SLU news

Biological control of tomato pests in Benin and Tanzania

Published: 05 February 2019

Growing tomatoes is not easy, there are many pests that attack the plants including various butterfly species. One example is the tomato leafminer, Tuta absoluta, which is an invasive pest in many countries in Africa. In a new project, Miriam Karlsson will investigate which natural enemies these butterflies have. The aim is to use natural enemies to fight the pests.

The tomato leafminer – an invasive pest in Africa

Miriam Karlsson will start working as a researcher at the Centre for Biological Control, CBC, on March 16th. She will investigate pests such as the tomato leafminer, a kind of moth that primarily attacks tomato.  Young larvae of the tomato leafminer penetrate tomato leaves and the production decreases. If the attack is severe, the plant can die. The tomato lefminer originates in Central America and has since spread to large parts of South America. Now it is an invasive species in large parts of Africa, southern Europe and Asia.

– We want to give farmers alternatives to chemical pesticides. Today, the tomato leafminer is resistant to many chemical agents. The long-term goal is to use natural enemies to control the tomato leafminer, and therefore we will start with identifying the most important natural enemies to harmful moths. We hope to find out who is eating what, i.e. which predator exists, and finding parasitoids that we can multiply and use as biological pesticides, says Miriam.

Miriam defended her thesis in 2011 at SLU in Alnarp on insect communication. Then she worked in Ethiopia where she researched fruit flies. Now, Miriam lives in Benin in western Africa where she worked with fruit flies and parasitoids at IITA (International Institute of Tropical Agriculture), in collaboration with the University of Abomey-Calavi.

Information exchange is important

- I look forward to working in Mattias Jonsson's research group. In addition to studying natural enemies, an important goal of the project is teaching. It is vital that students get access to the information that is available about pests and cultivation and research methods is very important, says Miriam.

Why did Miriam decide to do research on insects and cultivation?

- Agriculture is extremely important, everyone on the planet must eat. It is important that the growers have good alternatives to chemical pesticides and that there are cultivation methods that work for both the producer and the consumer.

What does Miriam do when she's not researching?

- In Benin I like to run, walk on the beach and grow things in the garden, right now the favourite is arugula. In Sweden, I will start playing the violin again. In Benin it is too humid, so I have not had the possibility for a while.