘Interactions between meat ants Intact Ant-discarded (Iridomyrmex spadius) and bellyache Seed type and burial duration (months) bush (Jatropha gossypiifolia)’, Australian Figure 2.1 Viability of intact and ant-discarded seeds as affected by burial duration and rainfall Journal of Experimental Agriculture regime, averaged over all burial depths 44(12): 1157–64.

Bebawi, FF & Campbell, SD 2002, ‘Effects 70 natural rainfall of fire on germination and viability of rainfall-excluded 60 bellyache bush (Jatropha gossypiifolia) standard error seeds’, Australian Journal of Experimental 50 Agriculture 42(8): 1063–9. 40 Bebawi, FF & Campbell, SD 2002, ‘Impact of fire on bellyache bush 30 (Jatropha gossypiifolia) plant mortality and seedling recruitment’, Tropical (%) viability Seed 20 Grasslands 36 (3): 129–37. 10 Bebawi, FF & Campbell, SD 2002, ‘The 0 response of bellyache bush (Jatropha 0 0 5 10 20 40 0 0 5 10 20 40 gossypiifolia) plants cut off at different (with (without (with (without mulch) mulch) mulch) mulch) heights and seasonal times’, Tropical Intact Ant-discarded Grasslands 36(2): 65–8. Seed type and burial depth (cm) Figure 2.2 Viability of intact and ant-discarded seeds as affected by burial depth and rainfall For further information on this research regime, averaged over all years project and access to key publications, visit the invasive plant and animal no pasture medium grazing no grazing science pages on the Biosecurity 90 high grazing low grazing standard error Queensland website at 80 www.biosecurity.qld.gov.au 70

60

50

40 Mortality (%) Mortality 30

20

10

0 10 2 3 4 5 6 7 8 9 Treatment duration (years)

Figure 2.3 Mortality of bellyache bush plants as affected by simulated grazing regime and treatment duration, averaged over all plant densities

Part 1 Integrated weed management 7 3. Ecology of Captain Cook tree (Cascabela thevetia) in northern Queensland

Project dates Experiment 2 (initiated in Experiment 6 (initiated in July 2007 – June 2012 December 2007) August 2009) We determine the age to reproductive We detail sap-flow velocity and water- Project leader maturity of peach-flowering and yellow- use efficiency of three size classes Dr Faiz Bebawi flowering plants under different light (60–90 mm, 91–130 mm and Tropical Weeds Research Centre and plant density conditions at the 131–230 mm basal stem diameter) of Tel: (07) 4761 5716 Tropical Weeds Research Centre (TWRC). Captain Cook trees (peach-flowering Email: [email protected] The experiment uses a 2 × 4 × 2 factorial type) growing under natural conditions replicated four times using a split-split at Will Creek, Mingela. We establish Other staff in 2010–11 plot design. Factor A comprises light sap-flow sensors on 15 plants, including regime (natural light and 70% shade) two natives (eucalypt and black tea tree) Chris Crowley assigned to the main plots, factor B is to collect data on sap-flow velocity and Objective planting density (1, 2, 4 and 8 plants volume of water transpired on an hourly per pot) assigned to the sub-plots, and basis. Data is downloaded at monthly Better understand the ecology of Captain factor C is flowering type (peach and intervals from a Smart LoggerTM. Cook tree and the implications for timing yellow) assigned to the sub-sub-plots. Processed data will provide information and effectiveness of control strategies. We grow plants from seed in plastic pots on the periodicity of physiological (50 cm diameter × 40 cm depth) filled activity of Captain Cook trees, which Rationale with river loam soil and we monitor will be used to refine the timing of Captain Cook tree (Cascabela thevetia) growth rate (basal diameter and plant control activities to maximise mortality. is a Class 3 declared weed in height), age to reproductive maturity, Queensland. It is a garden escapee that flowering density (number of flowering Progress in 2010–11 has established some relatively large stalks) and seed production. Experiments 1, 4 and 5 are completed. infestations in northern Queensland, For key results, see Technical highlights particularly along banks of the Douglas Experiment 3 (initiated in 2008–09 and Technical highlights River and major creeks of the lower and January 2008) 2009–10. upper Burdekin catchment near Mingela We determine growth, seedling survival and Ravenswood. Captain Cook tree is and age to reproductive maturity of Experiment 2 toxic to humans and animals. Dense peach-flowering plants growing in This experiment is now completed, infestations of this weed out-compete the field at Will Creek, Mingela, under following the collection of three years native pastures and reduce plant and either full shade or natural light. of pod production data. Results show animal biodiversity, as well as pasture The experiment uses a completely that pod production was significantly productivity. It will continue to spread randomised design with six replications. affected by flowering types, light throughout its current range unless For the light treatment we cut-stump conditions, plant density, months controlled. Understanding the ecology dense infestations of established Captain and years. Both flowering biotypes of Captain Cook tree is essential to Cook tree plants. Cut-stumping involves produced pods all year round although developing effective management cutting plants at 5 cm height with a there was great variation between strategies and reducing its economic, brush-cutter and then immediately months (Figure 3.1). Yellow-flowering environmental and social impacts. applying herbicide to the cut surface. plants consistently produced more The control treatment (shade treatment) Methods pods than peach-flowering ones across is left uncut so that a fully closed all treatments (Figure 3.2). For both This project entails six experiments, canopy is present above the seedlings. flowering types, average pod production three of which are ongoing. We tag 25 seedlings (with cotyledons per plant was higher under full sunlight still attached to the hypocotyl) emerging than under shaded conditions. Increased after the first rainfall event in each plot plant density also caused a decline in and monitor their growth rate (basal pod production for both flowering types diameter and plant height), survival rate (Figure 3.2) and age to reproductive maturity. Other key findings were reported in Technical highlights 2008–09 and Technical highlights 2009–10.

8 Technical highlights: research projects 2010–11 . 25 peach in light Experiment 3 peach in shade Approximately 3.3 years after yellow in light 20 germination, 81% of peach-flowering yellow in shade plants exposed to full sunlight conditions standard error were alive. In contrast, 45% of plants 15 growing under full shade had died. Those remaining alive were on average 1.3 m and 0.4 m in height when grown 10 under sunlight and shaded conditions, respectively. Furthermore, 44% of the original plants exposed to full Pod production (pods per plant) (pods production Pod 5 sunlight have started producing pods, compared with no plants in shaded areas (Figure 3.3). The experiment is ongoing. 0 J F M A M J J A S O N D Month Figure 3.1 Pod production of the peach-flowering and yellow-flowering biotypes of Captain Cook tree as affected by months and light conditions

30 peach in light peach in shade yellow in light 25 yellow in shade standard error 20

15

10

Pod production (pods per plant) (pods production Pod 5

0 1 2 4 8 Plant density (plants per pot) Figure 3.2 Pod production of the peach-flowering and yellow-flowering biotypes of Captain Cook tree as affected by plant densities and light conditions

60 light shade 50 standard error

40

30

20 Podding plants (%) plants Podding

10

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Years after germination

Figure 3.3 Percentage of peach-flowering plants producing pods under light and shaded conditions at Mingela

Part 1 Integrated weed management 9 6 growing degree days 140

water volume (L) 120 5

100 4

80 3 60

2 Growing degree days degree Growing 40 (L) consumption Water

1 20

0 0 JFMAMJJASOND Month

Figure 3.4 Water consumption of Captain Cook tree (across all size classes) associated with growing degree days

Experiment 6 Funding in 2010–11 Mature, adult and old Captain Cook trees Queensland Government consumed an average of 1023, 908 and 657 L of water per year, respectively. Collaborators However, considerable variation in water • John Ramsey, Landholder (Meadow consumption occurred on a monthly Vale Cattle Station, Mingela) basis (Figure 3.4), and there was a strong correlation (R2 = 0.70) between growing • Bob J. Mayer, Senior Biometrician degree days and water consumption. [Department of Employment, Water consumption and the number of Economic Development and growing degree days were lowest during Innovation (DEEDI), Oonoonba] winter and highest during the summer • Carole Wright, Biometrician (DEEDI, months. Oonoonba) More information For further information on this research project, visit the invasive plant and animal science pages on the Biosecurity Queensland website at www.biosecurity.qld.gov.au

