''Chaetorellia acrolophi'' is a species of
tephritid fruit fly known as the knapweed peacock fly. 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
''Centaurea'' () is a genus of over 700 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 reg ...
, especially
spotted knapweed
''Centaurea stoebe'', the spotted knapweed or panicled knapweed, is a species of ''Centaurea'' native to eastern Europe, although it has spread to North America, where it is considered an invasive species. It forms a tumbleweed, helping to in ...
(''Centaurea maculosa'').
The adult fly is light greenish brown with brown-banded wings and iridescent green eyes. It is 3 to 5 millimeters lon
external imageThe female lays about 70 eggs beneath the
bracts
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 usually different from foliage leaves. They may be smaller, larger, or of ...
on immature
flower heads
A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...
. When 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 ...
emerges from the egg a few days later it burrows into the flower head and feeds on the developing florets. As the larva grows it begins to feed on the developing seeds, often consuming the entire contents of the flower head during its two-week larval stage. It
pupa
A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...
tes inside the empty flower head.
This fly is native to Europe. It was first released as a knapweed biocontrol in the 1990s in
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...
, and it is currently established in much of the western United States. It is host-specific to invasive knapweeds, preferring spotted knapweed, and has not been known to attack any native plants. The fly is often outcompeted by other species that attack knapweed flower heads, such as certain weevils, so it does best where there are no competitors.
Distribution
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
,
Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
, East to
Belarus
Belarus,, , ; alternatively and formerly known as Byelorussia (from Russian ). officially the Republic of Belarus,; rus, Республика Беларусь, Respublika Belarus. is a landlocked country in Eastern Europe. It is bordered by R ...
,
Turkey
Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...
. Introduced to
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
.
References
External links
Cornell Biocontrol Profile
Tephritinae
Insects used for control of invasive plants
Insects described in 1989
Diptera of Europe
Diptera of North America
{{Tephritinae-stub