The battle against mosquitoes

A mosquito is sitting on a green leaf.

Aedes is a genus of mosquitoes that can transmit serious diseases; this genus is currently spreading in Germany. © Getty Images/FrankRamspott

Mosquitoes of the genus Aedes can transmit dangerous viral diseases such as dengue, yellow fever or Zika. However, combating the spread of mosquitoes with an environmentally friendly approach is still a challenge. Decades of chemical insecticide use have caused mosquitoes to develop resistance. "In addition, chemical insecticides may be harmful to human health and the environment," says Lucas Henrique Prates, whose native Brazil is one of the world's largest consumers of conventional pesticides. While still a bachelor's student, Prates discovered his main research interest: environmentally friendly methods to control insect pests.

Since 2020, the doctoral student at the Institute of Insect Biotechnology at Justus Liebig University Giessen (JLU) has been developing an innovative method to control the spread of mosquitoes using RNA interference (RNAi). "RNA interference is a natural defense mechanism that living organisms use to ward off viruses," he explains. It involves preventing the spread of the virus by interrupting the translation of its messenger RNA into a protein. Modern biotechnology takes advantage of this mechanism. The use of double-stranded RNA (dsRNA) makes it possible to target specific genes to "turn them off." Prates' research targets genes that control important life functions in mosquito larvae.

In his current experiments, Prates is producing dsRNA in bacterial cultures and using it to enrich the diet of Aedes larvae. "In the process, I have to work very precisely and cleanly to avoid contamination," he says. "I then have to monitor the development of the larvae - until their death, if everything works out - on a daily basis. That's why I'm sometimes in the lab on weekends or at Christmas!" The biggest challenge in his research work, he says, is protecting the dsRNA on its way tot he target: "The molecules break down very easily on their way into the larval cells."

‘I’m fascinated by the natural sciences, based on which we can at least attempt to understand the world.’

Even in his school days in Janaúba in the north of the state of Minas Gerais, Lucas Prates was enthusiastic about biology, chemistry and physics: "What fascinates me about the natural sciences is that we can at least try to understand the world on the basis of them." In 2012, while studying for a bachelor's degree in chemical engineering at the Universidade Federal de Viçosa, he spent a year studying in Aveiro, Portugal. "It broadened my horizons enormously; without that experience, I would be a different person today!"

Prates wrote his master's thesis in Viçosa on the use of essential oils as biopesticides. After graduation, he saw no future in Brazil, where the Bolsonaro government had drastically cut budgets for research and science. "Besides, I was eager to gain more experience abroad. Professor Marc Schetelig's research group at JLU, which perfectly matched my interests, was very welcoming. And luckily, I got a doctoral scholarship from the DAAD, for which I am very grateful."

A minor culture shock upon arrival in Germany

Arriving in Germany nevertheless meant a culture shock for Prates at first: "In Brazil, you can do a lot digitally and pay everywhere with a card - I was irritated that here you have to fill out forms by hand and carry cash. And the language is of course very difficult, for example the correct form of address. The 20-year-old trainer at the gym was very surprised that I called him by “Sie” instead of “du”! Meanwhile, though, I almost feel at home here." He says he also understands now why it is difficult to make contacts outside of university in Germany: "In Brazil, you get to know a lot of people very quickly, but you lose contact just as quickly whenyou move. In Germany, friendships often last for decades. I wouldn't say one is better than the other, it's just a cultural difference."

In addition to fitness training, Lucas Prates plays squash and enjoys jogging; a year ago he participated in the Berlin Marathon: "It was great to feel the energy of the city!" What else does he like about Germany? "The security, the solution-oriented thinking of the people, the change of seasons. The German bread and cake. And of course the beer!"

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