Ovipositor

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Ovipositor of long-horned grasshopper (the two cerci are also visible) GrassHopperOviPositor.jpg
Ovipositor of long-horned grasshopper (the two cerci are also visible)

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 typically its form is adapted to functions such as preparing a place for the egg, transmitting the egg, and then placing it properly. For most insects, the organ is used merely to attach the egg to some surface, but for many parasitic species (primarily in wasps and other Hymenoptera), it is a piercing organ as well.

Contents

Some ovipositors only retract partly when not in use, and the basal part that sticks out is known as the scape, or more specifically oviscape, the word scape deriving from the Latin word scāpus , meaning "stalk" or "shaft".

In insects

The process of oviposition in Dolichomitus imperator:
1. Tapping with her antennae, the wasp listens for the vibrations that indicate a host is present
2. With the longer ovipositor, the wasp drills a hole through the bark
3. The wasp inserts the ovipositor into the cavity which contains the host larva
4. Making corrections
5-6. Depositing the eggs Dolichomitus imperator Oviposition R Bartz.jpg

The process of oviposition in Dolichomitus imperator :
1. Tapping with her antennae, the wasp listens for the vibrations that indicate a host is present
2. With the longer ovipositor, the wasp drills a hole through the bark
3. The wasp inserts the ovipositor into the cavity which contains the host larva
4. Making corrections
5-6. Depositing the eggs

Grasshoppers use their ovipositors to force a burrow into the earth to receive the eggs. Cicadas pierce the wood of twigs with their ovipositors to insert the eggs. Sawflies slit the tissues of plants by means of the ovipositor and so do some species of long-horned grasshoppers. In the ichneumon wasp genus Megarhyssa , the females have a slender ovipositor (terebra) several inches long that is used to drill into the wood of tree trunks. [1] These species are parasitic in the larval stage on the larvae of horntail wasps, hence the egg must be deposited directly into the host's body as it is feeding. The ovipositors of Megarhyssa are among the longest egg-laying organs (relative to body size) known. [2]

The stingers of the Aculeata (wasps, hornets, bees, and ants) are ovipositors, highly modified and with associated venom glands. They are used to paralyze prey, or as defensive weapons. The penetrating sting plus venom allows the wasp to lay eggs with less risk of injury from the host. In some cases, the injection also introduces virus particles that suppress the host's immune system and prevent it from destroying the eggs. [3] However, in virtually all stinging Hymenoptera, the ovipositor is no longer used for egg-laying. An exception is the family Chrysididae, members of the Hymenoptera, in which species such as Chrysis ignita have reduced stinging apparatus and a functional ovipositor.

Fig wasp ovipositors have specialized serrated teeth to penetrate fruits, but gall wasps have either uniform teeth or no teeth on their ovipositors, meaning the morphology of the organ is related to the life history. [4]

Members of the Dipteran (fly) families Tephritidae and Pyrgotidae have well-developed ovipositors that are partly retracted when not in use, with the part that sticks out being the oviscape. Oestridae, another family within Diptera, often have short hairy ovipositors, the species Cuterebra fontinella has one of the shortest within the family. [5]

Ovipositors exist not only in winged insects, but also in Apterygota, where the ovipositor has an additional function in gathering the spermatophore during mating. Little is known about the egg-laying habits of these insects in the wild. [6]

In fish

Female bitterlings in the genus Rhodeus have an ovipositor in the form of a tubular extension of the genital orifice. During breeding season, they use it when depositing eggs in the mantle cavity of freshwater mussels, where their eggs develop in reasonable security. Seahorses have an ovipositor for introducing eggs into the brood pouch of the male, who carries them until it is time to release the fry into a suitable situation in the open water.

In amphibians

The marbled newt, or Triturus marmoratus, females participate in parental investment by ovipositing their eggs. They carefully wrap them in aquatic leaves as a form of protection, scattering them throughout a pond to avoid predation. Females are not able to breathe during the oviposition process; therefore, the benefit to wrapping the eggs outweigh the cost of holding their breath. [7]

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Related Research Articles

<span class="mw-page-title-main">Hymenoptera</span> Order of insects comprising sawflies, wasps, bees, and ants

Hymenoptera is a large order of insects, comprising the 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 parasitic. Females typically have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. This ovipositor is often modified into a stinger. The young develop through holometabolism —that is, they have a wormlike larval stage and an inactive pupal stage before they mature.

<span class="mw-page-title-main">Sawfly</span> Suborder of insects

Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay their eggs. The name is associated especially with the Tenthredinoidea, by far the largest superfamily in the suborder, with about 7,000 known species; in the entire suborder, there are 8,000 described species in more than 800 genera. Symphyta is paraphyletic, consisting of several basal groups within the order Hymenoptera, each one rooted inside the previous group, ending with the Apocrita which are not sawflies.

