381
alive after attack, as well as true parasitoids that consume and eventually kill their
considerably larger hosts. In this contribution, a distinction is made between these
three, very different life habits and consideration is made of parasitism and parasitoidism as trophically distinctive feeding modes (Frank and Gillett-Kaufman 2006;
Labandeira 2002).
A recurring issue that informs the definition of parasitism is whether herbivory,
in the broadest sense of the interaction, a form of parasitism (Windsor 1998;
Eggleton and Gaston 1990). Efforts also have been made to circumscribe a special
type of herbivory that occurs in concealed plant tissues, such as leaf mines or galls,
as parasitism (Janzen 1975; Price 1980). Whether the broader or the narrower version of herbivory is considered as parasitism, it would render moot much of the
specialized trophic biology of animal–animal interaction inherent in true parasitism.
Moreover, if parasites are defined as species that exploit other free-living species
(Windsor 1998), then minimally about half of all species are parasites (May 1988;
Bush et al. 2001), or parasites probably outnumber free-living species by a factor of
4 (May 1992). Such an inordinate broadening of the definition of parasitism would
provide sustenance to the claim that parasitism is a confounding concept (Araújo
et al. 2003). Historically, herbivory has been considered as a fundamental trophic
interaction limited to plants as the consumed organisms (Ings et al. 2009), whereas
parasitism—as well as predation and parasitoidism—have considered animals as
the consumed organisms. That distinction is retained herein.
11.2.1 Predation
Predation is a type of trophic interaction of a consumer that requires multiple prey
items throughout its lifetime and always results in death of its prey (Morris 1998).
Such a definition excludes consumption of multiple organisms that do not result in
their individual deaths, nor is predation the prolonged consumption of a single organism (a host) that eventually results in its death. Consequently, distinctions are made
between prey and host. Prey is the term that applies to an organism that is killed
quickly by a consumer involved in predation. By contrast, a host, unlike prey, is
defined as a temporally prolonged food resource used by a parasite or parasitoid. One
type of host is an organism that is not killed by its consumer after a brief encounter,
which involves minor consumption such as a blood-feeding mosquito on a vertebrate
host. Such a relationship is parasitism. A second type of host is an organism that is
killed only after a prolonged process of consumption, such as a wasp larva feeding
internally on an herbivorous caterpillar. Such an interaction is parasitoidism.
11.2.2 Parasitism
Parasitism is an intimate trophic interaction between a consumer and its’ typically
much larger host that does not result in death of the host (Morris 1998). Parasitism
does not include herbivory, for reasons mentioned above, because one fundamental
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution
alive after attack, as well as true parasitoids that consume and eventually kill their
considerably larger hosts. In this contribution, a distinction is made between these
three, very different life habits and consideration is made of parasitism and parasitoidism as trophically distinctive feeding modes (Frank and Gillett-Kaufman 2006;
Labandeira 2002).
A recurring issue that informs the definition of parasitism is whether herbivory,
in the broadest sense of the interaction, a form of parasitism (Windsor 1998;
Eggleton and Gaston 1990). Efforts also have been made to circumscribe a special
type of herbivory that occurs in concealed plant tissues, such as leaf mines or galls,
as parasitism (Janzen 1975; Price 1980). Whether the broader or the narrower version of herbivory is considered as parasitism, it would render moot much of the
specialized trophic biology of animal–animal interaction inherent in true parasitism.
Moreover, if parasites are defined as species that exploit other free-living species
(Windsor 1998), then minimally about half of all species are parasites (May 1988;
Bush et al. 2001), or parasites probably outnumber free-living species by a factor of
4 (May 1992). Such an inordinate broadening of the definition of parasitism would
provide sustenance to the claim that parasitism is a confounding concept (Araújo
et al. 2003). Historically, herbivory has been considered as a fundamental trophic
interaction limited to plants as the consumed organisms (Ings et al. 2009), whereas
parasitism—as well as predation and parasitoidism—have considered animals as
the consumed organisms. That distinction is retained herein.
11.2.1 Predation
Predation is a type of trophic interaction of a consumer that requires multiple prey
items throughout its lifetime and always results in death of its prey (Morris 1998).
Such a definition excludes consumption of multiple organisms that do not result in
their individual deaths, nor is predation the prolonged consumption of a single organism (a host) that eventually results in its death. Consequently, distinctions are made
between prey and host. Prey is the term that applies to an organism that is killed
quickly by a consumer involved in predation. By contrast, a host, unlike prey, is
defined as a temporally prolonged food resource used by a parasite or parasitoid. One
type of host is an organism that is not killed by its consumer after a brief encounter,
which involves minor consumption such as a blood-feeding mosquito on a vertebrate
host. Such a relationship is parasitism. A second type of host is an organism that is
killed only after a prolonged process of consumption, such as a wasp larva feeding
internally on an herbivorous caterpillar. Such an interaction is parasitoidism.
11.2.2 Parasitism
Parasitism is an intimate trophic interaction between a consumer and its’ typically
much larger host that does not result in death of the host (Morris 1998). Parasitism
does not include herbivory, for reasons mentioned above, because one fundamental
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution