2020 was a year like no other — researchers in search of answers to some of the world’s most pressing questions were forced to think outside the box when trials and experiments were put on hold due to the COVID-19 pandemic. Globally, communities are facing food insecurity challenges more intensely than ever before, emphasizing the ongoing value of research that looks at the sustainable production of crops. Despite a challenging year, Virginia Tech’s Feed the Future Integrated Pest Management Innovation Lab (IPM IL) and its partners aim to highlight some of the 2020 research outputs that will continue to help foster improved livelihoods around the world.

Fall armyworm

• In a study conducted by IPM IL partners at the International Center for Insect Physiology and Ecology (ICIPE), and other institutions, including the International Institute of Tropical Agriculture (IITA), the International Maize and Wheat Improvement Center (CIMMYT) and the Development Economics Group in the Netherlands, economic impacts of the fall armyworm (FAW) and its management strategies were assessed in Ethiopia. It was found that FAW exposure significantly negatively affects maize yield and sales, but not consumption. There was also a significant intensification of pesticide use in response to FAW exposure and it was found that extension services currently do not have the capacity to help manage such emerging threats, further suggesting the need for improved institutional capacity to address the impacts of invasive species spread.
• Through the IPM IL’s Feed the Future Nepal Integrated Pest Management associate award, implemented by International Development Enterprises (iDE), researchers found that candidates for augmentative biological control of FAW are present in three countries: Kenya, Tanzania and Nepal. The discovery of natural enemies in both Africa and Asia — and, in particular, one of the species in both places — has important implications not only for suppressing FAW, but also for south-south and cross-continental technology transfer of their mass-production.

Tuta absoluta

• A common pathway for the introduction and spread of invasive species is through trade and transport; however, commodity flows are difficult to understand with unavailable quality data. IPM IL collaborators at Virginia Tech, the University of Virginia, iDE, and the Indian Institute of Horticultural Research developed a network-based approach to model the seasonal flow of agricultural produce and examine its role in pest spread, specifically for the tomato leafminer: Tuta absoluta. The study indicated that regional trade plays an important role in the spread of the tomato pest. The potential economic impact of its invasion could range from USD $17–25 million.
• Tuta absoluta has emerged in Tanzania and other African countries, but its ecology in their environment is not well known. IPM IL partners at Sokoine University of Agriculture in Tanzania tested effects of season, location, altitude, time, host and insecticides on the spatial and temporal abundance of the pest. It was found that all factors, and interactions between each, significantly affect Tuta absoluta populations. Additionally, tomato was the most preferred host at all locations and seasons.

Crop protection

• Rice blast is one of the most destructive diseases of rice in Cambodia and throughout the world, depleting both rice yields and quality. IPM IL collaborators at the Ministry of Agriculture, Forest and Fisheries in Cambodia, the International Rice Research Institute (IRRI) and Nagoya University conducted a series of experiments to assess ecological management practices of the disease. Results showed that the use of a resistant rice variety is effective in reducing leaf and neck blast incidence. It was also found that application of the beneficial fungus Trichoderma could reduce rice blast incidence in certain susceptible rice varieties, with comparable yields to conventional farmer practice.
• Mango is a vital fruit crop in Bangladesh; however, yield quality and quantity and exports are dramatically affected by the fruit fly, Bactrocera dorsalis. In a study conducted by the Bangladesh Agricultural Research Institute (BARI) and the IPM IL team, a range of integrated pest management (IPM) practices were applied to compare the efficacy and economic benefits of ecological practices on the pest. Among the treatments, bagging mangos with double-layer brown paper bags at 42 days before harvest showed the best performance, reducing fruit infestation to zero and significantly increasing yields compared to conventional pesticide management.
• IPM IL partners at Tribhuvan University assessed the current, potential and future suitable areas for cultivation of finger millet in Nepal to help develop strategies to cultivate the crop at national demand. The model revealed elevations most suitable for cultivation and that 39.7% of Nepal is currently suitable, though only 4.5% is under cultivation at present. It was estimated that 10% of land suitable for finger millet would be lost due to climate change by 2070.