Bangasternus fausti
Encyclopedia
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
against noxious knapweeds
, particularly spotted knapweed
(Centaurea maculosa), squarrose knapweed (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 head
s 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 pupa
tes 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.
Curculionidae
Curculionidae is the family of the "true" weevils . It was formerly recognized in 1998 as the largest of any animal family, with over 40,000 species described worldwide at that time...
known as the broad-nosed seed head weevil. It is used as an agent of biological pest control
Biological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
against noxious knapweeds
Centaurea
Centaurea is a genus of between 350 and 600 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich...
, particularly spotted knapweed
Centaurea maculosa
Centaurea maculosa, the spotted knapweed, is a species of Centaurea native to eastern Europe.It has been introduced to North America, where it is considered an invasive plant species in much of the western United States and Canada. In 2000, C. maculosa occupied more than in the US.Knapweed is a...
(Centaurea maculosa), squarrose knapweed (Centaurea virgata ssp. squarrosa), and diffuse knapweed
Diffuse knapweed
Diffuse Knapweed , also known as White Knapweed or Tumble Knapweed, is a member of the genus Centaurea in the family Asteraceae. It is native to Asia Minor , the Balkans, , Ukraine, and southern Russia. Diffuse knapweed is an annual or biennial plant, generally growing to between 10 and 60 cm...
(Centaurea diffusa).
The adult weevil is dark gray and hairy and about 4 millimeters long. The female lays eggs on the flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
s 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 pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
tes 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
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, and it is currently established in the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
. It is host-specific to invasive knapweeds and has not been known to attack any native plants.