Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, sooner or causing the death of these hosts. Different species specialise in hosts from different insect orders, most Lepidoptera, though some select beetles, flies, or bugs. Parasitoid wasp species differ in which host life-stage they attack: eggs, pupae, or adults, they follow one of two major strategies within parasitism: either they are endoparasitic, developing inside the host, koinobiont, allowing the host to continue to feed and moult. Some endoparasitic wasps of the superfamily Ichneumonoidea have a mutualistic relationship with polydnaviruses, the viruses suppressing the host's immune defenses. Parasitoidism evolved only once in the Hymenoptera, during the Permian, leading to a single clade, but the parasitic lifestyle has secondarily been lost several times including among the ants and yellowjacket wasps.
As a result, the order Hymenoptera contains many families of parasitoids, intermixed with non-parasitoid groups. The parasitoid wasps include some large groups, some estimates giving the Chalcidoidea as many as 500,000 species, the Ichneumonidae 100,000 species, the Braconidae up to 50,000 species. Host insects have evolved a range of defences against parasitoid wasps, including hiding and camouflage markings. Many parasitoid wasps are considered beneficial to humans because they control agricultural pests; some are applied commercially in biological pest control, starting in the 1920s with Encarsia formosa to control whitefly in greenhouses. Parasitoidism in wasps influenced the thinking of Charles Darwin. Parasitoid wasps range from some of the smallest species of insects to wasps about an inch long. Most females have a long, sharp ovipositor at the tip of the abdomen, sometimes lacking venom glands, never modified into a sting. Parasitoids can be classified in a variety of ways, they can live within their host's body as endoparasitoids, or feed on it from outside as ectoparasitoids: both strategies are found among the wasps.
Parasitoids can be divided according to their effect on their hosts. Idiobionts prevent further development of the host after immobilizing it, while koinobionts allow the host to continue its development while they are feeding upon it. Most ectoparasitoid wasps are idiobiont, as the host could damage or dislodge the external parasitoid if allowed to move or moult. Most endoparasitoid wasps are koinobionts, giving them the advantage of a host that continues to grow larger and remains able to avoid predators. Many parasitoid wasps use larval Lepidoptera as hosts, but some groups parasitize different host life stages of nearly all other orders of insects Coleoptera, Diptera and other Hymenoptera; some attack arthropods other than insects: for instance, the Pompilidae specialise in catching spiders: these are quick and dangerous prey as large as the wasp itself, but the spider wasp is quicker, swiftly stinging her prey to immobilise it. Adult female wasps of most species oviposit into their hosts' eggs.
Some inject a mix of secretory products that paralyse the host or protect the egg from the host's immune system. If a polydnavirus is included, it infects the nuclei of host hemocytes and other cells, causing symptoms that benefit the parasite. Host size is important for the development of the parasitoid, as the host is its entire food supply until it emerges as an adult; some species preferentially lay female eggs in larger hosts and male eggs in smaller hosts, as the reproductive capabilities of males are limited less by smaller adult body size. Some parasitoid wasps mark the host with chemical signals to show; this may both deter rivals from ovipositing, signal to itself that no further egg is needed in that host reducing the chances that offspring will have to compete for food and increasing the offspring's survival. On or inside the host the parasitoid egg hatches into two or more larvae. Endoparasitoid eggs can absorb fluids from the host body and grow several times in size from when they were first laid before hatching.
The first instar larvae is highly mobile and may have strong mandibles or other structures to compete with other parasitiod larvae. The following instars are more grub-like. Parasitoid larvae have incomplete digestive systems with no rear opening; this prevents the hosts from being contaminated by their wastes. The larva feeds on the host's tissues until ready to pupate. A meconium, or the accumulated wastes from the larva is cast out as the larva transitions to a prepupa. Depending on its species, the parasitoid may eat its way out of the host or remain in the more or less empty skin. In either case it generally spins a cocoon and pupates; as adults, parasitoid wasps feed on nectar from flowers. Females of some species will drink hemolymph from hosts to gain additional nutrients for egg production. Polydnaviruses are a unique group of insect viruses that have a mutualistic relationship with some parasitic wasps; the polydnavirus replicates in the oviducts of an adult female parasitoid wasp. The wasp benefits from this relationship be
The Jurassic period was a geologic period and system that spanned 56 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era known as the Age of Reptiles; the start of the period was marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian-Toarcian extinction in the Early Jurassic, the Tithonian event at the end; the Jurassic period is divided into three epochs: Early and Late. In stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, Upper Jurassic series of rock formations; the Jurassic is named after the Jura Mountains within the European Alps, where limestone strata from the period were first identified. By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north, Gondwana to the south; this created more coastlines and shifted the continental climate from dry to humid, many of the arid deserts of the Triassic were replaced by lush rainforests.
