71-402: The Orussidae or the parasitic wood wasps represent a small family of sawflies (" Symphyta "). Currently, about 93 extant and four fossil species are known. They take a key position in phylogenetic analyses of Hymenoptera , because they form the sister taxon of the megadiverse apocritan wasps, and the common ancestor of Orussidae + Apocrita evolved parasitism for the first time in course of
142-441: A complete metamorphosis with four distinct life stages – egg, larva, pupa and adult. The female uses her ovipositor to drill into plant material (or, in the case of Orussoidea, other insects) and then lays eggs in groups called rafts or pods. After hatching, larvae feed on plants, often in groups. As they approach adulthood, the larvae seek a protected spot to pupate, typically in bark or the soil. Large populations of species such as
213-428: A dagger ( † ). Many species of sawfly have retained their ancestral attributes throughout time, specifically their plant-eating habits, wing veins and the unmodified abdomen, where the first two segments appear like the succeeding segments. The absence of the narrow wasp waist distinguishes sawflies from other members of hymenoptera, although some are Batesian mimics with coloration similar to wasps and bees, and
284-402: A family or genus of hosts. For example, Iris sawfly larvae, emerging in summer, can quickly defoliate species of Iris including the yellow flag and other freshwater species. Similarly the rose sawflies, Arge pagana and A. ochropus , defoliate rose bushes. The giant woodwasp or horntail, Urocerus gigas , has a long ovipositor, which with its black and yellow colouration make it
355-465: A good mimic of a hornet . Despite the alarming appearance, the insect cannot sting. The eggs are laid in the wood of conifers such as Douglas fir , pine, spruce , and larch . The larvae eat tunnels in the wood, causing economic damage. Alternative measures to control sawflies can be taken. Small-scale, mechanical methods include visually confirming larval presence on a plant and subsequently removing them, either by pruning damaged leaves or removing
426-835: A humid and warm climate. The cladogram is based on Schulmeister 2003. Xyeloidea ( Triassic –present) [REDACTED] Tenthredinoidea [REDACTED] Pamphilioidea [REDACTED] Cephoidea (stem sawflies) [REDACTED] Siricoidea (horntails or wood wasps) [REDACTED] Xiphydrioidea (wood wasps) [REDACTED] Orussoidea ( parasitic wood wasps) [REDACTED] Apocrita ( ants , bees , wasps ) [REDACTED] There are approximately 8,000 species of sawfly in more than 800 genera, although new species continue to be discovered. However, earlier studies indicated that 10,000 species grouped into about 1,000 genera were known. Early phylogenies such as that of Alexandr Rasnitsyn , based on morphology and behaviour, identified nine clades which did not reflect
497-503: A large number of families. Some traditional taxa such as the Parasitica (containing many families of parasitoid wasps ) have been found on molecular analysis to be paraphyletic . Parasitoidism evolved once, and 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 sawflies are paraphyletic as
568-416: A leaf. Larvae that feed on wood will pupate in the tunnels they have constructed. In one species, the jumping-disc sawfly ( Phyllotoma aceris ) forms a cocoon which can act like a parachute. The larvae live in sycamore trees and do not damage the upper or lower cuticles of leaves that they feed on. When fully developed, they cut small perforations in the upper cuticle to form a circle. After this, they weave
639-594: A more recent specimen taken at Hastings about 1880, but after re-examination this turned out to be Xiphydria prolongata (Geoffroy, 1785) ( Xiphydriidae ). Benson (1951) supposed O. abietinus "to have occurred in Britain in former times." The oldest members of Orussoidea , the group containing Orussidae and its close relatives, are known from the Middle Jurassic Karabastau Formation of Kazakhstan. The oldest known members of modern Orussidae are from
710-438: A number of chemicals, including maldison , dimethoate , carbaryl , imidacloprid , etc., if removing larvae from trees is not effective enough. Apocrita 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
