''Exapion fuscirostre'' (formerly ''Apion fuscirostre'') is a species of straight-snouted weevil known by the general common name Scotch broom seed 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 the

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is injurious to agricultural or horticultural crops, natural habitats or ecosystems, or humans or liv ...

known as

Scotch broom ''Cytisus scoparius'' ( syn. ''Sarothamnus scoparius''), the common broom or Scotch broom, is a deciduous leguminous shrub native to western and central Europe. In Britain and Ireland, the standard name is broom; this name is also used for other ...

(''Cytisus scoparius''). The adult weevil is dark gray with a dark band across its elytra and is a laterally compressed shape with a long snout and light brown legs. It is long. The adult feeds on new growth at the tips of stems, but the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

does much more damage to the plant. The adult female lays eggs inside the plant's seed pod, where the larvae hatch and consume the seeds over a period of a few weeks. This weevil is native to Europe. It has been released in the western United States, where it has shown promise as a biocontrol agent for Scotch broom. It is now widespread in the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

. There is a parasitic wasp, '' Pteromalus sequester'', that uses the weevil as a host. This could possibly hinder efforts to keep the weevil established, but further study is needed.

References

* Coombs, E. M., et al., Eds. (2004). ''Biological Control of Invasive Plants in the United States''. Corvallis: Oregon State University Press, 164.

External links

Control of Scotch Broom
Brentidae Beetles described in 1775 Taxa named by Johan Christian Fabricius Insects used for control of invasive plants Biological pest control beetles {{Brentidae-stub