The role of host patch characteristics and dispersal capability in distribution and abundance of Arhopalus rusticus in central Argentina

Abstract

Host patch characteristics may influence the abundance of a species, but this will depend on the species’ dispersal ability and the distance between suitable patches. In central Argentina, an area of introduced pine forest was planted for wood production in the 1940s. In 2006, an invading longhorn beetle, Arhopalus rusticus (L.) (Coleoptera: Cerambycidae), was detected in the area. Since then, the species has expanded its range until it occupies the whole area. We analyze how the configuration of host patches and flight performance of A. rusticus affect its distribution. The study was performed in the center-west of Córdoba Province, Argentina, with 24 000 ha of introduced pine forests the main pine production zone of the province. Land cover was estimated using Landsat 8 scenes. Landscape was quantified by estimating the focal patch's area, fractal dimension index (FRAC), and Euclidean nearest neighbor distance (ENN). Focal patch area showed a positive relationship with A. rusticus abundance, whereas ENN and FRAC had a negative relationship. The dispersal ability of A. rusticus was determined by putting recently emerged individuals to fly in flight mills. The flight performance results indicated that the species was probably introduced in the area by human activity, then rapidly established and expanded to the whole area. This indicates the importance of preventing its arrival in other pine production areas of Argentina, as it has proved to be an extremely successful invader.