378
ensued toward top-to-down food webs, explained by the trophic cascade hypothesis,
exemplified by hymenopteran parasitoid clades Stephanoidea and Evanioidea.
Clade-specific innovations spurring the MMPR included long, flexible ovipositors
(wasps), host seeking, triungulin and planidium larvae (mantispids, beetles, twistedwing parasites, flies), and extrudable, telescoped ovipositors (flies). After the
MMPR, in phases 3 and 4 (Late Cretaceous to Recent), parasitoids increased in
taxonomic diversity, becoming integrated into food webs that continue to the
present day.
Keywords Food webs · Idiobiont · Koinobiont · Ovipositor drill · Telescoped
ovipositor · Triungulin larvae
It seems clear that the ancestral hymenopteran and dipteran parasitoids found themselves in
a relatively unexploited adaptive zone. The resultant adaptive radiation onto different host
species, possibly occurring simultaneously with the adaptive radiation of the modern insect
orders, is responsible for the huge number of species we observe today. (H.C.J. Godfray 1994)
… parasites [and parasitoids] strongly affect food web structure. Indeed, they disproportionately dominate food web links. … yet some parasites [parasitoids] have population
dynamic impacts that are hugely disproportionate to their small size … recognition of parasite [parasitoid] links may have important consequences for ecosystem stability because
they can increase connectance and nestedness. (Lafferty et al. 2006, insertions ours to conform with modern terminology)
11.1 Introduction
One of the enduring features of continental ecosystems during and since the mid
Mesozoic has been the ecological expansion of insect parasitism in general and the
emergence of the insect parasitoid guild in particular. This underappreciated fact
only recently has been recognized (Labandeira 2002, 2015; Li et al. 2018a), given
the increasingly important role that insect (Freeland and Boulton 1992; Mills 1994;
Lafferty et al. 2006; Dunne et al. 2013) and other (Kuris et al. 2008; Hughes et al.
2011a) parasitoids play in the trophic structure of modern terrestrial ecosystems.
For example, one of the best-studied systems has been the leaf miner–parasitoid
community in Central America, which spotlights the importance of top-to-bottom
parasitoid regulation of leaf-mining herbivores in local food webs (Memmott et al.
1994, 2000). According to the fossil record, parasitism—in the broad sense that
includes parasitoidism (Lafferty et al. 2006)—began in the marine realm, evolving
at least 136 times across 15 of the conventionally recognized 43 phyla ranging from
Cnidaria to Arthropoda (Weinstein and Kuris 2016). Of these phyla, it is Arthropoda,
both marine and continental, that had the most numerous independent originations
of parasitism, constituting about 64% of total originations. It is in the continental
C. C. Labandeira and L. Li
ensued toward top-to-down food webs, explained by the trophic cascade hypothesis,
exemplified by hymenopteran parasitoid clades Stephanoidea and Evanioidea.
Clade-specific innovations spurring the MMPR included long, flexible ovipositors
(wasps), host seeking, triungulin and planidium larvae (mantispids, beetles, twistedwing parasites, flies), and extrudable, telescoped ovipositors (flies). After the
MMPR, in phases 3 and 4 (Late Cretaceous to Recent), parasitoids increased in
taxonomic diversity, becoming integrated into food webs that continue to the
present day.
Keywords Food webs · Idiobiont · Koinobiont · Ovipositor drill · Telescoped
ovipositor · Triungulin larvae
It seems clear that the ancestral hymenopteran and dipteran parasitoids found themselves in
a relatively unexploited adaptive zone. The resultant adaptive radiation onto different host
species, possibly occurring simultaneously with the adaptive radiation of the modern insect
orders, is responsible for the huge number of species we observe today. (H.C.J. Godfray 1994)
… parasites [and parasitoids] strongly affect food web structure. Indeed, they disproportionately dominate food web links. … yet some parasites [parasitoids] have population
dynamic impacts that are hugely disproportionate to their small size … recognition of parasite [parasitoid] links may have important consequences for ecosystem stability because
they can increase connectance and nestedness. (Lafferty et al. 2006, insertions ours to conform with modern terminology)
11.1 Introduction
One of the enduring features of continental ecosystems during and since the mid
Mesozoic has been the ecological expansion of insect parasitism in general and the
emergence of the insect parasitoid guild in particular. This underappreciated fact
only recently has been recognized (Labandeira 2002, 2015; Li et al. 2018a), given
the increasingly important role that insect (Freeland and Boulton 1992; Mills 1994;
Lafferty et al. 2006; Dunne et al. 2013) and other (Kuris et al. 2008; Hughes et al.
2011a) parasitoids play in the trophic structure of modern terrestrial ecosystems.
For example, one of the best-studied systems has been the leaf miner–parasitoid
community in Central America, which spotlights the importance of top-to-bottom
parasitoid regulation of leaf-mining herbivores in local food webs (Memmott et al.
1994, 2000). According to the fossil record, parasitism—in the broad sense that
includes parasitoidism (Lafferty et al. 2006)—began in the marine realm, evolving
at least 136 times across 15 of the conventionally recognized 43 phyla ranging from
Cnidaria to Arthropoda (Weinstein and Kuris 2016). Of these phyla, it is Arthropoda,
both marine and continental, that had the most numerous independent originations
of parasitism, constituting about 64% of total originations. It is in the continental
C. C. Labandeira and L. Li