10 Technical highlights: research projects 2010–11 4. Weed seed dynamics

Project dates Methods Funding in 2010–11 August 2007 – June 2020 A long-term experiment designed to • Land Protection Fund ($47 000) determine the seed longevity of up to • Queensland Government Project leader 12 priority weed species is conducted on Dr Faiz Bebawi the grounds of TWRC. The experiment Collaborators uses a 2 × 2 × 4 × 12 factorial design, Tropical Weeds Research Centre • Bob J. Mayer, Senior Biometrician with factor A comprising two soil types Tel: (07) 4761 5716 (DEEDI, Oonoonba) Email: [email protected] (alluvial and clay), factor B two levels of grass cover (nil or full cover), factor C • Carole Wright, Biometrician (DEEDI, Other staff in 2010–11 four burial depths (0, 2.5, 10 and 20 cm) Oonoonba) and factor D ten sampling periods Chris Crowley (0, 3 and 6 months; 1, 2, 4, 6, 8, 10 and More information Objectives 13 years). Each treatment is replicated For further information on this four times. research project, visit the invasive • Determine the seed longevity of Species buried so far include nine Class 2 plant and animal science pages on the several priority weeds found in or Class 3 declared weeds—calotrope Biosecurity Queensland website at central and northern Queensland for (Calotropis procera), yellow-flowering www.biosecurity.qld.gov.au which data is currently limited. and peach-flowering Captain Cook • Develop germination and viability tree (Cascabela thevetia), chinee apple testing techniques for the (Ziziphus mauritiana), gamba grass abovementioned weeds if none (Andropogon gayanus), orange-flowering are available. and pink-flowering lantana Lantana( • Disseminate the results and camara), mesquite (Prosopis pallida), implications of the research through parthenium (Parthenium hysterophorus), scientific publications, media prickly acacia (Acacia nilotica ssp. stories and presentations to relevant indica) and yellow bells (Tecoma stans), stakeholder groups. along with two other species—leucaena (Leucaena leucocephala ssp. glabrata) Rationale and neem (Azadirachta indica). Currently there are many declared weeds for which we know very little about Progress in 2010–11 seed ecology, particularly germination Preliminary results suggest that chinee requirements and longevity. Such apple, Captain Cook tree, calotrope, information is important in control neem and yellow bells have short-lived programs as it allows land managers seed banks, with no viable seed recorded to plan activities based on the length after 24 months burial. To confirm this of time that will be required to deplete finding, we buried a fresh batch of seeds seed banks in the absence of any of chinee apple and the peach-flowering replenishment. This project will provide variety of Captain Cook tree in October this information for priority species in 2010 to expose them to another set of central and northern Queensland. environmental conditions. Fresh viable seed of calotrope are currently sourced for a repeat burial. Mesquite has also demonstrated a rapid loss of viable seed from the seed bank following burial (< 1% viability after 24 months burial). In contrast, prickly acacia, leucaena, lantana and parthenium are showing a greater level of persistence. Gamba grass from the Cape York region was added to the trial in June 2010.

Part 1 Integrated weed management 11 5. Controlling calotrope (Calotropis procera) in northern Australia

Project dates Methods Mechanical control June 2010 – June 2014 Establishment of an advisory We explore in detail the efficacy of mechanical control by first quantifying committee Project leader the level of damage required to An advisory committee, initially set up Dr Shane Campbell cause mortality and then comparing after the 2007 MLA workshop, has been Tropical Weeds Research Centre the efficacy of a range of available re-established to oversee the project Tel: (07) 4761 5704 equipment. and ensure it achieves its objectives. Email: [email protected] An initial stakeholder workshop was Herbivory study Other staff in 2010–11 held to present the proposed research To help quantify whether biological program and ensure that it is appropriate control agents could deleteriously Chris O’Donnell, Laura Roden, Kelli to address critical information gaps on Pukallus and Wayne Vogler affect the growth and development of calotrope. calotrope, we undertake a simulated herbivory study in the glasshouse Objective Foliar herbicide control at TWRC. Potted calotrope plants Develop improved control options for To compare new and unregistered foliar (C. procera and C. gigantea) are grown calotrope. herbicides with currently available until they are 14 weeks old and are then options, we conduct a split-plot Rationale subjected to one of seven damage levels experiment comprising 22 herbicide (nil, leaf, stem, root, leaf + stem, leaf + Several prioritisation processes have treatments (main plot) and two plant root, stem + root) either once, twice or listed calotrope (Calotropis procera) as sizes (sub-plot) on a property in three times at eight-weekly intervals. an economic and environmental weed in Queensland’s gulf country. Chemicals We monitor their growth, development northern Australia’s rangelands. Native tested include metsulfuron-methyl, and reproductive status at each interval to tropical Africa and Asia, calotrope 2,4‑D, triclopyr, triclopyr + picloram, before destructively harvesting all plants has spread into areas of northern fluroxypr, aminopyralid + fluroxypr, eight weeks after the third treatment. Queensland, the Northern Territory and 2,4‑D + picloram, triclopyr + picloram the Kimberley in Western Australia, but + aminopyralid, 2,4‑D + picloram, Progress in 2010–11 this represents only a small portion of its metsulfuron-methyl + 2,4‑D, and four potential range. new unregistered formulations (one Establishment of an advisory from DuPont Australia and three from committee A national literature review by Grace Dow AgroSciences). The most effective (2006) and a workshop sponsored by The advisory committee—comprising herbicides will be further trialled to Meat and Livestock Australia (MLA) representatives from state and territory refine rates and test for seasonal effects. in 2007 identified key gaps in our governments, pastoral companies, understanding of the invasiveness and natural resource management bodies, Practical options for control of impacts of calotrope and our ability to community groups and Charles Darwin manage it. These included distribution isolated plants University—had its inaugural meeting and rate of spread, reproductive biology, We also aim to identify herbicide at Katherine in 2010. A stakeholder grazing effects and methods of control. products and techniques that can be workshop was held afterwards to discuss easily and practically used as part the proposed research program. This project is part of a larger of day-to-day activities to control collaborative MLA-funded research isolated calotrope plants without using Foliar herbicide control project aimed at addressing these excessive equipment. Firstly, we conduct knowledge gaps. Biosecurity Queensland We applied herbicides in April 2010, with an experiment at the same location is focusing on improving control several products showing good brownout as the foliar herbicide trial using two options, while other aspects are being soon after. Monitoring will continue for herbicides (Vigilant® gel and Roundup investigated primarily by Charles 12–24 months, given calotrope’s ability Powermax®) as either a cut stump or Darwin University and the Northern to remain dormant and reshoot many frill application. Secondly, we test the Territory Government Department of months after treatment. efficacy of tebuthiuron at a site near Natural Resources, Environment, The Charters Towers, with pellets applied Practical options for control of Arts and Sport (NRETAS). either around the plant’s drip zone or at isolated plants the base of the stem, to test the efficacy The cut stump or frill application and of a residual herbicide and determine if the tebuthiuron experiment commenced the placement location of the pellets is in June 2010 and February 2011 important. respectively.

12 Technical highlights: research projects 2010–11 Photo 5.1 Experimentalist Laura Roden (left) and scientific assistant Kirsty Gough inspect flowers on C. gigantea and C. procera during the simulated herbivory trial

Herbivory study More information

We have initiated the herbivory study Key publication in March 2011, with both the single and Vitelli, J, Madigan, B, Wilkinson, P double treatments now imposed. & van Haaren, P 2008, ‘Calotrope (Calotropis procera) control’, The Other activities Rangeland Journal 30(3): 339–48. A monitoring site was established on For further information on this research Helen Springs Station to assess the project and access to key publications, efficacy of basal bark and tebuthiuron visit the invasive plant and animal science control (undertaken by a commercial pages on the Biosecurity Queensland contractor). Data analysis is in progress. website at www.biosecurity.qld.gov.au Collaborators at Charles Darwin University have recently commenced studies into the ecology of calotrope and identified a suitable PhD candidate to join their team.

Reference Grace, BS 2006, ‘The biology of Australian weeds 45. Calotropis procera (Aiton) W.T. Aiton’, Plant Protection Quarterly 21(4): 152–60.

