Project Description | SCAU-China

Project Identification

Possible direction

Early in the project, we identified three key directions: eradication, detection , and post-bite treatment through brainstorming.

We recognize that these directions are closely related to the important issues facing areas that have been invaded by S.invicta. However, due to the lack of sufficient information and clear evidence to support, we are currently unable to determine which direction we should further refine our research.

Therefore, we are committed to conducting more in-depth research and studies with a scientifically rigorous methodology in order to obtain clearer choices of directions and effective solutions.

Current status

To align our project with real needs, multiple stakeholder interviews were conducted to fully understand the current societal impacts on S. invicta. From this we realized that the direction of S. invicta control is the most urgent for society today. Among them, research and development of biocontrol products have a bright future.

CURRENT ATATUS

GOVERNMENT
PEASANTS
HOSPITALS
EXPERTS

GOVERNMENT

Lack of funds and materials for prevention and control; Low efficiency of prevention and control; Bait currently used for S. invicta control vulnerable to climate and environmental factors in the field, and poor moisture resistance;

PEASANTS

Stings are common, but serious cases are rare; Indicators of drug eradication do not address the root causes, leading to low willingness to administer drugs.

HOSPITALS

Treatment facilities are available, the coverage of rural areas is high, and there is no shortage of treatment.

EXPERTS

Currently, S. invicta detection is not an urgent problem, but eradication is the main issue. Bait-based chemical control technology (Please set a jump link) , whose primary goal is to kill the queen and then eliminate the entire invading ant colony, is mainly used in the prevention and control of S. invicta. It is necessary to kill all the ant queens if we want to completely eradicate the nest. However, with the appearance of multiple queen populations, it becomes extremely difficult to kill all the ant queens with a single application. Meanwhile, misuse of chemical insecticides can cause environmental pollution.

For more information, click on the images

(For details onS.invicta hazard, see Human Practice: Engaging with Affected People.)

Focus on urgent social needs

URGENT SOCIAL NEEDS

Government
Farmers
Enterprises
Experts

Government

Low cost, good effect, stronger waterproof performance of toxic bait as a means of control.

Farmers

Minimize the pesticide pollution caused by drugs to farm animals, fish ponds, and water sources; Easy to use for non-professionals.

Enterprises

Focus on field testing of drugs; Popularization of the differences between S. invicta control and traditional pest control concepts and methods.

Experts

Focus on biosafety; Improve the ability to target the ant queen.

For more information, click on the images

"Based on the actual needs of society for S. invicta prevention and control, we compiled the current standards that an excellent S. invicta control solution should meet (Fig. 5). Accordingly, we set our team's design goals.

Figure.5 Criteria for a good solution in S. invicta control

The Design Goal of Engineering Bacteria

Eco-friendly,safe
Efficient
Low cost
Strong waterresistance

For more information, click on the images

(see Human Practice: Defining a Good Solutionfor more details on how we defined our project goals.)

Eco-friendly,safe

With the help of synthetic biology, we hope to try to create a live bacterium drug to replace the chemical drugs in conventional bait, minimizing the safety risks to the environment and creatures under the regulation of genetic engineering.

Simultaneously, farmers only need to use the product and perform simple application operations to achieve the purpose of green and scientific participation in controlling S. invicta.

In the future, we also expect that our engineered live bacterial medicines will be safe for use in water protection zones, environmentally sensitive areas, organic farms, and other environments.

Efficient

In our project, based on S. invicta cross-feeding(Please set a jump link), we hope to introduce genetic circuits to regulate the timing of drug release and improve drug targeting to the ant queen, thus achieving faster and more efficient S. invicta control with the same or even less bait.

Low cost

We expect that the result will be drugs that are at best cost parity with traditional chemical baits, and preferably less.

Strong waterresistance

We expect to reduce bait sensitivity to environmental climatic factors and improve bait/medication moisture resistance when used in the field.

Conclusion

Through this project, we hope to provide eco-friendly, safe, user-friendly, low-cost, more effective, more targeted, and water-resistant biological control agents for S. invicta control worldwide. That is why our team decided to develop Queen Ant's Assassin (QAA).

Cross-feeding: On the one hand, S. invicta workers cannot directly ingest and swallow solid food. They must feed solid food to fourth instar larvae, which digest the food from solid to liquid and then feed it back to the workers, who feed it to the ant queen, reproductive ants, etc., and share it with other workers, a behavior called "cross-feeding". (Fig. 6) On the other hand, adult S. invicta cannot digest solid proteins, so most of the protein digestion in the colony is done by the larvae. The larvae then extract excess amino acids and soluble proteins from the nymphs through cross-feeding and pass them on to the colony, especially to the ant queen, who receives large amounts of essential free amino acids from the 4th instar larvae every day, either directly or indirectly, to reproduce.

Significance of the 4th instar larvae of S. invicta in the nest: The developmental stages of S. invicta include eggs, 1st, 2nd, 3rd, and 4th instar larvae, prepupae, pupae, and adults. Of these, the 4th instar larvae are particularly important to the survival of S. invicta colony because they are entirely responsible for digesting solid food and are the source of nutrients for the queen and adult workers.(Fig. 7) The 4th instar larvae can feed on solid particles 45.8 μm in diameter and larger. The solid food must be digested by the 4th instar larvae and then fed to the ant queen and younger larvae through cross-feeding by the brood ants to provide nutrients such as proteins, fats, and carbohydrates for the entire colony to maintain normal colony development.(Yu-Ke, YAet al.,2021)

Principles of poison baiting: The baits are usually made by mixing S. Invicta's favorite food with a small amount of chemicals. After distributing the poisoned bait, S. invicta will carry the poisoned bait back to the nest. By "cross-feeding", the baits will gradually be transmitted to the larvae, other workers, reproductive ants, and even the ant queen within 48 to 72 hours. If the ant queen is poisoned or refuses to eat and finally dies, the whole nest of ants will be destroyed due to loss of reproductive ability, thus achieving the purpose of exterminating the whole community.