The three larval instars of Hydraena particeps Perkins, 1981 are described, based on material collected in the field and reared in the laboratory. Illustrations of structural features and chaetotaxy are provided. For the first time the three larval instars of one species of the genus Hydraena are described. Several characters are compared to those of Hydraena hernandoi Fresneda and Lagar from Europe and the North American Hydraena circulata Perkins.