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.Zhang Z-Q, ed. (2011) Animal Biodiversity: An Outline of Higher-Level Classification and Survey of Taxonomic Richness. Auckland, N. Z.: Magnolia Press 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 gravid female giant wētā, Deinacrida heteracantha, although it is likely that 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 griffenflies) 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 210 g.
Dragonflies and damselflies (Odonata)
The largest wingspan of any living species of odonate (the order that includes dragonflies and damselflies) belongs to Megaloprepus caerulatus, reaching 19 centimeters (7.5 inches) in wingspan. Petalura ingentissima has the largest wingspan of any dragonfly at , although Tetracanthagyna plagiata comes in with a close second of .
The largest wing surface area of any living species of odonate belongs to Chlorogomphus papilio, a dragonfly.
The longest body length of any living species of odonate belongs to Mecistogaster lucretia with a body length of .
The heaviest living species of odonate is probably either Petalura ingentissima or Tetracanthagyna plagiata. However, other species such as Anax strenuus and Anotogaster sieboldii and other species in Petalura, Tetracanthagyna, Anax and Anotogaster could also be contenders.
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 order Palaeodictyoptera, Mazothairos enormis from the Carboniferous period, with estimated wingspan about .
Grasshoppers, crickets, and relatives (Orthoptera)
The order Orthoptera contains two suborders (Caelifera and Ensifera), with four infraorders (Gryllidea, Tettigoniidea, Tridactylidea, and Acrididea) and multiple different families within them both.
The heaviest of this widespread, varied complex of insects is the Little Barrier Island giant wētā, Deinacrida heteracantha, of New Zealand; one specimen weighed and measured nearly , giving it one of the largest insect weights ever known. These heavyweight insects can be over long.
The largest (heaviest) macropredatory (animal that will eat prey of a similar size or larger than itself) Orthopteran is Sia ferox (also known as "Riokku" (リオック) or the "Giant Raspy Cricket"), from the family Stenopelmatidae (suborder Ensifera). It can measure more than and weigh more than . Other species of macropredatory Orthoptera can get almost as large: Sia incisa, Anostostoma australasiae and Motuweta isolata (all from the superfamily Stenopelmatoidea). The giant predatory katydids (family Tettigoniidae) of the genus Saga aren't quite as robust.
The heaviest katydids (family Tettigoniidae) are the members of the genus Panoploscelis (The "spiny lobster katydids"). The largest species within the genus Saga are almost as heavy.
The katydid (family Tettigoniidae) Pseudophyllanax imperialis has the largest wingspan of any Orthoptera, at more than . Other genera of Orthoptera can have wingspans almost as large (over ): Arachnacris, Siliquofera, Pseudophyllus, Tropidacris and Titanacris.
The heaviest species of grasshopper (nanorder Acridomorpha) are the females of the endangered giant bladder grasshopper; Physophorina livingstoni.
The subspecies Tropidacris cristata dux has the largest wingspan of any grasshopper (nanorder Acridomorpha): at . Other species of Tropidacris and the closely related genus Titanacris can have wingspans almost as large.
The grasshopper Proscopia gigantea has the largest body length of any grasshopper (nanorder Acridomorpha) and of any Orthopteran at over . Other species of Proscopia and the closely related genus Pseudoproscopia (all from the family Proscopiidae) can reach lengths almost as large (over ).
The largest species of true cricket (Grylloidea) are the members of the genus Brachytrupes, which can reach a lengths of up to .
Titanopterans (Titanoptera) (extinct)
Related to modern orthopterans, Triassic insects of the extinct suborder of TitanopteraOrder Orthoptera, Orthoptera Species File (Version 5.0/5.0); retrieved 20 August 2022 surpassed them in size. The wingspan of Gigatitan vulgaris was as large as of 40 centimetres (16 in). Clatrotitan andersoni also reached a huge size, having a forewing of 13.8 centimetres (5.4 in) long.
Earwigs (Dermaptera)
The largest of the earwigs is the Saint Helena earwig (Labidura herculeana), which is up to in length. There are no recent records of this species and it is generally considered extinct. The largest certainly living species is the Australian giant earwig (Titanolabis colossea), which is about long.
Scorpionflies (Mecoptera)
The largest scorpionfly, the common scorpionfly (Panorpa communis), can reach a body length of about .UK Safari
Stick insects (Phasmatodea)
The longest known stick insects are also the longest known insects, notably species in the tribe Pharnaciini, but they are generally relatively lightweight because of their slender shape. Female of these stick insects usually reach considerably larger sizes than males of the same species. The longest known is a currently undescribed species of Phryganistria, informally referred to as Phryganistria "chinensis", that was discovered in China in 2014. A wild collected female kept at the Insect Museum of West China in Chengdu was the record holder with a total length, including extended legs, of , and a body length of , but it was surpassed by one of its captive bred young that reached in total length.