Funding in 2010–11 • MLA ($90 000) • Queensland Government

Collaborators • MLA • Charles Darwin University • NRETAS, Northern Territory • Barkly Landcare Association

Part 1 Integrated weed management 13 6. Herbicide application research

Project dates Methods Bellyache bush splatter gun trial June 2008 – ongoing Captain Cook tree trials We conduct a splatter gun screening trial on bellyache bush. Each treatment Project leader We conduct four experiments near is replicated three times and individual Mingela to determine which herbicides John McKenzie plots comprise 20 plants. For this trial and rates are most effective in Tropical Weeds Research Centre we use an NJ Phillips Powermaster controlling Captain Cook tree using TM Tel: (07) 4761 5718 Forestry applicator with a portable basal bark spraying, foliar spraying, Email: [email protected] LPG power supply. Chemicals are cut stump, stem injection and splatter applied at 4 mL for each 50 cm of plant Other staff in 2010–11 gun spraying techniques. Experiments height. Herbicides used in this trial have for each technique are completely generally been found effective when Dannielle Brazier randomised, incorporating three using foliar application methods. replications. We test the efficacy of Objectives herbicides on three size classes (< 20, Progress in 2010–11 • Evaluate the effectiveness of chemical 20–50 and > 50 mm basal diameter at control techniques, including basal 20 cm above the ground). Each size class Captain Cook tree trials bark spraying, foliar spraying, cut comprises 10 plants that are tagged and From the rate screening trials, we have stump, stem injection and splatter painted for future reference. We also identified chemicals and application gun spraying, on Captain Cook tree. record their reproductive status prior rates that will provide high mortality to treatment. • Evaluate the effectiveness of stem of Captain Cook tree using basal bark injection on prickly acacia, chinee Based on results from the screening spraying, foliar spraying, cut stump and apple and calotrope. trials, we undertake further trials to stem injection techniques (Table 6.1). Fluroxypyr has proven most effective • Evaluate the effectiveness of splatter refine rates for the most promising for basal bark spraying, foliar spraying gun spraying on bellyache bush. herbicides. These are conducted at the same site and use a methodology similar and cut stump applications, while Rationale to that of the screening trials. glyphosate caused the highest mortality using stem injection. Stem injection, Captain Cook tree (Cascabela thevetia) Stem injection trials cut stump and basal bark spraying can is a Class 3 weed. It is a garden escapee be applied at any time of the year with We conduct stem injection trials that has established some relatively large no variation in final results. However, on prickly acacia, chinee apple infestations in northern Queensland, plants that are treated when they are not and calotrope using a completely particularly along the banks of the actively growing tend to send out stem randomised block design. Each Douglas River and major creeks of the suckers in the first season. While they treatment is replicated three times and lower and upper Burdekin catchment near eventually succumb to the treatment individual plots comprise 20 plants. Mingela and Ravenswood. Developing in the next season, they take longer to For the screening trial we apply 1 mL effective control techniques is essential die. Further work is required to finetune of herbicide mix from a PhillipsTM to stopping the continued spread of this the methodology and rates used in the tree injector gun into incisions with weed. Presently, there is no registered splatter gun trial. chemical available for its control. centres 7 cm apart. Incisions are cut with a tommyhawk axe at an angle of Stem injection trials There is a need to further explore water- approximately 10 degrees to the stem based herbicide applications that are at a height that is comfortable to the Calotrope suitable for sensitive environments and applicator. We also record the number Herbicides, application rates and efficacy cheaper than those that use diesel as the and height of incisions for each plant. in the rate screening trial conducted near carrier. We investigated stem injection as Herbicides used for this trial are either Georgetown (along the Gilbert River) are a possible method to reduce the amount registered for stem injection for other summarised in Table 6.2. Compared with of chemical required and to eliminate species or have active ingredients that the initial screening trial (reported in the diesel component for treating large, have been effective in controlling these Technical highlights 2009–10), mortality established trees along creek systems. weeds when using other application in all treatments was low. The fact that methods. There is also a need for a highly mobile plants at the Georgetown site had almost control technique (such as splatter gun Based on results from the screening twice the cross-sectional area as plants spraying) to control bellyache bush in trials, we undertake further trials to at Greenvale may have contributed to inaccessible locations where it is not refine rates for the most promising these results. possible to use vehicle-mounted foliar herbicides. These are conducted at the spray equipment. same site and use a methodology similar to that of the screening trials.

14 Technical highlights: research projects 2010–11 Table 6.1 Mortality of Captain Cook tree using various treatments and active ingredients in the rate screening trials

Treatmenta Active ingredient Rate and carrier Mortality (%)b Basal bark fluroxypyr (333 g L–1) 1:112 diesel 85* Basal barkc fluroxypyr (333 g L–1) 1:112 diesel 98† Basal bark control 1 diesel 0‡ Basal barkc control 1 diesel 0‡ Cut stump fluroxypyr (333 g L–1) 1:112 water + wetter 100† Cut stump fluroxypyr (333 g L–1) 1:55 water + wetter 100† Cut stump fluroxypyr (333 g L–1) 1:55 diesel 100† Cut stump control diesel 21* Cut stump control water + wetter 12* Foliar fluroxypyr (333 g L–1) 1:334 water + wetter 77† Foliar fluroxypyr (333 g L–1) 1:167 water + wetter 92† Foliar aminopyralid (10 g L–1) fluroxypyr (140 g L–1) 1:140 water + wetter 72† triclopyr (300 g L–1) + picloram (100 g L–1) + Foliar 1:300 water + wetter aminopyralid (8 g L–1) 11* Foliar control water + wetter 5* Stem injection glyphosate (360 g L–1) 1:0 water 97† Stem injection glyphosate (360 g L-1) 1:0 97† Stem injection triclopyr (200 g L–1) + picloram (100 g L–1) 1:4 water + wetter 90† Stem injection triclopyr (200 g L–1) + picloram (100 g L–1) 1:4 water 96† Stem injection control water + wetter 0* Stem injection control water 0* Splatter gun fluroxypyr (333 g L–1) 1:9 water + wetter 91† Splatter gun aminopyralid (10 g L–1) fluroxypyr (140 g L–1) 1:3 water + wetter 93† Splatter gun glyphosate (360 g L–1) 1:9 water + wetter 61* Splatter gun control water + wetter 0‡ a Stem injection treatments refer to the second rate screening trial; splatter gun treatments refer to the initial screening trial. b Mortality values followed by the same symbol are not significantly different, p < 0.05. c Double application height (1 m above ground) was used.

Table 6.2 Mortality of calotrope in the stem injection rate screening trial

Active ingredient Rate and carrier Mortality (%)a triclopyr (200 g L–1) + picloram (100 g L–1) 1:4 water + wetter 20* 2,4-D (300 g L–1)+ picloram (75 g L–1) 1:3 water + wetter 9* 2,4-D (625 g L–1) 1:7 water + wetter 10* glyphosate (360 g L–1) 1:0 water + wetter 24* glyphosate (360 g L–1) 1:1 water + wetter 13* imazapyr (150 g L–1) + glyphosate (150 g L–1) 1:4 water + wetter 72† control water + wetter 0‡ a Mortality values followed by the same symbol are not significantly different, p < 0.05.

