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 β = 1.5, which were determined by the values of AUC_diff, 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.

Understanding the distribution patterns and underlying maintenance mechanisms of insect species is a core issue in the field of insect ecology. However, research gaps remain regarding the environmental factors that determine the distribution of insect species along altitudinal gradients in Guandi Mountain, China. Here, we explored these determinants based on the distribution pattern and diversity of insect species from 1600 m to 2800 m in the Guandi Mountain, which covers all typical vegetation ecosystems in this area. Our results showed that the insect community showed certain differentiation characteristics with the altitude gradient. The results of RDA and correlation analysis also support the above speculation and indicate that soil physicochemical properties are closely related to the distribution and diversity of insect taxa orders along the altitude gradient. In addition, the soil temperature showed an obvious decreasing trend with increasing altitude, and temperature was also the most significant environmental factor affecting the insect community structure and diversity on the altitude gradient. These findings provide a reference for exploring the maintenance mechanisms affecting the structure, distribution pattern, and diversity of insect communities in mountain ecosystems, and the effects of global warming on insect communities.

Outbreaks of pine wilt disease (PWD, caused by the pinewood nematode Bursaphelenchus xylophilus), have caused mass mortality of the genus Pinus in Eurasia. Climate change may greatly influence the distribution and population dynamics of longhorn beetles of the genus Monochamus (the main vector of B. xylophilus), the survival and development of B. xylophilus, and the resistance of pines. The aim of this study was to investigate the effect of climatic variables associated with extensive PWD outbreaks in Masson pine (Pinus massoniana Lamb.) forest across the eastern part of the Three Gorges Reservoir region. Since its discovery in 2006, the most serious PWD outbreak occurred from 2014 to 2018; the most striking characteristic of this outbreak is the consistent increase in Masson pine mortality and extent of the affected areas. Moreover, 28 out of 46 PWD biological relevant climatic variables were selected and used for redundancy analysis. The ordination biplots reflect the complicated quantitative relationship between the PWD epidemic variables and the biologically relevant climatic variables of temperature, precipitation, relative humidity, and wind speed. The results will be useful for understanding the role climatic variables play in PWD outbreaks, for predicting the spread and pattern of PWD outbreaks, and for the advance preparation of management strategies with the purpose of preventing future PWD outbreaks.

Monochamus saltuarius Gebler was first identified as a new vector of pine wilt disease in Northeast China in 2018, and monitoring of M. saltuarius has become a key strategy to prevent and control the disease in this region. However, the potential distributions of M. saltuarius in China are unclear. In this study, we clarified bioclimatic environmental variables affecting the distribution of M. saltuarius, predicted the geographically suitable habitats of M. saltuarius in current and future climate conditions, and determined changes in the spatial pattern of a suitable distribution area of M. saltuarius under current and future climate conditions. This is the first study to use the optimized maximum entropy model and ArcGIS to accurately predict suitable geographical areas for M. saltuarius based on different climatic conditions in China. and the average area under the receiver operating characteristic curve reached 0.954 ± 0.0024. Of the 32 bioclimatic variables, temperature seasonality, precipitation of wettest month, precipitation seasonality, maximum temperature of the warmest month, and elevation played significant roles in determining the potential distribution of M. saltuarius, with contribution rates to the model of 32.1, 31.8, 11.5, 7.5, and 6.5%, respectively. Under the current climate scenario, the predicted suitable areas for M. saltuarius were mainly at latitudes north of 33° in China, and larger suitable areas were mainly distributed in Northeast China and North China, with areas of 87.04 × 10⁴ and 73.15 × 10⁴ km², respectively. Using future climatic scenarios SSP126 and SSP585, the predicted suitable areas of M. saltuarius will continue to expand from that of 2040, 2070, and 2100, with highly and moderately suitable areas showing larger increasing trends but low suitable distribution areas will decrease to varying degrees. The potential suitable areas of M. saltuarius may increase greatly in Northwest, Central, and Eastern China. This study provides important scientific theoretical knowledge for effectively controlling and preventing M. saltuarius and pine wilt disease in northern China.

Nutrients consumed during the adult stage are a key factor affecting the growth, development, and reproduction of insect offspring and thus could play an important role in insect population research. However, there is absence of conclusive evidence regarding the direct effects of parental (F₀) nutritional status on offspring (F₁) fitness in insects. Carposina sasakii Matsumura is a serious, widespread fruit-boring pest that negatively impacts orchards and the agricultural economy across East Asia. In this study, life history data of F₁ directly descended from F₀ C. sasakii fed with seven different nutrients (water as control, 5 g·L⁻¹ honey solution, 10 g·L⁻¹ honey solution, 5 g·L⁻¹ sucrose solution, 10 g·L⁻¹ sucrose solution, 15 g·L⁻¹ sucrose solution, and 20 g·L⁻¹ sucrose solution) were collected under laboratory conditions. The growth and development indices, age-stage specific survival rate, age-stage specific fecundity, age-stage specific life expectancy, age-stage specific reproductive value, and population parameters of these offspring were analyzed according to the age-stage, two-sex life table theory. The results showed that the nutritional status of F₀ differentially affects the growth, development, and reproduction of F₁. The F₁ offspring of F₀ adult C. sasakii fed with 10 g·L⁻¹ sucrose had significantly higher life table parameters than those of other treatments (intrinsic rate of increase, r = 0.0615 ± 0.0076; finite rate of increase, λ = 1.0634 ± 0.0081; net reproductive rate, R₀ = 12.61 ± 3.57); thus, 10 g·L⁻¹ sucrose was more suitable for raising C. sasakii in the laboratory than other treatments. This study not only provides clear evidence for the implications of altering F₀ nutritional conditions on the fitness of F₁ in insects, but also lays the foundation for the implementation of feeding technologies within the context of a well-conceived laboratory rearing strategy for C. sasakii.