The aphid genus Macromyzus Takahashi is a small East-Asia genus of the tribe Macrosiphini (Hemiptera: Aphidinae). Globally, there are five recognized species: Macromyzus (Anthracosiphoniella) maculatus (Basu), Macromyzus (Macromyzus) indicus David & Narayanan, M. (M.) manoji Raha & Raychaudhuri, M. (M.) spinosus Su & Qiao, and M. (M.) woodwardiae (Takahashi). In this study, we report the first record of the aphid genus Macromyzus Takahashi in Laos. We present a decription of a new species of this genus associated with Diplazium esculentum (Retz.) Sw. (Athyriaceae). Additionally, for the first time, we conducted scanning electron microscopy research on the morphology and sensilla of representative of this genus.

• Minho Lee(Insect Biosystematics Laboratory, Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea) Corresponding author
• Mariusz Kanturski(Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Bankowa 9, 40–007 Katowice, Poland)
• Seunghwan Lee(Insect Biosystematics Laboratory, Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea)