Identification of volatiles from Pinus silvestris attractive for Monochamus galloprovincialis using a SPME-GC/MS platform

INTRODUCTION

A myriad of volatile organic compounds (VOCs) released by terrestrial vegetation plays an important role in environmental sciences. A thorough chemical identification of these species at the molecular level is essential in various fields, ranging from atmospheric chemistry to ecology of forest ecosystems. In particular, the recognition of VOCs profiles in a context of plant-insect communication is a key issue for the development of forest protection tools.

PURPOSE

This work was aimed at the development of a simple, robust and reliable method for the identification of volatiles emitted from plant materials, which can attract or deter pest insects. Specifically, volatiles emitted from the bark of Pinus sylvestris were studied, which might attract the black pine sawyer beetle Monochamus galloprovincialis-a serious pest of the tree and a vector of a parasitic nematode Bursaphelenchus xylophius.

METHOD

The volatiles from bark samples were collected using a solid-phase micro-extraction technique, and subsequently analysed by gas-chromatography/mass-spectrometry (GC/MS). The characterisation of the volatile fraction was based on the comparison with data in mass spectral libraries, and in most cases, with the available authentic standards. The identified compounds were screened against the available entomological data to select insect attractors.

RESULTS

The identified components included terpenes (α-pinene, ∆-3-carene, and para-cymenene), oxygenated terpenes (α-terpineol and verbenone), sesquiterpenes (α-longipinene, longifolene, E-β-farnesene, γ-cadinene and pentadecane), and diterpenes (manoyl oxide and (+)-pimaral). Of these, longifolene and (+)-pimaral are of particular interest as plausible attractors for the M. galloprovincialis beetle that might find application in the construction of insect bait traps.

Concentrations of bisphenol A in the composite food samples from the 2008 Canadian total diet study in Quebec City and dietary intake estimates

A total of 154 food composite samples from the 2008 total diet study in Quebec City were analysed for bisphenol A (BPA), and BPA was detected in less than half (36%, or 55 samples) of the samples tested. High concentrations of BPA were found mostly in the composite samples containing canned foods, with the highest BPA level being observed in canned fish (106 ng g(-1)), followed by canned corn (83.7 ng g(-1)), canned soups (22.2-44.4 ng g(-1)), canned baked beans (23.5 ng g(-1)), canned peas (16.8 ng g(-1)), canned evaporated milk (15.3 ng g(-1)), and canned luncheon meats (10.5 ng g(-1)). BPA levels in baby food composite samples were low, with 2.75 ng g(-1) in canned liquid infant formula, and 0.84-2.46 ng g(-1) in jarred baby foods. BPA was also detected in some foods that are not canned or in jars, such as yeast (8.52 ng g(-1)), baking powder (0.64 ng g(-1)), some cheeses (0.68-2.24 ng g(-1)), breads and some cereals (0.40-1.73 ng g(-1)), and fast foods (1.1-10.9 ng g(-1)). Dietary intakes of BPA were low for all age-sex groups, with 0.17-0.33 µg kg(-1) body weight day(-1) for infants, 0.082-0.23 µg kg(-1) body weight day(-1) for children aged from 1 to 19 years, and 0.052-0.081 µg kg(-1) body weight day(-1) for adults, well below the established regulatory limits. BPA intakes from 19 of the 55 samples account for more than 95% of the total dietary intakes, and most of the 19 samples were either canned or in jars. Intakes of BPA from non-canned foods are low.