Prediction of migratory routes of the invasive fall armyworm in eastern China using a trajectory analytical approach

Abstract

BACKGROUND: The fall armyworm (FAW), an invasive pest from the Americas, is rapidly spreading through the Old World, and has recently invaded the Indochinese Peninsula and southern China. In the Americas, FAW migrates from winter-breeding areas in the south into summer-breeding areas throughout North America where it is a major pest of corn. Asian populations are also likely to evolve migrations into the corn-producing regions of eastern China, where they will pose a serious threat to food security. RESULTS: To evaluate the invasion risk in easternChina, the rate of expansion and future migratory range was modelled by a trajectory simulation approach, combined with flight behavior and meteorological data. Our results predict that FAW will migrate from its new year-round breeding regions into the two main corn-producing regions of eastern China (Huang-Huai-Hai Summer Corn and Northeast Spring Corn Regions), via two pathways. The western pathway originates in Myanmar and Yunnan, and FAW will take four migration steps (i.e. four generations) to reach the Huang-Huai-Hai Region by July. Migration along the eastern pathway from Indochina and southern China progresses faster, with FAW reaching the Huang-Huai-Hai Region in three steps by June and reaching the Northeast Spring Region in July. CONCLUSION:Our results indicate that there is a high risk that FAW will invade the major corn-producing areas of eastern China via two migration pathways, and cause significant impacts to agricultural productivity. Information on migration pathways and timings can be used to inform integrated pest management strategies for this emerging pest.

High risk of the fall armyworm invading Japan and the Korean Peninsula via overseas migration

“…Based on biological characteristics of the migration of S. frugiperda, trajectories were calculated with the following parameters. (i) S. frugiperda flies downwind at high altitude (Wolf, Westbrook, Raulston, & Lingren, 1995;Nagoshi, Meagher, & Fleischer, 2009), without considering a directional deflection angle (Li et al, 2019) trajectory modelling, and this speed is similar to that of other similar-sized noctuid moths (Westbrook, 2007;Li et al, 2019;Minter et al, 2018). (iii) The noctuid insects fly at night, taking off at dusk and landing at dawn on the next day (Qi, Lv, Lan, Xie, and Zhang, 2013;Wang et al, 2017).…”

“…(vi) Radar observations show that moths usually fly in a low-level jet stream at altitudes with wind speed > 10 m/s (Johnson, 1987;Westbrook et al, 2016;Wolf et al, 1990). In this study, we used six different initial heights: 500, 750, 1,000, 1,250, 1,500 and 1,750 m above mean sea level (Li et al, 2019), and thus, six trajectories were calculated on one night at one departure point.…”

Development of a simple and accurate molecular tool for Spodoptera frugiperda species identification using LAMP

“…The origin of S. frugiperda populations in Korea has not been identified as of 2019. Based on meteorological predictions, they might migrate from some part of China and East Asia to Korea at least twice (end of May to end of June and July) (Li et al, 2020;Wu et al, 2019).…”

High risk of the Fall Armyworm invading into Japan and the Korean Peninsula via overseas migration

“…In the following two years, it swept through 44 countries in sub-Saharan Africa (Nagoshi et al, 2018; Rwomushana et al, 2018), caused heavy losses to African food production (Stokstad & Erik, 2017). In May 2018, S. frugiperda was first found in India (Sharanabasappa et al, 2018), then spread rapidly to other Asian countries including Thailand, Sri Lanka, Bangladesh, Myanmar, Vietnam, Laos and China (Guo, Zhao, He, Zhang & Wang, 2018; Wu, Jiang & Wu, 2019a; NATESC, 2019ab). On 11 January, 2019, the first confirmation of the invasion of S. frugiperda was made in Yunnan Province, China (Jiang & Zhu, 2019; NATESC, 2019a).…”