Fig wasp
Encyclopedia
Fig wasps are wasp
s of the family Agaonidae which pollinate
fig
s or are otherwise associated with figs, a coevolutional relationship that has been developing for at least 80 million years. They have been seen to fly farther than any known pollen-bearing insect, and in some regions of the world where wind can gust at up to 30 kilometres per hour (18.6 mph), they can travel downwind approximately 100 miles in their 48-hour lifespan.
The family as presently defined is polyphyletic, including several unrelated lineages whose similarities are based upon their shared association with figs; efforts are underway to resolve the matter, and remove a number of constituent groups to other families, particularly the Pteromalidae
and Torymidae
. Thus, the number of genera in the family is in flux. Probably only the Agaoninae should be regarded as belonging to the Agaonidae, whilst the Sycoecinae, Otitesellinae and Sycoryctinae should be included in the Pteromalidae. Placement of the Sycophaginae and Epichrysomallinae remains uncertain.
Among the Agaonidae, the female is a normal insect, while the males are mostly wingless. The males' only tasks are to mate with the females while still within the fig syconium
and to chew a hole for the females to escape from the fig interior. This is the reverse of Strepsiptera
and the bagworm, where the male is a normal insect and the female never leaves the host.
Most fig inflorescence
s contain three kinds of flower
s: male, short female, and long female. Female fig wasps can reach the ovaries of short female flowers with their ovipositors, but not long female flowers. Thus the short flowers grow wasps, whereas the long flowers become seeds. In figs of this sort, the crunchy bits in the fruit contain both seeds and wasps. However, there are several commercial and ornamental varieties of fig that are self-fertile and do not require pollination; these varieties are not visited by fig wasps.
Pollinating fig wasps (Agaoninae) are specific to specific figs. The common fig Ficus carica is pollinated by Blastophaga psenes.
of the fig wasp is closely intertwined with that of the fig tree it inhabits. The wasps that inhabit a particular tree can be loosely divided into two groups; pollinating and non-pollinating. The pollinating variety forms a mutually beneficial symbiosis
with the tree, whereas the non-pollinating variety is parasitic. Both life cycles, however, are very similar.
Though the lives of individual species differ, a general fig wasp life cycle is as follows. In the beginning of the cycle, a mature female pollinator wasp enters the "fruit" (actually a stem-like structure known as a syconium
) through a small natural opening, the ostiole
, which is covered in male flowers, and deposits
her eggs in the cavity, which is covered in female flowers. Forcing her way through the ostiole, she often loses her wings and most of her antennae
. To facilitate her passage through the ostiole the underside of the female's head is covered with short spines that provide purchase on the walls of the ostiole. In depositing her eggs, the female also deposits pollen she picked up from her original host fig. This pollinates some of the female flowers on the inside surface of the fig and allows them to mature. After the female wasp lays her eggs and follows through with pollination, she dies, allowing the fig to consume her corpse. After pollination, there are several species of non-pollinating wasps which deposit their eggs before the figs harden. These wasps act as parasites to either the fig or the pollinating wasps. As the fig develops, the wasp eggs hatch and develop into larva
e. After going through the pupal stage, the mature male’s first act is to mate with a female. The males of many species lack wings and are unable to survive outside the fig for a sustained period of time. After mating, a male wasp begins to dig out of the fig, creating a tunnel for the females to escape through.
Once out of the fig, the male wasps quickly die. The females find their way out, picking up pollen as they do. They then fly to another tree of the same species where they deposit their eggs and allow the cycle to begin again.
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
s of the family Agaonidae which pollinate
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
fig
Ficus
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...
s or are otherwise associated with figs, a coevolutional relationship that has been developing for at least 80 million years. They have been seen to fly farther than any known pollen-bearing insect, and in some regions of the world where wind can gust at up to 30 kilometres per hour (18.6 mph), they can travel downwind approximately 100 miles in their 48-hour lifespan.
The family as presently defined is polyphyletic, including several unrelated lineages whose similarities are based upon their shared association with figs; efforts are underway to resolve the matter, and remove a number of constituent groups to other families, particularly the Pteromalidae
Pteromalidae
Pteromalidae is a very large family of parasitic wasps, with some 3,450 described species in some 640 genera...
and Torymidae
Torymidae
Torymidae is a family of wasps that consists of attractive metallic species with enlarged hind legs, and generally with a long ovipositor. Many are parasitoids on gall-forming insects, and some are phytophagous species, sometimes usurping the galls formed by other insects. There are over 960...
. Thus, the number of genera in the family is in flux. Probably only the Agaoninae should be regarded as belonging to the Agaonidae, whilst the Sycoecinae, Otitesellinae and Sycoryctinae should be included in the Pteromalidae. Placement of the Sycophaginae and Epichrysomallinae remains uncertain.
Syconium
A syconium is the type of fruit borne by figs , formed of an enlarged, fleshy, hollow receptacle with multiple ovaries on the inside surface. In essence, it is really a fleshy stem with a number of flowers, so it is considered both a multiple and accessory fruit. The name comes from the Greek word...
and to chew a hole for the females to escape from the fig interior. This is the reverse of Strepsiptera
Strepsiptera
The Strepsiptera are an order of insects with ten families making up about 600 species...
and the bagworm, where the male is a normal insect and the female never leaves the host.
