Chaetorellia australis
Encyclopedia
Chaetorellia australis is a species of tephritid fruit fly
known as the yellow starthistle peacock fly. It is used as an agent of biological pest control
against the noxious weed yellow starthistle (Centaurea solstitialis).
The adult fly is light golden yellow in color with small black spots on its body and stripes on its wings. The male fly is about 4 millimeters long and the female is slightly longer due to her large ovipositor
. The female lays up to 240 cylindrical eggs beneath the bract
s on the flower head
s of yellow starthistle. The larva
emerges and tunnels into the flower head, where it feeds on developing seeds. A larva might destroy up to 90% of the developing seeds inside a given flower head. It overwinters inside the head and pupa
tes into an adult fly. There are at least two generations per year. The first generation often utilizes the minor weed cornflower
(Centaurea cyanus) before continuing reproduction on yellow starthistle. Sometimes the fly is difficult to introduce to an area if there is no cornflower growing nearby.
C. australis generally occurs in low numbers and does not seem to have had much impact on starthistle seed production.
This fly is native to southern Europe and the Mediterranean. It was first introduced to the United States for the purposes of biocontrol in 1988. It is now established throughout the northwestern United States.
Tephritidae
Tephritidae is one of two fly families referred to as "fruit flies", the other family being Drosophilidae. Tephritidae does not include the biological model organisms of the genus Drosophila , which is often called the "common fruit fly". There are nearly 5,000 described species of tephritid...
known as the yellow starthistle peacock fly. 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 fly is light golden yellow in color with small black spots on its body and stripes on its wings. The male fly is about 4 millimeters long and the female is slightly longer due to her large ovipositor
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
. The female lays up to 240 cylindrical eggs beneath the bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s 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 of yellow starthistle. 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 and tunnels into the flower head, where it feeds on developing seeds. A larva might destroy up to 90% of the developing seeds inside a given flower head. It overwinters inside the head 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 into an adult fly. There are at least two generations per year. The first generation often utilizes the minor weed cornflower
Cornflower
Centaurea cyanus is a small annual flowering plant in the family Asteraceae, native to Europe. "Cornflower" is also erroneously used for chicory, and more correctly for a few other Centaurea species; to distinguish C...
(Centaurea cyanus) before continuing reproduction on yellow starthistle. Sometimes the fly is difficult to introduce to an area if there is no cornflower growing nearby.
C. australis generally occurs in low numbers and does not seem to have had much impact on starthistle seed production.
This fly is native to southern Europe and the Mediterranean. It was first introduced to the United States for the purposes of biocontrol in 1988. It is now established throughout the northwestern United States.