Aim
To synthesize the species distribution modelling (SDM) literature to inform which variables have been used in MaxEnt models for different taxa and to quantify how frequently they have been important for species’ distributions.

Location
Global.

Methods
We conducted a quantitative synthesis analysing the contribution of over 400 distinct environmental variables to 2040 MaxEnt SDMs for nearly 1900 species representing over 300 families. Environmental variables were grouped into 24 related factors and results were analysed by examining the frequency with which variables were found to be most important, the mean contribution of each variable (at various taxonomic levels), and using TrueSkill™, a Bayesian skill rating system.

Results
Precipitation, temperature, bathymetry, distance to water and habitat patch characteristics were the most important variables overall. Precipitation and temperature were analysed most frequently and one of these variables was often the most important predictor in the model (nearly 80% of models, when tested). Notably, distance to water was the most important variable in the highest proportion of models in which it was tested (42% of 225 models). For terrestrial species, precipitation, temperature and distance to water had the highest overall contributions, whereas for aquatic species, bathymetry, precipitation and temperature were most important.

Main conclusions
Over all MaxEnt models published, the ability to discriminate occurrence from reference sites was high (average AUC = 0.92). Much of this discriminatory ability was due to temperature and precipitation variables. Further, variability (temperature) and extremes (minimum precipitation) were the most predictive. More generally, the most commonly tested variables were not always the most predictive, with, for instance, ‘distance to water’ infrequently tested, but found to be very important when it was. Thus, the results from this study summarize the MaxEnt SDM literature, and can aid in variable selection by identifying underutilized, but potentially important variables, which could be incorporated in future modelling efforts.

A quantitative synthesis of the importance of variables used in MaxEnt species distribution models

China is the world's fourth-largest country in terms of landmass. Its highly diverse biogeography presents opportunities for many invasive alien insects. However, physical and climate barriers sometimes prevent locally occurring species from spreading. China has 560 confirmed invasive alien species; 125 are insect pests, and 92 of these damage the agricultural ecosystem. The estimated annual economic loss due to alien invasive species is more than $18.9 billion. The most harmful invasive insects exhibit some common characteristics, such as high reproduction, competitive dominance, and high tolerance, and benefit from mutualist facilitation interactions. Regional cropping system structure adjustments have resulted in mono-agricultural ecosystems in cotton and other staple crops, providing opportunities for monophagous insect pests. Furthermore, human dietary shifts to fruits and vegetables and smallholder-based farming systems result in highly diverse agricultural ecosystems, which provide resource opportunities for polyphagous insects. Multiple cropping and widespread use of greenhouses provide continuous food and winter habitats for insect pests, greatly extending their geographic range. The current management system consists of early-warning, monitoring, eradication, and spread blocking technologies. This review provides valuable new synthetic information on integrated management practices based mainly on biological control for a number of invasive species. We encourage farmers and extension workers to be more involved in training and further research for novel protection methods that takes into consideration end users' needs.

Invasion and Management of Agricultural Alien Insects in China.

Accurate assessment of insect pest establishment risk is needed by national plant protection organizations to negotiate international trade of horticultural commodities that can potentially carry the pests and result in inadvertent introductions in the importing countries. We used mechanistic and correlative niche models to quantify and map the global patterns of the potential for establishment of codling moth (Cydia pomonella L.), a major pest of apples, peaches, pears, and other pome and stone fruits, and a quarantine pest in countries where it currently does not occur. The mechanistic model CLIMEX was calibrated using species-specific physiological tolerance thresholds, whereas the correlative model MaxEnt used species occurrences and climatic spatial data. Projected potential distribution from both models conformed well to the current known distribution of codling moth. None of the models predicted suitable environmental conditions in countries located between 20°N and 20°S potentially because of shorter photoperiod, and lack of chilling requirement (<60 d at ≤10°C) in these areas for codling moth to break diapause. Models predicted suitable conditions in South Korea and Japan where codling moth currently does not occur but where its preferred host species (i.e., apple) is present. Average annual temperature and latitude were the main environmental variables associated with codling moth distribution at global level. The predictive models developed in this study present the global risk of establishment of codling moth, and can be used for monitoring potential introductions of codling moth in different countries and by policy makers and trade negotiators in making science-based decisions.

https://bioone.org/journals/journal-of-economic-entomology/volume-108/issue-4/tov166/Assessing-the-Global-Risk-of-Establishment-of-Cydia-pomonella-Lepidoptera/10.1093/jee/tov166.pdf

Assessing the Global Risk of Establishment of Cydia pomonella (Lepidoptera: Tortricidae) using CLIMEX and MaxEnt Niche Models.