781-569: A silk hammocks within the circle; this silk hammock never touches the lower cuticle. Once inside, the upper-cuticle's disc separates and descends towards the surface with the larvae attaching themselves to the hammock. Once they reach the round, the larvae work their way into a sheltered area by jerking their discs along. The majority of sawfly species produce a single generation per year, but others may only have one generation every two years. Most sawflies are also female, making males rare. Sawflies are major economic pests of forestry . Species in
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#1732852245467852-436: A wingspan of 92 mm ( 3 + 1 ⁄ 2 in). The smaller species only reach lengths of 2.5 mm ( 3 ⁄ 32 in). Heads of sawflies vary in size, shape and sturdiness, as well as the positions of the eyes and antennae. They are characterised in four head types: open head, maxapontal head, closed head and genapontal head. The open head is simplistic, whereas all the other heads are derived. The head
923-545: 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. The primary distinction between sawflies and the Apocrita – the ants, bees, and wasps – is that the adults lack a "wasp waist", and instead have a broad connection between the abdomen and the thorax . Some sawflies are Batesian mimics of wasps and bees, and
994-509: 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 ( basal ) taxa within the Hymenoptera (some going back 250 million years), and one of the taxa within
1065-468: Is a clade whose name is in standard use. "Parasitica" is not a clade, as it is paraphyletic : the clade would contain the Aculeata. "Parasitica" is therefore a rankless grouping in many present classifications, if it appears at all. Parasitica comprises the majority of hymenopteran insects, its members living as parasitoids . Most species are small, with the ovipositor adapted for piercing. In some hosts,
1136-628: Is a monophyletic group that includes those species in which the female's ovipositor is modified into a stinger to inject venom . Groups within Aculeata include the familiar ants, bees, and various types of parasitic and predatory wasps; it also includes all of the social hymenopterans. Among the nonparasitic and nonsocial Aculeata, larvae are fed with captured prey (typically alive and paralyzed) or may be fed pollen and nectar. The social Aculeata feed their young prey ( paper wasps and hornets ), or pollen and nectar (bees), or perhaps seeds, fungi , or nonviable eggs (ants). The Apocrita contains
1207-589: Is a warning colouration because some larvae can secrete irritating fluids from glands located on their undersides. Sawflies are widely distributed throughout the world. The largest family, the Tenthredinidae, with some 5,000 species, are found on all continents except Antarctica, though they are most abundant and diverse in the temperate regions of the northern hemisphere; they are absent from New Zealand and there are few of them in Australia. The next largest family,
1278-460: Is also hypognathous, meaning that the lower mouthparts are directed downwards. When in use, the mouthparts may be directed forwards, but this is only caused when the sawfly swings its entire head forward in a pendulum motion. Unlike most primitive insects, the sutures (rigid joints between two or more hard elements on an organism) and sclerites (hardened body parts) are obsolescent or absent. The clypeus (a sclerite that makes up an insects "face")
1349-588: Is between 205.6 and 221.5 million years of age, making it among the oldest of all sawfly fossils. More Xyelid fossils have been discovered from the Middle Jurassic and the Cretaceous , but the family was less diverse then than during the Mesozoic and Tertiary . The subfamily Xyelinae were plentiful during these time periods, in which Tertiary faunas were dominated by the tribe Xyelini; these are indicative of
1420-499: Is coiled on the host. In some species the egg is possibly laid into the tunnel of the host if the host itself can not be reached, and the orussid larva itself crawls to the host. On its way to the host it may gnaw through the wood shavings left by the host. It has been disputed whether this material contributes to the nutrition of the larva. At least in Guiglia schauinslandi , the larva lives externally for its first two instars and then enters
1491-432: Is minimal, and fewer than 10 of these species actually cause a significant impact on sawfly populations. Many of these species attack their hosts in the grass or in other parasitoids. Well known and important parasitoids include Braconidae , Eulophidae and Ichneumonidae . Braconid wasps attack sawflies in many regions throughout the world, in which they are ectoparasitoids, meaning that the larvae live and feed outside of
