instars of scelionid egg parasitoids and the mandibulate first instars
produced by larval endoparasitoids in the family Braconidae (Fig.
7.1a,b). In contrast, gregarious parasitoids, such as trichogrammatids
have sacciform first instars that lack any adaptations for combat
(Fig. 7.1c). Most hymenopteran ectoparasitoids paralyse their host at
oviposition, which prevents the host from removing parasitoid larvae.Interactions between Larval Parasitoids and Their Hosts 131
Fig. 7.1. Various forms of parasitoid larvae. (a) Teleaform first instar with large
sickle-shaped mandibles (M) typical of parasitoids in the family Scelionidae. (b)
Mandibulate first instar of endoparasitic braconids in the subfamily Microgastrinae.
(c) Sacciform larva of gregarious parasitoids in the family Trichogrammatidae. (d)
Triungulin larva of parasitic Coleoptera in the family Ripiphoridae. (e) Planidial larva
of parasitoids in the family Eucharitidae. (f) Hymenopteriform larva typically pro-
duced during later instars by parasitic Hymenoptera. (g) Vesiculate larva with anal
vesicle (A) produced after the first instar by endoparasitic braconids in the subfamily
Microgastrinae. In (a)–(f), the head is orientated towards the top of the page. In (g),
the head is orientated to the left. Drawn by J.A. Johnson after the classification
scheme of Clausen (1940).