Insect pests pose a great threat to global food security Improved methods for assessment of the risk of pest establishment are needed to enhance informed decision-making, to develop cost-effective pest management strategies, and to design quarantine policies for preventing the spread of pests We evaluated the capabilities of a correlative and a process-based mechanistic niche model, and their combination, to assess the risk of pest establishment The correlative model MaxEnt and the process-based mechanistic model CLIMEX were used to assess the risk of establishment of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae) in California We integrated R indifferens occurrence records and spatial environmental variables using MaxEnt to assess the potential risk of establishment of this pest The CLIMEX model was developed using eco-physiological tolerances of R indifferens The predictive performance of the MaxEnt model improved by including the host species' distribution and Ecoclimatic Index generated using the CLIMEX model The best model predicted no risk for R indifferens establishment in the Central Valley around the areas where sweet cherries are produced in California Most of the high to very high risk areas for R indifferens were predicted in northern parts of California and the Sierra Nevada Mountains, where the fly exists on its native host, bitter cherry [Prunus emarginata (Douglas) Eaton] Precipitation of driest quarter, degree days with average temperatures ≥83°C, degree days with average temperatures ≤5°C, and mean diurnal range in temperature were the strongest predictors of R indifferens distribution in western North America We showed that the predictive power of correlative niche models can be improved by including outputs from the process-based mechanistic niche models Overall results suggest that R indifferens is unlikely to establish in the commercial cherry-growing areas in the Central Valley of California, largely because heat stress is too high and chilling requirement in those areas is not met

https://esajournals.onlinelibrary.wiley.com/doi/epdf/10.1890/ES14-00050.1

Evaluating correlative and mechanistic niche models for assessing the risk of pest establishment

Most agricultural pests are poikilothermic species expected to respond to climate change. Currently, they are a tremendous burden because of the high losses they inflict on crops and livestock. Smallholder farmers in developing countries of Africa are likely to suffer more under these changes than farmers in the developed world because more severe climatic changes are projected in these areas. African countries further have a lower ability to cope with impacts of climate change through the lack of suitable adapted management strategies and financial constraints. In this study we are predicting current and future habitat suitability under changing climatic conditions for Tuta absoluta, Ceratitis cosyra, and Bactrocera invadens, three important insect pests that are common across some parts of Africa and responsible for immense agricultural losses. We use presence records from different sources and bioclimatic variables to predict their habitat suitability using the maximum entropy modelling approach. We find that habitat suitability for B. invadens, C. cosyra and T. absoluta is partially increasing across the continent, especially in those areas already overlapping with or close to most suitable sites under current climate conditions. Assuming a habitat suitability at three different threshold levels we assessed where each species is likely to be present under future climatic conditions and if this is likely to have an impact on productive agricultural areas. Our results can be used by African policy makers, extensionists and farmers for agricultural adaptation measures to cope with the impacts of climate change.

Future Risks of Pest Species under Changing Climatic Conditions.

There have been relatively few attempts to model the distributions of the fruit flies Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), and Ceratitis rosa Karsch in China, but the geographic distributions of these species are of considerable concern in terms of biosecurity. In this study, two different modeling methods (genetic algorithm for rule-set prediction [GARP] and maximum entropy species distribution modeling [Maxent]) were used to predict the potential distributions of these three fly species in China, by using distribution records and a set of environmental predictor variables. The results showed that Maxent performed well, compared with modeling by GARP, at each test threshold. For all three species, the results predicted by Maxent agreed with the observed distributions in Africa and in other parts of the world. In China, C. capitata seems to have the highest number of favorable habitat areas, relative to C. cosyra and C. rosa, i.e., Yunnan, Guizhou, Guangxi, Guangdong, Hainan, Fujian, Sichuan and Chongqing, whereas C. cosyra has the smallest range of suitable areas, i.e., Yunnan, some parts of Hainan and Sichuan. The suitable areas for C. rosa are mainly restricted to Yunnan, Hainan, southern Guangdong, and a few areas of Sichuan. The indications are that on the whole, Southwest and South China are the areas with the highest risk for establishment from these three fly species. Jackknife tests reveal that environmental variables associated with temperature have the strongest influence on the potential distributions of all three species relative to other variables.

