Parasitoidism
- Pronunciation
- /par-uh-SI-toyd-iz-um/
- Category
- Behavior
- Singular
- parasitoidism
Definition
A parasitic life-history strategy in which an organism lives in intimate association with a single , consuming host tissues and inevitably killing the host, typically after the completes development. Parasitoidism occupies an evolutionary and ecological middle ground between (immediate death) and true (non-lethal, ongoing exploitation), distinguished by the delayed but certain mortality of the host. The strategy is especially common and taxonomically diverse among insects, particularly in the order Hymenoptera (ichneumonid, braconid, and chalcidoid ) and (tachinid flies), and also occurs in some mites, , and fungi.
Etymology
From + -ism, denoting the condition or practice; 'parasitoid' itself coined from + -oid, indicating resemblance to but with the fatal outcome characteristic of
Example
The braconid Cotesia glomerata practices parasitoidism by laying in caterpillars of Pieris brassicae; the wasp larvae develop internally, feeding on tissues without immediately killing the caterpillar, then emerge and pupate externally, by which point the host inevitably dies.
Related Terms
- Parasitoid
- Parasitism
- Predation
- kleptoparasitism
- hyperparasitoidism
- idiobiont
- koinobiont
- host manipulation
- Biological control
Usage Notes
contrast parasitoidism with ( killed immediately, multiple prey typically consumed) and with true (host usually survives, of may continue across multiple hosts). The term applies to the strategy, not the organism; the organism is a . Subcategories include idiobionts (host development arrested at parasitization) and koinobionts (host continues developing while parasitized). Parasitoidism is sometimes treated as one of six 'evolutionary strategies' within parasitism in ecological literature, though usage varies on whether parasitoidism is a subset of parasitism or a distinct category.