T. Heard - Academia.edu (original) (raw)

Papers by T. Heard

Research paper thumbnail of Diversity, Abundance, and Distribution of Insect Visitors to Macadamia Flowers

Environmental Entomology, 1994

Research paper thumbnail of Relative Tolerance to Vapor Heat Treatment of Eggs and Larvae of Bactrocera tryoni (Diptera: Tephritidae) in Mangoes

Journal of Economic Entomology, 1992

Research paper thumbnail of Vapor heat treatment for zucchini infested with Bactrocera cucumis (Diptera: Tephritidae)

Journal of economic entomology, 1993

Zucchini, Cucurbita pepo L., infested with 22-h-old eggs of Bactrocera cucumis (French) were comp... more Zucchini, Cucurbita pepo L., infested with 22-h-old eggs of Bactrocera cucumis (French) were completely disinfested using a vapor heat treatment of 45 degrees C with > 94% RH for 30 min. An estimated total of 178,219 eggs (22 h old) was treated without survivors, thus achieving probit 9 mortality. Twenty-two-h-old eggs were significantly more tolerant of heat than first, second, or third instars. All treatments were done in a Sanshu model EHK-1000B vapor heat treatment system.

Research paper thumbnail of Anti-staphylococcal properties of propolis from Australian stingless bees Tetragonula carbonaria

Research paper thumbnail of A guide to mapping Mimosa pigra in the Northern Territory, Australia

Research paper thumbnail of Research and management of Mimosa pigra: papers presented at the 3rd International Symposium on the Management of Mimosa pigra, Darwin, Australia, 22-25 September 2002

Research paper thumbnail of Phloroglucinols from Anti-Microbial Deposit-Resins of Australian Stingless Bees ( Tetragonula carbonaria )

Phytotherapy Research, 2014

Stingless bees accumulate deposits of plant resins that are mixed with beeswax to produce propoli... more Stingless bees accumulate deposits of plant resins that are mixed with beeswax to produce propolis. Previous studies have reported anti-microbial constituents of stingless bee (Tetragonula carbonaria) propolis from East Australia, but several components remained to be characterized. In the search of natural products yet unreported for Australian propolis, four bee deposit-resins of T. carbonaria bees were analysed by gas and liquid chromatography mass spectrometry with accurate mass measurements. Ethanolic extracts of the deposit-resins were tested in vitro against Staphylococcus aureus ATCC 25983 and Pseudomonas aeruginosa ATCC 27853 by the agar diffusion method. Phloroglucinols, flavonoids and isoprenoids were identified in samples. The crude extracts showed strong anti-staphylococcal effects but were less active against the Gram-negative bacterium. The diagnostic data enabled the identification of markers that can be used for profiling other Australian propolis sources and to target the isolation of bioactive phloroglucinols in future studies against antibiotic resistant S. aureus strains. Copyright © 2014 John Wiley & Sons, Ltd.

Research paper thumbnail of Preliminary results of a survey on the role of arthropod rearing in classical weed biological control

Proceedings of the XII International Symposium on Biological Control of Weeds, La Grande Motte, France, 22-27 April, 2007, 2008

The rearing of arthropods is an essential but sometimes neglected and underestimated part of a cl... more The rearing of arthropods is an essential but sometimes neglected and underestimated part of a classical weed biological control programme. Success in rearing is usually a prerequisite to conducting host-specificity tests, obtaining enough individuals for initial field release or, later, for large-scale implementation. Although most biological control researchers can list situations where agent development has been stopped or slowed due to rearing difficulties, failures seldom get reported in the literature, thus preventing us from gauging the extent and relevance of rearing issues. To rectify this, a questionnaire was developed to investigate the prevalence of rearing problems in weed biological control programmes and to classify their occurrence according to a list of variables (e.g. taxonomy, biological features, genetic issues and researcher/programme attributes). The questionnaire was sent to 80 researchers from eight countries; 65% responded, generating 79 useful responses. Results confirm that, of the challenges faced in programmes, rearing is the most prevalent (56% out of ten possible general problem categories). The most common rearing problems encountered were conditions that were not conducive to mating and/or oviposition (30% of reported arthropod cases) or development (22% of reported arthropod cases). Our results identify key areas for rearing improvement, thus contributing to increased weed biological control project successes.

