Australian Biological Control Laboratory Establishes Biocontrol Collaborations with Thailand

By Matthew Purcell, Australian Biological Control Laboratory (ABCL) and Commonwealth Scientific and Industrial Research Organization (CSIRO)

The USDA, ARS, Australian Biological Control Laboratory (ABCL) ABCL has established long-term collaborations with the Thailand Department of Agriculture (DOA) and the Thailand Royal Irrigation Department (RID).  This collaboration provides support in exploration to find biological control agents of US invasive weeds that are native to Thailand, particularly the climbing fern, Lygodium microphyllum, downy rose myrtle, Rhodomyrtus tomentosa, skunk vine, Paederia foetida and the aquatic weed, Hydrilla verticillata.

The floating aquatic weed giant salvinia, Salvinia molesta, is increasingly becoming problematic in water impoundments in Thailand. As part of the management strategy for giant salvinia, biological control is being planned as an effective management tool given its successful deployment in many countries around the world.  In 2018, ABCL invited staff from the Thailand DOA, Tanchanok Jongrukthai (Ann) and Phattaraporn Sappanukroh (Aoy), to visit Brisbane for training in biological control of weeds.  ABCL and CSIRO staff have extensive expertise in aquatic weed biocontrol, as have other invited participants from the Queensland Department of Agriculture and Forestry (DAF, Michael Day), the New South Wales Department of Agriculture (Dr Paul Sullivan, now retired) and the Brisbane City Council (Rachael Green and staff).  Ann and Aoy had training in biological control theory, field exploration, host specificity testing, quarantine testing, field post release monitoring and insect mass rearing. 

During their visit, giant salvinia weevils, Cyrtobagous salviniae, were collected from a local field site at Wappa Dam (Figure 1).  The DOA staff were instructed in the best practice for mass rearing weevils and maintenance of salvinia weevil cultures.  Live specimens were packaged, and hand carried back to Thailand for starting a quarantine culture. This was successful and supplemented by follow-up consignments of the weevils from Australia, and visits by DAF and ABCL staff for further instruction on maintaining cultures and host range testing under quarantine conditions (Figure 2).  Currently, testing is ongoing and field releases are being planned in Thailand, subject to regulatory release approval.

Invasive aquatic weeds are becoming an increasing concern in the reservoirs managed by the Thai RID, particularly in northern Thailand.  This year, new workshops were facilitated though the Australian Water Partnership in Bangkok and includes participation by Thai DOA, Thai RID, Griffith University in Brisbane, ABCL and CSIRO staff.  These workshops will develop a management plan and water quality indices for RID managed water impoundments in Thailand and include chemical and biological (algae and aquatic weeds) assessments.  Biological control, particularly of giant salvinia, is being considered as an integral part of the management plan.  In early December, ABCL and CSIRO staff demonstrated the theory of biological control and the practice of controlling both floating and submerged aquatic weeds, including water hyacinth, Eichhornia crassipes, giant salvinia and cabomba, Cabomba caroliniana.  Thai delegates were given a tour of ABCL facilities (Figure 3) and participated in a field day with demonstrations at Lake McDonald and Wappa Dam north of Brisbane (Figure 4).  Fortuitously, Dr Fernando McKay from FuEDEI was also visiting CSIRO in Brisbane, delivering live insects from Argentina for evaluation as biocontrol agents of fleabane, Conyza bonariensis an agricultural weed in Australia.  Fernando lectured to the Thai staff in the field, and given his vast experience, was able to make comparisons between invasive plants in both the native and introduced ranges.  ABCL Director, Matt Purcell participated in a follow-up workshop held in Suphan Buri, Thailand in February/March 2023.  Matt presented on weed biological control and consulted on the management of aquatic weeds in water reservoirs in northern Thailand.

The long-term collaboration of ABCL with Thailand DOA and RID is an example of the cooperative nature of research often conducted by the USDA ARS Overseas Biological Control Laboratories.  Mutually beneficial, non-profit public good research is fundamental to many biological control projects.

Figure 1.  Phattaraporn Sappanukroh (Aoy) collecting giant salvinia, Salvinia molesta, in Australia during training in 2018.

Figure 2.  ABCL staff consulting on giant salvinia weevil rearing with Thai staff at the Department of Agriculture in Bangkok.

Figure 3. ABCL staff Bradley Brown, Ciara Horton and Matthew Purcell with delegates from Thailand and Australia during a field demonstration on aquatic weed biological control at Wappa Dam north of Brisbane.

Figure 4.  ABCL Director Matthew Purcell talking to Thai delegates and participants at the EcoSciences Precinct and ABCL during a workshop held in early December.

Contact: Matthew Purcell

USDA ARS Australian Biological Control Laboratory (ABCL) is based at the Ecosciences Precinct in Brisbane, Australia, and is administered through a Specific Cooperative Agreement between ARS and Australia’s Federal research body, the Commonwealth Scientific and Industrial Research Organisation (CSIRO). The agreement has been a very productive, mutually beneficial, long-term collaborative relationship originating in 1985. Assisting with solving U.S. problems is reciprocated by ARS through supplying Australian scientists with biological control agents from the America’s to control invasive weeds in Australia.