Harnessing insect biodiversity for sustainable plant health in tropical Africa

Fall armyworm (FAW), a ravaging pest of the maize plant, is spreading globally. Every year, Africa, Asia, and the Near East lose 80 million tons of maize worth US$18 billion to the damaging effects of FAW.

Georg Goergen, IITA Entomologist and Biocontrol Specialist based in Cotonou, highlighted past and ongoing efforts to control the spread and effect of FAW on maize crops in a presentation titled: ‘Harnessing insect biodiversity for sustainable plant health in tropical Africa’.

Despite all the invented technology in terms of insecticides and genetically modified organisms (GMOs) for maize, FAW remains the most crucial maize pest to be overcome.

Goergen said no silver bullet control would eradicate this insect pest given the mode of FAW’s spread and infestation. Multiple approaches have to be combined.

He said among other measures to control the pest, biological control is the best. This involves introducing natural enemies to the Fall armyworm that would eat up the pest at the different stages of its development. He mentioned that farmers have their local solutions for controlling this pest, one of which is neem plant extracts.

The strategy for biological control is two-pronged. The first step is introducing parasitoids to eat up the FAW pest at maize’s vegetative phase as early damage prevention. Once the maize reaches its reproductive stage, controlling the infestation becomes more difficult.

Another biological control measure he identified is using biopesticides. He said the first commercially produced Baculovirus that IITA tested combined with other factors provides no risk for non-targeted insects. But factors that have slowed down the adoption of this solution include lack of awareness, high cost, UV sensitivity, and lack of training for users.

Goergen said IITA and other collaborators (USAID, CIMMYT, and Michigan State University) had been involved in producing animations for building awareness on this biopesticide so users can understand how to use it without having to go through long scripts of instructions.

Goergen also looks forward to collaborating with partners to develop insect 3D modeling to help farmers identify the insect pests and deal with them.

His work also detected a second armyworm species called the Southern armyworm (SAW), which took about two years to trace, and was also observed as an insect pest on cassava.

His contributions in controlling this voracious maize insect pest include surveillance activities, faunistic assessments, training workshops, and capacity building.

As the world marks the International Year of Plant Health in 2020, Goergen thanked all collaborators and participants, including IITA, who have contributed to his work’s success over the years.