In China, the invasive American serpentive leafminer, Liriomyza trifolii (Burgess), was first detected in Guangdong province in 2005. Within only a few years of its discovery, its range had expanded rapidly to another 11 provinces and caused economic damage to a wide range of agricultural crops. L. trifolii has displaced the previously established exotic species L. sativae Blanchard to become the dominant species on some major horticultural crops across Hainan Island. Differential insecticide susceptibilities and local specific cropping systems might be major factors driving the ongoing displacement of L. sativae by L. trifolii. Further research should focus on monitoring established species to collect detailed data to enhance overall understanding of biology and ecology of invasion by L. trifolii. Urgent action is needed to improve management programs for this widespread invasive insect pest.