On land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds appeared during the Jurassic, having evolved from a branch of theropod dinosaurs. Other major events include the appearance of the earliest lizards, the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to an aquatic mode of life; the oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, while pterosaurs were the dominant flying vertebrates. The chronostratigraphic term "Jurassic" is directly linked to the Jura Mountains, a mountain range following the course of the France–Switzerland border. During a tour of the region in 1795, Alexander von Humboldt recognized the limestone dominated mountain range of the Jura Mountains as a separate formation that had not been included in the established stratigraphic system defined by Abraham Gottlob Werner, he named it "Jura-Kalkstein" in 1799.
The name "Jura" is derived from the Celtic root *jor via Gaulish *iuris "wooded mountain", borrowed into Latin as a place name, evolved into Juria and Jura. The Jurassic period is divided into three epochs: Early and Late. In stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, Upper Jurassic series of rock formations known as Lias and Malm in Europe; the separation of the term Jurassic into three sections originated with Leopold von Buch. The faunal stages from youngest to oldest are: During the early Jurassic period, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana; the Jurassic North Atlantic Ocean was narrow, while the South Atlantic did not open until the following Cretaceous period, when Gondwana itself rifted apart. The Tethys Sea closed, the Neotethys basin appeared. Climates were warm, with no evidence of a glacier having appeared; as in the Triassic, there was no land over either pole, no extensive ice caps existed.
The Jurassic geological record is good in western Europe, where extensive marine sequences indicate a time when much of that future landmass was submerged under shallow tropical seas. In contrast, the North American Jurassic record is the poorest of the Mesozoic, with few outcrops at the surface. Though the epicontinental Sundance Sea left marine deposits in parts of the northern plains of the United States and Canada during the late Jurassic, most exposed sediments from this period are continental, such as the alluvial deposits of the Morrison Formation; the Jurassic was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus common, along with calcitic ooids, calcitic cements, invertebrate faunas with dominantly calcitic skeletons; the first of several massive batholiths were emplaced in the northern American cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are found in Russia, South America, Japan and the United Kingdom.
In Africa, Early Jurassic strata are distributed in a similar fashion to Late Triassic beds, with more common outcrops in the south and less common fossil beds which are predominated by tracks to the north. As the Jurassic proceeded and more iconic groups of dinosaurs like sauropods and ornithopods proliferated in Africa. Middle Jurassic strata are neither well studied in Africa. Late Jurassic strata are poorly represented apart from the spectacular Tendaguru fauna in Tanzania; the Late Jurassic life of Tendaguru is similar to that found in western North America's Morrison Formation. During the Jurassic period, the primary vertebrates living in the sea were marine reptiles; the latter include ichthyosaurs, which were at the peak of their diversity, plesiosaurs and marine crocodiles of the families Teleosauridae and Metriorhynchidae. Numerous turtles could be found in rivers. In the invertebrate world, several new groups appeared, including rudists (a reef-formi
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians have a larval phase of their life cycle; the larva's appearance is very different from the adult form including different unique structures and organs that do not occur in the adult form. Their diet may be different. Larvae are adapted to environments separate from adults. For example, some larvae such as tadpoles live exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some species like barnacles, adults are immobile but their larvae are mobile, use their mobile larval form to distribute themselves; some larvae are dependent on adults to feed them. In many eusocial Hymenoptera species, the larvae are fed by female workers.
In Ropalidia marginata the males are capable of feeding larvae but they are much less efficient, spending more time and getting less food to the larvae. The larvae of some species do not develop further into the adult form; this is a type of neoteny. It is a misunderstanding; this could be the case, but the larval stage has evolved secondarily, as in insects. In these cases the larval form may differ more than the adult form from the group's common origin. Within Insects, only Endopterygotes show different types of larvae. Several classifications have been suggested by many entomologists, following classification is based on Antonio Berlese classification in 1913. There are four main types of endopterygote larvae types: Apodous larvae – no legs at all and are poorly sclerotized. Based on sclerotization, three apodous forms are recognized. Eucephalous – with well sclerotized head capsule. Found in Nematocera and Cerambycidae families. Hemicephalus – with a reduced head capsule, retractable in to the thorax.
