391
acquire; for example, host tissues occasionally are altered such as a small puparium
of a strepsipteran parasitoid ensconced within the body of a stingless bee (Boucot
and Poinar Jr 2010).
11.3.5 Plant–Insect Interactions
Plant–insect interactions also can reveal the presence of parasitoids, recording the
identities of the plant host, often the insect herbivore, but rarely the insect parasitoid. The parasitoid often remains unidentifiable because of the lack of distinctive
features of the parasitoid entry hole, the induction of anomalous host behavior
resulting in atypical plant damage, or exit holes. For example, the galler damage
type DT83 (Labandeira et al. 2007b, page 13) has features consistent with a gall
midge (Diptera: Cecidomyiidae) gall, occurring on plant morphotype TY46
(Euphorbiaceae) from early Eocene Laguna del Hunco, Argentina. However, this
gall individual contains six, undistinctive, circular, parasitoid exit holes of varying
diameters that are unidentifiable to a culprit taxon. Similarly, although often considered a plant–insect interaction, an example of predation occurs in a seed with a
circular exit hole (Fig. 11.1m), but lacks sufficient characters to identify the seed
predator, such as a seed bug (Lattin 1999).
Leaf mines also can record the presence of parasitoid behavior from oviposition
scars (Krassilov 2008a). As leaf miners are concealed herbivores, an adult parasitoid must penetrate through or otherwise pierce foliar tissue with their ovipositor to
deposit an egg on or in the larval host or mine. Evidence for ovipositor piercings or
larval entry holes does occur on fossil leaf mines. These penetrations often are
termed “cut-outs” (Krassilov 2008a), or alternatively “predation holes” (Krassilov
2008b), some of which may be linear oviposition scars adjacent the leaf mine from
ovipositing parasitoids.
Another type of evidence reveals the presence of a parasitoid, in this case a fungus, in a series of distinctive, successive, bilaterally symmetrical holes adjacent
major veins found on the undersides of dicotyledonous leaves in humid, tropical
environments (Harper and Krings 2021). Such features are the “death grips” of a
zombie ant, such as the carpenter ant Camponotus, as it dies following zombification by the parasitoid fungus Ophiocordyceps (Hypocreales: Ophiocordycipitaceae),
a widespread plant–fungus–ant interaction across the modern tropics (Hughes et al.
2011a). Such distinctive evidence also has been found on a dicot leaf from the 48
million-year-old Messel Formation in central–west Germany (Hughes et al. 2011b).
This occurrence indicates that the parasitoid association has been present since the
early Eocene, and probably originated in the Cretaceous (Sung et al. 2007), during
the initial diversification of the parasitoid fungus clade. As in the case of plant galls
caused by mites and insects, the infected zombie ant and its characteristic leaf damage is considered the extended phenotype of the parasitoid fungus (Hughes 2014).
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution
acquire; for example, host tissues occasionally are altered such as a small puparium
of a strepsipteran parasitoid ensconced within the body of a stingless bee (Boucot
and Poinar Jr 2010).
11.3.5 Plant–Insect Interactions
Plant–insect interactions also can reveal the presence of parasitoids, recording the
identities of the plant host, often the insect herbivore, but rarely the insect parasitoid. The parasitoid often remains unidentifiable because of the lack of distinctive
features of the parasitoid entry hole, the induction of anomalous host behavior
resulting in atypical plant damage, or exit holes. For example, the galler damage
type DT83 (Labandeira et al. 2007b, page 13) has features consistent with a gall
midge (Diptera: Cecidomyiidae) gall, occurring on plant morphotype TY46
(Euphorbiaceae) from early Eocene Laguna del Hunco, Argentina. However, this
gall individual contains six, undistinctive, circular, parasitoid exit holes of varying
diameters that are unidentifiable to a culprit taxon. Similarly, although often considered a plant–insect interaction, an example of predation occurs in a seed with a
circular exit hole (Fig. 11.1m), but lacks sufficient characters to identify the seed
predator, such as a seed bug (Lattin 1999).
Leaf mines also can record the presence of parasitoid behavior from oviposition
scars (Krassilov 2008a). As leaf miners are concealed herbivores, an adult parasitoid must penetrate through or otherwise pierce foliar tissue with their ovipositor to
deposit an egg on or in the larval host or mine. Evidence for ovipositor piercings or
larval entry holes does occur on fossil leaf mines. These penetrations often are
termed “cut-outs” (Krassilov 2008a), or alternatively “predation holes” (Krassilov
2008b), some of which may be linear oviposition scars adjacent the leaf mine from
ovipositing parasitoids.
Another type of evidence reveals the presence of a parasitoid, in this case a fungus, in a series of distinctive, successive, bilaterally symmetrical holes adjacent
major veins found on the undersides of dicotyledonous leaves in humid, tropical
environments (Harper and Krings 2021). Such features are the “death grips” of a
zombie ant, such as the carpenter ant Camponotus, as it dies following zombification by the parasitoid fungus Ophiocordyceps (Hypocreales: Ophiocordycipitaceae),
a widespread plant–fungus–ant interaction across the modern tropics (Hughes et al.
2011a). Such distinctive evidence also has been found on a dicot leaf from the 48
million-year-old Messel Formation in central–west Germany (Hughes et al. 2011b).
This occurrence indicates that the parasitoid association has been present since the
early Eocene, and probably originated in the Cretaceous (Sung et al. 2007), during
the initial diversification of the parasitoid fungus clade. As in the case of plant galls
caused by mites and insects, the infected zombie ant and its characteristic leaf damage is considered the extended phenotype of the parasitoid fungus (Hughes 2014).
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution