<i>Saccharosydne</i> is the most diverse genus of the tribe Saccharosydnini. Male, female and nymphal <i>Saccharosydne</i> have been captured in recent collections from garlic (<i>Allium sativum</i>), rye (<i>Secale cereale</i>) and pampas grass (<i>Cortaderia spp.</i>) in Argentina. In this contribution, we describe and illustrate a new species <i>S. subandina</i> sp. nov., adding information on the geographical distribution and host plants. <i>Saccharosydne subandina</i> can be distinguished from its congeners by the following combination of features: uniformly light green-yellowish color with a distinctive rounded black macula on both genae; vertex 1.5x longer than wide, and projecting beyond eyes almost one half of its length; parameres divergent with internal and external angles acute; and dorsolateral angles of pygofer produced caudad. A key for species identification based on male genitalia and external morphology, is provided.Facultad de Ciencias Naturales y Museo