30-500: See below 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
60-618: A beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars, or that a cat should play with mice. Family (biology) Family ( Latin : familia , pl. : familiae ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between
90-457: A consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called the seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time
120-446: A family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching
150-652: A separate family, the Aphidiidae, the Aphidiinae are a lineage within the Braconidae. It is not yet clear to which braconid subfamilies they are most closely related. Ephedrini Praini Monoctonina Trioxina Aphidiina The Aphidiinae are subdivided into several tribes, the Ephedrini , Praini , Trioxini , Aclitini , and Aphidiini , with the latter subdivided into three subtribes. Most species reside in
180-483: A single individual. Due to the high diversity, the existence of numerous small and hard to identify species, and the majority of species being undiscovered, it has proven difficult to resolve the phylogeny of the ichneumonids. Even the relationships between subfamilies are unclear. The sheer diversity also means DNA sequence data is only available for a tiny fraction of the species, and detailed cladistic studies require major computing capacity. Extensive catalogues of
210-513: Is derived from Latin 'ichneumon', from Ancient Greek ἰχνεύμων (ikhneúmōn, "tracker"), from ἴχνος (íkhnos, "track, footstep"). The name first appeared in Aristotle 's " History of Animals ", c. 343 BC. Aristotle noted that the ichneumon preys upon spiders, is a wasp smaller than ordinary wasps, and carries its prey to a hole which they lay their larvae inside, and that they seal the hole with mud. Aristotle's writing, however, more accurately describes
240-531: Is subject to ongoing debate. Long believed to be rare in the tropics, and at its most species rich in the temperate region, the family became a classic textbook example of an 'exceptional' latitudinal diversity gradient . Recently this belief has been questioned, after the discovery of numerous new tropical species. A very few ichneumonid species lay their eggs in the ground, but the vast majority inject eggs either directly into their host 's body or onto its surface, and this may require penetration of substrate around
270-439: Is the basal branch of Apocrita , which together with Orussoidea makes up the lineage in which parasitoidism in Hymenoptera evolved, and some ichneumonids are thought to have been in stasis for millions of years and closely resemble the common ancestor in which parasitoidism evolved. This common ancestor was likely an Ectoparasitoid woodwasp that parasitized wood-boring beetle larvae in trees. The family has existed since at least
300-682: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Aphidiinae The Aphidiinae are a subfamily of tiny parasitoid wasps that use aphids as their hosts. Several species have been used in biological control programs of various aphids. Aphidiines are koinobiont endoparasitoids of adult and immature aphids. While
330-586: The Early Cretaceous ( c. 125 mya), but probably appeared already in the Jurassic (c. 181 mya), soon after the appearance of its major host groups. It diversified during the Oligocene. In 1999, the extant ichneumonids were divided into 39 subfamilies, whose names and definitions have varied considerably. In 2019, combined morphological and molecular phylogenetic analysis of the family resulted in
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#1732772361386360-404: The genus Ichneumon within the Ichneumonidae and thus can cause confusion. A group of ichneumonid specialists have proposed Darwin wasps as a better vernacular name for the family. Less exact terms are ichneumon flies (they are not closely related to true flies ) and scorpion wasps due to the extreme lengthening and curving of the abdomen ( scorpions are arachnids, not insects). The name
390-707: The mud daubers than the true ichneumon wasps, which do not construct mud nests and do not sting. Adult ichneumonids superficially resemble other wasps . They have a slender waist, two pairs of wings, a pair of large compound eyes on the side of the head and three ocelli on top of the head. Their size varies considerably from a few millimetres to seven or more centimetres. The ichneumonids have more antennal segments than typical, aculeate wasps ( Aculeata : Vespoidea and Apoidea ): ichneumonids typically possess 16 or more, while most other wasps have 13 or fewer. Unlike aculeate wasps, which have an ovipositor modified for prey capture and defense, and do not pass their eggs along
420-455: The stinger , ichneumonid females have an unmodified ovipositor which they use to lay eggs inside or on their host. Ichneumonids generally inject venom along with the egg, but only larger species (some in the genera Netelia and Ophion ) with relatively short ovipositors use the ovipositor in defense. Males do not possess stingers or ovipositors in either lineage. Ichneumonids are distinguished from their sister group Braconidae mainly on
450-463: The Ichneumonidae so troubling that it contributed to his increasing doubts about the nature and existence of a Creator. In an 1860 letter to the American naturalist Asa Gray , Darwin wrote: I own that I cannot see as plainly as others do, and as I should wish to do, evidence of design and beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that
