462
The second morphological feature is the development of a host-seeking firstinstar larva, the planidium, which occur in at least seven dipteran families (Askew
1971) and typically results in endoparasitoidism. Functionally analogous to the triungulin larva of some Neuroptera and Coleoptera and all Strepsiptera, the planidium larva is an active, more or less sclerotized, mobile and host seeking larva that
represents a departure from the common practice of the adult female dipteran
depositing her eggs directly on, in or adjacent the host (Clausen 1940; Askew 1971).
The planidium larva has evolved among Culicomorpha (Chironomidae),
Bibionomorpha
(Mycetophilidae),
Nemestrinimorpha
(Acroceridae,
Nemestrinidae), Asiloidea (Asilidae), Acalyptratae (Sciomyzidae) and Schizophora
(Rhinophoridae) (van Jutting 1938; Greathead 1963; Ferrar 1987; Eggleton and
Belshaw 1992), representing a broad swath of Diptera phylogeny and independent
originations minimally five or six times.
The trophic origins of the 23 parasitoid families of Diptera are highly diverse but
evolved overwhelmingly from saprophagy and predation. For most families it is
difficult to ascertain whether parasitoid flies evolved into other trophic modes
(Fig. 11.4b). Only two such transitions are known (Eggleton and Belshaw 1992).
First, parasitoidism in some Bombyliidae evolved into predation on grasshopper
egg pods (Yeates and Greathead 1997). Second, some Sarcophagidae evolved into
internal parasites in bees that consume the host only when it dies, a trophic transition that also is suspected in adult scarab beetle and bumble bee hosts. In general,
the origin of parasitoidism from predation occurred once in nematocerous clades
and several times in brachycerous (non-cyclorrhaphan) clades, whereas parasitoidism via saprophagy is confined to more derived clades among cyclorrhaphan flies.
These occurrences are consistent with the predominant detritivore to saprophage
diets of cyclorrhaphan flies.
11.5.2.5 Trichoptera (Caddisflies)
Wells (1992) described the life history of Orthotrichia muscari a member of
Hydroptilidae (purse-case caddisflies) from the Northern Territory of Australia
(Table 11.1). This microcaddisfly, in addition to nine other members of the
Orthotrichia aberrans species group, apparently are parasitoids of similarly aquatic
Philopotamidae (fingernet caddisflies) as well as other Hydroptilidae (Wells 2005).
This is the only known example of parasitoidism in Trichoptera, and represents the
only aquatic mode of parasitoidism that is unique to Insecta.
11.5.2.6 Lepidoptera (Moths)
Members of two families of Lepidoptera are known as ectoparasitoids (Table 11.1).
Epipyropidae (planthopper parasite moths) consist of 32 pantropical species that
attack fulgoroid planthoppers (Hemiptera: Auchenorrhyncha) and a few lepidopteran larvae (Jeon et al. 2002). The fossil record of planthopper parasite moths
C. C. Labandeira and L. Li
The second morphological feature is the development of a host-seeking firstinstar larva, the planidium, which occur in at least seven dipteran families (Askew
1971) and typically results in endoparasitoidism. Functionally analogous to the triungulin larva of some Neuroptera and Coleoptera and all Strepsiptera, the planidium larva is an active, more or less sclerotized, mobile and host seeking larva that
represents a departure from the common practice of the adult female dipteran
depositing her eggs directly on, in or adjacent the host (Clausen 1940; Askew 1971).
The planidium larva has evolved among Culicomorpha (Chironomidae),
Bibionomorpha
(Mycetophilidae),
Nemestrinimorpha
(Acroceridae,
Nemestrinidae), Asiloidea (Asilidae), Acalyptratae (Sciomyzidae) and Schizophora
(Rhinophoridae) (van Jutting 1938; Greathead 1963; Ferrar 1987; Eggleton and
Belshaw 1992), representing a broad swath of Diptera phylogeny and independent
originations minimally five or six times.
The trophic origins of the 23 parasitoid families of Diptera are highly diverse but
evolved overwhelmingly from saprophagy and predation. For most families it is
difficult to ascertain whether parasitoid flies evolved into other trophic modes
(Fig. 11.4b). Only two such transitions are known (Eggleton and Belshaw 1992).
First, parasitoidism in some Bombyliidae evolved into predation on grasshopper
egg pods (Yeates and Greathead 1997). Second, some Sarcophagidae evolved into
internal parasites in bees that consume the host only when it dies, a trophic transition that also is suspected in adult scarab beetle and bumble bee hosts. In general,
the origin of parasitoidism from predation occurred once in nematocerous clades
and several times in brachycerous (non-cyclorrhaphan) clades, whereas parasitoidism via saprophagy is confined to more derived clades among cyclorrhaphan flies.
These occurrences are consistent with the predominant detritivore to saprophage
diets of cyclorrhaphan flies.
11.5.2.5 Trichoptera (Caddisflies)
Wells (1992) described the life history of Orthotrichia muscari a member of
Hydroptilidae (purse-case caddisflies) from the Northern Territory of Australia
(Table 11.1). This microcaddisfly, in addition to nine other members of the
Orthotrichia aberrans species group, apparently are parasitoids of similarly aquatic
Philopotamidae (fingernet caddisflies) as well as other Hydroptilidae (Wells 2005).
This is the only known example of parasitoidism in Trichoptera, and represents the
only aquatic mode of parasitoidism that is unique to Insecta.
11.5.2.6 Lepidoptera (Moths)
Members of two families of Lepidoptera are known as ectoparasitoids (Table 11.1).
Epipyropidae (planthopper parasite moths) consist of 32 pantropical species that
attack fulgoroid planthoppers (Hemiptera: Auchenorrhyncha) and a few lepidopteran larvae (Jeon et al. 2002). The fossil record of planthopper parasite moths
C. C. Labandeira and L. Li