<span class="mw-page-title-main">Apocrita</span> Suborder of insects containing wasps, bees, and ants

Apocrita is a suborder of insects in the order Hymenoptera. It includes wasps, bees, and ants, and consists of many families. It contains the most advanced hymenopterans and is distinguished from Symphyta by the narrow "waist" (petiole) formed between the first two segments of the actual abdomen; the first abdominal segment is fused to the thorax, and is called the propodeum. Therefore, it is general practice, when discussing the body of an apocritan in a technical sense, to refer to the mesosoma and metasoma rather than the "thorax" and "abdomen", respectively. The evolution of a constricted waist was an important adaption for the parasitoid lifestyle of the ancestral apocritan, allowing more maneuverability of the female's ovipositor. The ovipositor either extends freely or is retracted, and may be developed into a stinger for both defense and paralyzing prey. Larvae are legless and blind, and either feed inside a host or in a nest cell provisioned by their mothers.

<span class="mw-page-title-main">Ichneumonoidea</span> Superfamily of wasps

The superfamily Ichneumonoidea contains one extinct and three extant families, including the two largest families within Hymenoptera: Ichneumonidae and Braconidae. The group is thought to contain as many as 100,000 species, many of which have not yet been described. Like other parasitoid wasps, they were long placed in the "Parasitica", variously considered as an infraorder or an unranked clade, now known to be paraphyletic.

<span class="mw-page-title-main">Ichneumonidae</span> Family of wasps

The Ichneumonidae, also known as ichneumon wasps, ichneumonid wasps, ichneumonids, or Darwin wasps, are a family of parasitoid wasps of the insect order Hymenoptera. They are one of the most diverse groups within the Hymenoptera with roughly 25,000 species described as of 2016. However, this likely represents less than a quarter of their true richness as reliable estimates are lacking, along with much of the most basic knowledge about their ecology, distribution, and evolution. It is estimated that there are more species in this family than there are species of birds and mammals combined. Ichneumonid wasps, with very few exceptions, attack the immature stages of holometabolous insects and spiders, eventually killing their hosts. They thus fulfill an important role as regulators of insect populations, both in natural and semi-natural systems, making them promising agents for biological control.

<span class="mw-page-title-main">Horntail</span> Family of sawflies

Horntail or wood wasp are any of the 150 non-social species of the hymenopteran family Siricidae, a type of wood-eating sawfly. The common name "horntail" derives from the stout, spine-like structure at the end of the adult's abdomen, which is used to pierce the host's bark to allow the eggs to be inserted into the wood. A typical adult horntail is brown, blue, or black with yellow or red parts, and may often reach up to 4 cm (1.6 in) long. The pigeon horntail can grow up to 5 cm (2.0 in) long, among the longest of all Hymenoptera.

<i>Megarhyssa</i> Genus of wasps

Megarhyssa, also known as giant ichneumonid wasps, giant ichneumons, or stump stabbers, is a genus of large ichneumon wasps, with some species known for having the longest ovipositors of any insects. They are idiobiont endoparasitoids of the larvae of wood-boring horntail wasps. The ovipositor can be mistaken for a large stinger.

<span class="mw-page-title-main">Wasp</span> Group of insects

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. The wasps do not constitute a clade, a complete natural group with a single ancestor, as bees and ants are deeply nested within the wasps, having evolved from wasp ancestors. Wasps that are members of the clade Aculeata can sting their prey.

<i>Xanthocryptus novozealandicus</i> Species of wasp

Xanthocryptus novozealandicus, the lemon tree borer parasite, is a wasp in the family Ichneumonidae. It is a native insect of New Zealand. It is also found in Australia and New Guinea. Females hunt for larvae of wood-boring beetles around March, including the lemon tree borer, a native cerambycid that tunnels into citrus trees, grapes and many native species. When a suitable host is found, the female pushes her ovipositor through the wood and injects her eggs into the grub. This has the incidental benefit of helping to control some pests. X. novozealandicus prefers to prey on second year lemon tree borer larvae. This specific parasite prefers to prey on larger second year larvae due to its larger size.

<i>Tremex columba</i> Species of sawfly

Tremex columba, also known as the pigeon tremex or pigeon horntail, is a species of horntail that is native to eastern and western North America.

<i>Rhyssa persuasoria</i> Species of wasp

Rhyssa persuasoria, also known as the sabre wasp, is a species belonging to the family Ichneumonidae subfamily Rhyssinae. Members of this subfamily, including those of Rhyssa and the allied Megarhyssa, are also known collectively as giant ichneumonid wasps or giant ichneumons.