Research paper thumbnail of Biological control of the bellyache bush

Pesticide Outlook, 2003

The weed Bellyache bush is declared noxious in several states of Australia and it is also present... more The weed Bellyache bush is declared noxious in several states of Australia and it is also present as a weed in Brazil, Jamaica, Trinidad, East Timor and Indonesia. It is native to the American Tropics but has become widely naturalised after being introduced as an ornamental plant and for use in folk medicine. This evergreen perennial grows up to 3 metres and reproduces by seed. In Australia it invades rangelands, particularly in riparian zones, forming dense thickets which displace useful species, reduce productivity of pastoral land and hinder cattle mustering. All parts of the plant are toxic and can cause the death of animals that ingest it. In Australia's tropical north, it is now widespread with the potential to cover enormous tracts of Queensland, Northern Territory and Western Australia. Attempts to control bellyache bush up until now have included herbicide (applications of registered products containing the active ingredient metsulfuron or fluroxypyr), mechanical destruction, burning and repeated cultivation of the soil. Mechanical, chemical and fire methods are effective but need to be repeated over a long period to control the seedling regrowth. In extensive rangeland systems this may not be practical or economically feasible. Hence bellyache bush is a good candidate for biological control which is selfperpetuating and imposes little cost on the land holder.

Research paper thumbnail of Global meliponiculture: challenges and opportunities

Apidologie, 2006

Stingless bees are social bees that live in tropical and subtropical areas of the world. All spec... more Stingless bees are social bees that live in tropical and subtropical areas of the world. All species produce honey, which has been appreciated by humans since ancient times. Here, the general panorama of meliponiculture is presented. Deforestation and poor management are the main problems faced by this incipient industry. For a profitable meliponiculture, much more biological information is needed, as well as field studies in natural conditions. In the near future, we suggest that the successful use of these pollinators will promote the development of new breeding techniques and commercialization possibilities, which must be designed to be sustainable.

Research paper thumbnail of Development of new biocontrol agents for Parkinsonia

CSIRO advises that the information contained in this publication comprises general statements bas... more CSIRO advises that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.

Research paper thumbnail of Examining the impact of control over time on the seed bank of Mimosa pigra on Top End, Australia floodplains

… and Management of …, 2002

Mimosa, Mimosa pigra L., is renowned for producing an abundance of seeds, many of which remain in... more Mimosa, Mimosa pigra L., is renowned for producing an abundance of seeds, many of which remain in the population as a persistent seed bank. Integrated control programs have been effective in reducing the above-ground cover of mimosa but little is known about its effect on the soil seed-bank. The viability of mimosa soil seed banks following integrated control was investigated in two floodplains in the Top End of northern Australia in relation to time since control and vegetation type. Mimosa seed banks under all vegetation types were considerably lower (by at least 50%) than under stands of mimosa. Most of this reduction occurred within the first year of control, although seed stores still remained in the soil three years after initial control. There were few consistent differences in the density of mimosa seed banks between vegetation types. The results also indicated considerably lower seed counts under mimosa compared to previous studies. The lower seed count under mimosa may be attributed to the effectiveness of current biological-control programs. Integrated control therefore appears to be reducing viable mimosa seed. Nevertheless, significant numbers of seeds remain in the seed bank, highlighting the importance of follow-up control and sound land-management practices (avoiding overgrazing and maintaining suitable vegetation cover) in order for competitive species to suppress mimosa re-establishment.

