Bangasternus orientalis
Encyclopedia
Bangasternus orientalis is a species of true weevil
known as the yellow starthistle bud weevil. It is used as an agent of biological pest control
against the noxious weed yellow starthistle (Centaurea solstitialis).
The adult weevil is brown with a thin coat of light mottled hairs. It is about 6 millimeters long. The female lays up to 470 eggs near the flower heads
of yellow starthistle and glues them with a dark-colored mucilage
. When the larva
emerges from its egg, it tunnels up into the flower head, where it consumes the flower parts and developing seeds. It then constructs a sort of cocoon from the remnants of the flower and seed parts and pupa
tes there. Most of the damage to the plant is done by the larva, which destroys 50-60% of the seeds in a given flower head. It is host-specific, attacking only yellow starthistle and sometimes purple starthistle
(C. calcitrapa); it does not attack any native plants.
This weevil is native to southern Europe and the Mediterranean. It was first released as a biocontrol agent in the United States in 1985. It is now established throughout the western United States, wherever yellow starthistle is found. It helps prevent the spread of the weed, but it is not as common or effective as other yellow starthistle biocontrol agents.
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 yellow starthistle bud 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 the noxious weed yellow starthistle (Centaurea solstitialis).
The adult weevil is brown with a thin coat of light mottled hairs. It is about 6 millimeters long. The female lays up to 470 eggs near the flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
of yellow starthistle and glues them with a dark-colored mucilage
Mucilage
Mucilage is a thick, gluey substance produced by most plants and some microorganisms. It is a polar glycoprotein and an exopolysaccharide.It occurs in various parts of nearly all classes of plant, usually in relatively small percentages, and is frequently associated with other substances, such as...
. When the larva
Larva
A larva 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...
emerges from its egg, it tunnels up into the flower head, where it consumes the flower parts and developing seeds. It then constructs a sort of cocoon from the remnants of the flower and seed parts and 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 there. Most of the damage to the plant is done by the larva, which destroys 50-60% of the seeds in a given flower head. It is host-specific, attacking only yellow starthistle and sometimes purple starthistle
Centaurea calcitrapa
Centaurea calcitrapa is a species of flowering plant known by several common names, including purple starthistle and red starthistle. It is native to Europe but is rarely found there, it is known across the globe as an introduced species and often a noxious weed...
(C. calcitrapa); it does not attack any native plants.
This weevil is native to southern Europe and the Mediterranean. It was first released as a biocontrol agent in the United States in 1985. It is now established throughout the western United States, wherever yellow starthistle is found. It helps prevent the spread of the weed, but it is not as common or effective as other yellow starthistle biocontrol agents.