<i>Kollasmosoma sentum</i> Species of wasp

Kollasmosoma sentum is a parasitoid wasp in the family Braconidae, which lays its eggs inside adult ants. It was featured as one of "the top 10 new species of 2012" in a list compiled by Conservationists at the Arizona State University International Institute for Species Exploration.

<i>Evania appendigaster</i> Species of wasp

Evania appendigaster, also known as the blue-eyed ensign wasp, is a species of wasp in the family Evaniidae. Its native range is not known, but it likely originated in Asia. Today it occurs throughout the tropics and subtropics and in many temperate regions. As with the rest of its family, the blue-eyed ensign wasp is a parasitoid known for specializing on cockroach eggs.

<span class="mw-page-title-main">Dufour's gland</span>

Dufour's gland is an abdominal gland of certain insects, part of the anatomy of the ovipositor or sting apparatus in female members of Apocrita. The diversification of Hymenoptera took place in the Cretaceous and the gland may have developed at about this time as it is present in all three groups of Apocrita, the wasps, bees and ants.

<i>Apocrypta</i> Genus of wasps

Apocrypta is an Old World genus of parasitic fig wasps in the family Pteromalidae. They are parasitoids of gall-wasps in the Sycophagini tribe, and especially Ceratosolen species, pollinators of the Sycomorus, Sycocarpus and Neomorphe sections of Ficus. They seem to be fig species-specific.

<i>Chrysis ignita</i> Species of wasp

Chrysis ignita is a species of cuckoo wasp. It is one of a group of species which are difficult to separate and which may be referred to as ruby-tailed wasps.

<i>Megarhyssa macrurus</i> Species of wasp

Megarhyssa macrurus, also known as the long-tailed giant ichneumonid wasp or long-tailed giant ichneumon wasp, is a species of large ichneumon wasp. It is a parasitoid, notable for its extremely long ovipositor which it uses to deposit an egg into a tunnel in dead wood bored by its host, the larva of a similarly large species of horntail.

<i>Leucospis dorsigera</i> Species of wasp

Leucospis dorsigera is a species of wasp belonging to the family Leucospidae.

<i>Pimpla rufipes</i> Species of wasp

Pimpla rufipes, the black slip wasp, is a species of wasp belonging to the family Ichneumonidae. It is distributed across Europe, Asia, and northern Africa.

<i>Vespula infernalis</i> Species of wasp

Vespula infernalis is an obligate parasitic wasp, parasitizing the nests of other species in the genus Vespula. Its common host species is V. acadica in North America. It is sometimes called the cuckoo yellowjacket wasp due to its inquiline lifestyle. They differ from other parasitic wasps in their intensely aggressive behaviour during invasion and occupation of the host colony. Several morphological adaptations such as bigger body parts and highly curved stingers are present in these wasps to aid their aggressive parasitic behaviour.

References

  1. Sezen, Uzay (22 July 2012). "Two ichneumon wasps competing to oviposit" . Retrieved 24 July 2012.
  2. Sezen, Uzay. "Giant ichneumon wasp ovipositing" . Retrieved 15 February 2016.
  3. "Evolutionary Genetics". www.zoology.ubc.ca.
  4. Elias, Larissa; Kjellberg, Finn; Farache, Fernando Henriche Antoniolli; Almeida, Eduardo; Rasplus, Jean-Yves; Cruaud, Astrid; Peng, Yan-Quiong; Yang, Da-Rong; Pereira, Rodrigo Augusto Santinelo (July 2018). "Ovipositor morphology correlates with life history evolution in agaonid fig wasps" (PDF). Acta Oecologica. 90: 109–116. Bibcode:2018AcO....90..109E. doi:10.1016/j.actao.2017.10.007. S2CID   90329549.
  5. Hadwen S (1915). "A description the egg and ovipositor of Cuterebra fontinella, Clark (Cottontail Bot.)". Journal of the Entomological Society of British Columbia. 5: 88–91.
  6. Matushkina, Natalia A. (January 2011). "Ovipositor Internal Microsculpture in the Relic Silverfish Tricholepidion gertschi (Insecta: Zygentoma)" (PDF). Psyche: A Journal of Entomology. 2011: 1–8. doi: 10.1155/2011/563852 . Archived (PDF) from the original on 2022-10-09. Retrieved 22 August 2020.
  7. Díaz-Paniagua, Carmen (1989). "Oviposition Behavior of Triturus marmoratus pygmaeus". Journal of Herpetology. 23 (2): 159–163. doi:10.2307/1564022. ISSN   0022-1511. JSTOR   1564022.