Research paper thumbnail of Antimicrobial activity of honey from the stingless bee Trigona carbonaria determined by agar diffusion, agar dilution, broth microdilution and time-kill methodology

Journal of Applied Microbiology, 2010

Aims: The aim of this study was to determine the spectrum of antimicrobial activity of 11 samples... more Aims: The aim of this study was to determine the spectrum of antimicrobial activity of 11 samples of stingless bee honey compared to medicinal, table and artificial honeys. Methods and Results: Activity was assessed by agar diffusion, agar dilution, broth microdilution and time-kill viability assays. By agar dilution, minimum inhibitory concentration (MIC) ranges were 4% to >10% (w ⁄ v) for Gram-positive bacteria, 6% to >16% (w ⁄ v) for Gram-negative bacteria and 6% to >10% (w ⁄ v) for Candida spp. By broth microdilution, all organisms with the exception of Candida albicans and Candida glabrata were inhibited at £32% (w ⁄ v). Geometric MIC (w ⁄ v) means for stingless bee honeys ranged from 7AE1% to 16AE0% and were 11AE7% for medicinal honey and 26AE5% for table honey. Treatment of organisms with 20% (w ⁄ v) stingless bee honey for 60 min resulted in decreases of 1-3 log for Staphylococcus aureus, >3 log for Pseudomonas aeruginosa and <1 log for C. albicans. Similar treatment with each control honey resulted in decreases of <1 log for all organisms. Conclusions: Stingless bee honey has broad-spectrum antibacterial activity although activity against Candida was limited. Stingless bee honey samples varied in activity and the basis for this remains to be determined. Significance and Impact of the Study: Stingless bee honey had similar activity to medicinal honey and may therefore have a role as a medicinal agent.

Research paper thumbnail of Nest defence in a stingless bee: What causes fighting swarms in Trigona carbonaria (Hymenoptera, Meliponini)?

Insectes Sociaux, 2008

The Australian stingless bee Trigona carbonaria sometimes displays a striking collective behaviou... more The Australian stingless bee Trigona carbonaria sometimes displays a striking collective behaviour, known as a fighting swarm in which thousands of workers fight and die. Molecular analysis of eight naturally-occurring fights showed they almost always comprise just two colonies, one of which is located within 2 m of the fight. Fighting swarms were experimentally triggered by manipulating colonies so that they received non-nestmate workers. Combined, our investigations suggest that T. carbonaria fighting swarms arise as a collective defence of the nest from conspecific invasion (e.g. robbery or nest usurpation).

Research paper thumbnail of Classical biological control for the protection of natural ecosystems

Biological Control, 2010

Of the 70 cases of classical biological control for the protection of nature found in our review,... more Of the 70 cases of classical biological control for the protection of nature found in our review, there were fewer projects against insect targets (21) than against invasive plants (49), in part, because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of 21 insect projects, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive plants, 98% (48) provided benefits to protection of biodiversity, while 47% (23) protected products, and 25% (12) preserved ecosystem services, again with many projects contributing to several goals. We classified projects into complete control (pest generally no longer important), partial control (control in some areas but not others), and ''in progress," for projects in development for which outcomes do not yet exist. For insects, of the 21 projects discussed, 62% (13) achieved complete control of the target pest, 19% (4) provided partial control, and 43% (9) are still in progress. By comparison, of the 49 invasive plant projects considered, 27% (13) achieved complete control, while 33% (16) provided partial control, and 49% (24) are still in progress. For both categories of pests, some projects' success ratings were scored twice when results varied by region. We found approximately twice as many projects directed against invasive plants than insects and that protection of biodiversity was the most frequent benefit of both insect and plant projects. Ecosystem service protection was provided in the fewest cases by either insect or plant biological control agents, but was more likely to be provided by projects directed against invasive plants, likely because of the strong effects plants exert on landscapes. Rates of complete success appeared to be higher for insect than plant targets (62% vs 27%), perhaps because most often herbivores gradually weaken, rather than outright kill, their hosts, which is not the case for natural enemies directed against pest insects. For both insect and plant biological control, nearly half of all projects reviewed were listed as currently in progress, suggesting that the use of biological control for the protection of wildlands is currently very active.

