Hydrothassa marginella is a Europe species of leaf beetles in the family Chrysomelinae
Hydrothassa marginella grows to 3.4 - 4.5mm in length and are dark metallic blue and orange-yellow in colour.[1] The pronotum is coloured yellowish with lateral margins. It may be confused with H. glabra or H. hannoveriana.
Hydrothassa marginella is a common and widespread species, active between the months of mid-April and August. It has various host plants, especially buttercups.[2] Adults overwinter in grass tussocks.
Hydrothassa marginella is prevalent in central and northern Europe.[3]