451
11.5.2.2 Coleoptera (Beetles)
The parasitoid habit in Coleoptera is expressed in ten families that occur sporadically across the order, variously as ectoparasitoids, endoparasitoids and cleptoparasitoids that extend to the Middle Jurassic and conceivably as early as the Late
Triassic (Table 11.1). For Coleoptera, host-searching behavior occurs typically in
first-instar larvae.
Carabidae (ground beetles) consist of approximately 1500 genera and 40,000
species that are allocated into approximately 80 tribes (Arndt et al. 2005). Of these
tribes, 7 have parasitoid life histories, including termite symbionts, ant symbionts
and ectoparasitoids on various invertebrates (Erwin 1979). When other suspected
tribes that house parasitoids are included (Erwin 1979), about a fourth of all carabid
tribes have one or more parasitoid species. In general, two major ectoparasitoid
groups of carabids are present. The first group attacks hosts in soils that include
beetle pupae and millipedes, whereas a second group parasitoidizes leaf beetles on
above-ground organs of plants (Erwin 1979). The earliest fossil Carabidae is Late
Triassic (Grimaldi and Engel 2005a, b), occurring approximately 230 million years
ago, although the parasitoid taxa are undoubtedly more recent than that, given their
phylogenetic placement (Maddison et al. 1999).
Staphylinidae (rove beetles) include the subfamily Aleocharinae that consist of
many ectoparasitoid genera on cyclorrhaphan, typically Pupipara, flies (Maus et al.
1998). Staphylinidae constitute about 48,000 species of which about one quarter are
in the Subfamily Aleocharinae (Thayer 2005). Of the Aleocharinae, only the genus
Aleochara are parasitoids, consisting of 400 described species and constituting
about one-third of the species-level diversity of the subfamily (Maus et al. 1998)
and about 0.08% of Staphylinidae. Typical microhabitats for parasitoid aleocharines
are moist, fleeting habitats such as carrion, dung, polypore fungi, kelp-laden beach
wrack, and decaying plant material in the nests of vertebrates and ants (Eggleton
and Belshaw 1992). Aleocharine parasitoid eggs, upon hatching, produce a mobile
triungulin stage analogous to the planidium of most dipteran parasitoids (Lawrence
et al. 1991; Arnett Jr and Thomas 2001). The triungulin first-instar larva actively
searches for potential hosts, attacks the appropriate host and either becomes attached
or enters the host, initiating the process of parasitoidization, seen in a variety of
hypermetamorphic parasitoids (Falin 2002; Engel 2005a; Haug et al. 2018).
Subsequent instars are typically sessile, grub-like and continue the process of parasitoidization to its consummation through starvation of social insect colonies
(Askew 1971; Godfray 1994). The earliest fossil Staphylinidae are Late Triassic in
age, occurring approximately 230 million years ago and, like Carabidae, are significantly older than their descendant parasitoid taxa that originate during the Early
Cretaceous (Chatzimanolis et al. 2012).
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution
11.5.2.2 Coleoptera (Beetles)
The parasitoid habit in Coleoptera is expressed in ten families that occur sporadically across the order, variously as ectoparasitoids, endoparasitoids and cleptoparasitoids that extend to the Middle Jurassic and conceivably as early as the Late
Triassic (Table 11.1). For Coleoptera, host-searching behavior occurs typically in
first-instar larvae.
Carabidae (ground beetles) consist of approximately 1500 genera and 40,000
species that are allocated into approximately 80 tribes (Arndt et al. 2005). Of these
tribes, 7 have parasitoid life histories, including termite symbionts, ant symbionts
and ectoparasitoids on various invertebrates (Erwin 1979). When other suspected
tribes that house parasitoids are included (Erwin 1979), about a fourth of all carabid
tribes have one or more parasitoid species. In general, two major ectoparasitoid
groups of carabids are present. The first group attacks hosts in soils that include
beetle pupae and millipedes, whereas a second group parasitoidizes leaf beetles on
above-ground organs of plants (Erwin 1979). The earliest fossil Carabidae is Late
Triassic (Grimaldi and Engel 2005a, b), occurring approximately 230 million years
ago, although the parasitoid taxa are undoubtedly more recent than that, given their
phylogenetic placement (Maddison et al. 1999).
Staphylinidae (rove beetles) include the subfamily Aleocharinae that consist of
many ectoparasitoid genera on cyclorrhaphan, typically Pupipara, flies (Maus et al.
1998). Staphylinidae constitute about 48,000 species of which about one quarter are
in the Subfamily Aleocharinae (Thayer 2005). Of the Aleocharinae, only the genus
Aleochara are parasitoids, consisting of 400 described species and constituting
about one-third of the species-level diversity of the subfamily (Maus et al. 1998)
and about 0.08% of Staphylinidae. Typical microhabitats for parasitoid aleocharines
are moist, fleeting habitats such as carrion, dung, polypore fungi, kelp-laden beach
wrack, and decaying plant material in the nests of vertebrates and ants (Eggleton
and Belshaw 1992). Aleocharine parasitoid eggs, upon hatching, produce a mobile
triungulin stage analogous to the planidium of most dipteran parasitoids (Lawrence
et al. 1991; Arnett Jr and Thomas 2001). The triungulin first-instar larva actively
searches for potential hosts, attacks the appropriate host and either becomes attached
or enters the host, initiating the process of parasitoidization, seen in a variety of
hypermetamorphic parasitoids (Falin 2002; Engel 2005a; Haug et al. 2018).
Subsequent instars are typically sessile, grub-like and continue the process of parasitoidization to its consummation through starvation of social insect colonies
(Askew 1971; Godfray 1994). The earliest fossil Staphylinidae are Late Triassic in
age, occurring approximately 230 million years ago and, like Carabidae, are significantly older than their descendant parasitoid taxa that originate during the Early
Cretaceous (Chatzimanolis et al. 2012).
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution