scholarly journals Landscape-Level And Stand-Level Factors Play Diverse Roles During Different Periods of Dendroctonus Valens Invasion In North China

Author(s):  
Zhongyi Zhan ◽  
Lili Ren ◽  
Linfeng Yu ◽  
Zhiwen Guo ◽  
Yujie Liu ◽  
...  

Abstract In recent years, the red turpentine beetle (RTB), an invasive pest species, has caused extensive pine mortality in North China. Although some studies have theoretically clarified the interference mechanism of multi-level factors with the development of RTB damage, knowledge about this mechanism from the empirical research is still limited. The aim of this study was to determine whether the primary factors influencing RTB occurrence change during different periods of RTB invasion. Stand-level variables of sample plots were obtained through field investigation and the forest resource survey data including forest stand characteristics, topographic characteristics, and soil properties. Remote sensing classified images were to develop the characteristic variables related to landscape composition and configuration around the sample plots at multiple scales. Generalized linear models (GLMs) and generalized linear mixed models (GLMMs) were used to explore the relative importance of stand-level and landscape-level variables in explaining the severity of RTB damage. Result showed that two stand-level factors, aspect and canopy density, were the best predictors of damage in the early stage of RTB invasion. The landscape-level factor, the proportion of Chinese pine (Pinus tabuliformis) patches, was the main predictor of damage in the middle stage of RTB invasion. The most effective spatial scale at which RTB responded to landscape pattern was 250 m. With the increasing severity of RTB damage, the factors driving RTB invasion have shifted from the stand-level to the landscape-level. This calls for an urgent consideration of multi-scale processes to address the changing disturbance regimes in ecosystem management.

2019 ◽  
Author(s):  
Daniel P. Bebber ◽  
Elsa Field ◽  
Gui Heng ◽  
Peter Mortimer ◽  
Timothy Holmes ◽  
...  

SummaryBiotic invasions threaten global biodiversity and ecosystem function. Such incursions present challenges to agriculture where invasive pest species cause significant production losses require major economic investment to control and can cause significant production losses. Pest Risk Analysis (PRA) is key to prioritizing agricultural biosecurity efforts, but is hampered by incomplete knowledge of current crop pest and pathogen distributions. Here we develop predictive models of current pest distributions and test these models using new observations at sub-national resolution. We apply generalized linear models (GLM) to estimate presence probabilities for 1739 crop pests in the CABI pest distribution database. We test model predictions for 100 unobserved pest occurrences in the People’s Republic of China (PRC), against observations of these pests abstracted from the Chinese literature. This resource has hitherto been omitted from databases on global pest distributions. Finally, we predict occurrences of all unobserved pests globally. Presence probability increases with host presence, presence in neighbouring regions, per capita GDP, and global prevalence. Presence probability decreases with mean distance from coast and known host number per pest. The models were good predictors of pest presence in Provinces of the PRC, with area under the ROC curve (AUC) values of 0.75 – 0.76. Large numbers of currently unobserved, but probably present pests (defined here as unreported pests with a predicted presence probability > 0.75), are predicted in China, India, southern Brazil and some countries of the former USSR. Our results shows that GLMs can predict presences of pseudo-absent pests at sub-national resolution. The Chinese scientific literature has been largely inaccessible to Western academia but contains important information that can support PRA. Prior studies have often assumed that unreported pests in a global distribution database represents a true absence. Our analysis provides a method for quantifying pseudo-absences to enable improved PRA and species distribution modelling.


2020 ◽  
Vol 71 (4) ◽  
pp. 257-272
Author(s):  
Onat Başbay ◽  
Mudar Salimeh ◽  
Eddie John

We review the continuing and extensive spread of Papilio demoleus in south-eastern Turkey and in regions of Turkey and Syria adjacent to the north-eastern Mediterranean. Since the authors documented the arrival of this attractive but potentially destructive papilionid species at coastal areas of Syria in 2019, regular monitoring has confirmed successful overwintering there, as well as in Turkey. As previously indicated, P. demoleus is widely recognized as an invasive pest species in Citrus-growing areas of the world and hence its arrival is of potential economic importance to a region in which citrus is widely grown.


