Biological control of African tulip tree
Project leader: Jason Callander
Spathodea campanulata (African tulip tree) is ranked among the 100 worst invasive species in the world. This weed has a major negative impact in its introduced range, quickly colonising disturbed areas to form monotypic stands. Once germinated, plants establish rapidly and can be very difficult to remove.
In this project, we seek to extend research undertaken overseas on 2 prospective biological control agents:
- a gall mite, Colomerus spathodeae (Acari: Eriophyidae)
- a flea beetle, Paradibolia coerulea (Coleoptera: Chrysomelidae).
We have established a colony of C. spathodeae in quarantine at the Ecosciences Precinct, developed the host test list and commenced host testing.
Biological control of Chromolaena odorata
Project leader: Jason Callander
Chromolaena odorata (Siam weed) was first found in Queensland in 1994 (in northern Queensland). It was targeted for eradication as part of a national cost-shared eradication program from 1995 to 2012. Since 2012, it has been a target for biological control in Australia, resulting in the release of the stem-galling agent Cecidochares connexa in 2019. It is now a category 3 restricted invasive plant in Queensland and a Class C weed in the Northern Territory.
C. connexa is established across much of the invasive range of C. odorata in Australia. The agent causes extensive galling of mature plants and some seedlings. In parts of the Dry Tropics around Townsville, severe infestations of C. connexa have been responsible for stem dieback and reduced flowering. However, in the Wet Tropics of Far North Queensland and in the Northern Territory, its impact has been less severe. In this project we seek to evaluate additional biological control agents to complement C. connexa to help further control the weed in its invasive range.
Biological control of lantana
Project leader: Jason Callander
Despite a rich history of biological control research, lantana remains a serious environmental and agricultural weed in Queensland. In this project we seek to add to previous research undertaken in Australia, Hawaii and South Africa. The lantana gall fly, Eutreta xanthochaeta, was introduced to Australia as a biological control agent for lantana twice in the 1970s but did not establish. It was reported to be very difficult to rear and, as other potential agents were being considered, the gall fly’s reintroduction was not pursued.
E. xanthochaeta has again been imported and we have established a colony in quarantine at the Ecosciences Precinct. We have nearly completed supplementary host testing of the agent. All appropriate non-target species have been represented in the testing, and further replication is needed. In addition, an application to release the lantana blister rust pathogen, Puccinia lantanae, which was tested by CABI (UK) under contract, has been submitted to the Australian Government for approval.
Restoring island resilience—Pacific weeds biological control research
Project leader: Jason Callander
In this project, we will explore biological control options for several weeds that have not previously been targeted for biological control in Australia or globally. While the exact composition of all new target species will depend on the priorities of individual Pacific Island countries, Singapore daisy (Sphagneticola trilobata) and ivy gourd (Coccinia grandis) are viewed as important in many of these countries.
We are currently exploring native ranges to seek potential candidate agents for S. trilobata. In Hawaii, 3 effective agents for control of C. grandis have been released. We will also provide effective biological control agents for individual countries’ priority weeds. This project is fully funded by Landcare Research New Zealand.
Biological control of snake cactus
Project leader: Jason Callander
Invasive cacti are found within most Australian states and territories, and there is potential for greatly increased distribution. Chemical control can be effective but is not always economically viable, so it is important to find cost-effective alternative approaches to control invasive cacti. Cochineal insects have been highly successful in providing high levels of control for many cactus species, but not all of them.
In this project we will focus on exploring additional prospective biological control agents for Cylindropuntia imbricata subs. spinosior and Cylindropuntia imbricata to complement existing cochineal agents. We have prioritised 3 species of cactus longhorn beetles: Moneilema armatum (black cactus longhorn beetle) and Moneilema appressum (which are root and stem borers associated with Cylindropuntia and Opuntia species), and Coenopoeus palmeri (which is closely associated with Cylindropuntia species).
Mikania biocontrol for Christmas Island
Project leader: Jason Callander
Parks Australia is funding the introduction of a biological control agent, the rust pathogen Puccinia spegazzinii, to control Mikania micrantha (mikania vine) on Christmas Island. P. spegazzinii has been approved for release in Australia to control M. p;micrantha.
M. micrantha will be imported from Christmas Island into quarantine at the Ecosciences Precinct and the biocontrol pathogen will be imported from Vanuatu (where it has established). We will establish a clean culture of P. spegazzinii on M. micrantha in quarantine, then export it to Christmas Island to facilitate mass-rearing of the agent (in the absence of quarantine facilities). We will train and mentor Parks Australia staff in culturing techniques, field release strategies and impact evaluation surveys.
