TY  - JOUR
A1  - Rostás, Michael
A1  - Maag, Daniel
A1  - Ikegami, Makihiko
A1  - Inbar, Moshe
T1  - Gall volatiles defend aphids against a browsing mammal
T2  - BMC Evolutionary Biology
N2  - Background: Plants have evolved an astonishing array of survival strategies. To defend against insects, for example, damaged plants emit volatile organic compounds that attract the herbivore’s natural enemies. So far, plant volatile responses have been studied extensively in conjunction with leaf chewing and sap sucking insects, yet little is known about the relationship between plant volatiles and gall-inducers, the most sophisticated herbivores. Here we describe a new role for volatiles as gall-insects were found to benefit from this plant defence.
Results: Chemical analyses of galls triggered by the gregarious aphid Slavum wertheimae on wild pistachio trees showed that these structures contained and emitted considerably higher quantities of plant terpenes than neighbouring leaves and fruits. Behavioural assays using goats as a generalist herbivore confirmed that the accumulated terpenes acted as olfactory signals and feeding deterrents, thus enabling the gall-inducers to escape from inadvertent predation by mammals.
Conclusions: Increased emission of plant volatiles in response to insect activity is commonly looked upon as a “cry for help” by the plant to attract the insect’s natural enemies. In contrast, we show that such volatiles can serve as a first line of insect defences that extends the ‘extended phenotype’ represented by galls, beyond physical boundaries. Our data support the Enemy hypothesis insofar that high levels of gall secondary metabolites confer protection against natural enemies.
KW  - capra hircus
KW  - enemy hypothesis
KW  - extended phenotype
KW  - herbivory
KW  - intraguild predation
KW  - plant defence
KW  - tannins
KW  - terpenes
KW  - volatile organic compounds
Y1  - 2013
UR  - https://opus.bibliothek.uni-wuerzburg.de/opus4-wuerzburg/frontdoor/index/index/docId/12868
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-128687
VL  - 13
IS  - 193
ER  -