Herbivores, volatile terpenes from

Conifer chemical ecology includes many other herbivores, predators and pathogens, aside from the bark beetles, weevils, sawflies, or budworms, and in these diverse interactions, terpenoid volatile emissions as well as accumulated oleoresin terpenes are likely to play many important roles in signaling and defense. 

Terpenes volatilization can be sensed by herbivores as they approach a potential host plant with imphcations for the defense strategies of plants. Volatile compounds can repel most potential generalist herbivores at some distance from the plant, but the same emitted VOCs have an opposite function in attracting host plant-specific herbivores. Terpenes secreted on plant surfaces as waxes or resins or deposited in... 

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