Found in Tipulidae and Brachycera families. Acephalus – without head capsule. Found in Cyclorrhapha Protopod larvae – larva have many different forms and unlike a normal insect form, they hatch from eggs which contains little yolk. Ex. first instar larvae of parasitic hymenoptera. Polypod larvae – known as eruciform larvae, these larva have abdominal prolegs, in addition to usual thoracic legs, they poorly sclerotized and inactive. They live in close contact with the food. Best example is caterpillars of lepidopterans. Oligopod larvae – have well developed head capsule and mouthparts are similar to the adult, but without compound eyes, they have six legs. No abdominal prolegs. Two types can be seen: Campodeiform – well sclerotized, dorso-ventrally flattened body. Long legged predators with prognathous mouthparts.. Scarabeiform – poorly sclerotized, flat thorax and abdomen. Short legged and inactive burrowing forms.. Crustacean larvae Ichthyoplankton Spawn Non-larval animal juvenile stages and other life cycle stages: In Porifera: olynthus, gemmule In Cnidaria: ephyra, strobila, hydranth, medusa In Mollusca: paralarva, young cephalopods In Platyhelminthes: hydatid cyst In Bryozoa: avicularium In Acanthocephala: cystacanth In Insecta: Nymphs and naiads, immature forms in hemimetabolous insects Subimago, a juvenile that resembles the adult in Ephemeroptera Instar, intermediate between each ecdysis Pupa and chrysalis, intermediate stages between larva and imago Protozoan life cycle stages Apicomplexan life cycle Algal life cycle stages: Codiolum-phase Conchocelis-phase Marine larval ecology Media related to Larvae at Wikimedia Commons The dictionary definition of larva at Wiktionary Arenas-Mena, C.
Indirect development, transdifferentiation and the macroregulatory evolution of metazoans. Philosophical Transactions of the Royal Society B: Biological Sciences. Feb 27, 2010 Vol.365 no.1540 653-669 Brusca, R. C. & Brusca, G. J.. Invertebrates. Sunderland, Mass.: Sinauer Associates. Hall, B. K. & Wake, M. H. eds.. The Origin and Evolution of Larval Forms. San Diego: Academic Press. Leis, J. M. & Carson-Ewart, B. M. eds.. The Larvae of Indo-Pacific Coastal Fishes. An Identification Guide to Marine Fish Larvae. Fauna Malesiana handbooks, vol. 2. Brill, Leiden. Minelli, A.. The larva. In: Perspectives in Animal Phylogeny and Evolution. Oxford University Press. P. 160-170. Link. Shanks, A. L.. An Identification Guide to the Larval Marine Invertebrates of the Pacific Northwest. Oregon State University Press, Corvallis. 256 pp. Smith, D. & Johnson, K. B.. A Guide to Marine Coastal Plankton and Marine Invertebrate Larvae. Kendall/Hunt Plublishing Company. Stanwell-Smith, D. Hood, A. & Peck, L. S.. A field guide to the pelagic invertebrates larvae of the maritime Antarctic.
British Antarctic Survey, Cambridge. Thyssen, P. J.. Keys for Identification of Immature Insects. In: Amendt, J. et al.. Current Concepts in Forensic Entomology, chapter 2, pp. 25–42. Springer: Dordrecht
The Apocrita are a suborder of insects in the order Hymenoptera. It includes wasps and ants, consists of many families, it contains the most advanced hymenopterans and is distinguished from Symphyta by the narrow "waist" formed between the first two segments of the actual abdomen. 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 or is retracted, may be developed into a stinger for both defense and paralyzing prey. Larvae are legless and blind, either feed inside a host or in a nest cell provisioned by their mothers; the Apocrita have been split into two groups, "Parasitica" and Aculeata, but these are rankless groupings in present classifications, if they appear at all.