Other very large species, formerly believed to be longest but now considered second longest is Phobaeticus chani; a specimen held in the Natural History Museum in London is in total length, including extended legs, and it has a body length of .Seow-Choen, F. (1995). "The longest insect in the world". Malayan Naturalist 48: 12. Females of the Australian Ctenomorpha gargantua have been confirmed at up to in total length (including extended legs and cerci, the latter of which are unusually long in this species); one captive individual was measured at , but that size remains unconfirmed. Another very large species is Phobaeticus kirbyi where the total length (including extended legs) is up to and the body alone up to .Brock, P. D. (1999). The amazing world of stick and leaf-insects. Essex, England: Cravitz. Another of the longest insect in terms of total length is Phobaeticus serratipes of Malaysia and Singapore, measuring up to in total length.
The spiny stick insect (Heteropteryx dilatata) of Southeast Asia does not reach the extreme lengths of its cousins, the body reaching up to long, but it is much bulkier. The largest Heteropteryx weighed about and was wide across the thickest part of the body.
Cockroaches and termites (Blattodea)
The largest cockroach in length and wingspan is the South American Megaloblatta longipennis, at up to and , respectively. Other contenders for longest are Blaberus giganteus, which is found in the same general region and may reach a length of up to , depending on source, and Princisia vanwaerebeki of Madagascar, which grows between 5.6 and 10 cm in length. The heaviest is the Australian giant burrowing cockroach (Macropanesthia rhinoceros), which can attain a length of and a weight of .
Termites
The largest of the termites is the African species Macrotermes bellicosus. The queen of this species can attain a length of and breadth of ; other adults, however, are about a third of this size.
Praying mantises (Mantodea)
The giant stick mantises Toxodera maxima and Ischnomantis gigas can reach lengths of over 17 cm, but are more gracile in build than other large mantises. Other species of Toxodera and Ischnomantis, and other genera of “stick mantises” (Heterochaeta, Solygia and Tauromantis), can attain lengths almost as large (over 16 cm).
Mantises of the tribe Hierodulini (of which Rhombodera fratricida is the largest known to science) can reach lengths of nearly and are more robust than comparably sized mantises of other genera (Tenodera, Macromantis, Idolomantis, Sphodromantis, Deroplatys, Plistospilota and Stagmatoptera). Some larger species have been known to capture and consume frogs, lizards, mice, small birds, small fish and even small snakes.
True bugs (Hemiptera)
The heaviest species of this order are the giant water bugs Lethocerus grandis and Lethocerus maximus. These can surpass a length of , although they are more slender and less heavy than most other insects of this size (principally the huge beetles).
The largest wingspan of any hemipteran belongs to the largest species of cicada: Megapomponia imperatoria, which has a head-body length of about and a wingspan of .Burton, Maurice; Burton, Robert (2002). International Wildlife Encyclopedia. 4, Chickaree – crabs (3rd ed.). Tarrytown, NY: Marshall Cavendish Corporation. p. 455. Flindt, R. (2006). Amazing Numbers in Biology, p. 10. The cicadas of the genus Tacua can also grow to comparably large sizes.
The largest total length of any hemipteran belongs to Gigantometra gigas (the largest species of water strider), which has a leg span of more than .
The largest type of aphid is the giant oak aphid (Stomaphis quercus), which can reach an overall length of .Giant Oak Aphid hunt is on. The Telegraph (2007-08-08) The biggest species of leafhopper is Ledromorpha planirostris, which can reach a length of .Ledromorpha planirostris. Bugs.bio.usyd.edu.au
Dobsonflies and relatives (Megaloptera)
Megaloptera includes dobsonflies, alderflies and relatives. The largest is the dobsonfly Acanthacorydalis fruhstorferi, which can have a wingspan of up to , making it the largest aquatic insect in the world by this measurement. This species is native to China and Vietnam, and its body can be up to long.
Net-winged insects (Neuroptera)
The largest Neuropteran is the Giant West African Antlion, Lachlathetes gigas, which has a wingspan of . Some forms of this ancient order could grow extremely large during the Jurassic period and may have ranked among the largest insects ever. Found in the Early Cretaceous sedimentary rocks, Makarkinia adamsi had wings nearly in length.
Lice (Psocodea)
The largest of this order of very small insects is a barklouse of the genus Psocus, the maximum size of which is about 1 cm (0.39 in).
Parasitic lice are insects within the infraorder Phthiraptera. The largest known species is the hog louse, Haematopinus suis, a sucking louse that lives on large livestock like pigs and cattle. It can range up to in length.ADW: Haematopinus suis: Information. Animaldiversity.ummz.umich.edu
Stoneflies (Plecoptera)
The largest species of stonefly is Pteronarcys californica of western North America, a species favored by fishermen as lures. This species can attain a length of and a wingspan of over .Pteronarcys californica – aka Giant Stonefly or Giant Salmonfly. Riverwood Blog – Fly Fishing Gear & Guided Fishing Trips in Oregon (2009-04-20)
Beetles (Coleoptera)