https://bioone.org/journals/journal-of-economic-entomology/volume-102/issue-5/029.102.0508/Potential-Geographical-Distributions-of-the-Fruit-Flies-Ceratitis-capitata-Ceratitis/10.1603/029.102.0508.pdf

Potential geographical distributions of the fruit flies Ceratitis capitata, Ceratitis cosyra, and Ceratitis rosa in China.

Soft-lock drawing of super-aligned carbon nanotube bundles for nanometre electrical contacts

Exotic fruit flies (Ceratitis spp.) are often serious agricultural pests. Here, we used pathway analysis and Monte Carlo simulations to assess the risk of introduction of Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), and Ceratitis rosa Karsch, into southern China with fruit consignments and incoming travelers. Historical data, expert opinions, relevant literature, and archives were used to set appropriate parameters in the pathway analysis. Based on the ongoing quarantine/ inspection strategies of China, as well as the interception records, we estimated the annual number of each fruit fly species entering Guangdong province undetected with commercially imported fruit, and the associated risk. We also estimated the gross number of pests arriving at Guangdong ports with incoming travelers and the associated risk. Sensitivity analysis also was performed to test the impact of parameter changes and to assess how the risk could be reduced. Results showed that the risk of introduction of the three fruit fly species into southern China with fruit consignments, which are mostly transported by ship, exists but is relatively low. In contrast, the risk of introduction with incoming travelers is high and hence deserves intensive attention. Sensitivity analysis indicated that either ensuring all shipments meet current phytosanitary requirements or increasing the proportion of fruit imports sampled for inspection could substantially reduce the risk associated with commercial imports. Sensitivity analysis also provided justification for banning importation of fresh fruit by international travelers. Thus, inspection and quarantine in conjunction with intensive detection were important mitigation measures to reduce the risk of Ceratitis spp. introduced into China.

https://bioone.org/journals/journal-of-economic-entomology/volume-103/issue-4/EC09217/Risk-of-Introducing-Exotic-Fruit-Flies-Ceratitis-capitata-Ceratitis-cosyra/10.1603/EC09217.pdf

Risk of introducing exotic fruit flies, Ceratitis capitata, Ceratitis cosyra, and Ceratitis rosa (Diptera: Tephritidae), into southern China.

Ultralong carbon nanotubes (CNTs) are in huge demand in many cutting-edge fields due to their macroscale lengths, perfect structures, and extraordinary properties, while their practical application is limited by the difficulties in their mass production. Herein, we report the synthesis of ultralong CNTs with a dramatically increased yield by a simple but efficient substrate interception and direction strategy (SIDS), which couples the advantages of floating-catalyst chemical vapor deposition with the flying-kite-like growth mechanism of ultralong CNTs. The SIDS-assisted approach prominently improves the catalyst utilization and significantly increases the yield. The areal density of the ultralong CNT arrays with length of over 1 cm reached a record-breaking value of ∼6700 CNTs mm-1, which is 2-3 orders of magnitude higher than the previously reported values obtained by traditional methods. The SIDS provides a solution for synthesizing high-quality ultralong CNTs with high yields, laying the foundation for their mass production.

Synthesis of Ultralong Carbon Nanotubes with Ultrahigh Yields.

/pdf/publisher-correction-soft-lock-drawing-of-super-aligned-1bsf0g8p.pdf

Baini Li

Papers

Potential geographical distributions of the fruit flies Ceratitis capitata, Ceratitis cosyra, and Ceratitis rosa in China.

Soft-lock drawing of super-aligned carbon nanotube bundles for nanometre electrical contacts

Risk of introducing exotic fruit flies, Ceratitis capitata, Ceratitis cosyra, and Ceratitis rosa (Diptera: Tephritidae), into southern China.

Synthesis of Ultralong Carbon Nanotubes with Ultrahigh Yields.

Publisher Correction: Soft-lock drawing of super-aligned carbon nanotube bundles for nanometre electrical contacts