Potential Global Distribution of Invasive Alien Species, Anthonomus grandis Boheman, under Current and Future Climate Using Optimal MaxEnt Model

Abstract

The boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), is an invasive alien species that can damage cotton plants and cause huge economic losses in the cotton industry. Currently, A. grandis is mainly distributed in the American continent. However, few studies have indicated the distribution and modification of its suitable global habitats after undergoing climate change. Based on the 339 distribution records of A. grandis and eight bioclimatic variables, we used the optimal MaxEnt model to predict the potential global distribution of A. grandis under the current (1970–2000) and future climatic scenarios (SSP5-8.5). The annual mean temperature (bio1) and isothermality (bio3) were the two most important bioclimatic variables, which indicates that the survival of A. grandis is extremely sensitive to temperature fluctuations. Under the current scenario, the highly suitable habitats were mainly distributed in America (the USA, Mexico, Brazil, Argentina, Paraguay, and Uruguay), Africa (South Africa, Ethiopia, and Mozambique), Asia (Pakistan, India, Thailand, Burma, and China), and Oceania (Australia). In future scenarios (SSP5-8.5), the potential suitable global habitats reached the highest level in America, Africa, Asia, and Oceania in the 2090s. Our study provides a meaningful reference for researchers, quarantine officers, and governments to devise suitable management control strategies for A. grandis.

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

“…The performance of the optimized MaxEnt model was excellent in this research, which indicates that the prediction results have high reliability [ 53 ]. The MaxEnt model established based on the default parameter conditions is not suitable and other setting parameters should be selected for this model [ 15 , 40 , 42 , 43 ]. After the optimization, the model parameters were set as FC = LQHP, β = 1.5, AUC diff = 0.018, and ΔAICc = 0, which indicates that the optimized model has high reliability.…”

“…“Create response curves” and “Do Jackknife to measure variable importance” were selected to analyze the importance of environmental factors. We used the “ENMeval” package in R software to calculate the values of β and FC [ 15 , 40 , 43 , 54 ]. This model has five features including linear (L), quadratic (Q), hinge (H), product (P), and threshold (T).…”

“…The AUC value was used to test the accuracy of model prediction [ 15 , 55 , 56 ]. Generally, a larger AUC value indicates better prediction.…”

“…Climate change has affected the natural range, abundance, and dispersal of insect populations worldwide [ 10 , 11 , 12 ]. Global warming is particularly affecting the growth, development, and distribution of insects, causing insects to expand their distribution areas to higher latitudes and elevations to cope with global warming [ 13 , 14 , 15 ]. As ectotherms, most insects are very sensitive to changes in the temperature of the external environment [ 16 , 17 ].…”

“…In addition, the MaxEnt model also had good prediction ability when a small amount of species distribution data were available [ 33 , 34 , 35 , 37 , 38 , 39 , 40 , 41 ]. However, previous studies have shown that the default parameters of the MaxEnt model may not be optimal for predicting species distribution [ 15 , 40 , 42 , 43 ]. Hence, to avoid overfitting of the MaxEnt model when predicting potential species distribution, which leads to a decrease in species transfer ability, optimizing the parameters of the MaxEnt model is necessary to balance its fitting degree and complexity of the MaxEnt model [ 40 , 44 ].…”