Author: Calvin Gwabara, Tanga

Researchers from the Sokoine University of Agriculture (SUA), in collaboration with experts from the Tanzania Plant Health and Pesticides Authority (TPHPA), are conducting experiments using beneficial insects to fight against invasive Fall Armyworms in maize crops.

Speaking to our correspondent, the Head of the Research Project, Prof. Gration Rwegasira from SUA, explained that after laboratory tests and subsequent trials at the greenhouse level, they have discovered that two types of insects, Trichogramma mwanzae and Telenomous remus, have shown significant potential in controlling the invasive Fall Armyworms.

“In our study, we identified these two types of tiny insects with the ability to control Fall Armyworms. They target the eggs of the armyworms rather than the worms themselves. By attacking the eggs, they prevent the population from increasing and cause the armyworms to disappear from the field because they cannot reproduce,” Prof. Rwegasira explained.

He added, “We know that the stage that affects farmers’ crops the most is the caterpillar stage. If the eggs aren’t hatched, it means the caterpillar won’t hatch either. So, by helping the farmer control these pests naturally, we eliminate the need for toxic pesticides.”

Currently, they are in the third phase of the project, which involves releasing these beneficial insects into maize fields in the Mvomero District in Morogoro and the Muheza District in Tanga. This step aims to observe how these insects work in real fields with invasive Fall Armyworms.

“Today, we released these insects into these fields. We’ll return in two weeks. This action should be taken when the maize plants are around three to four weeks old. During this time, the Fall Armyworms lay their eggs on the plants. Once they lay the eggs, these beneficial insects attack all the eggs in the field,” Prof. Rwegasira explained.

Furthermore, he mentioned that these beneficial insects lay their eggs inside the eggs of the Fall Armyworms, effectively stopping the next generation from developing. This method eliminates the destructive generation of armyworms while leaving the beneficial insects unharmed.

Prof. Rwegasira highlighted that the completion of this research will help farmers move away from the harmful use of toxic pesticides, which pose risks to both health and the environment. Additionally, these friendly insects will reduce production costs for farmers, especially in maize cultivation, leading to increased household income and contributing to the nation’s overall welfare.

A local farmer, Salehe Alfan Ally, residing in Dumila, Morogoro, praised the research for safeguarding their crops. He expressed that chemical treatments have become costly and unsustainable, leading to losses during harvest.

“In the past, we used to grow maize without applying pesticides. We only sprayed pesticides on tomato fields. However, since the arrival of the American Fall Armyworms in 2017, our lives have become difficult. Not everyone can afford to buy pesticides every two weeks until harvest. Sometimes we just give up and let the worms eat what’s left, resulting in poor yields,” Salehe explained.

Senior Agriculture Officer from the Mlingano Ward in Muheza, Tanga, Mr. Jimmy Mhina, commended SUA and TPHPA researchers for their innovative approach using beneficial insects. He urged that the experimental efforts succeed in the fields to alleviate farmers’ burdens caused by these destructive pests.

“Many farmers struggle to afford essentials like fertilizers and quality seeds. The arrival of these insects forces them to purchase expensive pesticides, which they can’t afford. So, they skip spraying, taking care of their fields the best they can and only treat the remaining produce with pesticides. This situation truly adds to the hardships and impoverishes our farmers,” Mr. Mhina explained.

American Fall Armyworms invaded Tanzania in 2017, initially in a few regions, but by 2019, they had spread to all parts of the country. According to the Food and Agriculture Organization (FAO) of the United Nations, which funded this research, Fall Armyworms can attack more than 80 different crops.