Fletcher, 1929 Euresia Dietz, 1910 Zenodochium Walsingham, 1908 (disputed) Blastobasis is the type genus of the gelechioid moth family Blastobasidae; in some arrangements these are placed in the case-bearer family (Coleophoridae) as a subfamily.

Within the Blastobasidae, the subfamily Blastobasinae (or tribe Blastobasini, if united with the concealer moths) has been established to distinguish the Blastobasis lineage from the group around Holcocera, but the delimitation is not yet well-resolved.

[2] The monophyly of this genus – the largest of its family, containing at present about half the described Blastobasidae species – is seriously in doubt.

Many presumed relatives have been separated in small or even monotypic genera, which may actually represent specialized lineages within the Blastobasis assemblage.

Agnoea, Auximobasis, Euresia and Zenodochium are sometimes included here but considered distinct by other authors.