Azolla
Guides
Pseudolampsis guttata
Waterfern Flea Beetle
A flea beetle in the family Chrysomelidae, evaluated as a potential biological control agent for the invasive aquatic fern Azolla filiculoides (red water fern) in South Africa. Laboratory host range testing has been conducted to assess its feeding specificity and suitability for introduction as a natural enemy.
Stenopelmus
marsh weevils
Stenopelmus is a genus of marsh weevils comprising at least two described species. The genus is best known for Stenopelmus rufinasus, a North American weevil introduced to Europe in the late 19th century alongside its host plant Azolla filiculoides. Members of this genus are specialized herbivores associated with aquatic ferns and have been employed as biological control agents for invasive water fern management.
Stenopelmus rufinasus
Azolla Weevil, Waterfern Weevil
Stenopelmus rufinasus is a small weevil native to North America, introduced to Europe in 1898 alongside its host plant Azolla filiculoides. The species is a specialized herbivore with rapid development, completing its life cycle in approximately 20 days and producing 4-6 generations annually under favorable conditions. It has been widely deployed as a biological control agent for invasive Azolla species, particularly in South Africa where it has achieved dramatic population reductions. Adults exhibit exceptional dispersal capabilities, documented to travel up to 350 km, and frequently occur in water bodies lacking visible host plants.