Abstract: Parthenium hysterophorus is an invasive weed globally, widely distributed in tropical and subtropical regions. The leaf beetle Zygogramma bicolorata, a natural enemy of P. hysterophorus, has shown to be an effective biological control agent in some countries/regions. Predicting the suitable habitats for P. hysterophorus and Z. bicolorata can provide valuable information for its biological control and regional management. Therefore, this study used the MaxEnt model, based on species global occurrence points and 21 environmental variables, to predict the suitable habitats for P. hysterophorus and Z. bicolorata worldwide under nearly current climate. The model suggested that the main factors affecting the distribution of suitable habitats for P. hysterophorus were mean temperature of coldest quarter (bio11), precipitation of wettest month (bio13), mean temperature of wettest quarter (bio8), and human influence index (HII). While the main factors affecting the distribution of suitable habitats for Z. bicolorata were mean temperature of warmest quarter (bio10), precipitation of wettest month (bio13), isothermality (bio3), and human influence index (HII). The model prediction indicates that the area of potential suitable habitats for P. hysterophorus and Z. bicolorata were 5426.79×10⁴ km² and 1410.59×10⁴ km² respectively, with an overlapping area of 1357.66×10⁴ km². These areas were mainly distributed in Asia (Pakistan, India, Southern China and most Southeast Asian countries), the Gulf Coast of North America (low and middle latitudes area of the United States, and the Eastern coast of Mexico), the Niger River Basin in Western Africa and the Zambezi River Basin in Southeastern Africa, as well as Central and Southern South America (Southeastern Brazil and Northern Argentina). The results of this study provide a basis for using Z. bicolorata to control P. hysterophorus in their overlapping regions.

Key words: Parthenium hysterophorus, Zygogramma bicolorata, suitable habitat, Maxent