Lymantria mathura (Moore, 1865), the rosy gypsy moth, is a polyphagous defoliator from the family Erebidae, which inhabits deciduous forests mainly in South and Southeast Asia. The broad trophic spectrum of this species makes it an important pest that threatens forests, urban greenery, ornamental plants, and fruit trees. Due to climate change, this species could become a threat beyond its natural range and the aim of our research was to assess the risk of invasion and establishment of L. mathura in Ukraine and to model the potential distribution of natural enemies of this moth.

GIS modeling in MapInfo Pro 15.0 (ESTIMap) and IDRISI Selva (Clark Labs) was used to model the potential distribution of L. mathura, and MaxEnt was used to model the potential distribution of entomophagous insects known to be effective in L. mathura biocontrol.

We found that the potential range of L. mathura covers almost all of Ukraine, except for the Carpathian highlands. The most important bioclimatic factors influencing its establishment are the mean annual temperature, the temperature of the warmest month, and the sum of active temperatures above 10 ℃, while the limiting factor is the mean temperature of the coldest month. Modeling suggests that natural enemies such as Cotesia melanoscela (Hymenoptera: Braconidae), Compsilura concinnata, and Carcelia gnava (Diptera: Tachinidae) could play a crucial role in biological control if L. mathura invades Ukraine.

Due to its high risk of introduction, broad climatic tolerance, excellent flight ability, and numerous suitable host plants, L. mathura poses a serious threat to Ukraine's plant resources. A key risk management strategy could be its inclusion in List A1 (absent) of the Ukrainian Regulated Pests List.