The flea beetle, Pseudolampsis guttata (LeConte) (Coleoptera: Chrysomelidae) was assessed for release on the South American fern, Azolla filiculoides Lamarck (Pteridophyta: Azollaceae) which is invasive in aquatic ecosystems in South Africa. Favourable biological characteristics of the beetle include: long-lived and mobile adults, short generation time, high rate of increase and high per capita feeding rates. However, laboratory host specificity trials indicated that this beetle is an oligophagous species capable of utilizing several species in the genus Azolla and could pose a threat to native southern African Azolla species. Pseudolampsis guttata was therefore considered unsuitable for release in South Africa.