On December 23，the top international journal of Science published the latest finding in research on insects by the NAU insect research team of the project of Mass Seasonal Bioflows of High-flying Insect Migrants (2016, 354:1584–1587). Associate Professor Hu Gao of NAU is the first author and correspondence author of the published paper, and NAU is listed the first affiliation under the authors. Associate Professor Jason Chapman of University of Exeter, UK is the co-correspondence author.
Migration is very popular and spectacular among animals, such as birds, wildebeests and salmon. Animal migration causes mobility of predators, preys and competitors across regions and areas, and also contributes to transmission of substance and energy and spread of pathogens, producing profound effect on ecosystems. Numerous insects also migrate to adapt to the changes in resources and habitats. However, insects are so small and fly in hundreds of meters to two to three kilometers up in theair that they are beyond the visibility by human eyes. Therefore, their behavior of migration and effect on ecosystems are little known. Specially designed vertical radar is a powerful and effective device for monitoring and studying these migrating insects. Professor Hu and colleagues analyzed the quantities of insect populations and their biomass based on the data collected for ten years by two vertical radar devices in southern UK, and they found an annual migration of as many as 3.5 trillion of insects, equivalent to 3200 tons of biomass. Insects with body weight of over 10mg seek and utilize favorable seasonal airflow for long-distance migration.Although there is generally a balance between northward migration in spring and southward migration in autumn of insects in most year years, transmission of substance and energy caused by the large-scale insect migration is having effects on the global ecosystem in terms of ecological service, ecological processes and biogeochemical processes.
This research has not only revealed the grand scenario of insect migration, but also demonstrated the prospect of application of vertical radar devices in insect supervision and measurement. Now, a number of research institutes are using this technology to perform investigations of insect migration in the hope of applying the vertical radar technology to automatic monitoring of the dynamics of major pest populations in China’s agriculture. Several vertical radar devices have been designed and installed in the country but there has been a bottleneck in data analysis, and Hu and colleague’s research finding would promote development of radar technology in research on insects in China.
Professor Hu has been devoted to research on laws and cataleptic mechanisms of migration of insects, and is proficient in using such software of GIS, R and so on for large data analysis. In 2015, Hu went to the Unite Kingdom for a two-year academic visit sponsored by the Jiangsu Province Preponderant Discipline Project and the National Scholarship Council. Hu made use of his proficiency in data analysis and analyzed the data collected for 10 years in one year of the visit, publishing three papers on insect research by radar, being the first author of two of the papers.
Professor Jason Chapman, the co-author of the paper in Science, has long been studying migrating insects, with over 50 papers published in high-level journals of Science, PNAS, Ecology Letter, Current Biology, Annual Review of Entomology and so on, in recent years.
The radar data used in the paper were collected by the research team on insect migration and spatial ecology who have developed two radar devices for vertical supervision of insect migration that have been working for 16 years accumulating massive data. Dr. Ka-Sing Lim, the engineer of radar technology, has recently developed three new-generation devices that are working well in the UK, the USA and Switzerland.
The other major authors of the paper are Dr. Suzanne Clark of the Rothamsted Research Station, Dr. Don Reynolds of University of Greenwich, Dr. Nir Horvitz of Hebrew University and Dr. Nir Sapir of University of Haifa.