Host selection and previous damage influence in Pissodes castaneus (Coleoptera: Curculionidae) feeding behavior

GERMANO, MÓNICA D

San Carlos de Bariloche

Conferencia; Adapting forest ecosystems and wood products to biotic and abiotic stress; 2019

European Union Marie-Curie project Topwood, INRA, INTA

The banded pine weevil, Pissodes castaneus (Coleoptera: Curculionidae) attacks the most commonly planted pine species in Argentinian Patagonia: Pinus ponderosa, P. contorta var. murrayana and P. radiata. The objective of this work was stablishing whether P. castaneus presents feeding preference, and if previous damage affects selection behavior. The experimental design consisted of a free choice arena in which 5 cm long branches were offered to one adult individual. Chosen branch and the number of feeding punctures was registered after 24 hs. Species offered for host preference assays were P. contorta var. murrayana, P. radiata and P. ponderosa. Damage influence assays were conducted offering damaged and non-damaged twigs of the most chosen species in the previous assay. Previous damage was obtained by offering branches to adult weevils during 24 hs before the assay. Host preference for P. contorta var. murrayana was found for females, and not for males. The number of feeding punctures was similar between sexes, and significantly larger in P. radiata in comparison to the other pine species. Although a slightly larger number of insects preferred feeding from damaged branches, no significant differences were found. In addition, the amount of feeding punctures was significantly larger in non-damaged braches. P. castaneus presented feeding preference for P. contorta var. murrayana. Even though this preference was associated to damage made by other pest species in the past, presented results suggest that host selection is independent of previous damage made by P. castaneus.