Part 1 Integrated weed management 15 Prickly acacia Table 6.3 Mortality of prickly acacia in the stem injection rate screening trial

Herbicides, application rates and efficacy Mortality (%) 18 months after treatment in the rate Active ingredient Rate and carrier 18 months after screening trial are summarised in treatmenta Table 6.3. Compared with the initial triclopyr (200 g L–1) + picloram 1:4 water 22† screening trial (reported in Technical (100 g L–1) highlights 2009–10), mortality in all 2,4-D (300 g L–1)+ picloram (75 g L–1) 1:1.5 water 9† treatments was low. The presence of seed –1 pods on test plants or particular choices glyphosate (360 g L ) 1:0.5 water 0* in the way treatments were applied control water 0* may have influenced overall efficacy. a Mortality values followed by the same symbol are not significantly different, p < 0.05. We have now established a second rate screening trial, using the same rates but Table 6.4 Mortality of chinee apple in the stem injection screening trial different cut spacing (label-recommended and 7 cm) and adding a wetter to all Mortality (%) treatments. Plants in this trial also do not Active ingredient Rate and carrier 24 months after a have developing pods. treatment triclopyr (200 g L–1) + picloram 1:4 water + wetter 16† Chinee apple (100 g L–1) Herbicides, application rates and efficacy 2,4-D (300 g L–1) + picloram (75 g L–1) 1:1.5 water + wetter 14† two years after treatment in the initial 2,4-D (625 g L–1) 1:6 water + wetter 0* screening trial are summarised in Table 6.4. imazapyr (150 g L–1) + glyphosate 1:4 water + wetter 1* Mortality in all treatments was low, with a (150 g L–1) maximum of only 16% recorded. glyphosate (360 g L–1) 1:2 water + wetter 0* Bellyache bush splatter gun trial hexazinone (250 g L–1) 1:2 water + wetter 0*

Herbicides, application rates and efficacy control water + wetter 0* two years after treatment in the initial a Mortality values followed by the same symbol are not significantly different, p < 0.05. screening trial are summarised in Table 6.5. Metsulfuron-methyl has proven highly Table 6.5 Mortality of bellyache bush in the splatter gun screening trial effective and we will now undertake additional work to refine application rates. Active ingredient Rate and carrier Mortality (%)a fluroxypyr (333 g L–1) 1:17 water + wetter 48* Funding in 2010–11 glyphosate (360 g L–1) 1:9 water + wetter 54* • Land Protection Fund ($76 000) metsulfuron-methyl (600 g kg–1) 2 g L–1 water + wetter 99† • Queensland Government control water + wetter 0‡ More information a Mortality values followed by the same symbol are not significantly different, p < 0.05. Key publications For further information on this research project and access to key publications, visit the invasive plant and animal science pages on the Biosecurity Queensland website Brazier, D, McKenzie, J, Owen, A, at www.biosecurity.qld.gov.au Campbell, SD, Vitelli, JS, Reid, A & Mayer, R 2010, ‘Evaluating herbicides for the control of the invasive weed florestina (Florestina tripteris DC.)’, in SM Zydenbos (ed.), Proceedings of the 17th Australasian Weeds Conference, New Zealand Plant Protection Society, Christchurch, New Zealand, pp. 421–3. McKenzie, J, Brazier, D, Owen, A, Vitelli, JS & Mayer, R 2010, ‘Stem injection: a control technique often overlooked for exotic woody weeds’, in SM Zydenbos (ed.), Proceedings of the 17th Australasian Weeds Conference, New Zealand Plant Protection Society, Christchurch, New Zealand, pp. 459–61.

16 Technical highlights: research projects 2010–11 7. Evaluating the effectiveness of the EZ‑Ject™ herbicide lance

Project dates flooded areas of fresh, brackish or salt Findings water, forming dense thickets capable of December 2007 – December 2010 This study established that the EZ‑Ject replacing existing ecosystems. (completed) herbicide system is an effective tool for If effective and subsequently registered controlling individual woody plants, Project leader for use in Queensland, this tool would although the degree of control varied Joseph Vitelli help the operator avoid direct contact among species, with efficacy influenced Ecosciences Precinct with both the herbicide and any thorns by herbicide and number of cartridges Tel: (07) 3255 4473 or spines on the plant. The technique injected. would be particularly useful in wetlands Email: [email protected] Cartridges filled with imazapyr were and other sensitive environments, significantly more effective than those allowing treatment of individual plants Other staff in 2010–11 filled with glyphosate at controlling without affecting surrounding native Barbara Madigan the three woody weed species. Injecting vegetation or contaminating waterways. plants with three imazapyr cartridges Objective Methods resulted in mortalities of 93–100%, Evaluate the effectiveness of the EZ‑JectTM compared to mortalities of 17–100% for Captain Cook tree near Mingela, velvety herbicide lance in controlling woody weeds glyphosate cartridges. Pond apple was tree pear near Inglewood and pond in Queensland using both glyphosate-filled the most susceptible species, requiring apple near Babinda are treated with and imazapyr-filled shells. one imazapyr cartridge to kill 97% or the EZ‑Ject herbicide lance in split-plot two glyphosate cartridges to kill 92% of Rationale design experiments with the herbicide as treated plants. Plant mortality increased the main plot (glyphosate and imazapyr) as the number of cartridges injected Using the EZ‑Ject™ herbicide lance is a and the number of cartridges as the sub- increased. However, mortality did relatively new technique for the control plot (0, 1, 2, 3 and 4 shells). We replicate not differ significantly for treatments of woody plants by stem injection. The each treatment four times and the receiving three and four imazapyr stainless steel lance has gripping teeth experimental unit consists of 15 plants. cartridges, as the lower cartridge at the end and a spring-loaded assembly All treated plants have a basal diameter density already met the manufacturer’s that injects .22 brass shells filled with of 10–15 cm. We assess plants 1, 6 recommendation of injecting one water-soluble herbicide into the cambium and 12 months after treatment using a cartridge per 10 cm basal circumference layer of woody plants. No mixing of, or damage-rating scale and determine plant when treating large plants (> 6.35 cm contact with, the herbicide is required mortality at the final assessment. diameter at breast height). by the operator. The longer version of the lance (1.5 m) holds up to 100 shells in each of four separate shell chambers. The shells are implanted at a downward angle evenly around the circumference of the base of the plant. Two herbicides (glyphosate and imazapyr) are registered for use with the lance in the United States and Canada. Plants may be injected at any time of the year and may be standing in water or wetlands, though the injection site should be above the water level. To trial this control method, three woody weeds were chosen, each from a different family and each infesting a different area of Queensland. Captain Cook tree (Cascabela thevetia), family Apocynaceae, is a Class 3 weed that Photo 7.1 Bullets of water-soluble herbicide injected into the base of woody weeds is highly toxic and invades native vegetation. Velvety tree pear (Opuntia tomentosa), family Cactaceae, is a Class 2 weed found predominantly in the brigalow belt of Queensland. Pond apple (Annona glabra), family Annonaceae, is a Weed of National Significance (WONS) and a Class 2 weed. It can grow in

Part 1 Integrated weed management 17 The cost of using three cartridges Funding in 2010–11 per tree to treat a weed infestation of Queensland Government 1500 plants ha–1 is $1070 ha–1, with labour costs accounting for 16% of this. More information The high chemical costs would preclude this technique from broad-scale use, but Key publication it could be valuable for treating woody Vitelli, JS & Madigan, BA 2011, weeds in sensitive areas, including those ‘Evaluating the efficacy of the EZ‑Ject with high conservation values. herbicide system in Queensland, Agribusiness will be canvassed to Australia’, The Rangeland Journal 33(3): identify businesses interested in 299–305. importing and distributing the herbicide lance and capsules. Once an importer has been identified, a consent-to-import permit will be sought from the Australian Pesticides and Veterinary Medicines Authority (APVMA) so that land managers can purchase the equipment.

