Xanthopan morgani
Encyclopedia
Xanthopan morgani, or Morgan's Sphinx, is a very large hawk moth from West Africa (Rhodesia
, Nyasaland
) and Madagascar
. It is the sole member of its genus, and little is known of the biology, though the adults have been found to visit orchids (see below).
In January 1862 while researching insect pollination of orchids, Charles Darwin
received a package of orchids from the distinguished horticulturist James Bateman
, and in a follow up letter with a second package Bateman's son Robert
confirmed the names of the specimens, including Angraecum sesquipedale
from Madagascar. Darwin was surprised at the defining characteristic of this species: the "astonishing length" of the whip-like green spur
forming the nectary of each flower, and remarked to Joseph Hooker
"I have just received such a Box full from Mr Bateman with the astounding Angræcum sesquipedalia with a nectary a foot long— Good Heavens what insect can suck it"[?] The spur of the flower is 20 centimetre from its tip to the tip of the flower's lip. The name "sesquipedale" is Latin for "one and a half feet," referring to the spur length.
From his observations and experiments with pushing a probe into the spur of the flower, Darwin surmised in his 1862 book Fertilisation of Orchids
that there must be a pollinator moth with a proboscis
long enough to reach the nectar at the end of the spur. In its attempt to get the nectar at the end of the spur the moth would get pollen rubbed off on its head. The next orchid it visited would then be pollinated in the same manner.
In 1903, such a moth was discovered in Madagascar. It was described as a sub-species of the African hawk moth and named Xanthopan morganii praedicta. The subspecific epithet "praedicta" was given in honor of the fact that Darwin predicted its existence, though the subspecies was later determined to be invalid (it is identical to the mainland form of the species). The moth approaches the flower to ascertain by scent whether or not it is the correct orchid species. Then the moth backs up over a foot and unrolls its proboscis, then flies forward, inserting it into the orchid's spur.
The larvae feed on Annona senegalensis
, Hexalobus crispiflorus, Uvaria
, Ibaria and Xylopia
species.
Rhodesia
Rhodesia , officially the Republic of Rhodesia from 1970, was an unrecognised state located in southern Africa that existed between 1965 and 1979 following its Unilateral Declaration of Independence from the United Kingdom on 11 November 1965...
, Nyasaland
Nyasaland
Nyasaland or the Nyasaland Protectorate, was a British protectorate located in Africa, which was established in 1907 when the former British Central Africa Protectorate changed its name. Since 1964, it has been known as Malawi....
) and Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
. It is the sole member of its genus, and little is known of the biology, though the adults have been found to visit orchids (see below).
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
received a package of orchids from the distinguished horticulturist James Bateman
James Bateman
James Bateman was a landowner and accomplished horticulturist. He developed Biddulph Grange after moving there around 1840, from nearby Knypersley Hall...
, and in a follow up letter with a second package Bateman's son Robert
Robert Bateman (artist)
Robert Bateman was an English painter, illustrator, sculptor, architect and scholar.He was the third son of James Bateman , the accomplished horticulturist and landowner, who built Biddulph Grange and its gardens, in Staffordshire.Robert attended the Royal Academy schools in the 1860s, and from...
confirmed the names of the specimens, including Angraecum sesquipedale
Angraecum sesquipedale
Angraecum sesquipedale is an epiphytic orchid in the genus Angraecum that is endemic to Madagascar. The orchid was first discovered by the French botanist Louis-Marie Aubert du Petit-Thouars in 1798, but was not described until 1822...
from Madagascar. Darwin was surprised at the defining characteristic of this species: the "astonishing length" of the whip-like green spur
Spur (biology)
A spur in botany is a spike, usually part of a flower.In certain plants, part of a sepal or petal develops into an elongated hollow spike extending behind the flower, containing nectar which is sucked by long-tongued animals . Plants with such structures include Delphinium, Aquilegia, Piperia, and...
forming the nectary of each flower, and remarked to Joseph Hooker
Joseph Dalton Hooker
Sir Joseph Dalton Hooker OM, GCSI, CB, MD, FRS was one of the greatest British botanists and explorers of the 19th century. Hooker was a founder of geographical botany, and Charles Darwin's closest friend...
"I have just received such a Box full from Mr Bateman with the astounding Angræcum sesquipedalia with a nectary a foot long— Good Heavens what insect can suck it"[?] The spur of the flower is 20 centimetre from its tip to the tip of the flower's lip. The name "sesquipedale" is Latin for "one and a half feet," referring to the spur length.
From his observations and experiments with pushing a probe into the spur of the flower, Darwin surmised in his 1862 book Fertilisation of Orchids
Fertilisation of Orchids
Fertilisation of Orchids is a book by Charles Darwin published on 15 May 1862 under the full explanatory title On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing...
that there must be a pollinator moth with a proboscis
Proboscis
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
long enough to reach the nectar at the end of the spur. In its attempt to get the nectar at the end of the spur the moth would get pollen rubbed off on its head. The next orchid it visited would then be pollinated in the same manner.
In 1903, such a moth was discovered in Madagascar. It was described as a sub-species of the African hawk moth and named Xanthopan morganii praedicta. The subspecific epithet "praedicta" was given in honor of the fact that Darwin predicted its existence, though the subspecies was later determined to be invalid (it is identical to the mainland form of the species). The moth approaches the flower to ascertain by scent whether or not it is the correct orchid species. Then the moth backs up over a foot and unrolls its proboscis, then flies forward, inserting it into the orchid's spur.
The larvae feed on Annona senegalensis
Annona senegalensis
Annona senegalensis, commonly known as African custard-apple, wild custard apple, and wild soursop, is a species of flowering plant in the custard apple family, Annonaceae. The specific epithet, senegalensis, translates to mean "of Senegal", the country where the type specimen was collected.A...
, Hexalobus crispiflorus, Uvaria
Uvaria
Uvaria is a genus of flowering plants in the soursop family, Annonaceae.-Selected species:* Uvaria calamistrata Hance* Uvaria chamae P.Beauv. – Finger-root* Uvaria grandiflora Uvaria is a genus of flowering plants in the soursop family, Annonaceae.-Selected species:* Uvaria calamistrata ...
, Ibaria and Xylopia
Xylopia
Xylopia is a genus of plant in family Annonaceae. This genus is solely composed of trees, distribution of which is pantropical . It contains the following species :* Xylopia africana, Oliv....
species.