The Ibaliidae are a small family of
hymenoptera
Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...
n superfamily
Cynipoidea
The Cynipoidea are a moderate-sized hymenopteran superfamily that presently includes five modern families and three extinct families, though others have been recognized in the past. The most familiar members of the group are phytophagous, especia ...
. Ibaliidae differ from most of the
cynipoids by the larvae being
parasitoid
In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...
s on other
wasp
A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...
larvae in the group
Siricidae. The Ibaliidae comprise three extant genera of fairly large
wasp
A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...
s, with a total of 20 species, and is a sister group to the rest of the
cynipoids except the small subfamily
Austrocynipidae.
Description
Their large size is a typical and obvious characteristic in the family, with lengths up to . The following distinct features are diagnostic characters, based on research by Ronquist
and Liu and Nordlander.
Body
The genae are swollen and pronounced. The female
antenna
Antenna ( antennas or antennae) may refer to:
Science and engineering
* Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves
* Antennae Galaxies, the name of two collid ...
consists of 11 segments, while the male antenna consists of 13 segments. A large portion of the
pronotum
The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on ea ...
is well developed, called the dorsal pronotal area, with
scutellar processes. The marginal cell of the forewing is elongated and thin. The
gaster is long and pronouncedly compressed laterally. The seventh
tergum
A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the Anatomical terms of location#Dorsal and ventral, dorsal ('upper') portion of an arthropod segment other than the head. The Anatomical terms of location#Ante ...
is large in females. An apical tubular process is present on the second
tarsomere The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, plur ...
of the hind leg. The
metafemur is short, no longer than the
metacoxa.
Reproduction and parasitism
The female lays the egg by
oviposition
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
through the oviposition shafts created by
Siricidae, and the egg is deposited inside a
siricid larva.
In the species ''Ibalia drewseni'' Borries, ''Ibalia leucospoides'' (Hochenwarth) and ''Ibalia japonica'' Matsumura, host detection by
symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...
in the siricid has been observed.
The larva lives it in its first instars as an endoparasite, and later exits the host and lives on the remaining host tissues. The primary
instar
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...
is polypodeiform with paired appendages on
segments 1–12, and in the second to fourth
instar
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...
s, the appendages are lost. Until the terminal
instar
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...
, the remaining
cauda {{About, the musical feature
The cauda is a characteristic feature of songs in the conductus style of '' a cappella'' music which flourished between the mid-12th and the mid-13th century. The conductus style placed strict rules on composition, and s ...
is gradually decreased.
The two subgenera of ''
Ibalia
''Ibalia'' is a genus of ibaliid wasps in the family Ibaliidae. There are about 14 described species in ''Ibalia''. All species are parasitoids of Siricidae species, which they seek out by detecting volatiles emitted by the fungi Siricidae larva ...
'' differ in host choice, the subgenus ''
Ibalia
''Ibalia'' is a genus of ibaliid wasps in the family Ibaliidae. There are about 14 described species in ''Ibalia''. All species are parasitoids of Siricidae species, which they seek out by detecting volatiles emitted by the fungi Siricidae larva ...
'' parasitizes coniferous-living
Siricinae larvae and the subgenus ''
Tremibalia'' parasitizes hardwood-living
Tremicinae larvae. Few details are known about the genera ''
Heteribalia'' and ''
Eileenella'', but both also parasitize wood-boring Siricidae.
Pest control
Several species in the genus ''Ibalia'' have been introduced to South America, Australia, and New Zealand,
sometimes to control previous accidentally introduced Siricidae species parasitizing economically important pine forests.
Species used are, for example, ''Ibalia leucospoides'' and ''I. ensiger'' Norton. Results from introductions vary, and studies of long-term effects are lacking, but in some areas, the effects on pests have been successful; Siricidae populations have been strongly limited. They are most effective in combination with other parasitoid organisms, such as
nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
s.
Distribution and evolution
The Ibaliidae are concentrated to the
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
, the single species in ''Eileenella'' found in
Papua New Guinea
Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
is the only specimen reported to be naturally occurring in the
Southern Hemisphere. ''
Ibalia
''Ibalia'' is a genus of ibaliid wasps in the family Ibaliidae. There are about 14 described species in ''Ibalia''. All species are parasitoids of Siricidae species, which they seek out by detecting volatiles emitted by the fungi Siricidae larva ...
'' is the most widespread and diverse genus, with the subgenus ''
Tremibalia'' concentrated in
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
and the eastern
Palearctic realm
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa.
The realm consists of several bioregions: the Euro-Sibe ...
, and ''
Ibalia
''Ibalia'' is a genus of ibaliid wasps in the family Ibaliidae. There are about 14 described species in ''Ibalia''. All species are parasitoids of Siricidae species, which they seek out by detecting volatiles emitted by the fungi Siricidae larva ...
'' in the western
Nearctic realm
The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface.
The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America t ...
. ''Heteribalia'' only occurs in
South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;;;;; ...
and
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
. Phylogenetic analyses have indicated the Ibaliidae have spread from the eastern Palearctic and northern Asian regions in the early
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
.
An insect-parasitic life mode is probably ancestral in the
cynipoid families, and the Ibaliidae are placed next to
Austrocynipidae, as a sister group to
Liopteridae
Liopteridae is a family of wood-boring parasitoid wasp
Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on o ...
,
Figitidae
Figitidae is a family of parasitoid wasps. The full diversity of this wasp family is not yet known, but about 1400 species have been described to over 130 genera. For example, the largest subfamily, Eucoilinae (previously considered as a separa ...
and
Cynipidae
Gall wasps, also incorrectly called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this genera ...
.
References
{{Taxonbar, from=Q1338907
Cynipoidea
Apocrita families
Endoparasites