The term Parasitica is an artificial group comprising the majority of hymenopteran insects, with respective members living as parasitoids on what amounts to nearly half of all insects, many noninsects. Most species are small, with the ovipositor adapted for piercing. In some hosts, the parasitoids induce metamorphosis prematurely, in others it is prolonged. There are species that are hyperparasites, parasitoids on other parasitoids; the Parasitica lay their eggs inside or on another insect and their larvae grow and develop within or on that host. The host is nearly always killed. Many parasitic hymenopterans are used as biological control agents to control pests, such as caterpillars, true bugs and hoppers and weevils; the Aculeata are a monophyletic group that includes those species in which the female's ovipositor is modified into a stinger to inject venom. Groups include the familiar ants and various types of parasitic and predatory wasps. Among the nonparasitic and nonsocial Aculeata, larvae are fed with captured prey or may be fed pollen and nectar.
The social Aculeata feed their young prey, or pollen and nectar, or seeds, fungi, or nonviable eggs. The Apocrita contains a large number of families; some traditional taxa such as the Parasitica have been found on molecular analysis to be paraphyletic. Parasitoidism evolved once, it is found today across most Apocritan families, though it has been secondarily lost several times; the phylogenetic tree gives a condensed overview of the phylogeny, illustrated with major groups. The tree is not resolved. Suborder Apocrita Aculeata Superfamily Apoidea Family Ampulicidae Family Andrenidae Family Apidae Family Colletidae Family Crabronidae Family Halictidae Family Heterogynaidae Family Megachilidae Family Melittidae Family Stenotritidae Family Sphecidae Superfamily Chrysidoidea Family Bethylidae Family Chrysididae Family Dryinidae Family Embolemidae Family Plumariidae Family Sclerogibbidae Family Scolebythidae Superfamily Vespoidea Family Bradynobaenidae Family Mutillidae Family Pompilidae Family Rhopalosomatidae Family Sapygidae Family Scoliidae Family Sierolomorphidae Family Tiphiidae Family Vespidae Superfamily Formicoidea Family Formicidae Parasitica Superfamily Ceraphronoidea Family Ceraphronidae Family Megaspilidae Superfamily Chalcidoidea Family Agaonidae Family Aphelinidae Family Chalcididae Family Encyrtidae Family Eucharitidae Family Eulophidae Family Eupelmidae Family Eurytomidae Family Leucospidae Family Mymaridae – the smallest of all insects Family Ormyridae Family Perilampidae Family Pteromalidae Family Rotoitidae Family Signiphoridae Family Tanaostigmatidae Family Tetracampidae Family Torymidae Family Trichogrammatidae Superfamily Cynipoidea Family Austrocynipidae Family Cynipidae Family Figitidae Family Ibaliidae Family Liopteridae Superfamily Diaprioidea Family Austroniidae Family Diapriidae Family Maamingidae Family Monomachidae Superfamily Evanioidea Family Aulacidae Family Evaniidae Family Gasteruptiidae Superfamily Ichneumonoidea Family Braconidae Family Ichneumonidae Superfamily Megalyroidea Family Megalyridae Superfamily Mymarommatoidea – sometimes called Serphitoidea Family Mymarommatidae Superfamily Platygastroidea Family Platygastridae Family Scelionidae Superfamily Proctotrupoidea Family Heloridae Family Pelecinidae Family Peradeniidae Family Proctorenyxidae Family Proctotrupidae Family Roproniidae Family Vanhorniidae Superfamily Stephanoidea Family Stephanidae Superfamily Trigonaloidea Family Trigonalidae Grimaldi, D. & Engel, M.
S.. Evolution of the Insects. Cambridge University Press. ISBN 978-0-521-82149-0. Suborder Apocrita – Ants and Wasps – BugGuide. Net — images and other information Science Direct — Apocrita. An Overview Tree of Life Balades Entomologiques — "entomological walks" with images
Ants are eusocial 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 Cretaceous period, about 140 million years ago, diversified after the rise of flowering plants. More than 12,500 of an estimated total of 22,000 species have been classified, they are identified by their elbowed antennae and the distinctive node-like structure that forms their slender waists. Ants form colonies that range in size from a few dozen predatory individuals living in small natural cavities to organised colonies that may occupy large territories and consist of millions of individuals. Larger colonies consist of various castes of sterile, wingless females, most of which are workers, as well as soldiers and other specialised groups. Nearly all ant colonies have some fertile males called "drones" and one or more fertile females called "queens"; the colonies are described as superorganisms because the ants appear to operate as a unified entity, collectively working together to support the colony.