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#17328522454671562-679: Is most frequent in the anal veins. In all sawflies, 2A and 3A tend to fuse with the first anal vein. This occurs in several families including Argidae, Diprionidae and Cimbicidae. The larvae of sawflies are easily mistaken for lepidopteran larvae (caterpillars). However, several morphological differences can distinguish the two: while both larvae share three pairs of thoracic legs and an apical pair of abdominal prolegs , lepidopteran caterpillars have four pairs of prolegs on abdominal segments 3–6 while sawfly larvae have five pairs of prolegs located on abdominal segments 2–6; crochets are present on lepidopteran larvae, whereas on sawfly larvae they are not;
1633-434: Is not always the case; Monterey pine sawfly ( Itycorsia ) larvae are solitary web-spinners that feed on Monterey pine trees inside a silken web. The adults feed on pollen and nectar. Sawflies are eaten by a wide variety of predators. While many birds find the larvae distasteful, some such as the currawong ( Strepera ) and stonechats ( Saxicola ) eat both adults and larvae. The larvae are an important food source for
1704-517: Is not divided into a pre- and postclypeus, but rather separated from the front. The antennal sclerites are fused with the surrounding head capsule, but these are sometimes separated by a suture. The number of segments in the antennae vary from six in the Accorduleceridae to 30 or more in the Pamphiliidae. The compound eyes are large with a number of facets, and there are three ocelli between
1775-404: Is two months to two years, though the adult life stage is often very short (approximately 7 – 9 days), only long enough for the females to lay their eggs. The female uses its ovipositor to drill into plant material to lay her eggs (though the family Orussoidea lay their eggs in other insects). Plant-eating sawflies most commonly are associated with leafy material but some specialize on wood, and
1846-830: The Argidae , with some 800 species, is also worldwide, but is most common in the tropics, especially in Africa, where they feed on woody and herbaceous angiosperms . Of the other families, the Blasticotomidae and Megalodontidae are Palearctic ; the Xyelidae, Pamphilidae , Diprionidae , Cimbicidae , and Cephidae are Holarctic , while the Siricidae are mainly Holarctic with some tropical species. The parasitic Orussidae are found worldwide, mostly in tropical and subtropical regions. The wood-boring Xiphydriidae are worldwide, but most species live in
1917-606: The Triassic . The oldest superfamily, the Xyeloidea , has existed into the presents. 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. Sawflies are distributed globally, though they are more diverse in the northernmost hemispheres. The suborder name "Symphyta" derives from the Greek word symphyton , meaning 'grown together', referring to
1988-458: The masked shrew ( Sorex cinereus ), the northern short-tailed shrew ( Blarina brevicauda ) and the deer mouse ( Peromyscus maniculatus ) predate heavily on sawfly cocoons. Insects such as ants and certain species of predatory wasps ( Vespula vulgaris ) eat adult sawflies and the larvae, as do lizards and frogs. Pardalotes , honeyeaters and fantails ( Rhipidura ) occasionally consume laid eggs, and several species of beetle larvae prey on
2059-465: 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 (plant or animal) or in a nest cell provisioned by their mothers. Apocrita has historically been split into two groups, Parasitica and Aculeata . Aculeata
2130-407: The pine sawfly can cause substantial damage to economic forestry , while others such as the iris sawfly are major pests in horticulture . Outbreaks of sawfly larvae can defoliate trees and may cause dieback, stunting or death. Sawflies can be controlled through the use of insecticides, natural predators and parasitoids, or mechanical methods. Sawflies first appeared 250 million years ago in
2201-527: 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
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2272-449: The 1930s and 1950s and C. pygmaeus in the 1930s and 1940s. Like all other hymenopteran insects, sawflies go through a complete metamorphosis with four distinct life stages – egg, larva, pupa and adult. Many species are parthenogenetic , meaning that females do not need fertilization to create viable eggs. Unfertilized eggs develop as male, while fertilized eggs develop into females ( arrhenotoky ). The lifespan of an individual sawfly
