''Bangasternus fausti'' is a species of
true weevil known as the broad-nosed seed head weevil. It is used as an agent of
biological pest control
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...
against
noxious knapweeds, particularly
spotted knapweed (''Centaurea maculosa''),
squarrose knapweed
''Centaurea virgata'' is a species of '' Centaurea''. It is native to Western Asia. The subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shap ...
(''Centaurea virgata'' ssp. ''squarrosa''), and
diffuse knapweed (''Centaurea diffusa'').
The adult weevil is dark gray and hairy and about 4 millimeters long. The female lays eggs on the
flower heads at an early stage of development
and stem tips. Upon emergence the larva burrows into the flower head or makes its way there by tunneling through the stem. It feeds upon the developing seeds, often consuming them entirely. If any other insects invade the flower head, the larva attacks them. It
pupates inside the seed head.
This weevil is native to southern Europe and the Middle East. It was first released as a knapweed biocontrol in the 1980s in
Oregon, and it is currently established in the
Pacific Northwest. It is host-specific to invasive knapweeds and has not been known to attack any native plants.
References
* Coombs, E. M., et al., Eds. (2004). ''Biological Control of Invasive Plants in the United States''. Corvallis: Oregon State University Press, 209.
External links
Cornell Biocontrol Profile
Molytinae
Insects used for control of invasive plants
Biological pest control beetles
Beetles described in 1890
{{Molytinae-stub