www.small-beings.org
www.small-beings.org
Die Pflanzenwespen oder Sägewespen (Symphyta) sind eine der beiden traditionellen Unterordnungen der Hautflügler (Hymenoptera) mit rund 9000 bekannten Arten. Im Gegensatz zu den weit artenreicheren Taillenwespen (Apocrita) verfügen sie nicht über den Hinterleibseinschnitt, die „Wespentaille“. Die Pflanzenwespen bilden jedoch keine natürliche Verwandtschaftsgruppe (Klade), sondern eine paraphyletische Zusammenfassung der urtümlicheren Hautflügler. Sie sind überwiegend Pflanzen- oder Nektarfresser; nur die knapp 90 Arten der Familie Orussidae entwickeln sich als Parasitoide von Larven anderer Insektenarten. Die Orussidae stellen die Schwestergruppe der Taillenwespen dar und lassen sich als evolutionäres Bindeglied zwischen den Unterordnungen ansehen.Die Larven leben meist auf Pflanzen und ähneln den Schmetterlingsraupen, man nennt sie auch „Afterraupen“. Die zahlreichen Arten der Pflanzenwespen sind vor allem in den gemäßigten Klimaregionen beheimatet. In Mitteleuropa kommen etwa 800 Arten der Pflanzenwespen vor; zu ihnen zählen zahlreiche als Schädlinge eingestufte Arten. Die meisten Pflanzenwespen sind an bestimmte Wirtspflanzen gebunden. Insbesondere die Ablage der Eier erfolgt bei der Mehrzahl der Arten in das Pflanzengewebe.
Die systematische Übersicht stellt verschiedene Familien von Pflanzenwespen vor, darunter die Blattwespenartigen, Gespinstblattwespenartigen, Halmwespenartigen, Holzwespenartigen und Schwerwespen. Die entsprechenden Familien und ihre Mitglieder werden aufgelistet. Die Literaturangabe nennt das Buch "Hymenoptera, Unterordnung Symphyta: Pflanzenwespen" von Wolfgang Schedl als Quelle. Ein Weblink verweist auf den Electronic World Catalog of Symphyta mit weiteren Informationen zu den Pflanzenwespen.
Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay their eggs. The name is associated especially with the Tenthredinoidea, by far the largest superfamily in the suborder, with about 7,000 known species; in the entire suborder, there are 8,000 described species in more than 800 genera. Symphyta is paraphyletic, consisting of several basal groups within the order Hymenoptera, each one rooted inside the previous group, ending with the Apocrita which are not sawflies. 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 the ovipositor can be mistaken for a stinger. Sawflies vary in length, most measuring 2.5 to 20 millimetres (3⁄32 to 25⁄32 inch); 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 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 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 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 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 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 summary provides information about sawflies, a suborder of insects known as Symphyta. The name "Symphyta" refers to their distinctive lack of a wasp waist and their saw-like ovipositor used for egg-laying. The suborder is considered primitive and makes up less than 10% of hymenopteran species. Sawflies are widely distributed throughout the world and are mostly herbivorous, feeding on plants with chemical defenses. Some sawfly species are major pests in forestry and horticulture, causing damage to trees and plants. Predators and parasites are used as control measures against sawflies.