Research paper thumbnail of Biology and Host Range of the Green-seed Weevil, Sibinia fastigiata , for Biological Control of Mimosa pigra

Biocontrol Science and Technology, 1997

ABSTRACT Aspects of the biology and host range of Sibinia fastigiata Clark (Coleoptera: Curculion... more ABSTRACT Aspects of the biology and host range of Sibinia fastigiata Clark (Coleoptera: Curculionidae) were studied to assess its safety for release in Australia as a biological control agent of the weed Mimosa pigra L . (Mimosaceae) . Larvae feed on the seeds and adults on open flowers of their host . Adults oviposit on to immature seeds 3 mm long or less and hence seeds of this length and maturity were used in the host range tests and for rearing . Females are shown to avoid previously attacked seeds enhancing their effectiveness as seed destroyers . Survival of adults was higher when provided with open flowers . The host range was determined using laboratory control - choice oviposition tests on excised plant material and , in the field in the native range , no - choice oviposition tests on living plants , surveys of adults on plants , and breeding of insects from pods of plants of various legume species . The control - choice oviposition tests employed a new design in which the control plant alone was offered to the insects followed by a choice of test plants species . Other than M. pigra, only one plant species was acceptable for oviposition , the closely related M. asperata. Larval development also occurs on M. asperata and this host is occasionally used in the field . This insect was approved for release in March 1997 .

Research paper thumbnail of Herbicides and their application for the control of mimosa in the Northern Territory, Australia

… and management of …, 2004

There is a wide range of habits in which mimosa, Mimosa pigra L., can effectively colonise, and t... more There is a wide range of habits in which mimosa, Mimosa pigra L., can effectively colonise, and the selection of a herbicide and application technique must be appropriate to the situation. There are several interacting factors that can influence the effectiveness of a herbicide and the application technique including environmental, infestation characteristics and human resourcing issues. There are effective herbicides that are currently not registered for use in the Northern Territory and this limits the availability of choices in some situations. The registration of these options should be a priority.

Research paper thumbnail of Centres of origin: do they exist, can we identify them, does it matter?

Research paper thumbnail of Host-specificity testing of exotic arthropod biological control agents: The biological basis for improvement in safety

Research paper thumbnail of Classical biological control for the protection of natural ecosystems

Of the 70 cases of classical biological control for the protection of nature found in our review,... more Of the 70 cases of classical biological control for the protection of nature found in our review, there were fewer projects against insect targets (21) than against invasive plants (49), in part, because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of 21 insect projects, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive plants, 98% (48) provided benefits to protection of biodiversity, while 47% (23) protected products, and 25% (12) preserved ecosystem services, again with many projects contributing to several goals. We classified projects into complete control (pest generally no longer important), partial control (control in some areas but not others), and ''in progress," for projects in development for which outcomes do not yet exist. For insects, of the 21 projects discussed, 62% (13) achieved complete control of the target pest, 19% (4) provided partial control, and 43% (9) are still in progress. By comparison, of the 49 invasive plant projects considered, 27% (13) achieved complete control, while 33% (16) provided partial control, and 49% (24) are still in progress. For both categories of pests, some projects' success ratings were scored twice when results varied by region. We found approximately twice as many projects directed against invasive plants than insects and that protection of biodiversity was the most frequent benefit of both insect and plant projects. Ecosystem service protection was provided in the fewest cases by either insect or plant biological control agents, but was more likely to be provided by projects directed against invasive plants, likely because of the strong effects plants exert on landscapes. Rates of complete success appeared to be higher for insect than plant targets (62% vs 27%), perhaps because most often herbivores gradually weaken, rather than outright kill, their hosts, which is not the case for natural enemies directed against pest insects. For both insect and plant biological control, nearly half of all projects reviewed were listed as currently in progress, suggesting that the use of biological control for the protection of wildlands is currently very active.