18 Technical highlights: research projects 2010–11 8. Biological control of bellyache bush (Jatropha gossypiifolia)

Project dates Methods Progress in 2010–11 July 2007 – June 2012 Staff from the CSIRO Mexican Field All three Queensland bellyache bush Station and CABI Europe – United varieties were susceptible to all three Project leader Kingdom (CABI Europe–UK), through rust strains, but the strain from Trinidad Dr K. Dhileepan other collaborative links, collect fresh showed consistently high virulence on Ecosciences Precinct spore material of Phakopsora jatrophicola all three Queensland bellyache bush Tel: (07) 3255 4449 ex J. gossypiifolia from different varieties (Figure 8.1). The strains from Email: [email protected] geographic regions and send them to Brazil and Trinidad were also less virulent facilities at Egham, United Kingdom. than the previously assessed rust strain from El Zapote, Mexico, towards the Other staff in 2010–11 In order to quantify the degree non-target plant J. curcas. Because of its Mariano Treviño of susceptibility of individual comparatively high virulence towards all J. gossypiifolia varieties towards Queensland varieties of J. gossypiifolia Objectives particular P. jatrophicola strains, we and its low virulence towards J. curcas, inoculate rust strains from Brazil, • Identify suitable biological control the strain from Trinidad was selected for Trinidad and the Pacific coast of Mexico agents for host-specificity testing host-specificity testing. on the three varieties Queensland through review of earlier survey work Bronze, Queensland Green and Full host-specificity testing of the rust and exploration (in collaboration with Queensland Purple. The rust strain most strain from Trinidad has commenced. the CSIRO). virulent towards all Queensland varieties In March 2011, we exported a shipment • Conduct pathogenicity and host of J. gossypiifolia is then selected for full of 13 test plant species (10 plants each) to range testing of the Jatropha rust host-specificity tests conducted under CABI Europe–UK. The evaluation status fungus (Phakopsora jatrophicola) quarantine by our collaborators at CABI and test results of the 13 non-target as a potential biocontrol agent for Europe–UK. species are summarised in Table 8.1. bellyache bush. The rust caused restricted sporulation on J. multifida as well as on one individual Rationale plant of J. integerrima with hirsute Bellyache bush (Jatropha gossypiifolia) leaves. Other individuals of J. integerrima is a serious and expanding weed exhibiting non-hirsute, waxy leaves of northern Queensland. It invades proved to be less susceptible. J. podagrica rangeland, particularly in riparian showed chlorotic and necrotic leaf spots, zones, and forms dense thickets that but no sporulation, following inoculation. reduce productivity and biodiversity. No macroscopic symptoms or sporulation All parts of the plant, especially the were evident on other test plant species. seeds, are toxic to grazing animals. Bellyache bush is a declared target Pacific strain Trinidad strain El Zapote strain standard error for biological control and an effective 250 biocontrol agent is needed to halt further )

-–1 spread and reduce its impact. The only biological control agent released 200 to date, the bellyache bush jewel bug (Agonosoma trilineatum), is not known 150 to be established in the field. Hence, the bellyache bush biological control 100 program was recommenced in 2007 to Virulence (pustules plant further screen potential agents identified plant (pustules Virulence 50 during earlier surveys in Central America and to conduct additional 0 surveys in South America. Queensland Bronze Queensland Green Queensland Purple Bellyache bush variety

Figure 8.1 Virulence of three strains of P. jatrophicola towards the three Queensland bellyache bush varieties

Part 1 Integrated weed management 19 Table 8.1 Response of 13 non-target test plant species to inoculation with the P. jatrophicola strain from Trinidad

Family Test plant species No-choice host-specificity test results Euphorbiaceae Jatropha integerrima Restricted sporulation in a plant with hirsute leaves and not on plants with normal leaves Jatropha multifida Restricted sporulation

Jatropha podagrica Chlorotic and necrotic leaf spots; no sporulation

Aleurites moluccana Necrotic leaf spots; no sporulation

Manihot esculenta Some chlorotic leaf spots (not associated with the rust); no sporulation

Euphorbia pulcherrima Occasionally protuberances (not associated with the rust); no sporulation

Alchornea ilicifolia No macroscopic symptoms

Macaranga tanarius No macroscopic symptoms

Phyllanthaceae Cleistanthus dallachyanus Under evaluation

Breynia oblongifolia Small pinhole-like necrotic leaf spotting; no sporulation

Antidesma parvifolium Under evaluation

Picrodendraceae Petalostigma pubescens Under evaluation

Putranjivaceae Drypetes deplanchei Under evaluation

Funding in 2010–11 More information • Land Protection Fund ($47 000) Key publications • MLA ($30 000) Heard, TA, Chan, RR, Senaratne, KADW, • Queensland Government (Blueprint Palmer, WA, Lockett, CJ & Lukitsch, B for the Bush) 2009, ‘Agonosoma trilineatum (Heteroptera: Scutelleridae) a Collaborators biological control agent of the weed bellyache bush, Jatropha gossypiifolia • Marion Seier (CABI Europe–UK, (Euphorbiaceae)’, Biological Control United Kingdom) 48(2): 196–203. • Tim Heard (CSIRO Ecosystem Sciences, Brisbane) Bebawi, FF, Lockett, CJ, Davis, KM & Lukitsch, BV 2007, ‘Damage potential of • Ricardo Segura (CSIRO Ecosystem an introduced biological control agent Sciences, Mexican Field Station) Agonosoma trilineatum (F.) on bellyache • Tanya Scharaschkin (Queensland bush (Jatropha gossypiifolia L.)’, University of Technology, Science and Biological Control 41(3): 415–22. Engineering Faculty) Bebawi, FF, Vitelli, JS, Campbell, SD, Vogler, WD, Lockett, CJ, Grace, BS, Lukitsch, B & Heard, TA 2007, ‘The biology of Australian weeds 47. Jatropha gossypiifolia L.’, Plant Protection Quarterly 22(2): 42–58. For further information on this research project and access to key publications, visit the invasive plant and animal science pages on the Biosecurity Queensland website at www.biosecurity.qld.gov.au

20 Technical highlights: research projects 2010–11 9. Biological control of parthenium (Parthenium hysterophorus)

Project dates in Australia. Identification of beneficial Progress in 2010–11 plants exhibiting high competitive May 2007 – June 2014 In central Queensland, we surveyed indices, in particular under changing 17 sites in March 2011. Surveys at three climate—specifically elevated carbon Project leader sites in northern Queensland were dioxide (CO )—would help to manage 2 conducted in April 2011. Dr K. Dhileepan parthenium more effectively. Ecosciences Precinct Parthenium summer rust Tel: (07) 3255 4449 Methods Email: [email protected] The summer rust was evident at all Biological control agent sites with parthenium infestations. The Other staff in 2010–11 monitoring proportion of infected plants was high Mariano Treviño and Kelli Pukallus Parthenium sites in central and northern at all three sites in northern Queensland Queensland are monitored at the end (Cardigan Station, Felspar and Plain Asad Shabbir and Ruey Toh (The of the parthenium growing season. At Creek), but the proportion of leaves with University of Queensland PhD students) each site, we record the incidence and rust infection remained low at all these sites (Figure 9.1). In central Queensland, Objectives abundance of various biological control agents—the summer rust (P. xanthii var. parthenium was evident in only 7 of • Monitor the field persistence and parthenii-hysterophorae), the clear- the 17 sampling sites, but the summer abundance of parthenium biological wing moth (C. ithacae) and the stem- rust was observed at all sites with control agents. galling weevil (C. albocinereus)—along parthenium infestations. The proportion of plants and leaves infected varied • Evaluate the role of beneficial with information on other established widely between sites (Figure 9.1). competitive plants to enhance the biological control agents and the abundance of parthenium. effectiveness of weed biological Parthenium clear-wing moth control agents. Biological control and competitive We have previously confirmed field Rationale plants under elevated CO2 establishment of the clear-wing moth at 5 of the 13 release sites and 2 nearby non- Parthenium (Parthenium hysterophorus) We conduct an experiment in controlled- release sites in central Queensland. In is a WONS and a Class 2 declared weed environment rooms to quantify the 2011 the clear-wing moth was recovered in Queensland. Biological control is one combined effect of a stem-galling from a non-release site near Carfax, of the most effective and economically biological control agent (Epiblema confirming its continued persistence in viable management options for this strenuana) and plant suppression the field. High summer rainfall resulting weed. Among the various biological by buffel grass (Cenchrus ciliaris) in flooding could have affected the root- control agents introduced against on parthenium’s vegetative and boring larvae at many sites. parthenium in Queensland, the summer reproductive growth under ambient CO2 levels of 380 parts per million by volume rust (Puccinia xanthii var. parthenii- Parthenium stem-galling weevil hysterophorae, previously reported (ppmv) and under elevated CO2 levels as P. melampodii) is an agent suited (550 ppmv). The stem-galling weevil was not to areas with hot and dry weather recovered in any of the survey sites. conditions. It was introduced from Parthenium canopy architecture Limited establishment of this agent could be due to the dominance of the Mexico in 1999 and released at more Parthenium canopy architecture is studied stem-galling moth (E. strenuana) in all than 50 infested sites in Queensland. under three temperature (day/night parthenium-infested areas. The stem- The clear-wing moth (Carmenta ithacae), 22/15 °C, 27/20 °C, and 32/25 °C in thermal galling moth and the stem-galling also native to Mexico, was released time 12/12 hours) and two CO2 (ambient weevil share a similar feeding niche. from 1998 to 2002. The stem-galling and elevated) regimes in controlled- weevil (Conotrachelus albocinereus) from environment rooms. Identical light Argentina was released in Queensland (photoperiod 12 hours, ~ 250 μmol s–1) and from 1995 to 2000. Although all three relative humidity (65%) are maintained agents have established in the field, their in all rooms. We track plant development incidence and abundance in parthenium from the ninth day after transplantation infestations in central and northern using three-dimensional digitising Queensland is not fully known. every third day with a sonic digitiser. The role of competition from beneficial The last measurement is made after plants in managing parthenium is widely about 550 growing degree days. From known. So far, however, no information empirical data, we develop a virtual three- is available on the potential role of dimensional canopy architecture model of various native and introduced pasture a parthenium plant using the modelling plants in enhancing the effectiveness software L-systems. of parthenium biological control agents

