Scolytinae species are among the most damaging forest pests, and many of them are invasive. Over 1500 Scolytinae interceptions were recorded at New Zealand's borders between 1950 and 2000. Among the 103 species were Dendroctonus ponderosae, Ips typographus, and other high-risk species, but actual arrivals probably included many more species. Interceptions were primarily associated with dunnage, casewood (crating), and sawn timber, and originated from 59 countries, mainly from Europe, Australasia, northern Asia, and North America. New Zealand and United States interception data were highly correlated, and 7 of the 10 most intercepted species were shared. Interception frequency and establishment in New Zealand were not clearly related. By combining New Zealand and United States interceptions of true bark beetles we obtained data on species found in shipments from around the world. Logistic regression analysis showed that frequently intercepted species were about four times as likely as rarely intercepted species to be established somewhere. Interception records of wood and bark borers are valuable for the prediction of invaders and for our general understanding of invasions. The use of alternatives to solid wood packaging, such as processed wood, should be encouraged to reduce the spread of invasive wood and bark borers. Résumé : Les scolytinés sont parmi les ravageurs forestiers les plus dommageables et ils comptent plusieurs espèces envahissantes. Plus de 1500 interceptions de scolytinés ont été enregistrées aux frontières de la Nouvelle-Zélande entre 1950 et 2000. Parmi les 103 espèces, on trouvait Dendroctonus ponderosae, Ips typographus et d'autres espèces à haut risque mais les arrivées incluaient en réalité probablement beaucoup plus d'espèces. Les interceptions étaient principalement associées au bois d'arrimage, au bois de caisserie (emballages à claire-voie) et au bois scié et provenaient de 59 pays, surtout de l'Europe, de l'Australasie, du nord de l'Asie et de l'Amérique du Nord. Les données d'interception de la Nouvelle-Zélande et des États-Unis étaient étroitement corrélées et sept des dix espèces les plus souvent interceptées étaient communes. En Nouvelle-Zélande, la fréquence d'interception et l'établissement n'étaient pas clairement reliés.En combinant les interceptions des scolytes de l'écorce faites en Nouvelle-Zélande et aux États-Unis, les auteurs ont obtenu des données sur les espèces retrouvées dans les expéditions partout dans le monde. L'analyse de régression logistique a démontré que les espèces fréquemment interceptées avaient environ quatre fois plus de chances d'être éta-blies quelque part que les espèces rarement interceptées. Les données d'interception des xylophages et des insectes qui s'attaquent à l'écorce sont précieuses pour faire des prédictions au sujet des envahisseurs et pour notre compréhension générale des envahissements. L'utilisation de solutions de rechange à l'empaquetage avec du bois solide, telles que le bois transformé, devrait être encouragée pour réduire la dispers...

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In this paper we make comparisons between the observed oxygen and hydrogen stable isotope composition of leaf water and the predictions of the Craig-Gordon model of evaporative isotopic enrichment. Comparisons were made among two C species (Chenopodium album and Helianthus annuus) and two C species (Amaranthus retroflexus and Kochia scoparia), when plants were exposed to natural environmental conditions in the field. There were significant differences among the species for the hydrogen and oxygen isotopic composition of leaf water at mid-day. The Amaranthus and Helianthus plants had lower leaf water δD and δO values than did Kochia and Chenopodium. The observed leaf water δ values were significantly lower than those predicted by the evaporative enrichment model for all the species. The degree of discrepancy between the observed and modelled leaf water isotopic compositions differed among species. There was a strong linear relationship between the oxygen and hydrogen isotopic compositions of stem water, observed leaf water and the modelled leaf water for all species. The observed leaf water isotopic composition for the different species occurred at different points along the line connecting the stem water isotopic composition and the modelled leaf water isotopic composition in a plot of δD and δO. We interpret these linear relationships as mixing lines between the unfractionated source or stem water isotopic composition and the isotopic composition of water at the evaporation sites within leaves (as defined by the evaporative enrichment model).

Species boundaries within the aureoid Senecio complex (Packera) are poorly defined, possibly as a result of hybridization and introgression. The results of restriction site analysis of cpDNA using 16 enzymes and hybridization with lettuce probes representing over 95% of the chloroplast genome reveal a high level of intrapopulational polymorphism combined with a relatively low level of interspecific variation. Forty-nine populations representing 23 different species were examined, and only 20 variable restriction sites were identified. Eleven of the 20 variable sites were polymorphic in at least one population, and 14 of the 23 species were polymorphic for at least one site. The polymorphisms are widespread and are found in species representing all of the previously recognized subgroups of the aureoid complex. Individuals analyzed separately were shown to possess only a single haplorype. Although the polymorphisms may be the result of hybridization and introgression, it is difficult to explain the geographical patterns based on the current distribution of species. It is possible that the aureoid complex represents a single, polymorphic biological species. Keywords: Asteraceae, Senecio, aureoid complex, Packera, cpDNA, molecular systematics.

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The geographical distribution of chloroplast DNA (cpDNA) variation in 39 populations of two hybridizing Mexican red oaks, Quercus affinis and Q. laurina, was investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Six haplotypes were identified. Of these, two (H1 and H4), separated by four mutations, had high frequencies (58 and 23% of the individuals, respectively) and were present across the whole geographical range of both species, often co occurring in the same populations. The other four haplotypes were rare, geographically restricted, and are probably derived from the two frequent haplotypes. Latitudinal or other clinal patterns in diversity levels or haplotype composition of populations were not apparent. The pattern of haplotype distribution was characterized by some mosaicism, with contrasting populations often situated in proximity. Average within-population diversity (hS=0.299) and population differentiation (GST=0.499) were, respectively, higher and lower than values reported in previous studies of oak species. There was evidence for phylogeographical structure, as indicated by NST (0.566) being significantly higher than GST. Haplotypic variation was largely species-independent, although some very weak associations were detected between haplotypes H1 and H4 and morphological and nuclear molecular variation correspondingly characterizing Q. affinis and Q. laurina. These oaks probably did not experience a marked restriction to one or a few particular subregions of their present range during the last glacial cycle. It is more likely that substantial populations persisted throughout several episodes of climatic change, but experienced recurrent latitudinal and altitudinal migrations which may have caused the widespread distribution of haplotypes H1 and H4 and frequent intermixing of populations.

The seeds of four prairie fruits-chokecherry (Prunus virginiana), thorny buffaloberry (Shepherdia argentea), Woods' rose (Rosa woodsii) and hawthorn (Crataegus 9 mordenensis)-from Southern Alberta were investigated. The lipid contents of the seeds were found to be 10.4, 11.5, 3.7 and 3.4%, respectively. The tested seed lipids contained mainly linoleic acid in the range from 27.9 to 65.6% and oleic acid from 19.7 to 61.9%. The thorny buffaloberry and Woods' rose seed lipids contained 29.2 and 30.8% of linolenic acid, respectively. The contents of palmitic and stearic acids ranged from 3.2 to 5.4% and 1.6 to 2.2%, respectively. The contents of total tocopherols in the chokecherry, thorny buffaloberry, Woods' rose and hawthorn seed lipids accounted for 595, 897, 2,358 and 2,837 mg/kg, respectively. The main sterols in the lipids were b-sitosterol, D 5 -avenasterol, cycloartenol, campesterol, stigmasterol and gramisterol. The results of the present study show that the lipids from the seeds of the investigated prairie fruits could be a good source of valuable essential fatty acids, tocopherols and sterols, thus suggesting their application as functional foods and nutraceuticals.