Insects, which are a type of arthropod, are the most numerous group of multicellular organisms on the planet, with over a million species identified so far. The title of heaviest insect in the world has many contenders, the most frequently crowned of which is the larval stage of the goliath beetle, Goliathus goliatus, the maximum size of which is at least and . The highest confirmed weight of an adult insect is for a giant weta, Deinacrida heteracantha, although it is likely one of the elephant beetles, Megasoma elephas and Megasoma actaeon, or goliath beetles, both of which can commonly exceed and , can reach a greater weight. The longest insects are the stick insects, see below. Representatives of the extinct dragonfly-like order Meganisoptera (also known as griffinflies) such as the Carboniferous Meganeura monyi and the Permian Meganeuropsis permiana are the largest insect species ever known. These creatures had a wingspan of some . Their maximum body mass is uncertain, with estimates varying between 34 g and 240 g. Dragonflies and damselflies (Odonata) The largest living species of odonate (the order that includes dragonflies and damselflies) is Megaloprepus caerulatus, reaching 19 centimeters (7.5 inches) in wingspan, Tetracanthagyna plagiata of Southeast Asia is bulkier and heavier than Megaloprepus at up to across the wings and a body length of over . See also the extinct genera Meganeuropsis and Meganeura, although they are not certain to be included in the modern dragonfly order. Mayflies (Ephemeroptera) The largest mayflies are members of the genus Proboscidoplocia from Madagascar. These insects can reach a length of . Palaeodictyoptera (extinct) The largest insect of the Palaeodictyoptera order, Mazothairos enormis from the Carboniferous period reached a wingspan of about 56 centimeters (22 in). Grasshoppers, crickets, and relatives (Orthoptera) Arachnacris katydids and Tropidacris grasshoppers reach up to in length and in wingspan, making them the largest by these measurements. The largest Saga and Pseudophyllus bush crickets are only a few centimeters smaller. The heaviest of this widespread, varied complex of insects is the Little Barrier Island giant weta, Deinacrida heteracantha, of New Zealand; one specimen weighed and measured nearly , giving it one of the largest insects weights ever known. These heavyweight insects can be over long. The largest grasshopper species is often considered to be the Australian giant grasshopper (Valanga irregularis), which ranges up to in length. The American eastern lubber grasshopper (Romalea guttata) can allegedly range