480-492: The basis of wing venation. The fore wing of 95% of ichneumonids has vein 2m-cu (in the Comstock–Needham system ), which is absent in braconids. Vein 1rs-m of the fore wing is absent in all ichneumonids, but is present in 85% of braconids. In the hind wing of ichneumonids, vein rs-m joins Rs apical to (or rarely opposite) the split between veins Rs and R1. In braconids, vein rs-m joins basal to this split. The taxa also differ in
510-514: The book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,
540-540: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and
570-400: The following 41 subfamilies being recognized, in addition to the extinct Labenopimplinae . Famous ichneumonologists include: The perceived cruelty of the ichneumonids troubled philosophers, naturalists, and theologians in the 19th century, who found the parasitoid life cycle inconsistent with the notion of a world created by a loving and benevolent God. Charles Darwin found the example of
600-578: The host typically dies after some weeks, after which the ichneumonid larva emerges and pupates. Adult ichneumonids feed on a diversity of foods, including plant sap and nectar; females of some species also feed on their hosts by sipping body fluids released during oviposition, or even stabbing host and non-host insects to imbibe their body fluids. They spend much of their active time searching, either for hosts (female ichneumonids) or for emerging females (male ichneumonids). The parasitism pressure exerted by ichneumonids can be tremendous, and they are often one of
630-485: The host, as in wood-boring host larvae that live deep inside of tree trunks, requiring the ichneumon to drill its ovipositor through several centimeters of solid wood (e.g., Megarhyssa species). After hatching, the ichneumonid larva consumes its still living host. The most common hosts are larvae or pupae of Lepidoptera , Coleoptera and Hymenoptera . Some species in the subfamily Pimplinae also parasitise spiders. Hyperparasitoids such as Mesochorinae oviposit inside
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#1732772361386660-575: The ichneumonids include those by Aubert, Gauld, Perkins, and Townes . Due to the taxonomic difficulties involved, however, their classifications and terminology are often confusingly contradictory. Several prominent authors have gone as far as to publish major reviews that defy the International Code of Zoological Nomenclature . The large number of species in Ichneumonidae may be due to the evolution of parasitoidism in Hymenoptera, which occurred approximately 247 million years ago. Ichneumonidae
690-443: The ichneumonids was traditionally considered an exception to the common latitudinal gradient in species diversity , since the family was thought to be at its most species-rich in the temperate zone instead of the tropics, but numerous new tropical species have now been discovered. Insects in the family Ichneumonidae are commonly called ichneumon wasps , or ichneumonids . However, the term ichneumon wasps can refer specifically to
720-474: The larva of the 2–3 mm long Praon leaves the hollowed shell of the aphid from below to pupate in a volcano -like cocoon , most other Aphidiinae pupate inside the dead aphid and break out afterwards. These wasps are found worldwide, but are primarily found in the northern hemisphere. Several species have been introduced to countries outside of their natural range, both accidentally and purposefully for biocontrol. Although they have often been treated as
750-526: The larvae of other ichneumonoids. The hosts of some species are agricultural pests, therefore ichneumons are sometimes valuable for biological pest control , but the hosts of most species are unknown; host information has been reviewed and summarized by various researchers, e.g. Aubert, Perkins. and Townes . Ichneumonids use both idiobiont and koinobiont strategies. Idiobionts paralyze their host and prevent it from moving or growing. Koinobionts allow their host to continue to grow and develop. In both strategies,
780-591: The major regulators of invertebrate populations. It is quite common for 10-20% or more of a host's population to be parasitised (though reported parasitism rates often include non-ichneumonid parasitoids). The taxonomy of the ichneumonids is still poorly known. The family is highly diverse, containing 24,000 described species. Approximately 60,000 species are estimated to exist worldwide, though some estimates place this number at over 100,000. They are severely undersampled, and studies of their diversity typically produce very high numbers of species which are represented by only
810-526: 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 play an important role as regulators of insect populations, both in natural and semi-natural systems, making them promising agents for biological control . The distribution of
840-491: The ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae , but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging
870-495: The structure of the metasoma: about 90% of ichneumonids have a flexible suture between tergites 2 and 3, whereas these tergites are fused in braconids (though the suture is secondarily flexible in Aphidiinae ). Ichneumonids are found on all continents with the exception of Antarctica. They inhabit virtually all terrestrial habitats, wherever there are suitable invertebrate hosts. The distribution of ichneumonid species richness
900-488: Was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted the use of this term solely within
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