Problem overview
The Solenopsis invicta is a highly damaging and dangerous pest categorized as one of the "World's 100 worst invasive alien species." Since its invasion from South America to the United States in the 1930s, the S.invicta has infested over 100 million acres of land in 17 states across the United States and has shown a spreading trend northward to Washington and westward to Hawaii. In recent years, there has been an accelerated expansion of the S.invicta. It was first reported in Taiwan, China in 2003, and in the 19 years since then, it has spread to all southern provinces of China.
Guangdong province has the widest range, the largest affected area, and the most severe impact of S.invicta in China. Our campus located in the city of Guangzhou, the capital and largest city of Guangdong province. Most of our team members hail from Guangdong, making us well-acquainted with the threats posed by S.invicta. Even within our campus, regular efforts are made to exterminate S.invicta to prevent human bites.
We are aware that the spread of S.invicta leads to serious public health, ecological, and economic issues. The harm caused by S.invicta can be summarized as follows:
1. Highly aggressive behavior posing a threat to human health.
2. Disruption of ecological balance and a reduction in biodiversity.
3. Harm to agricultural and livestock production.
4. Damage to public facilities.
5. Accumulation
of significant economic losses.
Fig 1.The harm of S. invicta to the invasion area
Contact with affected persons
Our ultimate goal is to provide a green, safe, cost-effective, and more targeted biological control method for the global management of S. invicta through this project. We intend to utilize bait as the pesticide form for practical application. After initially designing our experimental approach and gaining an understanding of the current status of S. invicta spread through literature review, we realized the need for a more in-depth understanding of the actual harm caused by S. invicta. This includes gathering insights from different affected regions, consulting with the public on how they handle S. invicta bites and refining our project implementation based on input from professionals. Additionally, we aim to understand the necessary processes involved in pesticide design, market entry, and regulatory review.
In light of these considerations, we have identified five key stakeholders: government, farmers, healthcare personnel, biotechnology companies, and relevant research experts. During our consultations and interviews, we pay particular attention to gathering feedback from these stakeholders and continually updating our project based on their input.
Government
Investigation at Baitu Town, Qujiang District, Shaoguan city
Shaoguan county is one of the heavily affected areas by S. invicta in Guangdong Province, China, with the ants having spread throughout the region. It serves as a representative case for S. invicta prevention and control. Shaoguan county is an important agricultural production base and an ecological barrier in Guangdong Province, making it more susceptible to the harm and spread of S. invicta due to its unique agricultural characteristics. Shaoguan county places great importance on S. invicta prevention and control. It has innovatively established a new model of community-based S. invicta prevention and control. Leveraging intelligent monitoring technology for S. invicta data collection, the city encourages residents to actively participate in prevention and control efforts through a "destroy ant nests with subsidies" paid service approach.
The prevention and control of S. invicta in Baitu Town is regionally representative. It was the place of our first field survey, and we gained valuable insights into the implementation process, effectiveness, and challenges of red imported fire ant control. The local authorities provided us with recommendations and guidance for our project. During this research, we not only communicated with local government departments to understand the basics of S. invicta control but also conducted interviews with local agricultural workers. We visited field areas affected by S. invicta to gather insights into the perspectives and expectations of both the government and agricultural workers regarding our control methods and device concepts.
A successful solution must meet the following criteria:
1. The drug should be cost-effective.
2. The drug should be highly effective in eradicating ants and preventing nest recurrence.
Fig 2.Investigation at Baitu Town
Visit to Agriculture and Rural Affairs Bureau of Jiexi city，Jieyang city
Jiexi places high importance on S. invicta prevention and control. They have established a city-level command center and township working groups, formulated prevention and control plans and responsibilities, and allocated funds and resources for prevention and control efforts. The Agricultural Bureau is responsible for overseeing agricultural and rural affairs throughout the city, including monitoring and controlling major crop pests and diseases, guiding the development of the plant quarantine and inspection system, organizing and supervising plant quarantine and inspection work, conducting surveys of major plant quarantine pests, and managing invasive species in accordance with the law. Jiexi has adopted scientific prevention and control measures, tailored strategies, and community-based control methods. They conduct two concentrated "eradication" campaigns in spring and autumn, have established an intelligent monitoring and control management system, and set up two demonstration areas for prevention and control. Additionally, they have conducted technical training and educational outreach 4,352 times. According to statistics, during the concentrated "eradication" campaign in spring 2021, approximately 18,000 kilograms of bait were distributed, covering an area of approximately 108,000 mu (about 18,000 acres). In the autumn campaign, around 24,000 kilograms of bait were distributed, covering an area of approximately 144,000 mu (about 24,000 acres).
