Ichneumon wasp
Encyclopedia
The Ichneumonoidea are insect
s classified in the hymenoptera
n suborder Apocrita
. The superfamily
is made up of the ichneumon wasps (often inaccurately called "ichneumon flies"; family
Ichneumonidae
) and the braconids (family Braconidae
). Like other parasitic wasp
s, they were long placed in the "Parasitica", variously considered as an infraorder or an unranked clade
, but actually not a monophyletic group.
The superfamily Ichneumonoidea has been estimated to contain well over 80,000 different species. The ichneumon wasps are more familiar to non-entomologists, being larger and about three times as diverse as the braconids.
They are solitary insects, and most are parasitoid
s—the larva
e feeding on or in another insect which finally dies. Being in the same order, ichneumons are closely related to other hymenopterans such as ant
s and bee
s.
Members of the family Ichneumonidae are usually larger than members of the Braconidae, and are distinguished primarily by details of wing venation. Many species in both families utilize polydnavirus
es to suppress the immune system of the host insect.
Some members use many different insects as a host, others are very specific in host choice. Various ichneumons are used successfully as biological control agents
in controlling pests such as flies
or beetle
s.
Ichneumon wasp species are highly diverse, ranging from 3 millimetre (0.118110236220472 in) to 130 mm (5.1 in) long. Most are slender, with the females of many species (particularly in the genus Megarhyssa
) having an extremely long ovipositor
for laying eggs. The female finds a host and lays an egg on, near, or inside the host's body. Upon hatching, the larval ichneumon feeds either externally or internally, killing the host when they themselves are ready to pupa
te. Despite looking formidable, the ovipositor does not deliver a sting like many wasps or bees. It can be used by the wasps to bore into and lay eggs inside rotten wood.
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s classified in the hymenoptera
Hymenoptera
Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...
n suborder Apocrita
Apocrita
Apocrita is a suborder of insects in the order Hymenoptera.Apocrita includes wasps, bees and ants, and consists of many families. It includes the most advanced hymenopterans and is distinguished from Symphyta by the narrow "waist" formed between the first two segments of the actual abdomen; the...
. The superfamily
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
is made up of the ichneumon wasps (often inaccurately called "ichneumon flies"; family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Ichneumonidae
Ichneumonidae
Ichneumonidae is a family within the insect order Hymenoptera. Insects in this family are commonly called ichneumon wasps. Less exact terms are ichneumon flies , or scorpion wasps due to the extreme lengthening and curving of the abdomen...
) and the braconids (family Braconidae
Braconidae
Braconidae is a family of parasitoid wasps and one of the richest families of insects. Between 50,000 and 150,000 species exist worldwide. The species are grouped into about 45 subfamilies and 1,000 genera, some important ones being: Ademon, Aphanta, Asobara, Bracon hebetor, Cenocoelius, Chaenusa,...
). Like other parasitic wasp
Parasitic wasp
The term parasitoid wasp refers to a large evolutionary grade of hymenopteran superfamilies, mainly in the Apocrita. They are primarily parasitoids of other animals, mostly other arthropods...
s, they were long placed in the "Parasitica", variously considered as an infraorder or an unranked clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
, but actually not a monophyletic group.
The superfamily Ichneumonoidea has been estimated to contain well over 80,000 different species. The ichneumon wasps are more familiar to non-entomologists, being larger and about three times as diverse as the braconids.
They are solitary insects, and most are parasitoid
Parasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...
s—the 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 feeding on or in another insect which finally dies. Being in the same order, ichneumons are closely related to other hymenopterans such as ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s and bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s.
Members of the family Ichneumonidae are usually larger than members of the Braconidae, and are distinguished primarily by details of wing venation. Many species in both families utilize polydnavirus
Polydnavirus
The Polydnaviruses , are a family of insect viruses that contain two genera: Ichnoviruses and Bracoviruses . The ichnoviruses occur in ichneumonid wasps species and bracoviruses in braconid wasps. The genome of the virus is composed of multiple segments of double-stranded, superhelical DNA...
es to suppress the immune system of the host insect.
Some members use many different insects as a host, others are very specific in host choice. Various ichneumons are used successfully as biological control agents
Biological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
in controlling pests such as flies
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
or beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s.
Ichneumon wasp species are highly diverse, ranging from 3 millimetre (0.118110236220472 in) to 130 mm (5.1 in) long. Most are slender, with the females of many species (particularly in the genus Megarhyssa
Megarhyssa
Megarhyssa 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.-External links:* * -Species:...
) having an extremely long ovipositor
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
for laying eggs. The female finds a host and lays an egg on, near, or inside the host's body. Upon hatching, the larval ichneumon feeds either externally or internally, killing the host when they themselves are ready to pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
te. Despite looking formidable, the ovipositor does not deliver a sting like many wasps or bees. It can be used by the wasps to bore into and lay eggs inside rotten wood.