No abstract

O gorgulho-da-casca-do-pinus, Pissodes castaneus (De Geer, 1775) (Coleoptera, Curculionidae) é uma praga florestal que foi detectada no Brasil em 2001 e atualmente se encontra distribuída nos três estados da Região Sul, causando grande preocupação para o setor florestal. Os objetivos deste estudo foram isolar, identificar e avaliar a atividade comportamental dos voláteis produzidos pelos machos de P. castaneus. Nossos resultados indicam que a comunicação entre indivíduos desta espécie é mediada por feromônios, o que foi evidenciado pela atração significativa de fêmeas pelos voláteis produzidos pelos machos. Testes comportamentais realizados com os insetos e sua planta hospedeira, Pinus taeda, indicam que os compostos produzidos pelos machos atuam como feromônios sexuais e que os compostos liberados pela planta hospedeira não aumentam a atividade destes compostos. Os compostos produzidos pelos machos de P. castaneus foram identificados como (1R, 2S)-grandisal e (1R, 2S)-grandisol, em excesso enantiomérico superior a 95%.The banded pine weevil, Pissodes castaneus (De Geer, 1775) (Coleoptera, Curculionidae) is a forest pest recorded in Brazil since 2001, which is already distributed in the three states of the Southern Region, causing great concern to the forestry sector. Objectives of our study were to isolate, identify, and assess the behavioral activity of male-produced volatiles of P. castaneus. Our results indicate that communication between conspecifics of P. castaneus is mediated by pheromones, as verified by the significant attraction of females to male-produced volatiles. Behavioral tests performed with the insects and the host plant, Pinus taeda, showed that male-produced compounds may act as sex pheromones and that the compounds released by the host plant did not enhance the activity of the male-produced volatiles. The chemical structures of the male specific volatile compounds produced by P. castaneus were determined to be (1R, 2S)-grandisal and (1R, 2S)-grandisol in an enantiomeric excess exceeding 95%.

Summary Poly(hydroxybutyrate‐co‐hydroxyvalerate) (PHBV) is a polymer that can be used on preparation of controlled release systems containing actives principles. The release of the compounds encapsulated on those systems can occur by three different forms: diffusion, degradation and matrix polymeric rupture. Therefore, it is interesting to evaluate the behavior of polymeric matrix when it is submitted on a pH change, for example an agricultural soils simulations. The objective of this study is the understanding of the chemical degradation process of microparticles employed with agricultural application. The PHBV microparticles were prepared using o/w simple emulsion technique followed by solvent evaporation, using poly(vinyl alcohol) (PVA) as stabilizing agent. The evaluation of polymeric microparticles, submitted to chemical degradation process in pH 5.6 at room temperature, was determined by conventional characterization techniques such as Scanning Electron Microscopy (SEM), X‐ray diffraction (XRD) and Differential Scanning Calorimetry (DSC). By SEM images it is possible to suggest that the chemical degradation process occurred. The indicatives peaks of crystallinity of the PHBV microparticles decrease and occurred the rise of broader peaks relative at appearance of new amorphous regions. The data obtained by thermal analysis shown that microparticles degradation occurred on amorphous and crystallines portions of PHBV.