Research paper thumbnail of Diversity, Abundance, and Distribution of Insect Visitors to Macadamia Flowers

Environmental Entomology, 1994

Research paper thumbnail of Relative Tolerance to Vapor Heat Treatment of Eggs and Larvae of Bactrocera tryoni (Diptera: Tephritidae) in Mangoes

Journal of Economic Entomology, 1992

Research paper thumbnail of Vapor heat treatment for zucchini infested with Bactrocera cucumis (Diptera: Tephritidae)

Journal of economic entomology, 1993

Zucchini, Cucurbita pepo L., infested with 22-h-old eggs of Bactrocera cucumis (French) were comp... more Zucchini, Cucurbita pepo L., infested with 22-h-old eggs of Bactrocera cucumis (French) were completely disinfested using a vapor heat treatment of 45 degrees C with > 94% RH for 30 min. An estimated total of 178,219 eggs (22 h old) was treated without survivors, thus achieving probit 9 mortality. Twenty-two-h-old eggs were significantly more tolerant of heat than first, second, or third instars. All treatments were done in a Sanshu model EHK-1000B vapor heat treatment system.

Research paper thumbnail of Anti-staphylococcal properties of propolis from Australian stingless bees Tetragonula carbonaria

Research paper thumbnail of A guide to mapping Mimosa pigra in the Northern Territory, Australia

Research paper thumbnail of Research and management of Mimosa pigra: papers presented at the 3rd International Symposium on the Management of Mimosa pigra, Darwin, Australia, 22-25 September 2002

Research paper thumbnail of Phloroglucinols from Anti-Microbial Deposit-Resins of Australian Stingless Bees ( Tetragonula carbonaria )

Phytotherapy Research, 2014

Stingless bees accumulate deposits of plant resins that are mixed with beeswax to produce propoli... more Stingless bees accumulate deposits of plant resins that are mixed with beeswax to produce propolis. Previous studies have reported anti-microbial constituents of stingless bee (Tetragonula carbonaria) propolis from East Australia, but several components remained to be characterized. In the search of natural products yet unreported for Australian propolis, four bee deposit-resins of T. carbonaria bees were analysed by gas and liquid chromatography mass spectrometry with accurate mass measurements. Ethanolic extracts of the deposit-resins were tested in vitro against Staphylococcus aureus ATCC 25983 and Pseudomonas aeruginosa ATCC 27853 by the agar diffusion method. Phloroglucinols, flavonoids and isoprenoids were identified in samples. The crude extracts showed strong anti-staphylococcal effects but were less active against the Gram-negative bacterium. The diagnostic data enabled the identification of markers that can be used for profiling other Australian propolis sources and to target the isolation of bioactive phloroglucinols in future studies against antibiotic resistant S. aureus strains. Copyright © 2014 John Wiley &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Sons, Ltd.

Research paper thumbnail of Preliminary results of a survey on the role of arthropod rearing in classical weed biological control

Proceedings of the XII International Symposium on Biological Control of Weeds, La Grande Motte, France, 22-27 April, 2007, 2008

The rearing of arthropods is an essential but sometimes neglected and underestimated part of a cl... more The rearing of arthropods is an essential but sometimes neglected and underestimated part of a classical weed biological control programme. Success in rearing is usually a prerequisite to conducting host-specificity tests, obtaining enough individuals for initial field release or, later, for large-scale implementation. Although most biological control researchers can list situations where agent development has been stopped or slowed due to rearing difficulties, failures seldom get reported in the literature, thus preventing us from gauging the extent and relevance of rearing issues. To rectify this, a questionnaire was developed to investigate the prevalence of rearing problems in weed biological control programmes and to classify their occurrence according to a list of variables (e.g. taxonomy, biological features, genetic issues and researcher/programme attributes). The questionnaire was sent to 80 researchers from eight countries; 65% responded, generating 79 useful responses. Results confirm that, of the challenges faced in programmes, rearing is the most prevalent (56% out of ten possible general problem categories). The most common rearing problems encountered were conditions that were not conducive to mating and/or oviposition (30% of reported arthropod cases) or development (22% of reported arthropod cases). Our results identify key areas for rearing improvement, thus contributing to increased weed biological control project successes.