Biological and chemical approaches to ‘on-farm’ management of the invasive weed Navua sedge
Project leader: Kunjithapatham Dhileepan
Navua sedge (Cyperus aromaticus) is an extremely aggressive perennial sedge affecting the beef and dairy industries in Queensland’s Wet Tropics. The sedge is unpalatable and can form dense stands replacing palatable tropical pasture species. Current management options are mechanical and chemical, which are expensive and offer only short-term relief. Biological control is the most cost-effective and best long-term management option for the weed.
In this project we will develop biological and chemical approaches for effective management of Navua sedge. Navua sedge has been approved as a target for biological control in Australia, and a list of test plants for host-specificity testing has been compiled. Surveys in equatorial Africa have identified 2 promising biological control agents: a new smut fungus that attacks flower heads and seeds, and a rust fungus that attacks leaves and stems. Host-specificity testing of both pathogens is in progress in CABI (UK).
Biological control of Navua sedge using smut and rust diseases
Project leader: Kunjithapatham Dhileepan
Navua sedge (Cyperus aromaticus) is an extremely aggressive perennial sedge affecting the beef and dairy industries in Queensland’s Wet Tropics. Surveys in equatorial Africa have identified 2 promising biological control agents: a smut fungus (Cintractia kyllingae) that attacks flower heads and seeds, and a rust fungus (Uredo kyllingae-erectae) that attacks leaves and stems.
Both pathogens have been exported to CABI (UK), and studies on the biology and host specificity of the flower smut pathogen are in progress. If the smut pathogen is found to be host-specific, we will submit an application seeking approval to release it.
Recently, Navua sedge rust has been found in Queensland. Our future research will focus on monitoring its distribution, seasonality, field host range in the field and host specificity under glasshouse conditions.
Biological control of parthenium
Project leader: Kunjithapatham Dhileepan
Parthenium weed (Parthenium hysterophorus L.) is a noxious weed of grazing areas in Queensland and is a Weed of National Significance in Australia. Parthenium can cause severe human and animal health problems. In Australia, 11 biological control agents (9 insect species and 2 rust pathogens) have been released against parthenium. Most of these agents have become established and have proven effective against the weed in central Queensland.
Parthenium is spreading into southern Queensland and south-eastern Queensland, where many of the widespread and effective biological control agents used in central Queensland are not present. To control this spread, we have redistributed the following agents from central Queensland to southern and south-eastern Queensland:
- the seed-feeding weevil (Smicronyx lutulentus)
- the stem-boring weevil (Listronotus setosipennis)
- the root-boring moth (Carmenta ithacae)
- the summer rust (Puccinia xanthii var. parthenii-hysterophorae)
- the winter rust (Puccinia abrupta var. partheniicola).
Mass-rear and release of biological control agents for opuntioid cacti
Project leader: Kelli Murree
The project is supported by the Australian Government’s Future Drought Fund—Resilient Landscapes Program. The aim of the Future Drought Fund is to build drought resilience in the Australian agriculture sector, landscapes and communities.
This 5-year project is part of a broader biological control program of mass-rearing and releasing agents on target weed populations throughout Australia, working in collaboration with interstate organisations. Our work will focus on mass-rearing and releasing 2 agents throughout Australia: the brown prickly pear stem-borer (Lagocheirus funestus) for Opuntia species and a longhorn beetle (Coenopoeus palmeri) for Cylindropuntia species.
Rear and release of weed biological control agents
Project leader: Kelli Murree
In this project we aim to mass-rear, release and monitor biological control agents for invasive weed species in northern Queensland. Releases will include previously released agents and new agents following approval from federal regulators. The project supports local governments, landholders and other stakeholders within Queensland.
Biological control agent compendium
Project leader: Kelli Murree
In this project we will create a compendium detailing biological control agents released for the management of invasive weeds in Queensland. It will include for each agent:
- identifying features and biology
- release procedures
- locations (for field collections)
- general distribution
- impact.
All Queensland local government areas will benefit from having this single information source.
Biological control of prickly acacia—field release and monitoring of a gall thrips
Project leader: Boyang Shi
Biological control is the most cost-effective management option for prickly acacia, which is a serious weed of grazing areas and a Weed of National Significance. A gall thrips (Acaciothrips ebneri) that induces shoot-tip rosette galls on the weed was approved for field release in Australia and field releases commenced in January 2023.
There is evidence of establishment and dispersal of the gall thrips in most of the release sites. Given high rates of establishment and levels of damage, we will fast-track the spread of the agent into new areas, in partnership with NRM groups, graziers and other stakeholders. The agent will also be introduced into the Northern Territory and Western Australia.
The project is supported by the Australian Government’s Future Drought Fund—Resilient Landscapes Program.
