Virginia Tech scientist corrects history of biological control
April 17, 2020
For years, researchers claimed the first biological control of a weed occurred in 1902, in Hawaii. But a Virginia Tech entomologist has proved that the ecological approach to combating invasive species happened more than a century earlier.
Biological control, or the release of natural enemies to mitigate pests, is common these days in developed countries, such as the United States and Canada. But in developing countries, its implementation is fraught with difficulty, which is hurting smallholder farmers who lose nearly half of their crops every year to pests.
Muni Muniappan, director of the Feed the Future Innovation Lab for Integrated Pest Management at Virginia Tech, proved at the International Symposium of Biological Control of Weeds in Switzerland that those limitations are due in part to the inaccurately reported history of biocontrol itself. Muniappan is one of the world’s foremost experts on integrated pest management, providing natural solutions to crop problems in the developing world. His findings have important implications for the future of biocontrol and scientific misinformation in general.
“Misinformation on biological control activities in developing countries is mostly neglected,” Muniappan said, “but it’s critical that the information is reported correctly. In general, biocontrol in the developing world is difficult to sustain due to a lack of financial, institutional, and human resources. But the opportunities are there, and establishing history and documentation of relevance is one way to get it off the ground.”
The commonly reported origin of the biocontrol of weeds had been documented as occurring in 1902, when natural enemies were introduced to manage the lantana weed in Hawaii. However, Muniappan’s research, which required tracking down numerous sources that documented the origins of biocontrol, revealed an earlier date. The first occasion of biocontrol of weeds was actually more than a century before, in 1795, when natural enemies were serendipitously introduced into India, subsequently controlling invasive cactuses.
Muniappan’s research also showed that the first intentional introduction was in 1865, when natural enemies were introduced in Sri Lanka to manage a weed called Opuntia monacantha.
By tracking biocontrol’s history, Muniappan found that conflict belies many biocontrol activities in the developing world. For example, certain species of cactus are cultivated for food and fodder in many countries, while in others, such as Kenya and Tanzania, some cactuses are considered invasive and are controlled through the release of natural enemies. Catalyzing that knowledge, the IPM Innovation Lab has been instrumental in coordinating activities between regions to reduce discord.
“There is a high need to address conflicts emerging in developing countries from the activities in developed countries,” Muniappan said. “Scientists involved in biocontrol activities should communicate so that countries and regions can prevent counterproductive activities.”
The spread of invasive species poses a major global threat. It disproportionately affects developing countries that depend on natural resources for economic livelihoods.
The IPM Innovation Lab, funded by the U.S. Agency for International Development, has monitored and managed the spread of invasive species since the program’s inception in 1993. Currently, in East Africa, the program releases two natural enemies to manage the invasive weed Parthenium, which causes human, animal, and environmental health issues and pushes out native species. The project establishes collaboration between scientists from the U.S., Australia, and South Africa with scientists from Ethiopia, Kenya, and Uganda.
“This project has opened the door for future introduction of natural enemies to control other invasive weeds in Ethiopia by showing authorities that biological control can be safe and effective if done properly,” said Wondi Mersie, associate dean and director of research at Virginia State University and leader of the Parthenium project.
The IPM Innovation Lab is housed at the Center for International Research, Education, and Development, part of Outreach and International Affairs.
Written by Sara Hendery