Part 1 Integrated weed management 21 100 proportion of plants infected

90 proportion of leaves infected

80 standard error 70 60 50 40 30 20 Summer rust incidence (%) incidence rust Summer 10 Nil parthenium Nil Nil parthenium Nil parthenium Nil parthenium Nil parthenium Nil parthenium Nil parthenium Nil parthenium Nil parthenium Nil 0 parthenium Nil Carfax Hillside Felspar Emerald Overflow Cardigan Clermont Delargum Wycarbah Morbridge Oaky Creek Oaky Hay Mount Gracemere Springsure Plain Creek Plain Hutton Creek Hutton Kemmis Creek Kemmis Landsborough Moleyamber Creek Moleyamber Albinia National Park National Albinia

Northern Queensland Central Queensland Monitoring site

Figure 9.1 Incidence of P. xanthii var. parthenii-hysterophorae in Queensland Biological control and competitive

plants under elevated CO2 The experiment was carried out from May to July 2011. With biological control (E. strenuana), parthenium grew much more vigorously and produced significantly more biomass and more

flowers under elevated CO2 than under

ambient CO2. In contrast, buffel grass became less competitive and produced fewer tillers and less biomass under

elevated CO2 than under ambient CO2 (Photo 9.1). This suggests that under climate change, biological control with E. strenuana and competition from buffel grass may not be effective.

Parthenium canopy architecture Photo 9.1 Impact of plant competition and biological control on parthenium growing under A virtual three-dimensional canopy ambient (380 ppmv) and elevated (550 ppmv) CO2 levels architecture model of a parthenium plant was developed. Both temperature

and CO2 regimes significantly affected parthenium canopy size and structure. We currently use the virtual plant model to study the implications of changes in the parthenium canopy due to climate change on parthenium summer rust infection levels.

22 Technical highlights: research projects 2010–11 Funding in 2010–11 Dhileepan, K & McFadyen, RE 2001, ‘Effects of gall damage by the introduced • Queensland Government biocontrol agent Epiblema strenuana • AusAID ($8000) (Lep., Tortricidae) on the weed Parthenium hysterophorus (Asteraceae)’, Journal of Collaborators Applied Entomology 125(1–2): 1–8. Prof. Steve Adkins (School of Land, Crop Dhileepan, K, Setter, SD & McFadyen, RE and Food Sciences, The University of 2000, ‘Impact of defoliation by the Queensland) biocontrol agent Zygogramma bicolorata on the weed Parthenium hysterophorus More information in Australia’, BioControl 45(4): 501–12. Key publications Dhileepan, K, Setter, SD & McFadyen, RE 2000, ‘Response of the weed Parthenium Dhileepan, K & Strathie, L 2009, hysterophorus (Asteraceae) to defoliation ‘Parthenium hysterophorus L. by the introduced biocontrol agent (Asteraceae)’, in R Muniappan, Zygogramma bicolorata (Coleoptera: GVP Reddy & A Raman (eds), Biological Chrysomelidae)’, Biological Control control of tropical weeds using 19(1): 9–16. arthropods, Cambridge University Press, Cambridge, pp. 272–316. For further information on this research project and access to key publications, Dhileepan, K 2007, ‘Biological control of visit the invasive plant and animal science parthenium (Parthenium hysterophorus) pages on the Biosecurity Queensland in Australian rangeland translates website at www.biosecurity.qld.gov.au to improved grass production’, Weed Science 55(5): 497–501. Dhileepan, K 2004, ‘The applicability of the plant vigor and resource regulation hypotheses in explaining Epiblema gall moth – Parthenium weed interactions’, Entomologia Experimentalis et Applicata 113(1): 63–70. Dhileepan, K 2003, ‘Current status of the stem-boring weevil Listronotus setosipennis (Coleoptera: Curculionidae) introduced against the weed Parthenium hysterophorus (Asteraceae) in Australia’, Biocontrol Science and Technology 13(1): 3–12. Dhileepan, K 2003, ‘Seasonal variation in the effectiveness of the leaf- feeding beetle Zygogramma bicolorata (Coleoptera: Chrysomelidae) and stem-galling moth Epiblema strenuana (Lepidoptera: Tortricidae) as biocontrol agents on the weed Parthenium hysterophorus (Asteraceae)’, Bulletin of Entomological Research 93(5): 393–401. Dhileepan, K 2001, ‘Effectiveness of introduced biocontrol insects on the weed Parthenium hysterophorus (Asteraceae) in Australia’, Bulletin of Entomological Research 91(3): 167–176.

Part 1 Integrated weed management 23 10. Biological control of prickly acacia (Acacia nilotica ssp. indica)

Project dates Methods rust (Ravenelia acaciae-arabicae) is conducted on 17 species of closely January 2007 – June 2014 Native range surveys related Australian acacia species in the Project leader Our collaborators in India—the Arid quarantine at CABI Europe–UK. The Forest Research Institute and the plants necessary for the testing are sent Dr K. Dhileepan Institute of Forest Genetics and Tree from Australia either as potted plants Ecosciences Precinct Breeding—conduct surveys in natural or seeds. Tel: (07) 3255 4449 groves and plantations in Rajasthan, Email: [email protected] Gujarat, Tamil Nadu and Karnataka Progress in 2010–11 Other staff in 2010–11 states at regular intervals (four to six Native range surveys times a year, covering all seasons) to Catherine Lockett, Di Taylor and catalogue insect herbivores and plant Surveys continued at the predetermined Mariano Treviño pathogens associated with various sites in Tamil Nadu and Karnataka in southern India and in Gujarat and A. Balu, M. Senthilkumar, S. Murugesan subspecies of A. nilotica in India. Rajasthan in north-western India. and P. Senthilkumar (Institute of Forest Genetics and Tree Breeding, Coimbatore, Exclusion studies In southern India, the gall-inducing rust India) The impact of native insect herbivores (R. acaciae-arabicae) was observed at on seedling survival and growth under 10 of the 72 survey sites, all in Tamil Syed Irfan Ahmed, Sangeetha Singh, field conditions is evaluated in exclusion Nadu. Rust uredinia and telia are found Mahadeo Gorain and Anamika Sharma trials conducted over a two-year predominantly on the upper surface of (Arid Forest Research Institute, Jodhpur, period at four sites each in Rajasthan leaflets, while spermagonia occur on India) (Hanumangarh, Desuri, Bharatpur and fruits, inflorescences and shoot tips, Objectives Jodhpur) and Gujarat (Gandhinagar, with aecia causing hypertrophy on Nadyad, Junagarh and Bhuj), and two fruits, inflorescences and shoot tips, • Survey and assess the host range of sites in Tamil Nadu (Coimbatore and resulting in galls. Field surveys suggest insects and pathogens associated with Thoppur). At each site, staff maintain that R. acaciae-arabicae is specific to prickly acacia in the native range potted A. nilotica seedlings, with half A. nilotica ssp. indica, as the rust was not (India). of the seedlings protected from insect observed on other A. nilotica subspecies • Conduct host-specificity tests on herbivores (by spraying insecticides at or other Acacia species (e.g. A. ferruginea, prioritised biological control agents fortnightly intervals) and the remaining A. latronum, A. auriculiformis, A. catechu, for prickly acacia. half exposed to insect herbivores (by A. leucophloea and A. farnesiana) spraying with water). They sample the co-occurring with A. nilotica ssp. indica Rationale potted plants at quarterly intervals and in India. record the incidence and abundance of Prickly acacia (Acacia nilotica ssp. In north-western India, a second leaf various insects, along with details of indica) is a WONS and a Class 2 declared rust (R. evansii) was recorded at three several plant parameters (e.g. defoliation weed in Queensland. The plant is sites in Gujarat. levels, plant height, number of leaves, widespread throughout the grazing number of branches, basal stem areas of north-western Queensland, Exclusion studies diameter, above-ground and below- where it costs primary producers ground biomass). This information Results from exclusion trials in Gujarat $9 million per year by decreasing is used for prioritising agents for and Rajastahan were reported in pasture production and hindering the more detailed studies, including host- Technical highlights 2009–10. Trials in mustering of livestock. Biological control specificity tests. Tamil Nadu have now also concluded. research has been in progress since the At both sites native insect herbivores 1980s, but with limited success to date. Host-specificity tests reduced plant height, basal stem Improved climatic modelling and genetic diameter, number of branches, number Specialist insect herbivores and plant studies have suggested that the search of leaflets, leaf biomass, stem biomass pathogens exhibiting host-specificity in for biological control agents should be and root biomass (Figures 10.1 and 10.2). field surveys are tested in no-choice and concentrated in India, the native range Reductions in plant vigour at both sites choice trials in the glasshouse and field source of the prickly acacia populations were primarily due to the babul scale cages to confirm host-specificity. After in Australia. The occurrence of several (A. indicus) infesting shoots. native A. nilotica subspecies as well importing prioritised agents into the as other native and non-native Acacia quarantine at the Ecosciences Precinct, species (including species native to we conduct host-specificity testing of Australia) highlights the advantage of two agents, the leaf-webbing caterpillar conducting surveys in India, where the (Phycita sp.) and the babul scale field host-specificity of potential agents (Anomalococcus indicus), involving over could be determined. 80 species of test plants. No-choice host- specificity testing of the gall-inducing