Research paper thumbnail of Biological control of the bellyache bush

Pesticide Outlook, 2003

The weed Bellyache bush is declared noxious in several states of Australia and it is also present... more The weed Bellyache bush is declared noxious in several states of Australia and it is also present as a weed in Brazil, Jamaica, Trinidad, East Timor and Indonesia. It is native to the American Tropics but has become widely naturalised after being introduced as an ornamental plant and for use in folk medicine. This evergreen perennial grows up to 3 metres and reproduces by seed. In Australia it invades rangelands, particularly in riparian zones, forming dense thickets which displace useful species, reduce productivity of pastoral land and hinder cattle mustering. All parts of the plant are toxic and can cause the death of animals that ingest it. In Australia's tropical north, it is now widespread with the potential to cover enormous tracts of Queensland, Northern Territory and Western Australia. Attempts to control bellyache bush up until now have included herbicide (applications of registered products containing the active ingredient metsulfuron or fluroxypyr), mechanical destruction, burning and repeated cultivation of the soil. Mechanical, chemical and fire methods are effective but need to be repeated over a long period to control the seedling regrowth. In extensive rangeland systems this may not be practical or economically feasible. Hence bellyache bush is a good candidate for biological control which is selfperpetuating and imposes little cost on the land holder.

Research paper thumbnail of Global meliponiculture: challenges and opportunities

Apidologie, 2006

Stingless bees are social bees that live in tropical and subtropical areas of the world. All spec... more Stingless bees are social bees that live in tropical and subtropical areas of the world. All species produce honey, which has been appreciated by humans since ancient times. Here, the general panorama of meliponiculture is presented. Deforestation and poor management are the main problems faced by this incipient industry. For a profitable meliponiculture, much more biological information is needed, as well as field studies in natural conditions. In the near future, we suggest that the successful use of these pollinators will promote the development of new breeding techniques and commercialization possibilities, which must be designed to be sustainable.

Research paper thumbnail of Development of new biocontrol agents for Parkinsonia

CSIRO advises that the information contained in this publication comprises general statements bas... more CSIRO advises that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.

Research paper thumbnail of Examining the impact of control over time on the seed bank of Mimosa pigra on Top End, Australia floodplains

… and Management of …, 2002

Mimosa, Mimosa pigra L., is renowned for producing an abundance of seeds, many of which remain in... more Mimosa, Mimosa pigra L., is renowned for producing an abundance of seeds, many of which remain in the population as a persistent seed bank. Integrated control programs have been effective in reducing the above-ground cover of mimosa but little is known about its effect on the soil seed-bank. The viability of mimosa soil seed banks following integrated control was investigated in two floodplains in the Top End of northern Australia in relation to time since control and vegetation type. Mimosa seed banks under all vegetation types were considerably lower (by at least 50%) than under stands of mimosa. Most of this reduction occurred within the first year of control, although seed stores still remained in the soil three years after initial control. There were few consistent differences in the density of mimosa seed banks between vegetation types. The results also indicated considerably lower seed counts under mimosa compared to previous studies. The lower seed count under mimosa may be attributed to the effectiveness of current biological-control programs. Integrated control therefore appears to be reducing viable mimosa seed. Nevertheless, significant numbers of seeds remain in the seed bank, highlighting the importance of follow-up control and sound land-management practices (avoiding overgrazing and maintaining suitable vegetation cover) in order for competitive species to suppress mimosa re-establishment.

