Team:SMS Shenzhen/Applied Design



I Introduction to the Problem

In our design, our engineered bacteria work as a knife which breaks the surface of scale insect, and the ‘sucrose-induced enzyme release’ system makes sure that these enzymes would not harm other plants. Also, we transformed our bacteria into powder that can be easily used by the famers. We have instructions (see our modeling) for them to cultivate the bacteria to certain stage and then spread the solution to the plants suffering scale insect.

In view of the subtropical monsoon climate in Shenzhen, scale insects can be found everywhere when people walk through a grove, a park, a garden or even a school. These little white creatures are known for their wax covers which can effectively protect them from most contact pesticides and make them become one of the most annoying and formidable crop pests.

Plants like blueberry, citrus, pomelo and other crops can be easily infested by scale insects; therefore, when scale insects appear, it seems to be a calamity for farmers and planters. They are like a plague which can spread quickly from plants to plants, leaf to leaf, sucking the sap from their stems and bringing death to them. Usually, there is no way for farmers to efficaciously and environmental-friendly slaughter these little white creatures, which are like defiant robbers steal the sweet sap not only from crop plants but also from on urban plants.

For citizens who live in megalopolis, planting succulent plants have already become a new fashion today. However, when succulent plants are planted, no matter indoor or outdoor, they are easily infested by scale insects as well, for they often hide in the nooks and crannies of the succulents plants which make them difficult to detect and killed by insecticides.

In order to maintain optimal health of the succulent plant, people across the world have spent years seeking an ideal solution which can perpetually avoid the infestation of the scales and keep them from sucking out the sap of the plants.

II Current Solutions

Extant Solutions Weakness Additional Information
(1) Use horticultural oil or neem oil Even though the horticultural oil and neem oil are effective in killing some pest insects, scale insects have been excluded from its effectiveness. With assistance of the shell of scale insects, they will not be suffocated by the horticultural oil and are free enough to continue sucking the sap from plants. In some cases, horticultural oil and neem oil could be an effective and safe way to kill pest insects without harming the plants. The mechanism is that oil could block the air holes (spiracles) through which insects breathe, causing them to die from suffocation. 
(2) Use insecticide spray, like Malathion Malathion is a good spray to use for outdoor plants. However, its smell is intolerable for most people when used for indoor plants. Since most succulent plants are planted indoor, this is not an advisable solution. Malathion is a pesticide which widely used in agriculture, residential landscaping, public recreation areas, and in public health pest control programs such as mosquito eradication.
(3) Pick off or prune heavily-infested leaves This method could directly hurt the health condition of the succulent plants. Even though this is the easiest way to solve the infestation, this is also the most inadvisable one. Usually when succulent plants have been heavily infested, people have no choice but pick off the leaves and hurt their plants.
(4) Wash the plants with a strong stream of water Succulent plants should be cultivated in comparably dry environment. Too much water is actually a catastrophe for them. Although strong streams of water could wash off the scales, it will also destroy the plants at the same time in some degrees. N/A
(5) Use cotton swabs dipped into the alcohol It is always hard for people to control the amount of alcohol and the percentage of the alcohol that for killing the scales. When the amount of alcohol is not enough, no effect will occur; however, when using too much alcohol, because the leaves directly contact with the alcohol, they will be negatively affected. The word ‘alcohol’ is not very exactly defined here. In most cases, the ‘alcohol’ can be understand as common medical alcohol of unspecified concentration.
(6) Personal created spray: Use a little travel sized spray bottle with 70% isopropyl alcohol When using the 70% isopropyl alcohol, since it is not the final products, costumers themselves need to mix the alcohol with a certain amount of water. Even though this method seems to work well, inexperience of people could cause great inconvenience and may minimize its advantages. Original function: To decrease germs in minor cuts and scrapes. (This method is created by an unknown individual, so it dose not have any authoritative guarantee.)

III Our Solutions

The current solutions that enumerated above all have several defectives, which make them not the best solution to choose. But with our Pesticide Mate, all these drawbacks could be overcome. Unlike the commercially chemical insecticide, with the help of E. coli and three different enzymes that it produced, we can dissolve the solid shell of scale insects without doing any harm to the plants.

How Did We Design It?

We are inspired by verticillium lecanii, an amazing bacteria that can produce enzymes(chitinase & protease) to degrade scale insect’s hard shell. After being amazed by this, we thought that maybe we can design a kind of genetically engineered E.coli to provide these enzymes. In our design, our engineered bacteria work as a knife which breaks the surface of scale insect, and the ‘sucrose-induced enzyme release’ system makes sure that these enzymes would not harm other plants. Also, we transformed our bacteria into powder that can be easily used by the famers. We have instructions (see our modeling) for them to cultivate the bacteria to certain stage and then spread the solution to the plants suffering scale insect.

IV Our Project's Advantages:

1. Environmental-Friendly!

- It won’t do any harm to the environment. Comparing to chemical pesticides, it is clear that our biological Pesticide Mate would be much easier for the environment to degrade.

- Besides, since our Pesticide Mate would break the hard shell of the scale insects and cause damages on shells, it would be much easier for the pesticide to pass through. Although our Pesticide Mate cannot kill scale insects directly, it can decrease the amount of a huge amount of pesticide use.

- Imagine how much will the soil suffer if a huge amount of pesticide is used, and how serious will the problem be. It is clear that although people might stop their suffering of scale insect problem, the soil actually suffers more. Since chemical pesticides would have a long-term effect on the environment, it is critical that our Pesticide Mate can decrease a huge amount of pesticide use when killing scale insects.

2. Plants & Human-Friendly!

- Because of our “suicide design” inside our E.coli, E.coli that are unfortunately dropped onto the plants will kill themselves instead of causing any problem.

- Since scale insects often appear in fruit trees and crops, we consider that it is extremely important for us to ensure that our Pesticide Mate is harmless. Besides, if people use our Pesticide Mate at home, we certainly don’t want them to get any hurt from E.coli. Thus, by adding this design to our E.coli, we can avoid any potential problem E.coli may bring.

- In addition, pesticide residue is a great concern as well. By using our Pesticide Mate, there will be no concern about pesticide residue!

3. Cost-Friendly!

- Since most of the farmers in China are actually live in poverty, we absolutely want them to have a better life. We hope our project can be beneficial to them not only by letting them avoid scale insect problem but also by saving them a large amount of money. Therefore, they would be able to support their families and put food on tables.

- Cultivation of E.coli is simple and convenience for companies, and the cost of making this Pesticide Mate is very low. Thus, our Pesticide Mate will be really cheap for farmers to buy them and enjoy the advantage brought by our Pesticide Mate.

- Our Pesticide Mate will also decrease the amount of chemical pesticide use, so farmers would save lots of money on buying chemical pesticides. By developing this Pesticide Mate, we sincerely want to benefit farmers in our country and help them to gain a better life, and after avoiding scale insect problem, they would harvest more for sure.

4. Usage-Friendly!

- Since we wish to commercialize our Pesticide Mate and make all those advantages come true, we collaborate with team SIAT-SCIE to enhance our project.

- The enzyme that team SIAT-SCIE found in tardigrades-microscopic animals enables our E. coli to endure harsh circumstance but still maintain activity. Then, we could dry up our E. coli and turn it into powder form.

- After that, those powder-like E. coli can be packed and transport to different stores and cities. During this transportation, the activity of our powder-like E. coli is still remained and can be resurrected. Therefore, when this product comes into the market, the only thing that customers have to do is mix it with water and spray the special water on the infected plants.