RESUMO
Cerambycid species of the Spondylidinae subfamily are distributed worldwide and are known for being prolific invaders that infest conifers. In New Zealand, Arhopalus ferus (Mulsant), the burnt pine longhorn beetle, is well-established and requires monitoring at high-risk sites such as ports, airports, and sawmills as part of the requirements to meet pine log export standards set by the New Zealand Ministry of Primary Industries (MPI). Currently, its surveillance relies on traps baited with host volatiles (i.e., ethanol and α-pinene). We used volatile collections from adult beetles, electroantennograms, and field trapping bioassays to identify the pheromones emitted by the burnt pine longhorn beetle A. ferus and their effects on its behaviour. We show that A. ferus males emit mainly (E)-fuscumol and geranylacetone, as well as the minor components, α-terpinene and p-mentha-1,3,8-triene, and that all four compounds elicit a dose-dependent response in antennae of both sexes. Traps baited with the binary combination of geranylacetone plus fuscumol captured significantly more female A. ferus than did unbaited traps in two of three field experiments. α-Terpinene did not affect A. ferus trap catches and effects of p-mentha-1,3,8-triene on trap catch were not determined. Our findings provide further evidence of the use of fuscumol and geranylacetone as aggregation-sex pheromones by longhorn beetles in the Spondylidinae subfamily, and suggest that their deployment in survey traps may improve the efficacy of A. ferus monitoring in New Zealand and elsewhere.
RESUMO
Volatile terpenes are important compounds that influence fruit flavour and aroma of kiwifruit. Terpenes in plants also impact on the floral bouquet and defence against pests and pathogens in leaves and fruit. To better understand the overlapping roles that terpenes may fulfil in plants, a systematic gene, chemical and biochemical analysis of terpenes and terpene synthases (TPS) was undertaken in Red5 kiwifruit (Actinidia spp.). Analysis of the Red5 genome shows it contains only 22 TPS gene models, of which fifteen encode full-length TPS. Thirteen TPS can account for the major terpene volatiles produced in different tissues of Red5 kiwifruit and in response to different stimuli. The small Red5 TPS family displays surprisingly high functional redundancy with five TPS producing linalool/nerolidol. Treatment of leaves and fruit with methyl jasmonate enhanced expression of a subset of defence-related TPS genes and stimulated the release of terpenes. Six TPS genes were induced upon herbivory of leaves by the economically important insect pest Ctenopseustis obliquana (brown-headed leaf roller) and emission, but not accumulation, of (E)- and (Z)-nerolidol was strongly linked to herbivory. Our results provide a framework to understand the overlapping biological and ecological roles of terpenes in Actinidia and other horticultural crops.
RESUMO
Light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), is the target of the sterile insect technique, but reduced moth fitness from irradiation lowers the effective overflooding ratio of sterile to wild moths. New measures of insect quality are being sought to improve field performance of irradiated insects, thus improving the cost effectiveness of this technique. Male pupae were irradiated at intervals between 0 and 300 Gy, and adult flight success was assessed in a wind tunnel equipped with flight track recording software. A dose response was evident with reduced successful search behaviors at higher irradiation doses. Irradiation at 250 Gy reduced arrival success to 49% of untreated controls, during 2-min assays. Mark-release-recapture of males irradiated at 250 Gy indicated reduced male moth recapture in hedgerows (75% of control values of 7.22% +/- 1.20 [SEM] males recaptured) and in vineyards (78% of control values 10.5% +/- 1.66% [SEM] recaptured). Males dispersed similar distances in both habitats, and overflooding ratios dropped off rapidly from the release point in both landscapes. Transects of traps with central releases proved to be an efficient method for measuring the quality of released males. Relative field performance of moths was greater than suggested by wind tunnel performance, which could be due to time differences between the two assays, two-minute wind tunnel tests compared with days in the field treatments. Release strategies involving ground releases should consider the effect of limited postrelease dispersal. Aerial release could solve this problem and warrants investigation.
Assuntos
Voo Animal/efeitos da radiação , Mariposas/efeitos da radiação , Controle Biológico de Vetores , Animais , Masculino , VitisRESUMO
The ability of 29 peripheral quantitative computed tomography (pQCT) software analysis modes at defining cortical from trabecular bone at three tibial metaphyseal regions was evaluated using five cadaveric tibiae. The accuracy of pQCT was determined by comparing the bone mineral content (BMC) with the ash weight. The precision of the pQCT scanner was calculated using repeated measurements. All the analysis modes had a good accuracy when measuring total bone area and a poor accuracy when measuring cortical bone area at the proximal 5% and distal 4% regions. For trabecular bone measured at all three regions and cortical bone area measured at the proximal 10% region, the Stratec peel mode 5 was the most accurate analysis mode. Highly significant correlations (r = 0.71-0.98) and a moderate accuracy error (coefficient of variation [CV] = 5-22%) was found between ash weight and BMC when using this mode. The precision of bone mineral density (BMD) measurements was good (total, CV = 2-5%; trabecular, CV = 2-5%; cortical, CV = 4-6%). pQCT is a moderately accurate, precise method of measuring trabecular and total BMD at the tibial metaphysis. The authors recommend caution when interpreting results for cortical BMD, as cortical area measurements at the metaphyseal region are less accurate and less precise.
