EPPO Global Database

EPPO Reporting Service no. 07 - 2008 Num. article: 2008/152

Stenopelmus rufinasus (Coleoptera: Curculionidae): a biological control agent of Azolla filiculoides recorded in Spain

Stenopelmus rufinasus (Coleoptera: Curculionidae) was intentionally introduced in 1997 to South Africa as a host specific biological control agent for the invasive South American aquatic fern Azolla filiculoides (Azollaceae, EPPO List of Invasive Alien Plants) (Hill, 1998). The introduction of this insect led to the complete control of the weed by 2000 in South Africa (McConnachie et al., 2004). This weevil was first recorded in Europe in the United Kingdom by Jansen (1921) where it is thought to have been introduced along with A. filiculoides. In 2007 it was recorded in Ireland (J-R. Baars, pers comm., 2008) and Southern France (McConnachie, pers comm., 2008). Most recently the weevil was recorded on A. filiculoides on the Guadiana River, Extremadura Province in Western Spain in early June 2008. Although the weevil does not appear to have had the same impact on A. filiculoides in Europe as it does in South Africa (Gassmann et al., 2006), it has reduced the invasive potential of this weed in Europe.


Contact: Martin Hill, Department of Zoology and Entomology, Rhodes University, South Africa. E-mail: M.Hill@ru.ac.za
Gassmann A, Cock MJW, Shaw R ; Evans H (2006) The potential for biological control of invasive alien aquatic weeds in Europe: a review. Hydrobiologia 570, 217-222.
Hill MP (1998) Life history and laboratory host range of Stenopelmus rufinasus, a natural enemy for Azolla filiculoides in South Africa. Biocontrol 43, 215-224
Janson OE (1921) Stenopelmus rufinasus Gyll. an addition to the list of British Coleoptera. Entomologists Monthly Magazine 57, 225-226.
McConnachie AJ, Hill MP ; Byrne MJ (2004) Field assessment of a frond-feeding weevil, a successful biological control agent of red water fern, Azolla filiculoides, in southern Africa. Biological Control 29, 326-33.