2343-561: The Apocrita, to form one of two suborders of Hymenoptera. Symphyta are the more primitive group, with comparatively complete venation , larvae that are largely phytophagous , and 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 also been divided into three groups, true sawflies (phyllophaga), woodwasps or xylophaga (Siricidae), and Orussidae . The three groupings have been distinguished by
2414-507: The Diprionidae, such as the pine sawflies, Diprion pini and Neodiprion sertifer , cause serious damage to pines in regions such as Scandinavia. D. pini larvae defoliated 500,000 hectares (1,200,000 acres) in the largest outbreak in Finland, between 1998 and 2001. Up to 75% of the trees may die after such outbreaks, as D. pini can remove all the leaves late in the growing season, leaving
2485-465: The Late Cretaceous. Ophrynopus peritus Engel, 2008 was described from Dominican Amber , Baltorussus velteni Schedl, 2011 from Baltic Amber , Mesorussus taimyrensis Rasnitsyn, 1977 from the Late Cretaceous of Taimyr, Siberia und Minyorussus luzzii Basibuyuk, Quicke & Rasnitsyn, 2000 from the Late Cretaceous of New Jersey. Sawflies Sawflies are wasp -like insects that are in
2556-684: The Orussidae have been abandoned, since such earlier subdivisions could not be corroborated in phylogenetic analyses. The cladogram is based on Schulmeister 2003. The Orussoidea are sister to the Apocrita . Xyeloidea ( Triassic -present) [REDACTED] Tenthredinoidea [REDACTED] Pamphilioidea [REDACTED] Cephoidea (stem sawflies) [REDACTED] Siricoidea (horntails or wood wasps) [REDACTED] Xiphydrioidea (wood wasps) [REDACTED] Orussoidea ( parasitic wood wasps) [REDACTED] Apocrita ( ants , bees , wasps ) [REDACTED] An identification key for
2627-505: The Symphyta gave rise to the monophyletic suborder Apocrita ( wasps , bees , and ants ). In cladistic analyses the Orussoidea are consistently the sister group to the Apocrita. The oldest unambiguous sawfly fossils date back to the Middle or Late Triassic. These fossils, from the family Xyelidae , are the oldest of all Hymenoptera. One fossil, Archexyela ipswichensis from Queensland
2698-429: The chicks of several birds, including partridges . Sawfly and moth larvae form one third of the diet of nestling corn buntings ( Emberiza calandra ), with sawfly larvae being eaten more frequently on cool days. Black grouse ( Tetrao tetrix ) chicks show a strong preference for sawfly larvae. Sawfly larvae formed 43% of the diet of chestnut-backed chickadees ( Poecile rufescens ). Small carnivorous mammals such as
2769-462: The dorsal portions of the compound eyes. The tentorium comprises the whole inner skeleton of the head. Three segments make up the thorax: the mesothorax , metathorax and prothorax , as well as the exoskeletal plates that connect with these segments. The legs have spurs on their fourth segments, the tibiae. Sawflies have two pairs of translucent wings. The fore and hind wings are locked together with hooks. Parallel development in sawfly wings
2840-418: The eggs have hatched, some species such as the small brown sawfly will remain with them and protects the eggs by buzzing loudly and beating her wings to deter predators. There are six larval stages that sawflies go through, lasting 2 – 4 months, but this also depends on the species. When fully grown, the larvae emerge from the trees en masse and burrow themselves into the soil to pupate. During their time outside,
2911-636: The evolution of the Hymenoptera. They are also the only sawflies with carnivorous larvae. The fully winged sawflies are 2−23 mm long. They are predominantly black but species of Chalinus , Mocsarya and Orussobaius are more or less metallic. Some species have a red thorax or abdomen and conspicuous white or golden pilosity. Many Orussus species bear white spots on the legs. The antennae of males are composed of 11, those of females of 10 articles. The modified distal antennal articles of females (article 9 enlarged, article 10 very small) are involved in vibrational sounding to detect suitable oviposition sites and
