Hypervolume Niche Dynamics and Global Invasion Risk of Phenacoccus solenopsis under Climate Change.

As a globally invasive quarantine pest, the cotton mealybug, Phenacoccus solenopsis, is spreading rapidly, posing serious threats against agricultural and forestry production and biosecurity. In recent years, the niche conservatism hypothesis has been widely debated, which is particularly evident in invasive biology research. Identifying the niche dynamics of P. solenopsis, as well as assessing its global invasion risk, is of both theoretical and practical importance. Based on 462 occurrence points and 19 bioclimatic variables, we used n-dimensional hypervolume analysis to quantify the multidimensional climatic niche of this pest in both its native and invasive ranges. We examined niche conservatism and further optimized the MaxEnt model parameters to predict the global invasion risk of P. solenopsis under both current and future climate conditions. Our findings indicated that the niche hypervolume of this pest in invasive ranges was significantly larger than that in its native ranges, with 99.45% of the niche differentiation contributed by niche expansion, with the remaining less than 1% explained by space replacement. Niche expansion was most evident in Oceania and Eurasia. The area under the receiver operating characteristic curve (0.83) and true skill statistic (0.62) indicated the model's robust performance. The areas of suitable habitats for P. solenopsis are increasing significantly and the northward spread is obvious in future climate change scenarios. North Africa, northern China, Mediterranean regions, and northern Europe had an increased invasion risk of P. solenopsis. This study provided scientific support for the early warning and control of P. solenopsis.

Multidimensional climatic niche conservatism and invasion risk of Phenacoccus solenopsis.

The cotton mealybug Phenacoccus solenopsis, a globally invasive insect, is listed as a national quarantine pest in agriculture and forestry, which seriously threatens biological safety of China. Niche conservatism is a key assumption of species distribution model. An evaluation of the applicability of using ecological niche models to assess the invasion risk of cotton mealybug, and further optimizing model complexity, are of both theoretical and practical significance. Based on 706 occurrence records and key bioclimatic variables, we used n-dimensional hypervolume niche analysis method to quantify the climatic niche hypervolumes of this pest in both native and invasive sites, and further tested the niche conservatism hypothesis. MaxEnt model parameters were optimized to predict the invasion risk of the mealybug under current and future climate scenarios in China. The results showed that four climatic variables (annual mean temperature, mean temperature of wettest quarter, mean temperature of warmest quarter, and precipitation of driest quarter) were the key climate factors affecting the distribution of cotton mealybug. Compared with native climatic niche (hypervolume volume, HV=40.43), the niche hypervolume of cotton mealybug in the invasive areas was significantly reduced (HV=6.04). Niche contraction (the net differences between the amount of space enclosed by each hypervolume was 0.84) explained 98.8% of niche differentiation, whereas niche shift (the replacement of space between hypervolumes was 0.01) contributed less than 2%. The direction of climatic niche contraction of the pest in different invasive areas was not exactly consistent. The default parameters of MaxEnt model were unreliable (ΔAICc=14.27), and the optimal parameter combination was obtained as follows: feature combination was linear-quadratic-hinge-product and regularization multiplier was 0.5. The most suitable habitats of cotton mealybug were concentrated in the south of Huaihe River-Qinling Mountains line, and the north-central provinces contained a large area of low suitable habitat. The increase of suitable habitat was not significant at the end of 21 century (SSP1-2.6: 1.7%, SSP5-8.5: 0.7%). The multidimensional climatic niche of P. solenopsis was highly conservative. The species distribution model was suitable for analyzing its invasion risk. The northward spread was obvious, and climate change had less impact on the pest.

Potentially Suitable Geographical Area for Monochamus alternatus under Current and Future Climatic Scenarios Based on Optimized MaxEnt Model.

M. alternatus is considered to be an important and effective insect vector for the spread of the important international forest quarantine pest, Bursaphelenchus xylophilus. The precise determination of potential suitable areas of M. alternatus is essential to monitor, prevent, and control M. alternatus worldwide. According to the distribution points and climatic variables, the optimized MaxEnt model and ArcGIS were used to predict the current and future potentially suitable areas of M. alternatus worldwide. The optimized MaxEnt model parameters were set as feature combination (FC) = LQHP and ß = 1.5, which were determined by the values of AUCdiff, OR10, and ΔAICc. Bio2, Bio6, Bio10, Bio12, and Bio14 were the dominant bioclimatic variables affecting the distribution of M. alternatus. Under the current climate conditions, the potentially suitable habitats of M. alternatus were distributed across all continents except Antarctica, accounting for 4.17% of the Earth's total land area. Under future climate scenarios, the potentially suitable habitats of M. alternatus increased significantly, spreading to a global scale. The results of this study could provide a theoretical basis for the risk analysis of the global distribution and dispersal of M. alternatus as well as the precise monitoring and prevention of this beetle.

Historical range, extirpation and prospects for reintroduction of saigas in China.

An assessment of historical distribution patterns and potential reintroduction sites is important for reducing the risk of reintroduction failure of endangered species. The saiga antelope, Saiga tatarica, was extirpated in the mid-20th century in China. A captive population was established in the Wuwei Endangered Wildlife Breeding Centre (WEWBC) in the 1980s. Reintroduction is planned, but so far, no action has been taken. In this study, we delineated the historical distribution and potential reintroduction areas of saigas in China, using a literature review, interviews and predictive modelling. Results suggest that most of the seasonally suitable areas are non-overlapping, and China may have been a peripheral part of the main saiga range. WEWBC is not an ideal reintroduction site due to its low habitat suitability. Furthermore, we infer that two different movement patterns existed historically (regular migration and nomadic wandering). Our results demonstrate the challenges of restoring a free-ranging, self-sustaining saiga population in China. We recommend the setting up of additional breeding centres in protected areas within the potential saiga range in Xinjiang, and the development of a national action plan to provide a framework for the future recovery of the species.

