An advanced numerical trajectory model tracks a corn earworm moth migration event in Texas, USA

Authors: WU, QUI-LIN - Nanjing Agricultural University; HU, GAO - Nanjing Agricultural University; Westbrook, John; SWORD, GREGORY - Texas A&M University; ZHAI, BAO-PING - Nanjing Agricultural University

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2018
Publication Date: 9/5/2018
Citation: Wu, Q., Hu, G., Westbrook, J.K., Sword, G.A., Zhai, B. 2018. An advanced numerical trajectory model tracks a corn earworm moth migration event in Texas, USA. Insects. 9:115. https://doi.org/10.3390/insects9030115.
DOI: https://doi.org/10.3390/insects9030115

Interpretive Summary: The corn earworm is a migratory pest that infests corn, cotton, and numerous field crops, yet long-distance migrations are difficult to predict. We developed and verified an improved migration simulation method consisting of an advanced numerical weather prediction model (Weather Research and Forecasting or WRF) and a three-dimensional trajectory model that incorporates self-powered flight of corn earworm moths. The method was evaluated using a migration event of citrus pollen-marked corn earworm moths monitored by pheromone traps in Texas, on 20-22 March 1995. Simulated forward migration trajectories from southern Texas (where citrus was blooming) accurately identified 92.86% of locations that captured pollen-marked male corn earworms. We suggest that this improved method can be used for a wide range of applications in forecasting of migratory insects of public interest.

Technical Abstract: An improved numerical trajectory simulation method for estimating population movements and re-distributions of high-flying insects was verified. The method consists of two components: an advanced atmospheric numerical model (Weather Research and Forecasting or WRF), and a three-dimensional trajectory model based on high spatio-temporal resolution atmospheric conditions produced by WRF model and taking into account moth self-powered flight behaviors. The method was evaluated using a migration event of citrus pollen-marked corn earworm moths (Helicoverpa zea) monitored by pheromone traps in Texas, USA on 20-22 March 1995. It is shown that the forward trajectory analysis method accurately tracked possible landing locations of migratory H. zea taking-off from southern Texas where citrus was blooming. Specifically, there were 92.86% locations trapping pollen-marked male H. zea in agreement of the calculated fallout locations and trajectories, which also were well supported by published findings. In addition, results of the backward trajectories suggested that pollen-marked H. zea caught from all pheromone traps in central and northern Texas could be tracked back into the citrus growing region in southern Texas and northeastern Mexico. It is concluded that analysis on long-distance migration trajectories of H. zea was much improved. Furthermore, it is suggested that this improved method can improve the understanding of a specific migration event of H. zea, and can be used for a wide range of applications in forecasting and prediction of migratory insects of public interest.