24 Technical highlights: research projects 2010–11 Babul scale (A. indicus) crawlers (first 200 herbivore-excluded 40 herbivore-excluded herbivore-exposed herbivore-exposed instar nymphs) settled and survived on 160 standard error standard error 30 one non-target plant species (A. tortilis) 120 in no-choice tests. The rate of survival 20 80 and development of nymphs on the Plant height (cm) height Plant 10 non-target plant in comparison to 40 Basal stem diameter (mm) diameter stem Basal prickly acacia is being studied. No 0 0 crawler establishment or nymphal Thoppur Coimbatore Thoppur Coimbatore Trial site Trial site development occurred on other test plants (A. planifrons, A. leucophloea, 1200 25 herbivore-excluded herbivore-excluded A. mellifera, A. ferruginea, herbivore-exposed herbivore-exposed 1000 20 standard error standard error A. auriculiformis, A. catechu, 800 A. farnesiana, A. deanei and Piper 15 600 nigrum). 10 400 The leaf-feeding weevil (Dereodus Number of leaflets Number of Number of branches Number of 5 200 denticollis) fed on A. auriculiformis

0 0 leaves under no-choice conditions. Thoppur Coimbatore Thoppur Coimbatore Trial site Trial site Although adult weevils nibbled on the leaves of other test plants (A. farnesiana Figure 10.1 Impact of insect herbivores on plant height, basal stem diameter, number of and A. tortilis) initially, no adults branches and number of leaflets of prickly acacia seedlings in Tamil Nadu, India survived beyond three days. No adult feeding was evident on other test plants

250 (A. mellifera, A. ferruginea, A. catechu herbivore-excluded and A. deanei). herbivore-exposed 200 standard error Australia 150 Approvals to export three prioritised agents (Phycita sp., A. indicus and 100

Biomass (g) Biomass D. denticollis) from India to Australia were obtained from the National 50 Biodiversity Authority India and from the Ministry of Environment 0 and Forestry, Government of India. Thoppur Coimbatore Thoppur Coimbatore Thoppur Coimbatore Subsequently, permits to import these Leaf Stem Root Plant parameter and trial site agents into Australia were obtained from the relevant Australian regulatory Figure 10.2 Impact of insect herbivores on biomass of prickly acacia seedlings in Tamil Nadu, India authorities. We imported the three agents into a quarantine facility at the Alan Fletcher Research Station in Host-specificity tests The leaf-webbing caterpillar (Phycita sp.) January 2011 and later transferred them fed and completed development under to the new quarantine facility at the India no-choice conditions on two non- Ecosciences Precinct. Since then, we In no-choice tests, the semi lopper target acacias (A. planifrons and have established cultures of two agents (Isturgia disputaria) larvae fed and A. leucophloea), but the proportion of (Phycita sp. and A. indicus) and are completed development on two non- larvae completing development and currently conducting no-choice host- target acacias (A. planifrons and emerging as adults remained much specificity tests involving Australian A. leucophloea), but the proportion of higher (100%) on the target weed Acacia species. larvae completing development and (A. nilotica) than on A. planifrons (30%) emerging as adults was significantly and A. leucophloea (40%). No larval United Kingdom less on A. planifrons (30%) and feeding or development was evident The gall-inducing rust (R. acaciae-arabicae) A. leucophloea (10%) than on A. nilotica on other test plants (A. mellifera, was imported into quarantine facilities of (100%). No larval development occurred A. ferruginea, A. auriculiformis, CABI Europe–UK on leaves of A. nilotica on other test plants (A. mellifera, A. catechu, A. farnesiana, A. deanei, ssp. indica in October 2010. At CABI, the A. ferruginea, A. auriculiformis, A. tortilis, Anacardium occidentale and rust (IMI 398973 ex Tamil Nadu, India) was A. catechu, A. farnesiana, A. deanei, Mangifera indica). established and maintained as a uredinial A. tortilis and Delonix regia).

Part 1 Integrated weed management 25 infection (Photo 10.1) on Australian A. nilotica plants under quarantine greenhouse conditions. The rust completed its urediniospore infection cycle—from spore penetration to sporulation and uredinia formation—on average in 21 days. The rust also regularly produced teliospores within existing uredinia, but spermogonia or aecia were not observed on inoculated A. nilotica plants. An initial host-specificity assessment of the rust (IMI 398973) on 17 Acacia species under quarantine greenhouse conditions showed that the pathogen evoked a range of macroscopic symptoms on the non-target species. These varied in consistency and intensity. With the exception of Acacia sutherlandii, Photo 10.1 Uredinia of R. acaciae-arabicae on A. nilotica ssp. indica leaves R. acaciae-arabicae was not able to sporulate on any of the evaluated test plant species, internal mycelium (if present) was always limited, and the initiation of uredinia was not observed. A. sutherlandii, native to Queensland, is not a reported host of R. acaciae- arabicae or of R. evansii (the name under which the rust was previously known), but under greenhouse conditions the rust was able to produce uredinia bearing viable urediniospores on this non-target species (Photo 10.2). Sporulation was, however, less prolific than that observed on A. nilotica and was always accompanied by strong plant defence responses. Furthermore, although urediniospores of R. acaciae- arabicae produced on A. sutherlandii Photo 10.2 Uredinia of R. acaciae-arabicae on A. sutherlandii leaves were viable, re-inoculation of the spores onto A. nilotica and A. sutherlandii resulted in successful sporulation only Collaborators Dhileepan, K, Lockett, CJ, Robinson, M on the natural host A. nilotica. Possible • Roger Shivas, Principal Plant & Pukallus, K 2009, ‘Prioritising reasons for this could be either a loss Pathologist (DEEDI) potential guilds of specialist herbivores of virulence in urediniospores cycling as biological control agents for prickly • Marion Seier (CABI Europe–UK, through A. sutherlandii or a lower acacia through simulated herbivory’, United Kingdom) concentration of spore inoculum applied Annals of Applied Biology 154(1): 97–105. due to the initially limited production of • Arid Forest Research Institute, Dhileepan, K, Senaratne, KADW & R. acaciae-arabicea on A. sutherlandii. Jodhpur, Rajasthan, India Raghu, S 2006, ‘A systematic approach to • Institute of Forest Genetics and Tree biological control agent exploration and Funding in 2010–11 Breeding, Coimbatore, Tamil Nadu, India prioritisation for prickly acacia (Acacia • MLA ($85 000) More information nilotica ssp. indica)’, Australian Journal • Rural Industries Research and of Entomology 45(4): 303–07. Key publications Development Corporation ($41 000) For further information on this research • Land Protection Fund ($38 000) Dhileepan, K 2009, ‘Acacia nilotica ssp. project and access to key publications, indica (L.) Willd. ex Del. (Mimosaceae)’, visit the invasive plant and animal science • Queensland Government in R Muniappan, GVP Reddy & A Raman pages on the Biosecurity Queensland (eds), Biological control of tropical weeds website at www.biosecurity.qld.gov.au using arthropods, Cambridge University Press, Cambridge, pp. 17–37.