Research paper thumbnail of Antimicrobial activity of honey from the stingless bee Trigona carbonaria determined by agar diffusion, agar dilution, broth microdilution and time-kill methodology

Journal of Applied Microbiology, 2010

Aims: The aim of this study was to determine the spectrum of antimicrobial activity of 11 samples... more Aims: The aim of this study was to determine the spectrum of antimicrobial activity of 11 samples of stingless bee honey compared to medicinal, table and artificial honeys. Methods and Results: Activity was assessed by agar diffusion, agar dilution, broth microdilution and time-kill viability assays. By agar dilution, minimum inhibitory concentration (MIC) ranges were 4% to >10% (w ⁄ v) for Gram-positive bacteria, 6% to >16% (w ⁄ v) for Gram-negative bacteria and 6% to >10% (w ⁄ v) for Candida spp. By broth microdilution, all organisms with the exception of Candida albicans and Candida glabrata were inhibited at £32% (w ⁄ v). Geometric MIC (w ⁄ v) means for stingless bee honeys ranged from 7AE1% to 16AE0% and were 11AE7% for medicinal honey and 26AE5% for table honey. Treatment of organisms with 20% (w ⁄ v) stingless bee honey for 60 min resulted in decreases of 1-3 log for Staphylococcus aureus, >3 log for Pseudomonas aeruginosa and <1 log for C. albicans. Similar treatment with each control honey resulted in decreases of <1 log for all organisms. Conclusions: Stingless bee honey has broad-spectrum antibacterial activity although activity against Candida was limited. Stingless bee honey samples varied in activity and the basis for this remains to be determined. Significance and Impact of the Study: Stingless bee honey had similar activity to medicinal honey and may therefore have a role as a medicinal agent.

Research paper thumbnail of Nest defence in a stingless bee: What causes fighting swarms in Trigona carbonaria (Hymenoptera, Meliponini)?

Insectes Sociaux, 2008

The Australian stingless bee Trigona carbonaria sometimes displays a striking collective behaviou... more The Australian stingless bee Trigona carbonaria sometimes displays a striking collective behaviour, known as a fighting swarm in which thousands of workers fight and die. Molecular analysis of eight naturally-occurring fights showed they almost always comprise just two colonies, one of which is located within 2 m of the fight. Fighting swarms were experimentally triggered by manipulating colonies so that they received non-nestmate workers. Combined, our investigations suggest that T. carbonaria fighting swarms arise as a collective defence of the nest from conspecific invasion (e.g. robbery or nest usurpation).

Research paper thumbnail of Classical biological control for the protection of natural ecosystems

Biological Control, 2010

Of the 70 cases of classical biological control for the protection of nature found in our review,... more Of the 70 cases of classical biological control for the protection of nature found in our review, there were fewer projects against insect targets (21) than against invasive plants (49), in part, because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of 21 insect projects, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive plants, 98% (48) provided benefits to protection of biodiversity, while 47% (23) protected products, and 25% (12) preserved ecosystem services, again with many projects contributing to several goals. We classified projects into complete control (pest generally no longer important), partial control (control in some areas but not others), and ''in progress," for projects in development for which outcomes do not yet exist. For insects, of the 21 projects discussed, 62% (13) achieved complete control of the target pest, 19% (4) provided partial control, and 43% (9) are still in progress. By comparison, of the 49 invasive plant projects considered, 27% (13) achieved complete control, while 33% (16) provided partial control, and 49% (24) are still in progress. For both categories of pests, some projects' success ratings were scored twice when results varied by region. We found approximately twice as many projects directed against invasive plants than insects and that protection of biodiversity was the most frequent benefit of both insect and plant projects. Ecosystem service protection was provided in the fewest cases by either insect or plant biological control agents, but was more likely to be provided by projects directed against invasive plants, likely because of the strong effects plants exert on landscapes. Rates of complete success appeared to be higher for insect than plant targets (62% vs 27%), perhaps because most often herbivores gradually weaken, rather than outright kill, their hosts, which is not the case for natural enemies directed against pest insects. For both insect and plant biological control, nearly half of all projects reviewed were listed as currently in progress, suggesting that the use of biological control for the protection of wildlands is currently very active.

