Boll weevil invasion process in Argentina

Abstract

The boll weevil, Anthonomus grandis grandis Boheman, is the most destructive cotton pest in the Western Hemisphere. In 1993, the pest was reported in Argentina, and in 1994 boll weevils were captured in cotton fields in Formosa Province on the border between Argentina and Paraguay. The pest has subsequently moved to new areas, and in 2006 it was reported in Argentina’s main cotton growing region. This study describes the first stage of the boll weevil invasion into areas of Argentina using a network of pheromone traps from 1997 to 2000 in Pilcomayo and Pilagás departments. A temporal autocorrelation analysis of the numbers of collected boll weevils in seven localities, and a synchrony analysis of 70 rural settlements for the 1997–2000 period, were the approaches we used to characterize boll weevil dispersal and establishment. Total abundances of boll weevils varied but a positive correlation between total number of individuals captured and the number of traps that captured them was detected. While short term temporal autocorrelation was observed, spatial synchrony was not found. The role of alternative hosts in facilitating the advance of boll weevils into Argentina is discussed.