26 Technical highlights: research projects 2010–11 11. Biological control of Hudson pear (Cylindropuntia rosea)

Project dates October 2009 – June 2012

Project leader Dr Bill Palmer Ecosciences Precinct Tel: (07) 3255 4469 Email: [email protected]

Other staff in 2010–11 Peter Jones

Objectives • Obtain permission to release the cochineal insect Dactylopius tomentosus as a biological control Photo 11.1 A male D. tomentosus fertilising a mature female (hidden underneath waxy secretion) agent for Hudson pear in Australia by providing evidence of its host- specificity through laboratory Our collaborators in New South Wales Given the problems encountered with experimentation within quarantine. source the culture, test plants, design D. tomentosus from Mexico, the question experiments in consultation with us, remains whether Hudson pear in • Determine the effectiveness of this arrange for mass-rearing and release Australia is really C. rosea or perhaps a biotype of D. tomentosus against of the bug in the infested areas of New hybrid. Linking our Hudson pear with various other Cylindropuntia spp. South Wales and write reports. similar genotypes in Mexico would found in Australia. also enable appropriate native range Rationale Progress in 2010–11 collections of D. tomentosus. In August 2010, collaborator Dr Carla Hudson pear (Cylindropuntia rosea) Chavez Moreno hand-carried a Funding in 2010–11 is native to Mexico. In Australia, it population of D. tomentosus collected on New South Wales Government is found primarily in north-western the required host C. rosea to Australia, Department of Primary Industries New South Wales, but it also occurs where it was placed in quarantine. ($31 000) in Queensland. It was approved as a However, the insect could not use target for biological control by the Australian populations of Hudson pear Collaborators Natural Resource Management Standing nor other Cylindropuntia spp. presently Committee in 2008. Biosecurity • Royce Holtkamp (New South Wales found in Australia. The culture was Queensland has been contracted by Government Department of Primary maintained on Mexican cladode material the New South Wales Government Industries) for many months but all attempts to rear Department of Primary Industries to it on Australian material failed. • Catherine Mathenge (University of test the host-specificity of the cochineal Western Sydney) insect D. tomentosus in quarantine. We are now attempting to culture • Carla Chavez Moreno (University of other populations of D. tomentosus: Michoacan, Mexico) Methods a population infesting C. kleiniae was We culture the bug, care for the plants obtained from South Australia and • Mayra Pérez and Sandi Cuen and test for appropriate host-specificity host testing commenced; a population (Aridamerica AC, Mexico) to ensure that the insect does not attack currently giving effective biological • Helmuth Zimmermann (Helmuth any native or economically desirable control of C. fulgida in South Africa will Zimmermann & Associates, plant. We also evaluate the efficacy also be imported. South Africa) of the insect against other weedy We have also arranged for genetic Cylindropuntia spp. found in Australia. studies to be undertaken on C. rosea More information If testing determines that the insect from Mexico and Spain, C. fulgida For further information on this is safe to release in Australia, the from South Africa and most of the research project, visit the invasive appropriate permissions will be obtained Australian Cylindopuntia spp. in order plant and animal science pages on the from regulatory authorities to enable its to have an improved understanding Biosecurity Queensland website at release from quarantine. of the taxonomy of this genus. www.biosecurity.qld.gov.au

Part 1 Integrated weed management 27 12. Biological control of mother-of-millions (Bryophyllum spp.)

Project dates Methods The PhD student’s field studies of S. aurantii indicated that additional January 2000 – July 2012 Potential biocontrol agents are imported biocontrol agents would be desirable to for host-specificity testing in quarantine. control mother-of-millions effectively. Project leader If approval for release is obtained, we Dr Bill Palmer mass-rear agents and release them Funding in 2010–11 Ecosciences Precinct throughout the range of the weed Land Protection Fund ($73 000) Tel: (07) 3255 4469 in Queensland. We then monitor the Email: [email protected] releases to determine establishment progress and any effects of the agent. Collaborators Other staff in 2010–11 The process laid out in the Biological • Dr Bruce Wilson, General Manager, Invasive Plants and Animals Wilmot Senaratne and Liz Snow Control Act 1987 involves applying to the appropriate ministerial council. If (Biosecurity Queensland) Objectives the ministerial council unanimously • Michelle Rafter, PhD student (The supports the application, a biological University of Queensland) • Achieve biological control of mother- control authority will seek the views of-millions by introducing and of all stakeholders and determine the More information releasing exotic insect species or benefits and costs of the proposed pathogens. biological control. If, on balance, the Key publications • Produce risk, economic, stakeholder benefits outweigh costs, the ministerial McLaren, DA, Palmer, WA & Morfe, TA and partner analyses for the mother- council may by unanimous opinion 2006, ‘Costs associated with declaring of-millions weed problem. approve the declaration of target and organisms through the Biological Control • Support any application under the agent organisms under the Act. Act when conflicts of interest threaten weed biological control projects’, in Biological Control Act 1987 through A PhD student, receiving some support C Preston, JH Watts & ND Crossman the various processes of the Act and supervision from Biosecurity (eds), Proceedings of the 15th Australian and determine whether the Act can Queensland, studies populations of Weeds Conference, Weed Management be used to assist biological control mother-of-millions in the Western Society of South Australia, Adelaide, projects. Downs to determine the effects of the pp. 549–52. South African citrus thrips Rationale (Scirtothrips aurantii). Witt, ABR 2004, ‘Initial screening of the Mother-of-millions (Bryophyllum spp.), stem-boring weevil Osphilia tenuipes, a a native of Madagascar, is a Class 2 Progress in 2010–11 candidate agent for the biological control declared weed in Queensland. It is We maintained cultures of O. tenuipes of Bryophyllum delagoense in Australia’, toxic to cattle and can have substantial and A. sedi in quarantine throughout Biocontrol 49(2): 197–209. economic and environmental impacts. the year. These insects remain promising Witt, ABR, McConnachie, AJ & Surveys for potential biocontrol biocontrol agents if they can be approved Stals, R 2004, ‘Alcidodes sedi (Col.: agents for mother-of-millions began for release. The insects were relocated Curculionidae), a natural enemy of in 2000. The weevils Osphilia tenuipes to the new quarantine facility at the Bryophyllum delagoense (Crassulaceae) and Alcidodes sedi were studied in Ecosciences Precinct in February 2011. in South Africa and a possible candidate detail in the quarantine facility at the Additional host testing of both insect agent for the biological control of this Alan Fletcher Research Station, while species was undertaken following the weed in Australia’, Biological Control preliminary studies of two further discovery that naturalised populations 31(3): 380–87. agents were undertaken in South Africa. previously considered to be Kalanchoe Hannan-Jones, MA & Playford, J 2002, All potential biocontrol agents for crenata were now considered to be ‘The biology of Australian weeds 40. mother-of-millions had narrow host Kalanchoe spathulata. The results of this Bryophyllum Salisb. species’, Plant ranges but were capable of attacking testing suggested that this plant was a Protection Quarterly 17(2): 42–57. very closely related, exotic, ornamental good host for both insect species. plants such as Kalanchoe blossfeldiana For further information on this research and Echeveria spp. An application for agent release through project and access to key publications, the Biological Control Act 1987 was visit the invasive plant and animal science Due to potential conflicts of interest, all submitted to the Australian Weeds pages on the Biosecurity Queensland agents would require approval through Committee for discussion. With the website at www.biosecurity.qld.gov.au the Biological Control Act 1987. When support of this committee, an application biological control targets and agents are was made to and approved by the declared under the Act, proponents are Primary Industries Ministerial Council. not legally liable for identified adverse The next step is to prepare nationwide effects and legal injunctions cannot be notification and invite affected brought to prevent releases of the agent. stakeholders to respond.

28 Technical highlights: research projects 2010–11