Migration and Dispersion of Empoasca vitis in Tea Plantations Analyzed by HYSPLIT

  Objective  Migratory and dispersal behaviors of Empoasca vitis (Göthe) at tea plantations were analyzed.

  Method  Yellow insect-trapping boards attached to ballons were strategically placed at varying heights and orientations in a tea plantation to catch E. vitis. The HYSPLIT-4 airflow dynamics model and meteorological data were used to analyze and simulate the insect migration and dispersion patterns. Based upon the field survey and the data on the population density and dispersion, factors driving the E. vitis movement were postulated.

  Result  The maximum flying altitude of E. vitis was 8 m. The insect population steadily declined from 2 m up to 8 m. The HYSPLIT-4 generated insect movement trajectory indicated that the migration time was the only determinant, not the flying altitude nor dispersal distance. The 24h-migration of the insects ranged 35.70-178.10 km and transformed between aggregated and random distribution patterns that typified the dispersion.

  Conclusion   E. vitis migrated from region to region affected by prevailing air currents. The movement transitioned between aggregated and random dispersion in the field and regions. Consequently, effective pest control should be executed in the target area and extended no more than 200 km from the border.