Olfactory Response of the Green Lacewing Chrysoperla Externa to Volatile Organic Compounds of Eucalyptus Urograndis
The evaluation of the direct effects of the relationship between plants and predators without considering the participation of herbivores can provide vital information for the study of ecological interactions and integrated pest management. In this context, the present work studied the behavioral responses of Chrysoperla externa (Neuroptera: Chrysopidae) larvae to the volatile organic compounds of young and mature, undamaged and damaged leaves of Eucalyptus urograndis (Myrtaceae), and
... e the chemical composition of leaf essential oils and their effects on the green lacewing. The responses of the C. externa larvae to the odors emitted by leaves were evaluated by an experimental behavior test using a Y-tube olfactometer. The essential oil was extracted by hydrodistillation of the young and mature leaves with and without damage. The larvae respond attractively to the volatiles emitted without the participation of herbivores, and it selected preferentially odors emitted by young leaves with simulated herbivory. The chemical composition was analyzed using gas chromatography coupled with mass spectrometry. This research identified 32 compounds; some of them had not been identified in other studies. Young leaves had a higher content of essential oil compared to mature leaves. Among the compounds identified, eucalyptol, α-Terpineol, Aromadendrene, and α-Terpinyl acetate are the major compounds. An inversion in the content of eucalyptol (which decreases) and α-terpinyl acetate (which increases) is observed when young and mature leaves are damage. Thus, this work contributed with basic data on the potential use of eucalyptus forests as maintainers of natural chrysopids populations.