Editing Mecoptera (section)

==Biology==
===Morphology===

Mecoptera are small to medium-sized insects with long beaklike [[Rostrum (anatomy)|rostra]], membranous wings and slender, elongated bodies. They have relatively simple mouthparts, with a long [[Insect mouthparts#Labium|labium]], long [[Mandible (arthropod mouthpart)|mandible]]s and fleshy [[palp]]s, which resemble those of the more primitive [[true flies]]. Like many other insects, they possess [[compound eye]]s on the sides of their heads, and three [[ocelli]] on the top. The antennae are filiform (thread-shaped) and contain multiple segments.<ref name=IIBD>{{cite book |author1=Hoell, H.V. |author2=Doyen, J.T. |author3=Purcell, A.H. |year=1998 |title=Introduction to Insect Biology and Diversity, 2nd ed |publisher= Oxford University Press |pages= 488–491|isbn= 978-0-19-510033-4}}</ref><ref name="GullanCranston2014">{{cite book|author1=Gullan, P.J.|author2=Cranston, P.S.|title=The Insects: An Outline of Entomology|url=https://books.google.com/books?id=lF5hBAAAQBAJ&pg=PT1345|year=2014 |publisher=Wiley |isbn=978-1-118-84616-2 |pages=1345–1347}}</ref>

The fore and hind wings are similar in shape, being long and narrow, with numerous cross-veins, and somewhat resembling those of primitive insects such as [[mayflies]]. A few genera, however, have reduced wings, or have lost them altogether. The [[Insect morphology#Abdomen|abdomen]] is cylindrical with eleven segments, the first of which is fused to the [[metathorax]]. The [[Cercus|cerci]] consist of one or two segments. The abdomen typically curves upwards in the male, superficially resembling the tail of a [[scorpion]], the tip containing an enlarged structure called the genital bulb.<ref name=IIBD/><ref name="GullanCranston2014"/>

The [[caterpillar]]-like [[larva]]e have hard [[sclerotised]] heads with mandibles (jaws), short true legs on the thorax, [[proleg]]s on the first eight abdominal segments, and a suction disc or pair of hooks on the terminal tenth segment. The pupae have free appendages rather than being secured within a cocoon (they are exarate).<ref name="GullanCranston2014"/>

===Ecology===
[[File:Panorpa communis with prey Diogma glabrata glabrata.jpg|thumb|A [[Panorpidae|Panorpid]] scorpionfly feeding on a dead insect]]

Mecopterans mostly inhabit moist environments although a few species are found in semi-desert habitats. Scorpionflies, family Panorpidae, generally live in broad-leaf woodlands with plentiful damp leaf litter. Snow scorpionflies, family Boreidae, appear in winter and are to be seen on snowfields and on moss; the larvae being able to jump like [[flea]]s. Hangingflies, family Bittacidae, occur in forests, grassland and caves with high moisture levels. They mostly breed among mosses, in leaf litter and other moist places, but their reproductive habits have been little studied, and at least one species, ''[[Nannochorista philpotti]]'', has aquatic larvae.<ref name=Dunford/>

Adult mecopterans are mostly [[scavenger]]s, feeding on decaying vegetation and the soft bodies of dead invertebrates. ''[[Panorpa]]'' raid [[spider web]]s to feed on trapped insects and even the spiders themselves, and hangingflies capture flies and moths with their specially modified legs. Some groups consume [[pollen]], [[nectar]], [[midge]] larvae, [[carrion]] and moss fragments.<ref name=Dunford/> Most mecopterans live in moist environments; in hotter climates, the adults may therefore be active and visible only for short periods of the year.<ref name=IIBD/>

===Mating behaviour===
[[File:Panorpa communis copula.jpg|thumb|left|''[[Panorpa communis]]'' mating]]

Various courtship behaviours have been observed among mecopterans, with males often emitting [[pheromone]]s to attract mates. The male may provide an edible gift such as a dead insect or a brown salivary secretion to the female. Some boreids have hook-like wings which the male uses to pick up and place the female on his back while copulating. Male panorpids vibrate their wings or even [[stridulate]] while approaching a female.<ref name=Dunford/>

[[File:Bittacidae_fg1.jpg|thumb|upright|[[Bittacidae|Hangingflies]] have distinct mating behaviour.]]

Hangingflies (Bittacidae) provide a nuptial meal in the form of a captured insect prey, such as a caterpillar, bug, or fly. The male attracts a female with a pheromone from vesicles on his abdomen; he retracts these once a female is nearby, and presents her with the prey. While she evaluates the gift, he locates her genitalia with his. If she stays to eat the prey, his genitalia attach to hers, and the female lowers herself into an upside-down hanging position, and eats the prey while mating. Larger prey result in longer mating times. In ''Hylobittacus apicalis'', prey  {{convert|3|to|14|mm|in}} long give between 1 and 17 minutes of mating. Larger males of that species give prey as big as houseflies, earning up to 29 minutes of mating, maximal sperm transfer, more oviposition, and a refractory period during which the female does not mate with other males: all of these increase the number of offspring the male is likely to have.<ref>{{cite book |author1=Gullan, P. J. |author2=Cranston, P. S. |date=2010 |title=The Insects: An Outline of Entomology |publisher=Wiley |edition=4th |isbn=978-1-118-84615-5 |page=129}}</ref>

===Life-cycle===
The female lays the eggs in close contact with moisture, and the eggs typically absorb water and increase in size after deposition. In species that live in hot conditions, the eggs may not hatch for several months, the larvae only emerging when the dry season has finished. More typically, however, they hatch after a relatively short period of time. The larvae are usually quite [[caterpillar]]-like, with short, clawed, true legs, and a number of abdominal [[proleg]]s. They have sclerotised heads with mandibulate mouthparts. Larvae possess compound eyes, which is unique among [[holometabolous]] insects.<ref>{{Cite journal|last1=Chen|first1=Qing-Xiao|last2=Hua|first2=Bao-Zhen|date=2016-06-03|title=Ultrastructure and Morphology of Compound Eyes of the Scorpionfly Panorpa dubia (Insecta: Mecoptera: Panorpidae)|journal=PLOS ONE|volume=11|issue=6|pages=e0156970|doi=10.1371/journal.pone.0156970|issn=1932-6203|pmc=4892548|pmid=27258365|bibcode=2016PLoSO..1156970C|doi-access=free}}</ref> The tenth abdominal segment bears either a suction disc, or, less commonly, a pair of hooks. They generally eat vegetation or scavenge for dead insects, although some predatory larvae are known.  The larva crawls into the soil or decaying wood to [[pupa]]te, and does not spin a cocoon. The pupae are [[Holometabolism#Pupa|exarate]], meaning the limbs are free of the body, and are able to move their mandibles, but are otherwise entirely nonmotile. In drier environments, they may spend several months in [[diapause]], before emerging as adults once the conditions are more suitable.<ref name=IIBD/>

[[File:Skorpionsfliege Panorpa communis male genital.jpg|thumb|The raised [[scorpion]]-like tail of the male has earned the scorpionflies a sinister reputation, but they do not sting.]]