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2982-899: The family Eulophidae attack sawflies, although their impact is low. Two species in the genus Pediobius have been studied; the two species are internal larval parasitoids and have only been found in the northern hemisphere. Parasitism of sawflies by eulophids in grass exceeds 50%, but only 5% in wheat. It is unknown as to why the attack rate in wheat is low. Furthermore, some fungal and bacterial diseases are known to infect eggs and pupa in warm wet weather. Outbreaks of certain sawfly species, such as Diprion polytomum , have led scientists to investigate and possibly collect their natural enemies to control them. Parasites of D. polytomum have been extensively investigated, showing that 31 species of hymenopterous and dipterous parasites attack it. These parasites have been used in successful biological control against pest sawflies, including Cephus cinctus throughout
3053-405: 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 (or gaster ) rather than the "thorax" and "abdomen", respectively. The evolution of a constricted waist was an important adaption for
3124-707: The genera of the World was published by Vilhemsen (2003). The following list summarizes the genera and species and their gross distribution together with indications on identification keys: Twelve species of Orussidae are distributed in the United States and in Canada: In Great Britain, Orussus abietinus (Scopoli, 1763) was recorded by Stephens (1835) upon two specimens caught by William Elford Leach in Darenth Wood and Devonshire around 1817. Morice (1904) recorded
3195-567: The genus Collyria . Unlike braconids, the larvae are endoparasitoids, meaning that the larvae live and feed inside the hosts body. One well known ichneumonid is Collyria coxator , which is a dominant parasitoid of C. pygmaeus . Recorded parasitism rates in Europe are between 20–76%, and as many as eight eggs can be found in a single larva, but only one Collyria individual will emerge from its host. The larva may remain inside of their host until spring, where it emerges and pupates. Several species in
3266-699: The group's distinctive lack of a wasp waist between prostomium and peristomium. Its common name, "sawfly", derives from the saw -like ovipositor that is 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 also known as "wood-wasps". In his original description of Hymenoptera in 1863, German zoologist Carl Gerstaecker divided them into three groups, Hymenoptera aculeata , Hymenoptera apocrita and Hymenoptera phytophaga . However, four years later in 1867, he described just two groups, H. apocrita syn. genuina and H. symphyta syn. phytophaga . Consequently,
3337-524: The historical superfamilies. Such classifications were replaced by those using molecular methods, starting with Dowton and Austin (1994). As of 2013, the Symphyta are treated as nine superfamilies (one extinct) and 25 families. Most sawflies belong to the Tenthredinoidea superfamily, with about 7,000 species worldwide. Tenthredinoidea has six families, of which Tenthredinidae is by far the largest with some 5,500 species. Extinct taxa are indicated by
3408-415: The host larvae living concealed inside wood by generating vibrations by tapping the tips of their antennae against the wood surface. The vibrations are picked up by the modified fore legs. After locating the host, the female drills into the wood with the very long ovipositor and lays the egg. The egg is very elongate with a small expansion on the anterior end and a long expansion on the posterior end. The egg
3479-473: The host larvae living concealed inside wood. Contrary to other "Symphyta", the antennae insert near the lower edge of the compound eyes and close to the mandible. The mandibles are orthognathous and lack evident teeth. The number of palpomeres of the maxilla and the labium varies and is used as a taxonomic character. On the wings, some cross-veins are reduced in comparison with the more complete venation of other basal Hymenoptera. Similar as in most other sawflies,
3550-593: The hosts body; braconids have more of an impact on sawfly populations in the New World than they do in the Old World, possibly because there are no ichneumonid parasitoids in North America. Some braconid wasps that attack sawflies include Bracon cephi , B. lisogaster , B. terabeila and Heteropilus cephi . Female braconids locate sawfly larvae through the vibrations they produce when feeding, followed by inserting
3621-416: The larvae can be quickly dispatched by simply dropping foliage into a vessel of plain or saltwater, diluted hydrogen peroxide or isopropyl alcohol, insecticidal soap, or other garden chemical. In large-scale, industrial settings, where beneficial insect predators can also be used to eliminate larvae, as well as parasites, which have both been previously used in control programs. Small trees can be sprayed with
