MIGRATION IN THE MACROPTEROUS FORM OF THE WINGLESS GRASSHOPPER, PHAULACRIDIUM VITTATUM (SJÖSTEDT) DURING AN OUTBREAK

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Abstract

The first observations of long-range diurnal migration by individual, long-winged forms of Phaulacridium vittatum (the “wingless grasshopper”) were made during the Braidwood grasshopper outbreak of 1980/81. Flights were downwind at altitudes from 10–50 m and over distances from 100 to > 500 m. Spatial and temporal changes in populations over the area infested (ca 400 km2), suggested that migration resulted in a dispersal with prevailing wind of macropterous forms, from barren pastures at the centre of the infested area to more favourable pastures at its periphery. These required cumulative net displacements by individuals of not more than 10 km.

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