Repellent Activity of the Essential Oil from the Heartwood of Pilgerodendron uviferum (D. Don) Florin against Aegorhinus superciliosus (Coleoptera: Curculionidae)

Abstract

Abstract:The weevil Aegorhinus superciliosus Guérin (Coleoptera: Curculionidae), which is endemic to Central-Southern Chile and Argentina, is one of the major berry pests in Chile and the most important pest in the La Araucanía Region (38˝44 1 9"S, 72˝35 1 25"W). Due to the poor effectiveness and problems surrounding the implementation of the traditional control methods using organophosphate and carbamate insecticides, new strategies for controlling this pest are needed. In this communication, we evaluated the behavioral responses of male and female A. superciliosus to volatile compounds released from the essential oil (EO) obtained from the heartwood of Pilgerodendron uviferum (D. Don) Florin using olfactometric bioassays. The composition of the EO was analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). According to these analyses, δ-cadinol (24.16%), cubenol (22.64%), 15-copaenol (15.46%) and δ-cadinene (10.81%) were the principal components of the EO. The Pilgerodendron uviferum EO, which is almost exclusively composed of sesquiterpenes (99.5%), exhibited a repellent effect against A. superciliosus adults, regardless of the sex or concentration used (56.6 mg/cm 3 and 1.58ˆ10´2 mg/cm 3 ). The EO has low volatility and greater persistence than the EOs composed of monoterpenes and is considered a good model in the search for raspberry weevil repellents.

Antifeedant Effects of Essential Oil, Extracts, and Isolated Sesquiterpenes from Pilgerodendron uviferum (D. Don) Florin Heartwood on Red Clover Borer Hylastinus obscurus (Coleoptera: Curculionidae)

“…As in other species of Cupressaceae that were characterized by terpenoid biosynthesis, the composition of the PEE and DCME extracts from P. uviferum heartwood demonstrated high levels of sesquiterpenes. This agreed with chemical analyses of P. uviferum heartwood that was described in a previous study [18], which reported the presence of ten sesquiterpenes and five diterpenes in a heartwood methanol extract. In addition to this, our study identified eleven sesquiterpenes that were previously undescribed in this species.…”

“…The EO composition of P. uviferum was obtained from Espinoza et al [18]. According to these analyses, three monoterpenes (0.43%) and 17 sesquiterpenes (86.62%) were present in EO, with torreyol (24.16%), cubenol (22.64%), 15-copaenol (15.46%), and δ-cadinene (10.81%) being the most abundant components [18].…”

“…According to these analyses, three monoterpenes (0.43%) and 17 sesquiterpenes (86.62%) were present in EO, with torreyol (24.16%), cubenol (22.64%), 15-copaenol (15.46%), and δ-cadinene (10.81%) being the most abundant components [18]. In this study, we identified 25 and 22 compounds in the PEE and DCME extracts, respectively (Table 1), accounting for 82.4% and 79.8% of all of the detected compounds, respectively.…”

“…The EO that was used here was produced in an earlier study by Espinoza et al [18]. The light petroleum ether (PEE) and dichloromethane (DCME) extracts were obtained using a Soxhlet extraction, as follows: milled P. uviferum heartwood (1.5 kg) was sequentially extracted over a period of 8 h using PEE, followed by DCME; the extracts were dried over anhydrous sodium sulfate, filtered using a frit funnel, and the solvent was evaporated under reduced pressure in a rotatory evaporator, which yielded 42 g of PEE (2.8%) and 25 g of DCME (1.7%).…”

“…Therefore, this tree may be a potential source of natural products for the control of the red clover borer. In fact, a recent study has shown a repellent effect for the essential oil of P. uviferum against the weevil Aegorhinus superciliosus [18], a major berry pest in Chile. The composition and characterization of EO and extracts of P. uviferum heartwood were determined using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS).…”