Ants have colonised every landmass on Earth. The only places lacking indigenous ants are a few remote or inhospitable islands. Ants thrive in most ecosystems and may form 15–25% of the terrestrial animal biomass, their success in so many environments has been attributed to their social organisation and their ability to modify habitats, tap resources, defend themselves. Their long co-evolution with other species has led to mimetic, commensal and mutualistic relationships. Ant societies have division of labour, communication between individuals, an ability to solve complex problems; these parallels with human societies have long been an subject of study. Many human cultures make use of ants in cuisine and rituals; some species are valued in their role as biological pest control agents. Their ability to exploit resources may bring ants into conflict with humans, however, as they can damage crops and invade buildings; some species, such as the red imported fire ant, are regarded as invasive species, establishing themselves in areas where they have been introduced accidentally.
The word ant and its chiefly dialectal form emmet come from ante, emete of Middle English, which come from ǣmette of Old English, these are all related to the dialectal Dutch emt and the Old High German āmeiza, from which comes the modern German Ameise. All of these words come from West Germanic *ēmaitijǭ, the original meaning of the word was "the biter"; the family name Formicidae is derived from the Latin formīca from which the words in other Romance languages, such as the Portuguese formiga, Italian formica, Spanish hormiga, Romanian furnică, French fourmi are derived. It has been hypothesised that a Proto-Indo-European word *morwi- was used, cf. Sanskrit vamrah, Latin formīca, Greek μύρμηξ mýrmēx, Old Church Slavonic mraviji, Old Irish moirb, Old Norse maurr, Dutch mier; the family Formicidae belongs to the order Hymenoptera, which includes sawflies and wasps. Ants evolved from a lineage within the stinging wasps, a 2013 study suggests that they are a sister group of the Apoidea. In 1966, E. O. Wilson and his colleagues identified the fossil remains of an ant that lived in the Cretaceous period.
The specimen, trapped in amber dating back to around 92 million years ago, has features found in some wasps, but not found in modern ants. Sphecomyrma was a ground forager, while Haidomyrmex and Haidomyrmodes, related genera in subfamily Sphecomyrminae, are reconstructed as active arboreal predators. Older ants in the genus Sphecomyrmodes have been found in 99 million year-old amber from Myanmar. A 2006 study suggested that ants arose tens of millions of years earlier than thought, up to 168 million years ago. After the rise of flowering plants about 100 million years ago they diversified and assumed ecological dominance around 60 million years ago; some groups, such as the Leptanillinae and Martialinae, are suggested to have diversified from early primitive ants that were to have been predators underneath the surface of the soil. During the Cretaceous period, a few species of primitive ants ranged on the Laurasian supercontinent, they were scarce in comparison to the populations of other insects, representing only about 1% of the entire insect population.
Ants became dominant after adaptive radiation at the beginning of the Paleogene period. By the Oligocene and Miocene, ants had come to represent 20–40% of all insects found in major fossil deposits. Of the species that lived in the Eocene epoch, around one in 10 genera survive to the present. Genera surviving today comprise 56% of the genera in Baltic amber fossils, 92% of the genera in Dominican amber fossils. Termites live in colonies and are sometimes called ` white ants', they are the sub-order Isoptera, together with cockroaches they form the order Blattodea. Blattodeans are related to mantids and other winged insects that do not undergo full metamorphosis. Like ants, termites are eusocial, with sterile workers, but they differ in the genetics of reproduction; the similarity of their social structure to that of ants is attributed to convergent evolution. Velvet ants are wingless female wasps. Ants are found on all continents except Antarctica, only a few large islands, such as Greenland, parts of Polynesia and the Hawaiian Islands lack native ant species.
Ants occupy a wide range of ecological niches and exploit many different food resources as direct or
Pierre André Latreille
Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, only regained his freedom after recognising a rare beetle species he found in the prison, Necrobia ruficollis, he published his first important work in 1796, was employed by the Muséum National d'Histoire Naturelle. His foresighted work on arthropod systematics and taxonomy gained him respect and accolades, including being asked to write the volume on arthropods for George Cuvier's monumental work, Le Règne Animal, the only part not by Cuvier himself. Latreille was considered the foremost entomologist of his time, was described by one of his pupils as "the prince of entomologists". Pierre André Latreille was born on 29 November 1762 in the town of Brive in the province of Limousin, as the illegitimate child of Jean Joseph Sahuguet d'Amarzit, général baron d'Espagnac, who never recognzed him, an unknown mother, who abandoned him at birth.