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#17328522454673692-403: The larvae from the leaves they are on. Larvae typically try to remain hidden on the underside of foliage. Upon removing larvae and/or the affected leaves from plants, they may be dispatched by squishing, or, alternatively, the cut leaves with larvae still attached may be fed to birds; if larger animals do not prey upon them, other insects will. However, this is not practical or useful for some, thus
3763-417: The larvae may link up to form a large colony if many other individuals are present. They gather in large groups during the day which gives them protection from potential enemies, and during the night they disperse to feed. The emergence of adults takes awhile, with some emerging anywhere between a couple months to 2 years. Some will reach the ground to form pupal chambers, but others may spin a cocoon attached to
3834-401: 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. The adults feed on pollen, nectar, honeydew, sap, other insects, including hemolymph of the larvae hosts; they have mouth pieces adapted to these types of feeding. Sawflies go through
3905-435: The members of the superfamily Orussoidea are parasitic . Predators include birds, insects 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 Hymenoptera, the rest being Diptera . Adult sawflies are short-lived, with a life expectancy of 7–9 days, though
3976-461: The name Symphyta is given to Gerstaecker as the zoological authority . In his description, Gerstaecker distinguished the two groups by the transfer of the first abdominal segment to the thorax in the Apocrita , compared to the Symphyta. Consequently, 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
4047-427: The ovipositor can be mistaken for a stinger . Sawflies vary in length, most measuring 2.5 to 20 millimetres ( 3 ⁄ 32 to 25 ⁄ 32 in); the largest known sawfly measured 55 mm ( 2 + 1 ⁄ 4 in). 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
4118-504: The ovipositor can be mistaken for a stinger. Most sawflies are stubby and soft-bodied, and fly weakly. Sawflies vary in length: Urocerus gigas , which can be mistaken as a wasp due to its black-and-yellow striped body, can grow up to 20 mm ( 3 ⁄ 4 in) in length, but among the largest sawflies ever discovered was Hoplitolyda duolunica from the Mesozoic, with a body length of 55 mm ( 2 + 1 ⁄ 4 in) and
4189-583: The ovipositors of these species (such as the family Siricidae ) are specially adapted for the task of drilling through bark. Once the incision has been made, the female will lay as many as 30 to 90 eggs. Females avoid the shade when laying their eggs because the larvae develop much slower and may not even survive, and they may not also survive if they are laid on immature and glaucous leaves. Hence, female sawflies search for young adult leaves to lay their eggs on. These eggs hatch in two to eight weeks, but such duration varies by species and also by temperature. Until
4260-511: The ovipostior and paralysing the larva before laying eggs inside the host. These eggs hatch inside the larva within a few days, where they feed on the host. The entire host's body may be consumed by the braconid larvae, except for the head capsule and epidermis . The larvae complete their development within two or three weeks. Ten species of wasps in the family Ichneumonidae attack sawfly populations, although these species are usually rare. The most important parasitoids in this family are species in
4331-517: The parasitoids induce metamorphosis prematurely, and in others it is prolonged. There are even species that are hyperparasites , or parasitoids on other parasitoids. The Parasitica lay their eggs inside or on another insect (egg, larva or pupa) 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 , flies , and weevils . Aculeata
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#17328522454674402-629: The prolegs of both larvae gradually disappear by the time they burrow into the ground, therefore making it difficult to distinguish the two; and sawfly larvae only have a single pair of minute eyes, whereas lepidopteran larvae have four to six eyes on each side of the head. Sawfly larvae behave like lepidopteran larvae, walking about and eating foliage. Some groups have larvae that are eyeless and almost legless; these larvae make tunnels in plant tissues including wood. Many species of sawfly larvae are strikingly coloured, exhibiting colour combinations such as black and white while others are black and yellow. This
