Rediscovery and redescription of two eriophyid mites (Acari, Prostigmata, Eriophyidae) from Baccharis salicifolia (Asteraceae), from Argentina with remarks on the eriophyoid coverflap base

The rediscovery of Aceria cortii Amrine & Stasny and Shevtchenkella baccharis (Keifer) is reported on Baccharis salicifolia (Asteraceae) from Central Argentina and both species are redescribed. Aceria cortii is a gall inducer in leaves and stems of the plant whereas S. baccharis is a leaf vagrant. The topography of the area anterior to the eriophyoid genital coverflap is discussed. This constitutes a first record of S. baccharis for South America.