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Background. Broad-scale monitoring of arthropods is often carried out with passive traps (e.g., Malaise traps) that can collect thousands of specimens per sample. The identification of individual specimens requires time and taxonomic expertise, limiting the geographical and temporal scale of research and monitoring studies. DNA metabarcoding of bulk-sample homogenates has been found to be faster, efficient and reliable, but the destruction of samples prevents a posteriori validation of species occurrences and relative abundances. Non-destructive metabarcoding of DNA extracted from collection medium has been applied in a limited number of studies, but further tests of efficiency are required with different trap types and collection media to assess the consistency of the method. Methods. We quantified the detection rate of arthropod species when applying nondestructive DNA metabarcoding with a short (127-bp) fragment of mitochondrial COI on two combinations of passive traps and collection media: (1) water with monopropylene glycol (H2O-MPG) used in window-flight traps (WFT, 53 in total); (2) ethanol with monopropylene glycol (EtOH-MPG) used in Malaise traps (MT, 27 in total). We then compared our results with those obtained for the same samples using morphological identification (for WFTs) or destructive metabarcoding of bulk homogenate (for MTs). This comparison was applied as part of a larger study of arthropod species richness in silver fir (Abies alba Mill., 1759) stands across a range of climate-induced tree dieback levels and forest management strategies. Results. Of the 53 H2O-MPG samples from WFTs, 16 produced no metabarcoding results, while the remaining 37 samples yielded 77 arthropod MOTUs in total, of [ABSTRACT FROM AUTHOR]

A large proportion of the insects which have invaded new regions and countries are emerging species, being found for the first time outside their native range. Being able to detect such species upon arrival at ports of entry before they establish in non-native countries is an urgent challenge. The deployment of traps baited with broad-spectrum semiochemical lures at ports-of-entry and other high-risk sites could be one such early detection tool. Rapid progress in the identification of semiochemicals for cerambycid beetles during the last 15 years has revealed that aggregation-sex pheromones and sex pheromones are often conserved at global levels for genera, tribes or subfamilies of the Cerambycidae. This possibly allows the development of generic attractants which attract multiple species simultaneously, especially when such pheromones are combined into blends. Here, we present the results of a worldwide field trial programme conducted during 2018-2021, using traps baited with a standardised 8-pheromone blend, usually complemented with plant volatiles. A total of 1308 traps were deployed at 302 sites covering simultaneously or sequentially 13 European countries, 10 Chinese provinces and some regions of the USA, Canada, Australia, Russia (Siberia) and the Caribbean (Martinique). We intended to test the following hypotheses: 1) if a species is regularly trapped in significant numbers by the blend on a continent, it increases the probability that it can be detected when it arrives in other countries/continents and 2) if the blend exerts an effective, generic attraction to multiple species, it is likely that previously unknown and unexpected species can be captured due to the high degree of conservation of pheromone structures within related taxa. A total of 78,321 longhorned beetles were trapped, representing 376 species from eight subfamilies, with 84 species captured in numbers greater than 50 individuals. Captures comprised 60 tribes, with 10 tribes including more than nine species trapped on different continents. Some invasive species were captured in both the native and invaded continents. This demonstrates the potential of multipheromone lures as effective tools for the detection of 'unexpected' cerambycid invaders, accidentally translocated outside their native ranges. Adding new pheromones with analogous well-conserved motifs is discussed, as well as the limitations of using such blends, especially for some cerambycid taxa which may be more attracted by the trap colour or other characteristics rather than to the chemical blend. [ABSTRACT FROM AUTHOR]

Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall) of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus) and two conifer species (Abies alba and Cupressus sempervirens) were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China), and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major difficulty. This situation could be improved by the development of molecular databases. [ABSTRACT FROM AUTHOR]

The Douglas-fir tussock moth (DFTM), Orgyia pseudotsugata McDunnough (Lepidoptera:Erebidae:Lymantriinae), is a native western North American defoliator of true fir, Abies spp. Mill., and Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. We investigated the population genetics and impact associated with the first recorded outbreak of DFTM in southern California (USA), and report the first collection of DFTM in Baja California Norte, Mexico. This latter population is similar genetically to populations from Washington, USA and British Columbia, Canada. We assessed forest stand characteristics, levels of defoliation, and mortality of white fir, Abies concolor Lindl., associated with the DFTM outbreak in the Transverse Mountain Ranges of southern California. We compared these data to those from southern California non-outbreak stands of A. concolor, and from virgin stands with an A. concolor component in the Sierra San Pedro Martir National Park (Mexico). Total stand density (ha-1) was significantly higher (22%) in non-outbreak stands than in outbreak stands. However, outbreak stands had significantly higher mortality of A. concolor than non-outbreak stands [whether expressed as density (70%) or basal area (m² ha-1) (32%)]. Total stand and A. concolor density and basal area for living and dead trees were significantly lower in the Sierra San Pedro Martir National Park than in southern California. Dead A. concolor comprised >95% of all tree mortality in both outbreak and non-outbreak areas in southern California, which corresponded to a mean 20% basal area loss of A. concolor associated with DFTM feeding injury within the outbreak area. The mean level of defoliation of A. concolor by DFTM was 39%, and 62% of all dead A. concolor were associated with DFTM defoliation. In stands with high levels of defoliation, larval feeding and tree mortality were also noted in Jeffrey pine, Pinus jeffreyi Grev. & Balf. The amount of dead A. concolor basal area associated with the fir engraver, Scolytus ventralis LeConte (Coleoptera: Scolytidae), in non-outbreak stands was 96% greater than in outbreak stands. Using the U.S.D.A. National Insect and Disease Risk Map software, a total of 13,534 ha were predicted to be at risk to basal area loss from future DFTM outbreaks on national forest lands in southern California. Changes in forest management practices and fire suppression policies likely led to an increase in the density and continuity of DFTM's preferred host in southern California and to a southward shift in the historic range of DFTM outbreaks. [ABSTRACT FROM AUTHOR]

Presents information pertaining to the occurrence of the major chromosomal rearrangements upon the T-deoxyribonucleic acid (T-DNA) transformation of Arabidopsis thaliana. Isolation of the flanking DNA regions; Exploitation of the agrobacterium-mediated T-DNA transformation; Reference to the extensive study of the T-DNA transformation process.