4473-679: The pupae. The larvae have several anti-predator adaptations . While adults are unable to sting, the larvae of species such as the spitfire sawfly regurgitate a distasteful irritating liquid, which makes predators such as ants avoid the larvae. In some species, the larvae cluster together, reducing their chances of being killed, and in some cases form together with their heads pointing outwards or tap their abdomens up and down. Some adults bear black and yellow markings that mimic wasps. Sawflies are hosts to many parasitoids, most of which are parasitic Hymenoptera; more than 40 species are known to attack them. However, information regarding these species
4544-562: The putrid(?) liquid in the dead host, where it remains until the adult emerges. Numerous morphological and genetic studies indicate that the Orussidae form the sister taxon of the Apocrita , the wasps, bees, and ants. Accordingly, parasitic life style has not evolved first in Apocrita but in the common ancestor of Orussidae + Apocrita. Earlier, the Orussidae were sometimes put into a separate suborder, Idiogastra, but today they are classified in their own superfamily, Orussoidea. Orussidae are demonstrably monophyletic. Tribes and subfamilies within
4615-461: The sole Hymenoptera in which the head bears a corona of erect teeth around the frontal ocelli. Contrary to Orussidae, the Stephanidae lack cenchri, and their mesosoma and metasoma are separated by a wasp waist, which is absent in Orussidae. Similar to the larvae of apocritan Hymenoptera, larvae of Orussidae have reduced some morphological features as a result of their parasitic life style inside
4686-435: The subtropical parts of Asia. Sawflies are mostly herbivores , feeding on plants that have a high concentration of chemical defences. These insects are either resistant to the chemical substances, or they avoid areas of the plant that have high concentrations of chemicals. The larvae primarily feed in groups; they are folivores , eating plants and fruits on native trees and shrubs, though some are parasitic. However, this
4757-522: The trees too weak to survive the winter. Little damage to trees only occurs when the tree is large or when there is minimal presence of larvae. Eucalyptus trees can regenerate quickly from damage inflicted by the larvae; however, they can be substantially damaged from outbreaks, especially if they are young. The trees can be defoliated completely and may cause "dieback", stunting or even death. Sawflies are serious pests in horticulture . Different species prefer different host plants, often being specific to
4828-444: 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 have utility and are common in the literature. While most hymenopteran superfamilies are monophyletic , as
4899-477: The tunnels of wood-boring insects. They are white, subcylindrical , weakly sclerotized with a distinct head capsule. The mouthparts are hypognathous . Eyes and legs are reduced or completely absent. The mandibles are well developed and strongly sclerotized. Palps of maxilla and labium lack. The surface of the body is subdivided into distinct segments, each bearing a transverse row of 8−10 backward pointing spines. Orussid sawflies have been collected only rarely. Over
4970-421: The wings are held at rest with a device called " cenchri ". The complete body is strongly sclerotized and bears a species-specific microstructure, which is relevant for species identification. The ovipositor is several times as long as the body, and at rest it extends inside the body from the abdomen to the prothorax, where it is coiled, and back towards the tip of the abdomen again. Orussidae and Stephanidae are
5041-600: The years, their abundance has been subject to strong fluctuations. The species are thermophilous and wasps are active during the hottest hours of the day. Therefore, they are rarely found by the entomologists specialized in sawflies. Only for few species the larval biology is known. Orussidae are parasitoids of xylobiontic larvae of beetles or Hymenoptera, particularly of the larvae of jewel beetles ( Buprestidae ), long-horned beetles ( Cerambycidae ), and wood wasps ( Siricidae , Xiphydriidae ). Orussids can be observed running around quickly on dead tree trunks. The females locate
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