A successful solution must meet the following criteria:
1. The drug delivery method should be user-friendly and easy to operate.
2. The device/bait should pay attention to waterproof to improve the effectiveness of the drug ;
3. Drugs need to be cost-effective.
Fig 3.Investigation at Agriculture and Rural Affairs Bureau of Jiexi city
Medical personnel
People's Hospital of Jiexi city
Conversation with research scientist of S. invict
Dr. Lei Wang from SCAU
A successful solution must meet the following criteria:
1. The project should address significant issues prevalent in the market.
2. It should overcome challenges such as limited versatility, non-user-friendliness
for non-professionals, and complex application environments.
Dr. Daifeng Cheng(Second PI) from SCAU
A successful solution must meet the following criteria
1. It should leverage the natural behaviors of S. invicta and be designed based on their behavioral traits, taking into account the
mechanism of action.
2. It should be designed in compliance with relevant pesticide review standards.
3. It should prioritize addressing any biosafety concerns associated with genetically modified technologies.
Visit to Biotechnology
Weizhuan Wang——CEO of Red Imported Fire Ant Technology Development Co., Ltd.
A successful solution must meet the following criteria
1. The method of drug delivery should be simple and practical, making it easy for users to administer.
2. The device design should be innovative, as current market devices are not very effective.
3. The drug dosage should be scientifically designed to ensure it reaches the queen ants and achieves the desired killing
effect.
The rapid spread and severe impact of S. invicta have garnered significant attention from relevant authorities since their discovery in China. As a highly adaptable invasive species, S. invicta have the potential to undergo significant biological changes when introduced to new regions. To achieve long-term and fundamental control of these ants in China, it is imperative to conduct indepth research on their native occurrence patterns and basic biological characteristics. Therefore, through this project, we aim to provide a green, cost-effective, and highly queen-targeted biological control method for S. invicta, contributing to global efforts in combating this invasive species.
Project Objectives:
1. Green, safe and easy to operate
2. Efficient and higher targeting of queen ants
3. Low cost
4. High water resistance
The first two steps of our work framework helped us gain a comprehensive understanding of the background of the S. invicta control issue and the perspectives and suggestions from various stakeholders. Building on this foundation, we outlined how to provide an effective and responsible solution for S. invicta extermination using synthetic biology methods. We clarified the objectives that our solution needs to achieve in order to meet the demands of stakeholders and achieve the best possible results.
Building on these insights, we continued to advance into the third phase of our framework: conceptualizing and designing our solution. In this phase, our team engaged with several experts and scholars in the field of S. invicta research and microbial experiments to brainstorm and refine our experimental plan.
Under the guidance of Dr. Lei Wang, we focused on the direction of exterminating S. invicta. Dr. Daifeng Cheng suggested the modification of gut microbiota to express lethal agents such as toxins or chemical compounds, targeting the queen to enhance the killing effect. Professor Hanghong Xu advised us to consider the survival of the chassis organism in the gut environment, leading us to choose E. coli as the chassis organism, which dominates in the gut of S.invicta larvae, has well-documented research, mature experimental techniques, and tolerance to ant venom. Dr. Zhe Hu suggested the application of Quorum Sensing systems as signals for initiating drug expression after engineering bacterial reproduction. Additionally, Mr. Boxiang Wang appreciated and expressed concerns about our novel dual-oscillation circuit concept since it was innovative but challenging. Consequently, we decided to replace the oscillation system after further research, optimizing our genetic circuitdescription.
Fig. 4 The project schematic
While completing the design of our project plan, we also contemplated how to transform our engineered bacteria into a practical biopesticide and how to design hardware devices to improve efficiency and ensure safety. During this process, we conducted surveys and consultations with various stakeholders, leading to the development of our preliminary plan, which involved choices related to drug carriers, hardware, and more.
Regarding drug selection, our focus was on improving bait moisture resistance while ensuring the lure's attractiveness to S.invicta and the protection of the engineered bacteria's activity. In terms of hardware devices, we aimed to reduce costs and enhance the safety of pest control efforts.(more details in hardware page)
Beyond the application format of the project, we emphasized simplicity of operation, waterproofing of the devices, financial feasibility, and targeted outreach to individuals with limited scientific background, as well as S.invicta control personnel, and the purchasers of the drugs.