Distribution and characterization of damage caused by Pissodes castaneus in Pinus spp. plantations of the Andean Patagonian Region, Argentina

Pissodes castaneus (Col.: Curculionidae) was first reported in the Patagonian Andean region in Neuquen province in 2005. This weevil generally attacks trees previously affected by other biotic or abiotic factors. In some plantations it is the main sanitary problem; however, its distributional area and infestation levels are still unknown. The aims of this study were: 1) to assess the current pest distribution in the Patagonian Andean Region, 2) to characterize and quantify the damage caused by Pissodes castaneus in Chubut province, and 3) to evaluate the association between infestation levels and silvicultural and environmental conditions in Chubut province plantations. Pissodes castaneus was registered in Neuquen, Rio Negro and Chubut provinces, being the proportion of infested plantations higher in the last provinces than in Neuquen. Infestation level ranged between 1.4 % and 45.7 %. Pinus contorta var. murrayana was the most affected species followed by Pinus radiata and Pinus ponderosa. The major mortality was registered in Pinus contorta var. murrayana. However, in young plantations of Pinus ponderosa it was found only as a damage agent causing the death of trees by annealing. Infestation level was positively associated to woody debris and to Sirex noctilio attack. Characteristics of the attack and the distribution reached by the insect in the region suggest that Pissodes castaneus should be considered in management guidelines.