Research paper thumbnail of Biology and Host Range of the Green-seed Weevil, Sibinia fastigiata , for Biological Control of Mimosa pigra

Biocontrol Science and Technology, 1997

ABSTRACT Aspects of the biology and host range of Sibinia fastigiata Clark (Coleoptera: Curculion... more ABSTRACT Aspects of the biology and host range of Sibinia fastigiata Clark (Coleoptera: Curculionidae) were studied to assess its safety for release in Australia as a biological control agent of the weed Mimosa pigra L . (Mimosaceae) . Larvae feed on the seeds and adults on open flowers of their host . Adults oviposit on to immature seeds 3 mm long or less and hence seeds of this length and maturity were used in the host range tests and for rearing . Females are shown to avoid previously attacked seeds enhancing their effectiveness as seed destroyers . Survival of adults was higher when provided with open flowers . The host range was determined using laboratory control - choice oviposition tests on excised plant material and , in the field in the native range , no - choice oviposition tests on living plants , surveys of adults on plants , and breeding of insects from pods of plants of various legume species . The control - choice oviposition tests employed a new design in which the control plant alone was offered to the insects followed by a choice of test plants species . Other than M. pigra, only one plant species was acceptable for oviposition , the closely related M. asperata. Larval development also occurs on M. asperata and this host is occasionally used in the field . This insect was approved for release in March 1997 .

Research paper thumbnail of Herbicides and their application for the control of mimosa in the Northern Territory, Australia

… and management of …, 2004

There is a wide range of habits in which mimosa, Mimosa pigra L., can effectively colonise, and t... more There is a wide range of habits in which mimosa, Mimosa pigra L., can effectively colonise, and the selection of a herbicide and application technique must be appropriate to the situation. There are several interacting factors that can influence the effectiveness of a herbicide and the application technique including environmental, infestation characteristics and human resourcing issues. There are effective herbicides that are currently not registered for use in the Northern Territory and this limits the availability of choices in some situations. The registration of these options should be a priority.

Research paper thumbnail of Centres of origin: do they exist, can we identify them, does it matter?

Research paper thumbnail of Host-specificity testing of exotic arthropod biological control agents: The biological basis for improvement in safety

Research paper thumbnail of Classical biological control for the protection of natural ecosystems

Of the 70 cases of classical biological control for the protection of nature found in our review,... more Of the 70 cases of classical biological control for the protection of nature found in our review, there were fewer projects against insect targets (21) than against invasive plants (49), in part, because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of 21 insect projects, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive plants, 98% (48) provided benefits to protection of biodiversity, while 47% (23) protected products, and 25% (12) preserved ecosystem services, again with many projects contributing to several goals. We classified projects into complete control (pest generally no longer important), partial control (control in some areas but not others), and ''in progress," for projects in development for which outcomes do not yet exist. For insects, of the 21 projects discussed, 62% (13) achieved complete control of the target pest, 19% (4) provided partial control, and 43% (9) are still in progress. By comparison, of the 49 invasive plant projects considered, 27% (13) achieved complete control, while 33% (16) provided partial control, and 49% (24) are still in progress. For both categories of pests, some projects' success ratings were scored twice when results varied by region. We found approximately twice as many projects directed against invasive plants than insects and that protection of biodiversity was the most frequent benefit of both insect and plant projects. Ecosystem service protection was provided in the fewest cases by either insect or plant biological control agents, but was more likely to be provided by projects directed against invasive plants, likely because of the strong effects plants exert on landscapes. Rates of complete success appeared to be higher for insect than plant targets (62% vs 27%), perhaps because most often herbivores gradually weaken, rather than outright kill, their hosts, which is not the case for natural enemies directed against pest insects. For both insect and plant biological control, nearly half of all projects reviewed were listed as currently in progress, suggesting that the use of biological control for the protection of wildlands is currently very active.