Parasitoid increases survival of its pupae by inducing hosts to fight predators.
Many true parasites and parasitoids modify the behaviour of their host, and these changes are thought to be to the benefit of the parasites. However, field tests of this hypothesis are scarce, and it is often unclear whether the host or the parasite profits from the behavioural changes, or even if parasitism is a cause or consequence of the behaviour. We show that braconid parasitoids (Glyptapanteles sp.) induce their caterpillar host (Thyrinteina leucocerae) to behave as a bodyguard of the parasitoid pupae. After parasitoid larvae exit from the host to pupate, the host stops feeding, remains close to the pupae, knocks off predators with violent head-swings, and dies before reaching adulthood. Unparasitized caterpillars do not show these behaviours. In the field, the presence of bodyguard hosts resulted in a two-fold reduction in mortality of parasitoid pupae. Hence, the behaviour appears to be parasitoid-induced and confers benefits exclusively to the parasitoid.
Grosman
Amir H
AH
Institute for Biodiversity and Ecosystem Dynamics, Section Population Biology, University of Amsterdam, Amsterdam, The Netherlands.
Janssen
Arne
A
de Brito
Elaine F
EF
Cordeiro
Eduardo G
EG
Colares
Felipe
F
Fonseca
Juliana Oliveira
JO
Lima
Eraldo R
ER
Pallini
Angelo
A
Sabelis
Maurice W
MW
D000818:Animals; D005260:Female; D005426:Flight, Animal; D006790:Host-Parasite Interactions; D007313:Insecta / Q000254:growth & development / Q000502:physiology*; D008297:Male; D009036:Moths / Q000502:physiology*; D011235:Predatory Behavior