Distribution of Basilepta melanopus Lefèvre in China as Affected by Climatic Changes

Objective Crucial for early warning and effective control of an epidemic due to climatic changes, accurate forecast of potential spread of Basilepta melanopus Lefèvre in China was studied.

Method Based on the existing databank on the B. melanopus population in China, applicability of the maximum entropy (MaxEnt) model to predict the regions conducive to the infestation, especially under the radical changes in climate, was examined.

Result The average AUC on 10 repeated runs using the prediction model was 0.907 with a standard deviation of 0.007 and a test sample omission rate as predicted. According to the model, the regions prone to proliferation of B. melanopus at present were southwest, east, central, and south China of an area measured approximately 2677300 km². In the foreseeable future, the boundary could move further northward to Heilongjiang Province. Under the SSP5_85 scenario for 2061-2080, the total area susceptible to the infestation could extend to 3765800 km², an alarming 39.23% of the entire nation. Major environment variables affecting the spread of B. melanopus population included the precipitation in the driest and the wettest months, the peak temperature in the hottest month, and the variation coefficient of temperature in the regions.

Conclusion The prediction on current B. melanopus distribution in China by the MaxEnt model agreed with actual observation. For the future, as the climate undergoes drastic changes, the mathematically extrapolated forecast could only be hoped to be accurate enough for planning effective countermeasures to combat the potentially wide-spread infestation.