Feasibility of biological control of sticky florestina
Project leader: Di Taylor
Sticky florestina (Florestina tripteris) is an annual herb native to southern Texas and Mexico. It is believed to have been accidentally introduced into Australia as a contaminant of buffel grass seed from southern Texas in 1964 and has naturalised in central western and south-western Queensland. Climate modelling suggests that sticky florestina has the potential to establish across 40% of Queensland (Osunkoya et al. unpublished data). Recent detections have also occurred in New South Wales.
In this project we assess the feasibility of classical biological control of sticky florestina in Australia. We will produce a literature review of currently available information on sticky florestina and generate a climatic suitability model to predict the potential distribution of the weed in Australia if left uncontrolled. Also, we will undertake a genetic study to confirm the source locations of the infestations in Australia, which can be used to guide future native range surveys for potential biological control agents. Our collaborators will conduct opportunistic surveys in the native range to identify natural enemies.
Biological control of bellyache bush
Project leader: Di Taylor
Bellyache bush (Jatropha gossypiifolia) is a serious weed of dry tropical regions of northern Australia, particularly riparian and subriparian habitats. Biological control is the most cost-effective method for controlling bellyache bush.
Host-specificity testing of the Jatropha rust (Phakopsora arthuriana) strain from Trinidad by CABI (UK) has been completed. We will prepare an application seeking approval to release the rust in Australia.
Also, a leaf-feeding midge (Prodiplosis hirsuta) from Paraguay will be imported into quarantine. Once we have established a colony, we will commence host testing.
We will collect leaf miner (Stomphastis thraustica) samples from the field to determine its field establishment.
Biological control of cat's claw creeper
Project leader: Di Taylor
Cat’s claw creeper (Dolichandra unguis-cati) is a Weed of National Significance. Biocontrol is the most desirable management option. So far, 3 agents have been approved for field release. The tingid and the jewel beetle are now widely established. Establishment of the leaf-tying moth has been noticed in release sites and it is spreading slowly.
Since cat’s claw creeper has abundant subterranean tuber reserves, additional agents are needed. Surveys identified a gall rust (Uropyxis rickiana) and a leaf rust (Prospodium macfadyenae) as prospective agents. A leaf-spot pathogen (Neoramulariopsis unguis-cati) that is causing widespread defoliation in South Africa is also a prospective agent. Preliminary testing of the leaf-spot pathogen and the gall rust has been completed. Full host-specificity testing for the leaf-spot pathogen has been completed at CABI (UK) with funding from Seqwater. We have submitted an application to the federal regulator seeking approval to release the leaf-spot pathogen.
Harrisia martinii biological control and integrated management
Project leader: Tamara Taylor
Native to Argentina, Harrisia martinii is a spiny perennial plant that can form dense infestations, choking out other pasture species and causing injuries to stock. A mealy bug biological control agent released in the 1970s appears to be providing some control in central Queensland, but not in the south due to poor establishment and limited impact caused by high summer and low winter temperatures.
A stem-feeding fly (Dasiops bourquini) has been identified as a potential new biological control agent. It is very damaging to H. martinii in Argentina, but initial attempts at rearing these flies (which require swarm mating) have failed in Argentina. However, new populations have been detected, leading to plans for renewed efforts to rear them in the laboratory when they are seasonally present as larvae from October 2025. If this is successful, they will be imported into quarantine in Brisbane for host-specificity testing.
Biological control of pasture weeds in Vanuatu
Project leader: Tamara Taylor
This project is based in Vanuatu, funded by the New Zealand Ministry of Foreign Affairs and Trade and managed by Landcare Research New Zealand. In this project, we are seeking a biological control agent for Senna obtusifolia and Senna tora (sicklepods), which will benefit both Vanuatu and Queensland.
Over the last 6 years, genetic analysis has identified regions overseas that are likely to host natural enemies of these weeds and these are being explored for control agents. A stem-galling weevil (Conotrachelus species) was imported from Mexico into quarantine in Brisbane in late 2025. We will undertake host-specificity testing once a colony is established. If appropriate, we will prepare applications seeking approval to release the agents in Australia and Vanuatu and submit these to the relevant regulatory authorities.
Biological control agents for riparian weed management—Madeira vine
Project leader: Tamara Taylor
This project is funded by Healthy Land and Water and is at stage 2 of 4 potential stages. We aim to improve the understanding of:
- the ecology, genetic diversity and environmental impact of Madeira vine in south-eastern Queensland
- the effectiveness of the current biological control agent, the leaf-feeding beetle (Plectonycha correntina).
Our work is likely to include pursuing a second biological control agent to assist with management of Madeira vine.
Last updated: 11 Feb 2026