2019 ◽  
Author(s):  
Camiel Doorenweerd ◽  
Michael San Jose ◽  
Norman Barr ◽  
Luc Leblanc ◽  
Daniel Rubinoff

AbstractDistance decay principles predict that species with larger geographic ranges would have greater intraspecific genetic diversity than more restricted species. However, invasive pest species may not follow this prediction, with confounding implications for tracking phenomena including original ranges, invasion pathways and source populations. We sequenced an 815 base-pair section of the COI gene for 441 specimens of Bactrocera correcta, 214 B. zonata and 372 Zeugodacus cucurbitae; three invasive pest fruit fly species with overlapping hostplants. For each species, we explored how many individuals would need to be included in a study to sample the majority of their haplotype diversity. We also tested for phylogeographic signal and used demographic estimators as a proxy for invasion potency. We find contrasting patterns of haplotype diversity amongst the species, where B. zonata has the highest diversity but most haplotypes were represented by singletons; B. correcta has ∼7 dominant haplotypes more evenly distributed; Z. cucurbitae has a single dominant haplotype with closely related singletons in a ‘star-shape’ surrounding it. We discuss how these differing patterns relate to their invasion histories. None of the species showed meaningful phylogeographic patterns, possibly due to gene-flow between areas across their distributions, obscuring or eliminating substructuring.


2019 ◽  
Vol 102 (3) ◽  
pp. 480
Author(s):  
Robert W. Jones ◽  
Carlos Illescas-Riquelme ◽  
Víctor López-Martínez ◽  
Néstor Bautista-Martínez ◽  
Charles W. O'Brien

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9564
Author(s):  
Somasundhari Shanmuganandam ◽  
Yiheng Hu ◽  
Tanja Strive ◽  
Benjamin Schwessinger ◽  
Robyn N. Hall

Background European brown hares (Lepus europaeus) and European rabbits (Oryctolagus cuniculus) are invasive pest species in Australia, with rabbits having a substantially larger environmental impact than hares. As their spatial distribution in Australia partially overlaps, we conducted a comparative microbiome study to determine how the composition of gastrointestinal microbiota varies between these species, since this may indicate species differences in diet, physiology, and other internal and external factors. Methods We analysed the faecal microbiome of nine wild hares and twelve wild rabbits from a sympatric periurban reserve in Canberra, Australia, using a 16S rRNA amplicon-based sequencing approach. Additionally, we compared the concordance between results from Illumina and Nanopore sequencing platforms. Results We identified significantly more variation in faecal microbiome composition between individual rabbits compared to hares, despite both species occupying a similar habitat. The faecal microbiome in both species was dominated by the phyla Firmicutes and Bacteroidetes, typical of many vertebrates. Many phyla, including Actinobacteria, Proteobacteria and Patescibacteria, were shared between rabbits and hares. In contrast, bacteria from phylum Verrucomicrobia were present only in rabbits, while phyla Lentisphaerae and Synergistetes were represented only in hares. We did not identify phylum Spirochaetes in Australian hares; this phylum was previously shown to be present at high relative abundance in European hare faecal samples. These differences in the composition of faecal microbiota may be indicative of less discriminate foraging behaviour in rabbits, which in turn may enable them to adapt quicker to new environments, and may reflect the severe environmental impacts that this species has in Australia.


2003 ◽  
Vol 4 (1) ◽  
pp. 19
Author(s):  
Gareth Hughes

The maximum pest limit (MPL) concept was developed as a practical method of implementing quarantine security measures against the import of invasive pest species of plants. The MPL itself is simply a threshold upper limit, above which the pest species in question is deemed capable of establishing a population if imported in a consignment of fruit or vegetables. This limit depends on various biological and ecological characteristics of the pest species in question. Important aspects of implementation relate to how treatment and sampling may be combined to reduce the probability that the MPL will be exceeded. If a specified level of treatment efficacy is required (for example, probit nine level), then choice of an appropriate sample size becomes the main problem for regulatory authorities seeking to maintain quarantine security. Accepted for publication 16 December 2002. Published 13 November 2003.


2010 ◽  
Vol 103 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Petr Starý ◽  
Ehsan Rakhshani ◽  
Jan Havelka ◽  
Željko Tomanović ◽  
Nikolas G. Kavallieratos ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document