Latreille orphaned from his earliest age, but had influential protectors – first a physician a merchant from Brive, a baron and his family, who brought him to Paris in 1778. He studied in Brive and in Paris at the Collège du Cardinal-Lemoine attached to the University of Paris to become a priest, he entered the Grand Séminaire of Limoges in 1780, left as a deacon in 1786. Despite being qualified to preach, Latreille wrote that he had never carried out his functions as a minister, although for a few years he signed the letters he wrote "l'Abbé Latreille" or "Latreille, Prêtre". During his studies, Latreille had taken on an interest in natural history, visiting the Jardin du Roi planted by Georges-Louis Leclerc, Comte de Buffon, catching insects around Paris, he received lessons on botany from René Just Haüy, which brought him in contact with Jean-Baptiste Lamarck. After the fall of the Ancien Régime and the start of the French Revolution, the Civil Constitution of the Clergy was declared in 1790, which required priests to swear an oath of allegiance to the state.
Latreille was therefore imprisoned in November 1793 under threat of execution. When the prison's doctor inspected the prisoners, he was surprised to find Latreille scrutinising a beetle on the dungeon floor; when Latreille explained that it was a rare insect, the physician was impressed, sent the insect to a 15-year-old local naturalist, Jean Baptiste Bory de Saint-Vincent. Bory de St.-Vincent knew Latreille's work, managed to obtain the release of Latreille and one of his cell-mates. All the other inmates were dead within one month; the beetle had been described by Johan Christian Fabricius in 1775, but recognising it had saved Latreille's life. Thereafter, Latreille lived as a teacher and corresponded with various entomologists, including Fabricius. In 1796, with Fabricius' encouragement, Latreille published his Précis des caractères génériques des insectes at his own expense, he was placed under house arrest in 1797, his books were confiscated, but the influence of Georges Cuvier, Bernard Germain de Lacépède and Jean-Baptiste Lamarck succeeded in freeing Latreille.
In 1798, Latreille was appointed to the museum, where he worked alongside Lamarck, curating the arthropod collections, published a number of zoological works. Following the death of Guillaume-Antoine Olivier in 1814, Latreille succeeded him as titular member of the Académie des sciences de l'Institut de France. In the following few years, Latreille was productive, producing important papers for the Mémoires du Muséum, all of the volume on arthropods for George Cuvier's Le Règne Animal, hundreds of entries in the Nouveau Dictionnaire d'Histoire Naturelle on entomological subjects; as Lamarck became blind, Latreille took on an increasing proportion of his teaching and research work. In 1821, Latreille was made a knight of the Légion d'honneur. In 1829 he succeeded Lamarck as professor of entomology. From 1824, Latreille's health deteriorated, he handed his lectures over to Jean Victoire Audouin and took on several assistants for his research work, including Amédée Louis Michel Lepeletier, Jean Guillaume Audinet-Serville and Félix Édouard Guérin-Méneville.
He was instrumental in the founding of the Société entomologique de France, served as its honorary president. Latreille's wife died in May of that year, he resigned his position at the museum on 10 April 1832, in order to move to the country and thereby avoid the cholera epidemic. He returned to Paris in November, died of bladder disease on 6 February 1833, he was survived by a niece whom he had adopted. The Société entomologique raised the money to pay for a monument to Latreille; this was erected over Latreille's grave at Père Lachaise Cemetery, comprised a 9-foot obelisk with various inscriptions, including one to the beetle which had saved Latreille's life: "Necrobia ruficollis Latreillii salvator". As testimony to the high esteem in which Latreille was held, many books were dedicated to him, up to 163 species were named in his honour between 1798 and 1850. Taxa commemorating Latreille include: Lumbrineris latreilli Audouin & H. Milne-Edwards, 183
Sawflies are the insects of the suborder Symphyta within the order Hymenoptera alongside ants 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 with the Tenthredinoidea, by far the largest superfamily, with about 7,000 known species. The suborder Symphyta is paraphyletic, consisting of several basal groups within the order Hymenoptera. Symphyta includes woodwasps and all the species within Hymenoptera that are not wasps or the descendants of wasps; the primary distinction between sawflies and their relatives the Apocrita – the ants and wasps – is that the adults lack a "wasp waist", instead have a broad connection between the abdomen and the thorax. Some sawflies are Batesian mimics of wasps and bees, the ovipositor can be mistaken for a stinger. Sawflies vary in most measuring 2.5 millimetres to 20 millimetres. The larvae are caterpillar-like, but can be distinguished by the number of prolegs and the absence of crochets in sawfly larvae.
