Editing Parasitism (section)

==== Parasitoids ====

{{main|Parasitoid|Parasitoid wasp}}

[[Parasitoid]]s are insects which sooner or later kill their hosts, placing their relationship close to predation.<ref>{{cite journal |last1=Stevens |first1=Alison N. P. |title=Predation, Herbivory, and Parasitism |journal=Nature Education Knowledge |date=2010 |volume=3 |issue=10 |page=36 |url=https://www.nature.com/scitable/knowledge/library/predation-herbivory-and-parasitism-13261134 |access-date=12 February 2018 |quote=Predation, herbivory, and parasitism exist along a continuum of severity in terms of the extent to which they negatively affect an organism's fitness. ... In most situations, parasites do not kill their hosts. An exception, however, occurs with parasitoids, which blur the line between parasitism and predation.}}</ref> Most parasitoids are [[parasitoid wasp]]s or other [[hymenoptera]]ns; others include [[dipterans]] such as [[phoridae|phorid flies]]. They can be divided into two groups, idiobionts and koinobionts, differing in their treatment of their hosts.<ref name=GullanCranston2010>{{cite book |last1=Gullan |first1=P. J. |last2=Cranston |first2=P. S. |date=2010 |title=The Insects: An Outline of Entomology |url=https://archive.org/details/insectsoutlineen00pjgu |url-access=limited |publisher=Wiley |edition=4th |isbn=978-1-118-84615-5 |pages=[https://archive.org/details/insectsoutlineen00pjgu/page/n332 308], 365–367, 375, 440–441}}</ref>

[[Idiobiont]] parasitoids sting their often-large prey on capture, either killing them outright or paralysing them immediately. The immobilised prey is then carried to a nest, sometimes alongside other prey if it is not large enough to support a parasitoid throughout its development. An [[oviposition|egg is laid]] on top of the prey and the nest is then sealed. The parasitoid develops rapidly through its larval and pupal stages, [[mass provisioning|feeding on the provisions]] left for it.<ref name=GullanCranston2010/>

[[Koinobiont]] parasitoids, which include [[Diptera|flies]] as well as wasps, lay their eggs inside young hosts, usually larvae. These are allowed to go on growing, so the host and parasitoid develop together for an extended period, ending when the parasitoids emerge as adults, leaving the prey dead, eaten from inside. Some koinobionts regulate their host's development, for example preventing it from [[pupa]]ting or making it [[ecdysis|moult]] whenever the parasitoid is ready to moult. They may do this by producing hormones that mimic the host's moulting hormones ([[ecdysteroid]]s), or by regulating the host's endocrine system.<ref name=GullanCranston2010/>

<gallery mode="packed">
File:Live Tetragnatha montana (RMNH.ARA.14127) parasitized by Acrodactyla quadrisculpta larva (RMNH.INS.593867) - BDJ.1.e992.jpg |Idiobiont [[parasitoid wasp]]s immediately paralyse their hosts for their larvae ([[Pimplinae]], pictured) to eat.<ref name=PoulinRandhawa2015/>
File:CSIRO ScienceImage 2357 Spotted alfalfa aphid being attacked by parasitic wasp.jpg|[[Koinobiont]] parasitoid wasps like this [[Braconidae|braconid]] lay their eggs via an [[ovipositor]] inside their hosts, which continue to grow and moult.
File:Female Apocephalus borealis ovipositing into the abdomen of a worker honey bee.png|[[Phoridae|Phorid fly]] (centre left) is [[oviposition|laying eggs]] in the abdomen of a worker [[honey-bee]], [[Behavior-altering parasites and parasitoids|altering its behaviour]].
</gallery>

{{anchor|Micropredator}}