Most fig inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s contain three kinds of flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s: male, short female, and long female. Female fig wasps can reach the ovaries of short female flowers with their ovipositors, but not long female flowers. Thus the short flowers grow wasps, whereas the long flowers become seeds. In figs of this sort, the crunchy bits in the fruit contain both seeds and wasps. However, there are several commercial and ornamental varieties of fig that are self-fertile and do not require pollination; these varieties are not visited by fig wasps.
Pollinating fig wasps (Agaoninae) are specific to specific figs. The common fig Ficus carica is pollinated by Blastophaga psenes.
Life cycle
The life cycleBiological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
of the fig wasp is closely intertwined with that of the fig tree it inhabits. The wasps that inhabit a particular tree can be loosely divided into two groups; pollinating and non-pollinating. The pollinating variety forms a mutually beneficial symbiosis
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
with the tree, whereas the non-pollinating variety is parasitic. Both life cycles, however, are very similar.
Though the lives of individual species differ, a general fig wasp life cycle is as follows. In the beginning of the cycle, a mature female pollinator wasp enters the "fruit" (actually a stem-like structure known as a syconium
Syconium
A syconium is the type of fruit borne by figs , formed of an enlarged, fleshy, hollow receptacle with multiple ovaries on the inside surface. In essence, it is really a fleshy stem with a number of flowers, so it is considered both a multiple and accessory fruit. The name comes from the Greek word...
) through a small natural opening, the ostiole
Ostiole
An ostiole is a small hole or opening through which algae or ascomycetal fungi release their mature spores. The term is also used in higher plants, for example to denote the opening of the involuted fig inflorescence through which fig wasps enter to pollinate and breed....
, which is covered in male flowers, and deposits
Oviposition
Oviposition is the process of laying eggs by oviparous animals.Some arthropods, for example, lay their eggs with an organ called the ovipositor.Fish , amphibians, reptiles, birds and monetremata also lay eggs....
her eggs in the cavity, which is covered in female flowers. Forcing her way through the ostiole, she often loses her wings and most of her antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
. To facilitate her passage through the ostiole the underside of the female's head is covered with short spines that provide purchase on the walls of the ostiole. In depositing her eggs, the female also deposits pollen she picked up from her original host fig. This pollinates some of the female flowers on the inside surface of the fig and allows them to mature. After the female wasp lays her eggs and follows through with pollination, she dies, allowing the fig to consume her corpse. After pollination, there are several species of non-pollinating wasps which deposit their eggs before the figs harden. These wasps act as parasites to either the fig or the pollinating wasps. As the fig develops, the wasp eggs hatch and develop into 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...
e. After going through the pupal stage, the mature male’s first act is to mate with a female. The males of many species lack wings and are unable to survive outside the fig for a sustained period of time. After mating, a male wasp begins to dig out of the fig, creating a tunnel for the females to escape through.
Once out of the fig, the male wasps quickly die. The females find their way out, picking up pollen as they do. They then fly to another tree of the same species where they deposit their eggs and allow the cycle to begin again.
Genera
Genera currently included in Agaonidae according to the Universal Chalcidoidea Database:- Acophila
- Adiyodiella
- Aepocerus
- Agaon
- Alfonsiella
- Allotriozoon
- Anidarnes
- Apocrypta
- Apocryptophagus
- Arachonia
- Asycobia
- Blastophaga
- Camarothorax
- Ceratosolen
- Comptoniella
- Courtella
- Critogaster
- Crossogaster
- Deilagaon
- Diaziella
- Dobunabaa
- Dolichoris
- Elisabethiella
- Epichrysomalla
- Eufroggattisca
- Eujacobsonia
- Eukoebelea
- Eupristina
- Grandiana
- Grasseiana
- Guadalia
- Herodotia
- Heterandrium
- Idarnes
- Josephiella
- Kradibia
- Lachaisea
- Leeuweniella
- Liporrhopalum
- Lipothymus
- Marginalia
- Meselatus
- Micranisa
- Micrognathophora
- Neoukobelea
- Neosycophila
- Nigeriella
- Odontofroggatia
- Otitesella
- Paragaon
- Parapilkhanivora
- Parasycobia
- PegoscapusPegoscapusPegoscapus is a genus of fig wasp native to the Americas. They range from Florida and Mexico in the north to Argentina in the south. Fig wasps have an obligate mutualism with the fig species they pollinate...
- Philocaenus
- Philosycella
- Philosycus
- Philotrypesis
- Philoverdance
- Platyscapa
- PleistodontesPleistodontesPleistodontes is a genus of fig wasps native to Australia and New Guinea, with one species from Java. Fig wasps have an obligate mutualism with the fig species they pollinate...
- Pseudidarnes
- Robertsia
- Seres
- Sycobia
- Sycobiomorphella
- Sycoecus
- Sycomacophila
- Sycophaga
- Sycophilodes
- Sycophilomorpha
- Sycoscapter
- Sycotetra
- Tenka
- TetrapusTetrapusTetrapus is a genus of fig wasp native to the Americas. Fig wasps have an obligate mutualism with the fig species they pollinate. Tetrapus pollinates figs in the subgenus Pharmacosycea....
- Walkerella
- Waterstoniella
- Watshamiella
- Wiebesia