SEM image of endoparasitoidic ciliates of the genus Collinia, which can cause mass mortality in affected krill populations.

A parasitoid spends a significant portion of its life history attached to or within a single host organism which it ultimately kills and consumes. Thus they are similar to parasites except in the fate of the host. In a truly parasitic relationship, the parasite and host live side by side with little damage to the host. The parasite takes enough nutrients to thrive without preventing the host from reproducing. In a parasitoid relationship, the host is killed before it can produce offspring. This article or section contains information that has not been verified and thus might not be reliable. ... Image File history File linksMetadata Collinia_sp. ... Image File history File linksMetadata Collinia_sp. ... Low temperature SEM magnification series for a snow crystal. ... Classes Karyorelictea Heterotrichea Spirotrichea Litostomatea Phyllopharyngea Nassophorea Colpodea Prostomatea Oligohymenophorea Plagiopylea See text for subclasses. ... Families Euphausiidae Euphausia Dana, 1852 Meganyctiphanes Holt and W. M. Tattersall, 1905 Nematobrachion Calman, 1905 Nematoscelis G. O. Sars, 1883 Nyctiphanes G. O. Sars, 1883 Pseudeuphausia Hansen, 1910 Stylocheiron G. O. Sars, 1883 Tessarabrachion Hansen, 1911 Thysanoessa Brandt, 1851 Thysanopoda Latreille, 1831 Bentheuphausiidae Bentheuphausia amblyops Krill are shrimp-like marine... A life cycle includes the major sexual stages of a species, especially in regard to its ploidy. ... In biology and ecology, an organism (in Greek organon = instrument) is a living complex adaptive system of organs that influence each other in such a way that they function as a more or less stable whole. ... A parasite is an organism that lives in or on the living tissue of a host organism at the expense of it. ... // Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ... Reproduction is the creation of one thing as a copy of, product of, or replacement for a similar thing, e. ...

This type of relationship seems to occur only in organisms that have fast reproduction rates (such as insects or mites). Parasitoids are also often closely coevolved with their hosts. Classes & Orders See taxonomy Insects are invertebrate animals of the Class Insecta, the largest and (on land) most widely-distributed taxon within the phylum Arthropoda. ... Families Tetranychidae - Spider mites Eriophyidae - Gall mites Sarcoptidae - Sarcoptic Mange mites The mites and ticks, order Acarina or Acari, belong to the Arachnida and are among the most diverse and successful of all the invertebrate groups, although some way behind the insects. ... Bumblebees and the flowers they pollinate co-evolve so that the flower is dependent on the bee and the bee is dependent on the flower for survival In Biology, Co-evolution is the mutual evolutionary influence between two species that become dependent on each other. ...

An endoparasitoid lives inside of the prey, while an ectoparasitoid lives outside.

There are three groups of insect that are particularly renowned for this type of lifestyle. The largest and best known group comprises the division Apocrita: Parasitica of the order Hymenoptera (including the chalcid wasps (family Chalcidae) and the ichneumon wasps (family Ichneumonidae). The other two are the tachinid flies (order Diptera, family Tachinidae) and the stylopid flies (order Strepsiptera, family Stylopidae). Superfamilies Apoidea Ceraphronoidea Chalcidoidea Chrysidoidea Cynipoidea Evanioidea Ichneumonoidea Megalyroidea Proctotrupoidea Sphecoidea Stephanoidea Triganalyoidea Vespoidea Many families, see article Apocrita is a suborder of insects in the order Hymenoptera. ... Suborders Apocrita Symphyta Many families, see article Hymenoptera is one of the larger orders of Insects, comprising the sawflies, wasps, bees, and ants. ... Subfamilies of Chalcid Wasps many subfamilies, Chalcid wasps (family Chalcidae) belong to the insect order Hymenoptera. ... Families Braconidae Ichneumonidae The Ichneumon wasps are insects classified in the parasitica group of the suborder Apocrita within the Order Hymenoptera. ... Genera  Lasiona  Lasioneura  Leptostylum  Trichopoda The tachinid flies (family Tachinidae) are by far the largest and most important group of insect parasitic flies, with over 1300 species in North America. ... Suborders Nematocera(Eudiptera) Brachycera Green Bottle Fly Flesh Fly Fannia a Lesser House Fly (unidentified species) Dolichopodidae (unidentified species) Diptera (di - two, ptera – wings), or true flies, is the order of insects in which the hind wings are reduced to halteres. ... Families Mengenillidae Mengeidae Stylopidae Bohartillidae Corioxenidae Halictophagidae Callipharixenidae Elenchidae Myrmecolacidae Species in the nine families of this small (~600 species) order of insects are parasites in other insects; their hosts include bees, wasps, leafhoppers, silverfish, and cockroaches. ...

In fiction

Many parasites potrayed in fiction are actually parasitoids, these include;

• The xenomorphs from the Alien films
• The Metroids from the series of the same name
• Several of the symbionts from the spiderman comics