The great majority of sawflies are plant-eating, though the members of the superfamily Orussoidea are parasitic. The adults feed on nectar. Predators include birds and small animals; the larvae of some species have anti-predator adaptations such as regurgitating irritating liquid and clustering together for safety in numbers. Sawflies are hosts to many parasitoids, most of which are the rest being Diptera. Adult sawflies are short-lived, with a life expectancy of 7–9 days, though the larval stage can last from months to years, depending on the species. Parthenogenetic females, which do not need to mate to produce fertilised eggs, are common in the suborder, though many species have males. Sawflies go through a complete metamorphosis with four distinct life stages – egg, larva and adult; the female uses her ovipositor to drill into plant material and lays eggs in groups called rafts or pods. After hatching, larvae feed on plants in groups; as they approach adulthood, the larvae seek a protected spot to pupate in bark or the soil.
Large populations of species such as the pine sawfly can cause substantial damage to economic forestry, while others such as the iris sawfly are important pests in horticulture. Outbreaks of sawfly larvae may cause dieback, stunting or death. Sawflies can be controlled through the use of insecticides, natural predators and parasites, or mechanical methods. Sawflies first appeared 250 million years ago in the Triassic; the oldest superfamily, the Xyeloidea, has existed into the present. Over 200 million years ago, a lineage of sawflies evolved a parasitoid lifestyle, with carnivorous larvae that ate the eggs or larvae of other insects. One branch of this lineage is Apocrita, the other is Orussidae, the parasitic wood wasps. Sawflies are distributed globally; the suborder name "Symphyta" derives from the Greek word symphyton, meaning "grown together", referring to the group's distinctive lack of a wasp waist between prostomium and peristomium. Its common name, "sawfly", derives from the saw-like ovipositor, used for egg-laying, in which a female makes a slit in either a stem or plant leaf to deposit the eggs.
The first known use of this name was in 1773. Sawflies are known as "wood-wasps". In his original description of Hymenoptera in 1863, German zoologist Carl Gerstäcker divided them into three groups, Hymenoptera aculeata, Hymenoptera apocrita and Hymenoptera phytophaga, but four years in 1867, he described just two groups, H. apocrita syn. genuina and H. symphyta syn. phytophaga. The name Symphyta is given to Gerstäcker as the zoological authority. In his description, Gerstäcker distinguished the two groups by the transfer of the first abdominal segment to the thorax in the Apocrita, compared to the Symphyta. There are only eight dorsal half segments in the Apocrita, against nine in the Symphyta; the larvae are distinguished in a similar way. The Symphyta have therefore traditionally been considered, alongside the Apocrita, to form one of two suborders of Hymenoptera. Symphyta are the more primitive group, with comparatively complete venation, larvae that are phytophagous, without a "wasp-waist", a symplesiomorphic feature.
Together, the Symphyta make up less than 10% of hymenopteran species. While the terms sawfly and Symphyta have been used synonymously, the Symphyta have been divided into three groups, true sawflies, woodwasps or xylophaga, Orussidae; the three groupings have been distinguished by the true sawflies' ventral serrated or saw-like ovipositor for sawing holes in vegetation to deposit eggs, while the woodwasp ovipositor penetrates wood and the Orussidae behave as external parasitoids of wood-boring beetles. The woodwasps themselves are a paraphyletic ancestral grade. Despite these limitations, the terms are common in the literature. While most hymenopteran superfamilies are monophyletic, as is Hymenoptera, the Symphyta has long been seen to be paraphyletic. Cladistic methods and molecular phylogenetics are improving the understanding of relationships between the superfamilies, resulting in revisions at the level of superfamily and family; the Symphyta are the most primitive taxa within the Hymenoptera, one of the taxa within the Symphyta gave rise to the monophyletic suborder Apocrita.
In cladistic analyses the Orussoidea are