The adder (Vipera berus) in Southern Altay Mountains: population characteristics, distribution, morphology and phylogenetic position.

As the most widely distributed snake in Eurasia, the adder (Vipera berus) has been extensively investigated in Europe but poorly understood in Asia. The Southern Altay Mountains represent the adder's southern distribution limit in Central Asia, whereas its population status has never been assessed. We conducted, for the first time, field surveys for the adder at two areas of Southern Altay Mountains using a combination of line transects and random searches. We also described the morphological characteristics of the collected specimens and conducted analyses of external morphology and molecular phylogeny. The results showed that the adder distributed in both survey sites and we recorded a total of 34 sightings. In Kanas river valley, the estimated encounter rate over a total of 137 km transects was 0.15 ± 0.05 sightings/km. The occurrence of melanism was only 17%. The small size was typical for the adders in Southern Altay Mountains in contrast to other geographic populations of the nominate subspecies. A phylogenetic tree obtained by Bayesian Inference based on DNA sequences of the mitochondrial cytochrome b (1,023 bp) grouped them within the Northern clade of the species but failed to separate them from the subspecies V. b. sachalinensis. Our discovery extends the distribution range of V. berus and provides a basis for further researches. We discuss the hypothesis that the adder expands its distribution border to the southwest along the mountains' elevation gradient, but the population abundance declines gradually due to a drying climate.

Perception, Price and Preference: Consumption and Protection of Wild Animals Used in Traditional Medicine.

A wide array of wildlife species, including many animals, are used in traditional medicines across many medicinal systems, including in Traditional Chinese Medicine (TCM). Due to over-exploitation and habitat loss, the populations of many animals commonly used in TCM have declined and are unable to meet market demand. A number of measures have been taken to try to reduce the impact that this large and growing market for TCM may have on wild animal species. Consumer preferences and behavior are known to play an important role in the consumption and protection of wild animals used in traditional medicine, and thus are likely to be an important factor in the success of many of these mechanisms--particularly given the significant percentage of TCMs that are over-the-counter products (access to which is not mediated by practitioners). In this study we conducted questionnaires and designed stated preference experiments embodying different simulation scenarios using a random sample of the population in Beijing to elicit individuals' knowledge, perceptions and preferences toward wild or farmed animal materials and their substitutes used in traditional Chinese medicine. We found that respondents had a stated preference for wild materials over farm-raised and other alternatives because they believe that the effectiveness of wild-sourced materials is more credible than that of other sources. However, we also found that, although respondents used TCM products, they had a poor understanding of the function or composition of either traditional Chinese medicines or proprietary Chinese medicines (PCM), and paid little attention to the composition of products when making purchasing decisions. Furthermore, awareness of the need for species protection, or "conservation consciousness" was found to play an important role in willingness to accept substitutions for wild animal materials, while traditional animal medicinal materials (TAMs) derived from well-known endangered species, such as bear bile and tiger bone, show relatively higher substitutability. These results suggest that there is still hope for conservation measures which seek to promote a transition to farmed animal, plant and synthetic ingredients and provide clear directions for future social marketing, education and engagement efforts.

Identification of ungulates used in a traditional Chinese medicine with DNA barcoding technology.

Horns of Saiga antelope (Saiga tatarica) have always been an ingredient of "Lingyangjiao", a traditional Chinese medicine (TCM). Persistent hunting for Saiga antelope has already threatened the survival of critical endangered populations in wild. To control the growing pressure, CITES and Chinese government have legislated for monitoring the trade of Saiga horns. However, similar ungulate horns are difficult to identify by their morphological characteristics, which has impeded the law enforcement. Besides Saiga antelope, other seven ungulate species which have similar horns are also sold and marked as "Lingyangjiao" in TCM markets to offset shortage of Saiga antelope horns. Such species are Gazella subgutturosa, Pantholops hodgsonii, Procapra picticaudata, Procapra gutturosa, Procapra przewalskii, Capra hircus, and Ovis aries. Our study aimed at implementing DNA barcoding technology to diagnose Saiga horns and the substitutes. We successfully extracted genomic DNA from horn samples. We recovered COI sequences of 644 bp with specific primers and 349 bp with nested PCR primers designed for degraded horn samples. The mean interspecific genetic distance of data set of the 644-bp full barcodes and the 349-bp mini-barcodes was 14.96% and 15.38%, respectively, and the mean intraspecific distance was 0.24% and 0.20%, respectively. Each species formed independent clades in neighbor-joining (NJ) phylogenetic tree of the two data sets with >99% supporting values, except P. gutturosa and P. przewalskii. The deep genetic distances gap and clear species clades in NJ tree of either full barcodes or mini-barcodes suggest that barcoding technology is an effective tool to diagnose Saiga horns and their substitutes. Barcoding diagnosis protocol developed here will simplify diagnosis of "Lingyangjiao" species and will facilitate conservation of endangered ungulates involved in TCM "Lingyangjiao" markets, especially the Saiga antelope.