The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), which is native to tropical Africa, has invaded more than 100 countries and constitutes a risk to the citrus sector. Studying its potential geographical distribution (PGD) in the context of global climate change is important for prevention and control efforts worldwide. Therefore, we used the CLIMEX model to project and assess the risk of global invasion by C. capitata under current (1981–2010) and future (2040–2059) climates. In the prevailing climatic conditions, the area of PGD for C. capitata was approximately 664.8 × 105 km2 and was concentrated in South America, southern Africa, southern North America, eastern Asia, and southern Europe. Under future climate conditions, the area of PGD for C. capitata is projected to decrease to approximately 544.1 × 105 km2 and shift to higher latitudes. Cold stress was shown to affect distribution at high latitudes, and heat stress was the main factor affecting distribution under current and future climates. According to the predicted results, countries with highly suitable habitats for C. capitata that have not yet been invaded, such as China, Myanmar, and Vietnam, must strengthen quarantine measures to prevent the introduction of this pest.
The southern armyworm (Spodoptera eridania), a polyphagous crop pest native to tropical America, has been found in Africa (2016) and India (2019), causing defoliation and damage to the reproductive structures of cassava, soybean, and tomato. The damage caused by this pest to crop systems has raised concerns regarding its potential risks. Therefore, we predicted the potential geographical distribution of S. eridania under climate change conditions using 19 bioclimatic variables based on an optimized MaxEnt model. The results showed that annual precipitation (bio12), mean temperature of the warmest quarter (bio10), and precipitation of the driest month (bio14) were important bioclimatic variables influencing the potential distribution. The prediction showed that the suitable habitat area was approximately 3426.43 × 104 km2, mainly concentrated in southern North America, South America, western Europe, central Africa, southern Asia, and eastern Oceania. In response to global climate change, suitable habitats for S. eridania will expand and shift to higher latitudes in the future, especially under the SSP5-8.5 scenario. Because of the current devastating effects on crop production, countries without S. eridania invasion, such as the European Union, Southeast Asian countries, and Australia, need to strengthen phytosanitary measures at border ports to prevent the introduction of this pest.
Solanum viarum has become extensively invasive owing to international trade, climate change, and land–use change. As it is classified as a quarantine weed by countries such as the U.S. and Mexico, it is critical to understand the prevailing historical dispersal, ecological niche dynamics, and distribution patterns. We reconstructed the historical invasion countries and analyzed the ecological niche shift of S. viarum. Using MaxEnt based on the conservativeness of ecological niches, we studied variations in the potential geographical distributions (PGDs) of S. viarum in ecosystems and variations in suitability probabilities along latitudinal gradients. The invasion history in six continents involved three phases: lag (before 1980), spread (1980–2010), and equilibrium (2010–present). The ecological niche remains conserved. The area of S. viarum PGDs had increased by 259 km2; the PGDs will expand to reach a maximum in the 2050s, SSP5–8.5. The PGDs of S. viarum will migrate to higher latitudes under the same future climate scenarios. The latitudes subject to high threats range from 20° to 30° in forest and cropland ecosystems, 15.5° to 27.5° (northern hemisphere) and 33.1° to 42.8° (southern hemisphere) in grassland ecosystems, and 20° to 35° in urban ecosystems. Global change has led to an increased threat of S. viarum at high latitudes. These findings provide a theoretical basis to monitor and control S. viarum.
Elodea nuttallii is an ornamental macrophyte native to North America that has been introduced to Europe and Asia, and having been established, has had detrimental effects on local aquatic ecosystems. In this study, we developed an optimized MaxEnt model to predict the global potential habitat suitability for E. nuttallii under the influence of climate change. The model incorporated 20 relevant impact factors and occurrence record data for E. nuttallii. The results reveal that under current and future climate scenarios, potentially suitable habitats for E. nuttallii can be found on six assessed continents, mainly in Western Europe, western and eastern North America, southeastern Asia, southeastern Oceania, and scattered coastal areas in South America and Africa. Moreover, temperature and precipitation were identified as factors having significant effects on the distribution of E. nuttallii. In the future, the area of habitats potentially suitable for E. nuttallii is predicted to expand, particularly towards higher latitudes.
Spodoptera frugiperda, the fall armyworm (FAW), is a widespread and polyphagous crop pest, causing serious crop yield losses worldwide, especially maize and other cereals. Biological control (biocontrol) is considered as the generally safer and more environmentally benign strategies compared to chemical insecticides in managing FAW. Chelonus insularis and Eiphosoma laphygmae are two promising classical biocontrol parasitoids against FAW. However, the optimal control areas for FAW with the two parasitoids in its invasive ranges remain unclear. This study is first time to integrate species distribution models and hotspot analysis to estimate the optimal areas for controlling FAW with these two parasitoids worldwide. Key variables influencing distribution include human influence index, temperature, and precipitation. The optimal control areas of FAW with C. insularis and E. laphygmae are in most of sub-Saharan Africa, Mediterranean regions, eastern, southern, and southeastern Asia, and Oceania. These areas are expected to expand to high-latitude areas under changing climatic conditions. Niche comparisons indicated that the FAW and C. insularis niches were closely aligned. Chelonus insularis and E. laphygmae are potentially effective against FAW in Africa, Asia, and Oceania. Our findings offer insights into the strategic use of the two parasitoids against FAW worldwide.